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View Full Version : N/a built KA ?? need advice



24Dee
12-12-2001, 09