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90240SR
01-31-2004, 10:45 AM
When upgrading to big brakes all araound, I have read to upgrade the master cylinder. Is this necesary for front only upgrade or only when doing rear as well?

Thanks

Need4Boost
01-31-2004, 10:55 AM
If you are doing just the fronts then you should be fine with the stock master cylinder. I have my fronts upgraded only and regularly track the car and it holds up fine. If you are upgrading all 4 calipers then I would definitely advice that you upgrade your master cylinder! I am going to upgrade mine anyways because it will give me a better pedal feel.

-Safa

asad
01-31-2004, 11:10 AM
When upgrading to big brakes all araound, I have read to upgrade the master cylinder. Is this necesary for front only upgrade or only when doing rear as well?

Thanks



If you're doing Z-brakes all around, you'll want to upgrade your MC. For other big brake upgrades, it really depends on the piston sizes used in the calipers.

Asad

Nikeboy355
01-31-2004, 11:14 AM
and also take into consideration that your car is older and the stock master cylinder might not be in such good condition... I just purchased the 300ZX master cylinder (Nissan part number 46010 30 P21) from the dealership for $210 and can't wait to put it in... I have Q45 brakes in the front and stocks in the rear and plan to track my car soon...

90240SR
01-31-2004, 01:39 PM
Asad,

How is this a factor? Is there a benefit of going with a pre packaged set like Rotora. Also, how much should the 300Z swap cost for parts. I have done some research and come up with about $500 for fronts, including pads, lines, calipers and rotors. My concern is this is so much cheaper than a package from Rotora or any other brand that I am worried I am missing something. Can you shed a little light on this. http://forums.freshalloy.com/images/graemlins/confused.gif

JeromeS13
01-31-2004, 02:03 PM
Asad,

How is this a factor? Is there a benefit of going with a pre packaged set like Rotora. Also, how much should the 300Z swap cost for parts. I have done some research and come up with about $500 for fronts, including pads, lines, calipers and rotors. My concern is this is so much cheaper than a package from Rotora or any other brand that I am worried I am missing something. Can you shed a little light on this. http://forums.freshalloy.com/images/graemlins/confused.gif



$500?? You should be able to do better than that. I only have about $250-300 invested in mine. That included rebuilt 30mm aluminum calipers, OE style rotors, stainless lines, and Axxis metal master pads.

Need4Boost
01-31-2004, 02:59 PM
Asad,

How is this a factor? Is there a benefit of going with a pre packaged set like Rotora. Also, how much should the 300Z swap cost for parts. I have done some research and come up with about $500 for fronts, including pads, lines, calipers and rotors. My concern is this is so much cheaper than a package from Rotora or any other brand that I am worried I am missing something. Can you shed a little light on this. http://forums.freshalloy.com/images/graemlins/confused.gif



For $500 thats really good especially since the parts aren't used. And honestly you probably will get equal if not better performance out of the nissan calipers! All you're doing is paying for the name. In the next year my car is going to be a full time road race car and guess what? I'm using the nissan calipers and will continue to do so until I can see that there is an apparent performance difference in the super expensive kits. The only way I'll slap those on is if my sponsor or future sponsor wants me to use them (with them paying of course).

The Z32 calipers are an excellent upgrade that will give you more than necessary performance!

-Safa

Ahhsk
01-31-2004, 03:51 PM
And honestly you probably will get equal if not better performance out of the nissan calipers! All you're doing is paying for the name.



Ok, im not really sure what you are saying, but the nissan Z32 caliper/ rotor combo doesnt come anywhere remotely close to the performance of a big brake upgrade (in my case AP six piston with 355mm rotors)

Unless your definition of braking performance is soley based on braking distances from 60mph. I can go 110 to zero and not get any fade, then do it again and not get any fade, then do it again....

The one time I managed to get a little bit of fade was when doing some rough AFC tuning where we were "riding the brakes" to spool the turbo and stay close to the speed limit.

asad
01-31-2004, 05:53 PM
How is this a factor?



The amount of fluid a caliper needs depends on the number and area of the pistons used.




Is there a benefit of going with a pre packaged set like Rotora.



Yes, you get larger rotors (often 2-piece for lighter weight) with more heat capacity. More heat capacity allows you to use less-aggressive pads but still have enough braking power for track days and the like. It's really only necessary if you find yourself fading the 300ZX brakes -- these packages usually have a significantly larger rotor than Z brakes (Z brakes are 'only' 11", typical aftermarket 'big brake' kits are in the 12-13" range).

Get the 300ZX brakes. If you find that it's not enough, you can always sell them and recoup most of the cost and put it toward bigger brakes.

Asad

90240SR
01-31-2004, 09:13 PM
Asad and all,

THanks. So last question. Can I uses aftermarket rotors? Will this cuase any problems with the swap, ie will the z32 calipers fit on after market "big" rotors? I read Asads quote, however I am not an engineering grad, I'm a marketing guy so, I am not sure how this will effect things.

The prices I quoted are:
1991 Used Z32 calipers $65 each/ $130 pair (A1 Auto wreckers - San Jose, CA) This sounds cheap I am concerned.
1991 Z32 Brembo drilled $178 pair (NOPI) Are these stock size or bigger? (no details given in description)
Stainless lines from goodrich $122 (NOPI)
AXIS performance metallic pads $32.02 (NOPI)

I am open to other vendors if you all can recommend.

Thanks all, I realy appreciate it.

Kookz
01-31-2004, 09:14 PM
Aftermarket rotors, yes. Aftermarket big rotors, no.

asad
01-31-2004, 10:11 PM
Can I uses aftermarket rotors? Will this cuase any problems with the swap, ie will the z32 calipers fit on after market "big" rotors?



The Z32 calipers will fit on Z32 rotors (stock and aftermarket 'stock replacement'). You can get caliper relocation brackets to allow the use of Z32 calipers on larger rotors.




1991 Z32 Brembo drilled $178 pair (NOPI) Are these stock size or bigger? (no details given in description)



If they're listed as Z32 rotors, they'll be stock-sized Z32 rotors.

Do you really want the x-drilled rotors? You can get undrilled Z32 Brembo rotors from Nopi for $31.22 each (part number 437+0921).

Asad

90240SR
01-31-2004, 11:50 PM
Are there any advantages to slotted vs. x-drilled and non of the above?

GlacierFreeze
01-31-2004, 11:55 PM
Advantage: Slotted and/or cross drilled both help disipate(sp?) heat vs. not at all.

edit...
Disadvantage: Heard pads don't last quite as long.

asad
02-01-2004, 09:05 AM
Advantage: Slotted and/or cross drilled both help disipate(sp?) heat vs. not at all.



Wrong, wrong, wrong.

drilled holes are NOT for cooling. How much airflow do you think goes through the brake rotor sideways? The purpose of drilled holes (and slots) is to allow built-up gases from under the pads to escape. With modern pad compounds that don't outgas much, it's really not necessary, plus the holes are often starting points for rotor cracking.



Disadvantage: Heard pads don't last quite as long.



This is true...think of a cheese grater...

Asad

90240SR
02-01-2004, 01:45 PM
What type of pads do you recommend?

Thx247
02-01-2004, 08:19 PM
Unless your definition of braking performance is soley based on braking distances from 60mph. I can go 110 to zero and not get any fade, then do it again and not get any fade, then do it again....



While the AP brake kit is more capable than Z brakes, it also cost$ alot more, not to mention the large wheel$ needed to clear those huge rotor$.

Unless there is a race course with 2 straight aways and 2 hairpins I don't see how thousand dollar brake and wheel kits can compete with $500 dollars wisely spent.

Ahhsk
02-01-2004, 09:21 PM
Unless there is a race course with 2 straight aways and 2 hairpins I don't see how thousand dollar brake and wheel kits can compete with $500 dollars wisely spent.



Ok, I started with the big brakes in Germany so I agree its great for fade free deceleration from high triple digits.

So you dont feel that a big brake system would be beneficial on a slower, complex course? The brakes would hold more heat corner to corner. It would be more necessary here than on the course you described.

If I had a set budget, brakes would be alloted the greater share.

Thx247
02-02-2004, 03:38 AM
Big brakes are great and all, but here is why I am questioning how big and to what cost is it still worthwhile:

The costs involved with running larger tires, more expensive brake pads and expensive wheels.

The additional weigh by running large wheels, tires and heavier rotor.

The fact that I can get brake pads that operate up to 1500F negates any concerns about heat impacting pad performance.

Small course or large course, I can run pad compounds that work best when they are hot, so even if my average pad temp were 900F, I would still have a pad that grips .6+ cF.

There also really isn't that much braking going on at your typical road course. The straight away, a tap here and there for a turn but most of the time you are not on the brakes more than 1-3 seconds.

Taking all that into mind I can't justify the additional expense and maintenance of having big brakes.

Ahhsk
02-02-2004, 05:23 AM
Good point, I agree on the pads, and buying 18" winter tires are going to suck too.

asad
02-02-2004, 08:53 AM
Big brakes are great and all, but here is why I am questioning how big and to what cost is it still worthwhile:



The advantage of big brakes is that you can run a street-compound pad and not have to worry about getting out of their temperature range on the track.

So basically it's convenience...instead of having to swap out pads (and likely rotors with the pads) for street and track duty, you can run the same pad all the time, with a compound that doesn't eat rotors.

Plus, they look sweet! http://forums.freshalloy.com/images/graemlins/grin.gif

Asad

Kookz
02-02-2004, 12:09 PM
There also really isn't that much braking going on at your typical road course. The straight away, a tap here and there for a turn but most of the time you are not on the brakes more than 1-3 seconds.

When you're pushing 130 rwhp, sure, but when you're making 2-3 times that power you'll be working the brakes a lot more. And yeah, not having to swap out pads is a nice convenience.

Need4Boost
02-02-2004, 12:30 PM
Ok, im not really sure what you are saying, but the nissan Z32 caliper/ rotor combo doesnt come anywhere remotely close to the performance of a big brake upgrade (in my case AP six piston with 355mm rotors)

Unless your definition of braking performance is soley based on braking distances from 60mph. I can go 110 to zero and not get any fade, then do it again and not get any fade, then do it again....

The one time I managed to get a little bit of fade was when doing some rough AFC tuning where we were "riding the brakes" to spool the turbo and stay close to the speed limit.



Okay wow, I hope you aren't basing your experience from street driving (which sounds like you are). http://forums.freshalloy.com/images/graemlins/rolleyes1.gif 1st of all, monster size brakes, means larger rotors, larger wheels, larger tires, also a lot more money spent, and most importantly a lot more heat to dissipatate!!! When your braking system heat soaks it will take a cold winter to cool those mofos before your next braking zone. I don't care if you are running aluminum or cast iron, it's still hard to cool the brakes when they are heat soaked. The bigger the mass is the longer it takes to cool down. This has been mentioned above. I'm repeating because maybe you missed it.

2nd, have you heard of unsprung weight? How about rotational mass? If you haven't learn it if you are going to give advice about braking performance. If you do know those terms then refresh your memory. Those 2 things don't just affect braking performance, but OVERALL performance of a car! Oh and they are the leading contributor to brake fade because of the heat generated from them.

And finally, back to the experience thing. I'm not talking out of my a$$ when I'm sharing my knowledge with you. I'm speaking from my experience working on 2 Rod Millen Mazda miata super production endurance and sprint race cars (with factory support from mazda), also my experience is from racing them when I was 19 years old. These cars had a seasonal budget of $1.2 million, FYI.

But let me guess, you're gonna ask me then why do these guys run such and such setup if its so bad. Easy answer, their seasonal budget is probably about $2 million which means they can afford paying for extreme R&D for advanced cooling systems and also they play by a different rule book that allows them to perform certain modifications.

To make a long story short, the setup that you (Ahhsk) are using, you will never come close to ever achieving the necessity for it with your car. Oh wait but you experienced brake fade once right, well I'm sure sufficient cooling was not incorporated for your setup. The Z32 setup is more than perfect for street 240sx/silvia or a spec race car 240sx.

redlyne
02-02-2004, 02:39 PM
I've been using Nissan stock pads and rotors for almost 3 years now and I've /never/ felt fade on the street, or the occasional autocross. My only gripe with the stock pads is the dust.

The OEM pads are pretty high quality peices. I don't know what you'll be doing with the car, but unless you're dragging around lots of fiberglass and thump, or you're running serious track laps with some power, the stock (nissan) pads should fine. And they're gentle on the rotors.


Sean

Kookz
02-02-2004, 03:17 PM
I don't care if you are running aluminum or cast iron, it's still hard to cool the brakes when they are heat soaked. The bigger the mass is the longer it takes to cool down. This has been mentioned above. I'm repeating because maybe you missed it.

http://forums.freshalloy.com/images/graemlins/rolleyes1.gif http://forums.freshalloy.com/images/graemlins/rolleyes1.gif

Heat dissipation comes from surface area, and a larger rotor has more of it than a smaller one.



2nd, have you heard of unsprung weight?

Hasn't your $$$$ race team heard of 2 piece rotors? I bet that Ahhsk's rotors are lighter than stock Z32s.





Oh and they are the leading contributor to brake fade because of the heat generated from them.

Damn it's getting deep. Slowing the rotor down is so much harder than stopping the car, and the more massive your rotor the more fade you get right? http://forums.freshalloy.com/images/graemlins/grin.gif


But let me guess, you're gonna ask me then why do these guys run such and such setup if its so bad. Easy answer, their seasonal budget is probably about $2 million which means they can afford paying for extreme R&D for advanced cooling systems and also they play by a different rule book that allows them to perform certain modifications.

Guess what, it's not the R&D that makes big brakes work, it's this little thing called physics.



Damn, I wonder why you aren't still working with that team...

Blurple240
02-02-2004, 04:01 PM
Crap that spewed from Need4Boost's mouth



Well chit, I'm running some Weld Prostar 15x3.5 skinnies on all 4 corners. Lightest wheel I could find.

Brakes. Screw brakes. I stop Flintstone's style, with my bare feet. I got sticky shoes mang.

Hubs? My skinnies are held on with 1 10x1.25mm bolt made from unobtanium. Sweetness.

I've also replaced all my body panels with aluminum foil, and my engine is a Waring Blender from my bar.

Oh, and I'm smoking crack now too. I won't be satisfied until I have 0% body fat. I'm thinking about cutting off my ears, since I don't really need them to go fast.

http://forums.freshalloy.com/images/graemlins/rolleyes1.gif

-john

edit: oh, and in case you're wondering how I know to do this, I've watched speedvision at least twice. At least.

asad
02-02-2004, 04:10 PM
I've been using Nissan stock pads and rotors for almost 3 years now and I've /never/ felt fade on the street, or the occasional autocross. My only gripe with the stock pads is the dust.



Street and autocross usage don't put a lot of demand on the heat capacity of a brake system. You don't see a lot of repeated hard braking on the street, and since autocrosses are so short you don't have the time to build a huge amount of heat in the brakes.

Asad

RDM_II
02-02-2004, 04:31 PM
These cars had a seasonal budget of $1.2 million, FYI.

.



Easy answer, their seasonal budget is probably about $2 million



So which is it, 1.2, or 2 flat?
Either way, your post is completely lacking in credibility, not like we'd believe anything else you might say.
Kookz owned you on all points, and I agree 110%.

Larger rotor=more surface area=more heat dissapation. 2piece rotor=less weight.
Larger rotor+less weight=less fade.

To get back on topic a little:


The prices I quoted are:
1991 Used Z32 calipers $65 each/ $130 pair (A1 Auto wreckers - San Jose, CA) This sounds cheap I am concerned.
1991 Z32 Brembo drilled $178 pair (NOPI) Are these stock size or bigger? (no details given in description)
Stainless lines from goodrich $122 (NOPI)
AXIS performance metallic pads $32.02 (NOPI)



Those prices are stupid ridiculous. Calipers can be had used for $40 each all day long at the right yard and NOPI's prices are about as fair as the dealer would be. Find another place to shop, please. Brembo blanks can be had for $30 from any auto parts wholesaler, lines for between $80-100 from various suppliers, call around and check, and pads easily $20.
I spent a total of $540 for all four Z calipers, rebuild kits, powdercoating, new crossdrilled rotors, new lines, and pads.

Need4Boost
02-02-2004, 05:07 PM
http://forums.freshalloy.com/images/graemlins/rolleyes1.gif http://forums.freshalloy.com/images/graemlins/rolleyes1.gif

Heat dissipation comes from surface area, and a larger rotor has more of it than a smaller one.



Hmmm, well what do you do when you've heat soaked the entire surface area? Lemme guess fall off rack http://forums.freshalloy.com/images/graemlins/rolleyes1.gif



Hasn't your $$$$ race team heard of 2 piece rotors? I bet that Ahhsk's rotors are lighter than stock Z32s.



Yes 2 piece rotors are used, sorry I didn't give you every single detail. I'll be sure to do that next time. Oh and I'm not denying the rotors are lighter, but what about the oversized calipers?





Guess what, it's not the R&D that makes big brakes work, it's this little thing called physics.



Wow you just shot yourself in the foot! Ask yourself how we understand and learn physics, its called R&D.





Damn, I wonder why you aren't still working with that team...



Well lets see, its this thing called going to a university. It maybe a new term you're not used to hearing. Oh, did you mention how many years experience you have racing?

-Good day and thanks for trying to justify spending thousands of dollars on equipment overbuilt for its purpose.

Kookz
02-02-2004, 06:10 PM
Hmmm, well what do you do when you've heat soaked the entire surface area? Lemme guess fall off rack

You're making no sense, as you're still better off with a larger rotor than 300zx, yet you state the opposite.



Yes 2 piece rotors are used, sorry I didn't give you every single detail. I'll be sure to do that next time. Oh and I'm not denying the rotors are lighter, but what about the oversized calipers?


Oh ok, so you meant that more unsprung weight it good, got it. Oh and the calipers...Hmm, my Wilwoods are 1/4 the weight of Z32 calipers, but hey who cares about facts.



Wow you just shot yourself in the foot! Ask yourself how we understand and learn physics, its called R&D.

http://forums.freshalloy.com/images/graemlins/rolleyes1.gif
You're saying that big brakes don't work better unless you spend millions on R&D, when the fact remains that they work better even if you don't spend any money on R&D.



Oh, did you mention how many years experience you have racing?

0, but all it takes is some common sense and a grasp of physics to realize that your truckfull of BS dropped it's load off in this thread.

asad
02-02-2004, 06:31 PM
Hmmm, well what do you do when you've heat soaked the entire surface area? Lemme guess fall off rack



Your logic has a clear fallacy. Your basic claim is:
"1st of all, monster size brakes, means larger rotors, larger wheels, larger tires, also a lot more money spent, and most importantly a lot more heat to dissipatate!!!"

The last point does not follow from the previous points -- a non sequitur. In fact, it seems like you pulled it out of thin air.

How does increasing the brake rotor size increase the amount of heat that you need to dissipate?

Here's some physics for you.

In order to decelerate a car you need to get rid of the car's kinetic energy.

Where does that energy go? It goes into heat -- heat input into the brake rotors, which is eventually dissipated.

Even if we assume that a smaller rotor is as effective at dissipating the heat (which it's not, due a) to the lower surface area, and b) in many cases, like the Z32 rotor vs. Ahhsk's AP rotors, a straight vaned vent design vs. a directional curved vane design), for a given amount of heat input, the smaller rotor WILL BE HOTTER. Period. SOLELY due to the fact that it has less heat capacity, so a given amount of heat input results in a higher temperature. The other two factors I mention will only serve to amplify this effect.

So while smaller brakes might give an improvement in unsprung weight, there's absolutely NO WAY you can claim that smaller brakes offer ANY sort of thermal advantage over larger brakes.




Oh and I'm not denying the rotors are lighter, but what about the oversized calipers?



I believe Ahhsk's setup uses AP CP5555 or CP5570 calipers, which weigh 6.6 lbs. I.e. the same as aluminum Z calipers. And less than the stock 240sx sliding calipers and the iron Z calipers.




Wow you just shot yourself in the foot! Ask yourself how we understand and learn physics, its called R&D.



You don't need a $2million R&D budget (or even a $1.2M budget) to understand the basic physics behind heat transfer. That was done over 100 years ago.

Asad

Thx247
02-02-2004, 07:03 PM
There also really isn't that much braking going on at your typical road course. The straight away, a tap here and there for a turn but most of the time you are not on the brakes more than 1-3 seconds.

When you're pushing 130 rwhp, sure, but when you're making 2-3 times that power you'll be working the brakes a lot more. And yeah, not having to swap out pads is a nice convenience.

\


Can't one of the ME's here go and figure out the heat capacity of these different systems? Or failing that, just figure out using rotor mass and surface area how much braking each kit is capable of given pad operating temperatures, levels of friction, tire grip,mass and speed of the car and whatever else you need


Common now...choppy chop

Need4Boost
02-02-2004, 07:57 PM
How does increasing the brake rotor size increase the amount of heat that you need to dissipate?



Well think about buddy, you have 2 circular planes one measuring 12 inches in diameter the other in 14 and each are half an inch thick and both are made of aluminum. Both are heated to 400 degrees F. Now answer me this, which one will cool down faster?




Here's some physics for you.

In order to decelerate a car you need to get rid of the car's kinetic energy.

Where does that energy go? It goes into heat -- heat input into the brake rotors, which is eventually dissipated.



I never disagreed with that, but how much time is needed to dissipate the heat? Obviously compared to a rotor thats smaller that not over kill like a lot of these kits are.




Even if we assume that a smaller rotor is as effective at dissipating the heat (which it's not, due a) to the lower surface area



to a certain extent! Depends on what car we are talking about. As far as I know we are talking in reference to the 240sx, and yes the massive rotors, calipers, wheels (to clear the calipers), & the tires is over kill. For track use the Z setup is more than enough. Yes obviously race rotors, pads, fluid, and SS lines are a must. But running 6 piston calipers, larger rotors and even a wheel and tire combo to accomodate the setup will probably make you slower.




in many cases, like the Z32 rotor vs. Ahhsk's AP rotors, a straight vaned vent design vs. a directional curved vane design), for a given amount of heat input, the smaller rotor WILL BE HOTTER. Period. SOLELY due to the fact that it has less heat capacity, so a given amount of heat input results in a higher temperature. The other two factors I mention will only serve to amplify this effect.



I hate to dissappoint you but even a lot of the big boys don't run slotted/vented rotors. Most of the time they are even banned from tracks! Drilled or slotted rotors will simply crack. They can't handle the heat! The only time these products are allowed on track is if you can show that your product was molded not drilled. Drilling makes mircoscopic cracks that expand into a disaster on track. So I would first find out if the AP setup is even molded before bragging about the product, or you end up slapping yourself in the face. Now if they are actually molded, AWESOME!




So while smaller brakes might give an improvement in unsprung weight, there's absolutely NO WAY you can claim that smaller brakes offer ANY sort of thermal advantage over larger brakes.



Once again, Z sized race rotor, caliper vs. Overkill aftermarket rotor, caliper (ex. AP) on a 240sx then YES the Z sized setup offers a thermal advantage! Less unsprung weight means less momentum to slow down!!!!!!!!!!! Less heat is then generated!!!!!!!!!!!!!! Clear enough?






Oh and I'm not denying the rotors are lighter, but what about the oversized calipers?



I believe Ahhsk's setup uses AP CP5555 or CP5570 calipers, which weigh 6.6 lbs. I.e. the same as aluminum Z calipers



Thats nice, but that wont make up for the rotor weight, bigger wheel and tire combo, and the unnecessary momentum.







Wow you just shot yourself in the foot! Ask yourself how we understand and learn physics, its called R&D.



You don't need a $2million R&D budget (or even a $1.2M budget) to understand the basic physics behind heat transfer. That was done over 100 years ago.



Hmmm you like to piece things the way you want. The amount of money that I was quoting is S-E-A-S-O-N-A-L B-U-D-G-E-T. Besides, if you think a company spending more money on R&D to find out ways to better undestand heat transfer, to better work around it, to figure out another way to beat heat is a waste because we know all we need to know from a 100 years ago, then I'm sure you're one of those guys running in the back of the line on track. Heat affects every aspect of the car; engine performance, braking performance, tire performance, overall wear and tear, and most importantly the driver! But who cares?

JeromeS13
02-02-2004, 08:07 PM
[QUOTE]
Well think about buddy, you have 2 circular planes one measuring 12 inches in diameter the other in 14 and each are half an inch thick and both are made of aluminum. Both are heated to 400 degrees F. Now answer me this, which one will cool down faster?



First of all, I hope your rotors are thicker than 1/2".

Second of all, don't you think that the thicker rotor will also take longer to heat up to that temperature, than the smaller?

Salty_X
02-02-2004, 08:27 PM
I hate to dissappoint you but even a lot of the big boys don't run slotted/vented rotors. Most of the time they are even banned from tracks! Drilled or slotted rotors will simply crack. They can't handle the heat! The only time these products are allowed on track is if you can show that your product was molded not drilled. Drilling makes mircoscopic cracks that expand into a disaster on track. So I would first find out if the AP setup is even molded before bragging about the product, or you end up slapping yourself in the face. Now if they are actually molded, AWESOME!


Vanes are different from slots dude.
http://www.imagestation.com/picture/sraid102/p9a18b825e6202672860b16485bbfd31b/f9bbc73a.jpg

What the hell are molded rotors?



Once again, Z sized race rotor, caliper vs. Overkill aftermarket rotor, caliper (ex. AP) on a 240sx then YES the Z sized setup offers a thermal advantage! Less unsprung weight means less momentum to slow down!!!!!!!!!!! Less heat is then generated!!!!!!!!!!!!!! Clear enough?


No, it's not clear enough. You think that ~20 pounds (if that) of extra weight on top of the 2400 pound car is going going to cause thermal overload on those giant brakes? Jeez...



Thats nice, but that wont make up for the rotor weight, bigger wheel and tire combo, and the unnecessary momentum.


If you do it right the weight gain will be minimal, yet the upgraded performance of the brakes and probably the tires too (might as well get some high performance tires too right?) will be great.

Ahhsk
02-02-2004, 08:44 PM
AP CP5555 802/3 3.0kg (caliper)
CP3581-1082/83 7.7kg (two piece rotor)

Im not really sure what my wheels weigh, but ill pull them off this weekend to find out (they were surprisingly light for 18s).

Your arguement always seems to wind its way back to $$$$, hey its your tax dollars at work http://forums.freshalloy.com/images/graemlins/tongue.gif

Wiisass
02-02-2004, 08:56 PM
Oh and I'm not denying the rotors are lighter, but what about the oversized calipers?



I believe Ahhsk's setup uses AP CP5555 or CP5570 calipers, which weigh 6.6 lbs. I.e. the same as aluminum Z calipers



Thats nice, but that wont make up for the rotor weight, bigger wheel and tire combo, and the unnecessary momentum.





You say you agree the rotors are lighter, then try and say the calipers are heavier, get proven wrong there, and then try and claim that the rotors are heavier. You're talking yourself in circles. Just give up.

Tim

asad
02-02-2004, 09:55 PM
Well think about buddy, you have 2 circular planes one measuring 12 inches in diameter the other in 14 and each are half an inch thick and both are made of aluminum. Both are heated to 400 degrees F. Now answer me this, which one will cool down faster?



YOU

ARE

MISSING

THE

POINT

COMPLETELY.

I'm going to break this down into bite-sized chunks so you can digest it easily, emphasizing the important points.

The larger rotor won't heat up as much in the first place.

It's not the brake temperature that's that will stay the same if you upgrade the brakes. It's the heat input to the braking system. Heat is not the same thing as temperature.

Let's repeat that, because it's important.

Heat is not the same thing as temperature

Heat is energy -- the kinetic energy that the car loses is transformed, by the brake system, into heat energy. This heat energy is absorbed by the rotor, and the heat capacity of the rotor determines its temperature.





but how much time is needed to dissipate the heat?



A larger rotor with more surface area will be able to dissipate the heat more quickly.



But running 6 piston calipers, larger rotors and even a wheel and tire combo to accomodate the setup will probably make you slower.



That's just a guess...keep reading.



I hate to dissappoint you but even a lot of the big boys don't run slotted/vented rotors. Most of the time they are even banned from tracks! Drilled or slotted rotors will simply crack.



http://forums.freshalloy.com/images/graemlins/rolleyes1.gif I didn't say ANYTHING about slots or holes. I'm talking about internal VENTS.






I believe Ahhsk's setup uses AP CP5555 or CP5570 calipers, which weigh 6.6 lbs. I.e. the same as aluminum Z calipers



Thats nice, but that wont make up for the rotor weight,



You mean the rotor that's lighter than stock Z rotors? I weighed a Wilwood 12.72" GT rotor with an aluminum hat...it weighed 4 lbs LESS than a 30mm Z rotor.




Less unsprung weight means less momentum to slow down!!!!!!!!!!! Less heat is then generated!!!!!!!!!!!!!! Clear enough?



No, it's not at all clear -- I'll clarify below for you.




bigger wheel and tire combo, and the unnecessary momentum.




Let's do a little calculation, shall we?

Linear kinetic energy of a 3000 lb car moving at 100 mph (that's 1361 kg and 44.7 m/s) (ignoring the wheels for now -- we'll add that in later)

KE_linear_car = 1/2 Mv^2 = 1359700 joules

Now for the rotational part...let's assume the original wheel and tire combo (with smaller brakes) weighs 40 lbs, and has a diameter of 25". Using the formula for the moment of inertia of a thin-walled hollow ring (i.e. an overestimate, since all of the mass of the wheel/tire isn't concentrated at the edge of the tire), and remembering that w (omega, angular speed) for a wheel that's rolling without slipping is simply related to the linear velocity by w = v/r

So the rotational kinetic energy is (where m is the wheel/tire mass, 18 kg, r is the overall radius, etc)

KE_rotational = 1/2 I w^2 = 1/2 m r^2 * v^2/r^2 = 1/2 mv^2 -- where this time, m is the weight of the wheel/tire combo -- = 71931 joules (that's for all 4 wheels and tires, in case you were wondering).

And of course there's the linear KE of the wheels themselves, which conveniently enough is the same as the rotational KE (neat property of infinitely thin shells that are rolling without slipping).

So the total KE is KE_linear_car + KE_linear_wheel + KE_rotational =

KE_total = 1359700 + 71931 + 71931 = 1503562 joules.

That's what we start with.

Now, let's increase the mass of the wheel/tire combo by 25% (a reasonable number, since it's clear that the brakes themselves add no additional weight)

KE_new_total = 1359700 + 1.25 * (71931 + 71931) = 1539528 joules.

That's a difference of (1539528-1503562)/1503562 = 0.02392 = 2.4%

Two point four percent. That's NOTHING. And remember -- that's an upper limit!

Yay for high-school physics.



Heat affects every aspect of the car; engine performance, braking performance, tire performance, overall wear and tear, and most importantly the driver!



And again, you confuse heat and temperature. Heat doesn't cause problems -- it's what happens if you can't control the heat (namely, higher temperature) that causes problems. Bigger brakes ARE the way to control braking heat, giving reduced temperatures.

Now, let's be clear here -- I'm not arguing whether or not bigger brakes are overkill. For most people on this board, I'm sure they are. But don't toss around words like 'heat', 'unsprung weight', and 'momentum' to a physicist and expect to get away with it. At the very least you should do a quick calculation and see if your argument makes sense.

While I was doing the calculation up above, I thought to myself, "Self, it would really suck if you did this calculation and the wheels end up being a big component of the total kinetic energy of the car" -- and I was fully prepared to eat my hat if that did turn out to be the case. Lucky for me, and not so lucky for you, I turned out to be right.

Asad

JeromeS13
02-02-2004, 10:06 PM
Ok. I haven't seen this in a while, so:

http://personal.atl.bellsouth.net/j/s/js1980/temp/owned.jpg

Salty_X
02-02-2004, 10:43 PM
I'd totally have Asad's baby. http://forums.freshalloy.com/images/graemlins/smirk.gif

BlackbirdS14
02-02-2004, 11:04 PM
I'd totally have Asad's baby. http://forums.freshalloy.com/images/graemlins/smirk.gif



Tanner is intersex, he forgot to tell us

Salty_X
02-02-2004, 11:32 PM
I'm just saying that if it were biologically possible I would totally do it. http://forums.freshalloy.com/images/graemlins/grin.gif
Thank god it isn't though, that would hurt like hell. http://forums.freshalloy.com/images/graemlins/tongue.gif

Need4Boost
02-03-2004, 01:42 PM
First of all to those who are taking these posts as attacks, I'm sorry that you are.




Heat is not the same thing as temperature

Heat is energy -- the kinetic energy that the car loses is transformed, by the brake system, into heat energy. This heat energy is absorbed by the rotor, and the heat capacity of the rotor determines its temperature.



I'm extatic that you understand this. Now lets read the hidden meaning. As the kinetic energy is transfered into heat (from slowing the cars weight), unnecessary heat is generated from unnecessary rotational mass because the use of an overkill design of a braking system.




You mean the rotor that's lighter than stock Z rotors? I weighed a Wilwood 12.72" GT rotor with an aluminum hat...it weighed 4 lbs LESS than a 30mm Z rotor.



You must be a journalist. Do you remember me saying that you like to piece together words to favor your fashion?....

by me

Hmmm you like to piece things the way you want.



also by me

Once again, Z sized race rotor, caliper vs. Overkill aftermarket rotor, caliper (ex. AP) on a 240sx then YES the Z sized setup offers a thermal advantage! Less unsprung weight means less momentum to slow down!!!!!!!!!!! Less heat is then generated!!!!!!!!!!!!!! Clear enough?




Obviously I was talking about a race spec Z rotor not a stock rotor.




Let's do a little calculation, shall we?...1503562 joules.That's what we start with....KE_new_total = 1359700 + 1.25 * (71931 + 71931) = 1539528 joules...That's a difference of .002392 = 2.4%...



first of all Asad you didn't calculate the KE_total for the larger brake kit. Lets say the weight difference between the a race spec Z setup and the big brake race kit is a good 4lbs on each side (fronts). That 10% in weight increase will in it self will increase the KE_total by 1.5% totalling 3.9%.




That's NOTHING...



Using you 2.4% difference will lose you about a tenth of a second at each corner (multiply that tenth/sec by however many turns there are on track). Try saying that to a race car driver. 2.4%, 1.5%, 3.9% who cares that's nothing, right? Well on paper you are ABSOLUTELY CORRECT because it's in theory. Apply it to real world environments and then you are slapped with reality! You then realized that you paid for a product that not the manufacturer sold you but their marketing department did.

....'Hey they will see that it works for our Prototype race car and think it will work magic on their cars when we show them the fancy equations applied to the weight of their cars.'

Overkill kits will not make you faster, but slower. I just hate seeing people spending insane amounts of money on kits that will never ever achieve their engineered purpose (take in consideration the precautions, additional modifications needed to have/keep them working right). Saying these bigger brakes are better is like saying running a 18 inch wide tire will give you better handling than a 10 inch wide tire on a 240sx.




But don't toss around words like 'heat', 'unsprung weight', and 'momentum' to a physicist and expect to get away with it.



I will when you have no track experience and no experience testing out different setups with lap times after lap times. Don't take this as an attack but I'm am using reality not calculations on paper. Believe Asad and everyone who out there is using/buying these kits for the 240, I would LOVE! nothing more than those kits giving our cars a beneficial stopping advantage over a race spec Z setup.

Regards

Kookz
02-03-2004, 02:18 PM
I'm extatic that you understand this.

You still don't.


unnecessary heat is generated from unnecessary rotational mass because the use of an overkill design of a braking system.

...however, that 2.4% increase in heat still leaves the rotor at a lower temperature because of it's increased heat capacity and cooling ability.


You must be a journalist. Do you remember me saying that you like to piece together words to favor your fashion?....

by me

Quote:
Hmmm you like to piece things the way you want.


You're the one piecing little tidbits of misinformation together to form one of the weakest arguments I've ever heard. You said that the lighter caliper won't make up for the heavier rotor, and asad says the rotor is LIGHTER, how is that piecing anything together?


Once again, Z sized race rotor, caliper vs. Overkill aftermarket rotor, caliper (ex. AP) on a 240sx then YES the Z sized setup offers a thermal advantage! Less unsprung weight means less momentum to slow down!!!!!!!!!!! Less heat is then generated!!!!!!!!!!!!!! Clear enough?

W R O N G! The Z setup offers a THERMAL DISADVANTAGE because it can't handle or dissipate as much heat as the larger setup. Go back and read Asad's blurb on the difference between heat and temperature, because you still don't understand it.


Lets say the weight difference between the a race spec Z setup and the big brake race kit is a good 4lbs on each side (fronts).

http://forums.freshalloy.com/images/graemlins/confused.gif



I will when you have no track experience and no experience testing out different setups with lap times after lap times. Don't take this as an attack but I'm am using reality not calculations on paper.

To previously quote Asad, "Who needs credentials when you have facts?"

So let's use this reality vs. paper thing. The reality is that RACE CARS USE THE LARGEST BRAKES THEY POSSIBLY CAN! That clear enough for you?

That 10% in weight increase will in it self will increase the KE_total by 1.5% totalling 3.9%.

Oh, Asad did make one mistake. The difference was .24%, not 2.4% And how you come up with 1.5% for a 4lb increase (and who knows where you got that) is beyond me.

asad
02-03-2004, 02:23 PM
unnecessary heat is generated from unnecessary rotational mass because the use of an overkill design of a braking system.



Yes it's clear that a small amount of additional heat is generated. BUT you're neglecting the increase in heat capacity of the larger rotor that leads to lower rotor temperatures. And remember, it's brake temperature we care about.




Obviously I was talking about a race spec Z rotor not a stock rotor.



Whoops, you're right. My bad.



That 10% in weight increase will in it self will increase the KE_total by 1.5% totalling 3.9%.



I didn't calculate it before because there was no need to -- I was assuming a stock Z rotor. I'm actually glad you pointed that out, because now we can compare apples-to-apples (2pc rotors to 2pc rotors).

Ok, so let's use your 4 lb weight difference (and let's assume that it's all in the rotor, because the calipers, as we've seen before, weigh the same). So...if the iron part of a 2-piece Z rotor weighs about 10 lbs...and the iron part of a big-brake rotor weighs about 4 lbs more...

Guess what...that's a 40% increase in heat capacity! And you're quibbling over a 4% increase in energy that needs to be dissipated? 4% increase in heat energy combined with a 40% increase in heat capacity means significantly lower brake temperatures when all is said and done.

Asad

asad
02-03-2004, 02:30 PM
Oh, Asad did make one mistake. The difference was .24%, not 2.4% And how you come up with 1.5% for a 4lb increase (and who knows where you got that) is beyond me.



Actually there was a typo in my post. The 2.4% number is correct, but I had the decimal point in the wrong place prior to that. I've fixed it now.

Asad

Kookz
02-03-2004, 02:31 PM
Doh. I didn't have a calc handy to check it, so I was just prayin it was kosher http://forums.freshalloy.com/images/graemlins/wink.gif

asad
02-03-2004, 02:32 PM
Doh. I didn't have a calc handy to check it, so I was just prayin it was kosher http://forums.freshalloy.com/images/graemlins/wink.gif



All of the calcs in my brake bias thread were done using Windows Calculator http://forums.freshalloy.com/images/graemlins/smile.gif

Asad

Need4Boost
02-03-2004, 03:20 PM
...however, that 2.4% increase in heat still leaves the rotor at a lower temperature because of it's increased heat capacity and cooling ability.




Kookz you're right if we were talking about the same rotational mass for the 2 different kits. More weight more heat is produced to slow it down.




W R O N G! The Z setup offers a THERMAL DISADVANTAGE because it can't handle or dissipate as much heat as the larger setup. Go back and read Asad's blurb on the difference between heat and temperature, because you still don't understand it.




A race spec Z setup is NOT a thermal disadvantage (given you don't have a clueless driver) for the 240sx. No I'm not denying the heat capacity of the bigger setups. You know what? Since you can hold so much more heat and also dissipate as well that means you can brake earlier and longer while I can do it with my setup later and for less time. But who cares your setup can handle more heat and wont fade from the prolonged braking distances.




So let's use this reality vs. paper thing. The reality is that RACE CARS USE THE LARGEST BRAKES THEY POSSIBLY CAN! That clear enough for you?



You're right, but within a specific wheel size. Teams set limits, if they don't the rule books do. But just taking what you said makes it sound like race cars are built with the brake size first. Hmmm I'll be sure to wave when I lap you due to you're superior thinking. A lot of these kits need additional clearance (ie bigger wheels, etc).




Guess what...that's a 40% increase in heat capacity! And you're quibbling over a 4% increase in energy that needs to be dissipated? 4% increase in heat energy combined with a 40% increase in heat capacity means significantly lower brake temperatures when all is said and done.



Okay Asad so we should ignore the additional weight just because it carries 40% more heat capacity? 1st of all the 40% heat capacity is not needed because a race spec Z setup (which will be lighter) will be just as affective if not better at stopping the 240sx. And it will cool fast enough for the next hard braking.

One of the main enemies in racing is heat and unnecessary weight.

Is anyone in these forums that road races their 240sx experiment with different brake setups in comparison to a race spec Z setup? Have you noticed any difference between the kits? A$$ dyno doesn't count, lap times do.

BrianS
02-03-2004, 03:28 PM
so much for this being a 'quick brake question' http://forums.freshalloy.com/images/graemlins/tongue.gif http://forums.freshalloy.com/images/graemlins/tongue.gif

need for boost, you said you are in a university now, please.....

go take your first calculus class

then take a few calc based physics classes, i would reccomend a kinetics and a statics class, they are usually the 'first two'

then take an introductory calc based thermodynamics class

then read all the stuff you just wrote and then stick your foot in your mouth

ive been owned by Asad too, but we all learn, and at least i swallowed my pride and cracked my phyics book open to figure out my mistakes and get it right next time

you seem to have just enough knowedge in your head...to get everything wrong when you apply it, so keep on reading and learning, itll all make sense before too long, but in the meantime u might want to avoid opening your mouth and removing all doubt

but i digress

aparently you took 'internet argueing 101' though...'this one time, i saw a civic run a 9, that means civis are the best cars ever...adn this on time, i saw a cavilere totally smoke a viper, so vipers suck'

*edit



Since you can hold so much more heat and also dissipate as well that means you can brake earlier and longer while I can do it with my setup later and for less time. But who cares your setup can handle more heat and wont fade from the prolonged braking distances.




just...wow...i cant even dignify this with a response

please, go educate yourself

Thx247
02-03-2004, 03:35 PM
Hey well since we've figured the physics out behind this, how about answering whats left over.

How much does this big kit setup cost including the tires and wheels?

Vs how much the Z setup costs? Aside from maybe being able to run street compound brake pads at the track, cost is the only other thing worth mention.

Kookz
02-03-2004, 03:36 PM
A race spec Z setup is NOT a thermal disadvantage (given you don't have a clueless driver) for the 240sx. No I'm not denying the heat capacity of the bigger setups. You know what? Since you can hold so much more heat and also dissipate as well that means you can brake earlier and longer while I can do it with my setup later and for less time. But who cares your setup can handle more heat and wont fade from the prolonged braking distances.

Well there's some brilliance there. I would just hope that you're kidding, but I'm afraid you're not. Greater heat capacity and greater ability to dissipate heat means that you can brake LATER. You think that braking earlier and longer will bring the brakes to a higher temperature, which shows that you really don't grasp the concept.



You're right, but within a specific wheel size. Teams set limits, if they don't the rule books do. But just taking what you said makes it sound like race cars are built with the brake size first. Hmmm I'll be sure to wave when I lap you due to you're superior thinking. A lot of these kits need additional clearance (ie bigger wheels, etc).

So why do teams run the largest wheels allowed by the rules? It's to run the largest brakes they can. Yet this is the very thing you argue against...wow.

masterbunta
02-03-2004, 03:56 PM
Its really very simple.....

1. Car companies put the smallest brakes they can because it is more cost effective.

2. The brakes kit is large enough when the extra heat dissapation is not needed or overkill. Then going bigger is not worth the extra mass added to the system.

Salty_X
02-03-2004, 04:33 PM
How much does this big kit setup cost including the tires and wheels? Vs how much the Z setup costs?


The only problem I see with lumping the cost of bigger wheels and tires in with the cost of big brake kits is that most people who upgrade to Z brakes also end up upgrading to bigger wheels and tires as well, whether it's because of vanity or performance reasons or something else entirely. Some stock wheels won't even work with the standard Z brake upgrade, necessitating bigger wheels/tires, so if the money isn't a problem (which it always is) it would seem more beneficial to go with a big brake kit like Ahhsk's.

And just to try and keep anybody from coming back and arguing about extra unsprung weight, I'll use this as an example. The stock 15x6 7-spoke alloy wheels on my S13 weigh ~18.5 lbs. My new 17" wheels are 8.5" wide in the front and 9.5" wide in the rear and each weigh 19 lbs. and 20 lbs., respectively (And that's for a cast wheel, mind you). That's a whopping ~4 lb. increase in unsprung weight!! http://forums.freshalloy.com/images/graemlins/shocked.gif http://forums.freshalloy.com/images/graemlins/smirk.gif Which would probably be cancelled out considering the lightweight design of the 2-piece rotors. Also the 215/45/17 and 235/40/17s each weigh 20 lbs. and 21 lbs., respectively (Just weighed on a digital bathroom scale): This is comparable to the stock-sized tire.
So you can get superior braking capabilities and larger contact patches (Which come in handy for more than just stopping) without any additional weight compared to doing a standard Z brake upgrade and running stock wheels.
All it comes down to is <font color="green[/img]$$$</font>.
I'd do it but the male prostitution business is down right now so I'm not making any cash yo... damn economy. http://forums.freshalloy.com/images/graemlins/mad.gif

Need4Boost
02-03-2004, 05:25 PM
Wow Thred thanks for sharing you incredile knowledge from your midnight racer video games.



just...wow...i cant even dignify this with a response



It's okay Thred thats what happens when you smoke too much pot. But my response was sarcastic, have a good day.





Well there's some brilliance there. I would just hope that you're kidding, but I'm afraid you're not. Greater heat capacity and greater ability to dissipate heat means that you can brake LATER. You think that braking earlier and longer will bring the brakes to a higher temperature, which shows that you really don't grasp the concept.




Yes Kookz I was kidding, actually being sarcastic.




So why do teams run the largest wheels allowed by the rules? It's to run the largest brakes they can. Yet this is the very thing you argue against...wow.




Yeah well unfortunately the classes that any member on these forums can/will be able to compete in will 95% of the time allow for 17 inch wheels and sometimes even 16 inch. Sometimes these overkill kits need 18 inch bling blings.

Need4Boost
02-03-2004, 06:09 PM
And just to try and keep anybody from coming back and arguing about extra unsprung weight, I'll use this as an example. The stock 15x6 7-spoke alloy wheels on my S13 weigh ~18.5 lbs. My new 17" wheels are 8.5" wide in the front and 9.5" wide in the rear and each weigh 19 lbs. and 20 lbs., respectively (And that's for a cast wheel, mind you). That's a whopping ~4 lb. increase in unsprung weight!! Which would probably be cancelled out considering the lightweight design of the 2-piece rotors. Also the 215/45/17 and 235/40/17s each weigh 20 lbs. and 21 lbs., respectively (Just weighed on a digital bathroom scale): This is comparable to the stock-sized tire.



Salty this is a great view but the only thing wrong is that you have just taken the same amount of weight, well a little more, and set it farther away from the center on the wheel. This would be even better...take a 16 inch lightweight style wheel, volk te37 about 16 pounds at 16x7.5 fronts and 17.5 pounds at 16x8.5. You've just increased your wheel size but decreased the wheel weight. Now match that up with a race spec Z setup. I garuantee that you will have the necessary contact patch and braking performance.

Thx247
02-03-2004, 06:35 PM
Yes it basically boils down to cost. There is no way I could afford to track the tires, wheels and pads for a big brake kit though, the budget for 17/18 inch tires alone would outstripe the cars value in half a year.

Ahhsk
02-03-2004, 06:40 PM
Hey well since we've figured the physics out behind this, how about answering whats left over.

How much does this big kit setup cost including the tires and wheels?

Vs how much the Z setup costs? Aside from maybe being able to run street compound brake pads at the track, cost is the only other thing worth mention.



About three large from retailers, although with off the shelf componenets from AP, Wilwood, Tilton ect, you could piece something together for far less (6 pot calipers $620, 4 pot Dynalites $289 each, hats, rotors, hardware c.$150, stainless lines $70, custom brackets c.$250).

Some 300HP setups use Isuzu NPR intercoolers, some use ARC. If you think its worth it buy it, if its not oh well. I had a large discretionary income early last year so I was like sure why not.

Need4Boost, Its great you want to race in Spec whatever class, I dont want to. Dont assume we have the same interests, and that your "race spec Z32 rotors" will be best for me. The ladies dont care about Z32 race spec rotors foo.

Need4Boost
02-03-2004, 06:49 PM
Need4Boost, Its great you want to race in Spec whatever class, I dont want to. Dont assume we have the same interests



Sorry for trying to enlighten everyone else and saving them the time and money (for the ones actually tracking their cars).




that your "race spec Z32 rotors" will be best for me. The ladies dont care about Z32 race spec rotors foo.



Oh wow sorry I didn't realize you were one of those guys that needs a car to pull tail (worn used tail). Continue as you were. http://forums.freshalloy.com/images/graemlins/rolleyes1.gif

Ahhsk
02-03-2004, 07:07 PM
read through the thread and please show me one "enlightened" person?

Humor, oh well its not the only concept that has eluded you.

http://www.zilvia.net/f/images/smilies/lock.gif

JeromeS13
02-03-2004, 07:19 PM
Oh wow sorry I didn't realize you were one of those guys that needs a car to pull tail (worn used tail). Continue as you were. http://forums.freshalloy.com/images/graemlins/rolleyes1.gif



Hmm... Apparently, you haven't seen Ahhsk lay it down at MJQ. He had a flock of like 1,000,821 on his cack.

CoolBlue
02-03-2004, 07:43 PM
What your saying might make sense if your only doing one or 2 laps, but if your on the track for extended periods of time, eventually your going to fade the smaller brakes. And not everyone has 1.2m or 2m dollar budgets to figure out to the nth degree exactly what size rotors and which brake compound to use that creates an equilibrium of heat generated per lap to heat dissipated per lap. With Ahhsk's setup, I imagine brake fade on the track is the last thing on his mind.

Kookz
02-03-2004, 07:54 PM
Synopsis of your argument:

Smaller brakes are better for a race car. Your logic? That you worked for a race team.

Flaw in your logic: Your race team, as well as any other, runs as large a brake system as they can.

Need4Boost
02-03-2004, 09:31 PM
Synopsis of your argument:

Smaller brakes are better for a race car. Your logic? That you worked for a race team.



Kookz get your eyes checked. My arguement is clearly against overkill kits that you still choose to side with just to justify your purchase. Prove your point in reality not theory. Reality vs theory...reality will always be the truth.




Flaw in your logic: Your race team, as well as any other, runs as large a brake system as they can.



Of course given the allowed wheel size but I promise they will not waste the weight on an overkill setup. Think about it.

IKu
02-03-2004, 10:29 PM
it almost seems like you are arguing just for the sake of arguing. you've been proven wrong, admit and move on. besides, nobody's really focusing on whether or not these kits are overkill:


Now, let's be clear here -- I'm not arguing whether or not bigger brakes are overkill. For most people on this board, I'm sure they are.



they're just telling you smaller brakes are not better.

jimc-s13
02-03-2004, 11:49 PM
This thread is pretty amusing. It is pretty clear that Need4Boost has no race experience, but he probably saw one on TV once or maybe even twice. It is also clear he knows nothing about the physics of braking. He's even changed what he's said so many times he could actually argue with himself. I'd say it is pretty clear he is just a troll.

For those actually looking for information on brakes, here are a few facts and opinions, based in the reality of running my car on a variety of tracks (Summit Point, Jefferson Circuit, VIR North, VIR Full, Roebling Road, Sebring 12-hour course, Homestead, more than once at all tracks except VIR and Homestead):

1. stock brakes are "good enough" for 240SXs with stock power, given some ducting, hi-temp brake fluid, and race pads. They may fade, depending on track and driver, but they will work. With much more than stock power (i.e. bolt-ons + no speed limiter), you will fade the brakes (as well as the motor running very hot from the extremely thin stock S13 radiator). I'm still running stock brakes and stock radiator on my 160+ whp 2900 lbs (without driver) S13, but both brake and motor heat need to be managed.

2. Z32 brakes are probably good enough for less than 180 whp 240s, depending on brake prep and track. Race pads will still be required for race-type driving, although at a track easy on brakes like Roebling Road you could probably get away with a good street pad like Axxis Ultimates. A "race-spec" Z32 setup would obviously be a little lighter but still require race pads and ducting at most tracks.

3. Larger brakes are probably overkill for most 240s. However, most 240s don't have 300+ whp. Those that do will be capable of generating far more heat than even "race-spec" Z32 brakes can absorb/dissipate. For them, larger brakes may not be overkill.

4. If someone wants to put huge brakes on their car, who cares? It's their car, their money, and they can do what they like. If it makes them slower at the track, it will still be by far less than typical differences in driver skill or other aspects of car prep. If you're building a race car, you have rules that constrain how large your brakes can be. If not, who cares? Do what you want to your own car.

5. Generally, bigger brakes are better on the track. A 14 inch brake rotor with 6-pot calipers on my S13 could probably handle Sebring on street pads without fading. Stock brakes at Sebring need a lot of cooling help to avoid fading. As already mentioned, pretty much all race teams run the largest brakes allowed by their rules, then spend a lot of money developing those brakes to be as efficient as possible because they're not big enough.

Interestingly, small tracks are usually harder on brakes than large tracks. In this situation, a larger brake will be much better than a smaller brake, because it can absorb much more heat and dissipate that heat much faster.

'97 S14 SE Turbo
02-04-2004, 02:46 AM
Quick and simple. He screwed up his point.

My understanding of what he wanted to say. "Too much capacity/capability is not necessary if you don't even need to use it."

For example. Using a severe heavy duty go anywhere off-roader for getting grocery at the local corner store.

Overkill.

But, he assumed that most of the 240sx owners here don't do much track running. Wrong...

Yeah, z32 sized brakes, even race spec, with deflecting cooling panels aren't enough for this 300rwhp S14...

Mav1178
02-04-2004, 03:43 AM
5. Generally, bigger brakes are better on the track. A 14 inch brake rotor with 6-pot calipers on my S13 could probably handle Sebring on street pads without fading. Stock brakes at Sebring need a lot of cooling help to avoid fading. As already mentioned, pretty much all race teams run the largest brakes allowed by their rules, then spend a lot of money developing those brakes to be as efficient as possible because they're not big enough.




On my big brake setup I was able to run Laguna Seca without a hint of brake fade.

Shoot I ran out of tire before I ran out of brakes. And it's a street pad!

-alex

BrianS
02-04-2004, 03:50 PM
For example. Using a severe heavy duty go anywhere off-roader for getting grocery at the local corner store.



so the moral of the thread is, dont buy a hummer http://forums.freshalloy.com/images/graemlins/grin.gif http://forums.freshalloy.com/images/graemlins/grin.gif

i hope everybody learned an important lesson

BrianS
02-04-2004, 03:51 PM
*damned adelphia...another double post

Need4Boost
02-06-2004, 09:10 AM
Man I'm such a moron. I'm so wrong about this whole brake thing and have absolutely no idea what I was talking about. You guys were right, I was talking myself in circles, I challenged some guy with a 1000 more post than me, a physcist, some kid with a 6piston kit,and a bunch of teenagers. D*mn what was I thinking?

But I thought I was so right. I guess the only thing I know how to do is race, well, wait you guys might want to tell me if that's even true. Sh*t I don't know I seem to be among the top 3 on track when I am but whatever. The point is I have no idea what I'm talking about. I'm going out right now and buying myself a $3500 big brake kit so I can stop as fast and hold/dissipate as much heat as you guys. http://forums.freshalloy.com/images/graemlins/rolleyes1.gif Oh and maybe a few books.

90240SR Listen to these guys I'm sure they will point you in the right direction for I am just a troll with REAL experience but my posts hold no credibility because I don't have 1000 post.


See you guys on track http://forums.freshalloy.com/images/graemlins/smile.gif

Kim_Jong_Il
02-06-2004, 09:28 AM
You do realize you're not the only guy on here that does track runs. Other people do plenty of events too and are listing their experience too. Not everyone is going to have the same opinion on what is best and it almost seems like you are trying to push you're expierence as cold, hard fact. Maybe you're just really light on your brakes, drive faster. http://forums.freshalloy.com/images/graemlins/wink.gif

'97 S14 SE Turbo
02-06-2004, 09:56 AM
Man I'm such a moron. I'm so wrong about this whole brake thing and have absolutely no idea what I was talking about. You guys were right, I was talking myself in circles, I challenged some guy with a 1000 more post than me, a physcist, some kid with a 6piston kit,and a bunch of teenagers. D*mn what was I thinking?

But I thought I was so right. I guess the only thing I know how to do is race, well, wait you guys might want to tell me if that's even true. Sh*t I don't know I seem to be among the top 3 on track when I am but whatever. The point is I have no idea what I'm talking about. I'm going out right now and buying myself a $3500 big brake kit so I can stop as fast and hold/dissipate as much heat as you guys. http://forums.freshalloy.com/images/graemlins/rolleyes1.gif Oh and maybe a few books.

90240SR Listen to these guys I'm sure they will point you in the right direction for I am just a troll with REAL experience but my posts hold no credibility because I don't have 1000 post.


See you guys on track http://forums.freshalloy.com/images/graemlins/smile.gif



As a guy that regulary does track events and a working professional in engineering, this is all I can say.

Grow up.

Blurple240
02-06-2004, 11:31 AM
Grow up.



You know wanna know what kind of person has to be always right and HAS to have everyone agree with them?

A 4 year old.

Oh, and I think it's hilarious that Mr. Track Star wants us to take him seriously when he doesn't know the difference between rotor vanes and slotted rotors. http://forums.freshalloy.com/images/graemlins/rolleyes1.gif

-john

Need4Boost
02-06-2004, 04:16 PM
'97 S14 SE Turbo...thanks for your professional engineering input and racing experience. Quick question though, is their such a thing as overkill designs? Food for thought.




You know wanna know what kind of person has to be always right and HAS to have everyone agree with them?

A 4 year old.

wants us to take him seriously when he doesn't know the difference between rotor vanes and slotted rotors



Okay I'm 4 yrs old...lol, Blurple-sperm whatever your name is, go home. Sign up for a track event or something. Wait isn't it about time to go catch the school bus.




seems like you are trying to push you're expierence as cold, hard fact.



Tweak 180sx just trying to be helpful and save a few guys $3000. My bad, seemed like I offended the ones that already did by telling them they wasted their money (that is pretty much what I said).



Maybe you're just really light on your brakes, drive faster.



lol, okay but I may need more than 5 gears http://forums.freshalloy.com/images/graemlins/smirk.gif

Ahhsk
02-06-2004, 06:20 PM
http://www.imagestation.com/picture/sraid102/p2da25251c725c5913f4bd6c216877139/f9b26b65.jpg

Its kinda sad that this thread will be locked because there is some good info, not that you provided tho.

Dude if your so hard up for cash stop "racing" get a job and STFU.

PS write Porsche, Ferrari, and the rest of the big boys to stop putting out slow cars that could go so much faster around a track if they would make the switch to "cross vented" "Z32 race spec" brakes.

Kookz
02-06-2004, 09:33 PM
Quick question though, is their such a thing as overkill designs? Food for thought.

Yup. You didn't choose to argue that, however. You argued that smaller brakes would be faster around a track.

JimC said it best. Race teams run the largest brakes they can get under their wheels, then they spend money on cooling them because they're not big enough.

'97 S14 SE Turbo
02-07-2004, 01:49 AM
'97 S14 SE Turbo...thanks for your professional engineering input and racing experience. Quick question though, is their such a thing as overkill designs? Food for thought.




The limitation to engineering is the budget given.

With the unlimited budget, there is no such thing as overkill when it comes to design.

When to comes to racing, it's all about heat management at the lightest possible weight. Hence Carbon brakes.

You can call it overkill if you are using carbon brakes on a grocery getter. But large disk calipers systems on fairly high powered cars like ours are on par.

You obviously don't have real world understanding of how things really work. Go back to school. and don't forget. Grow up.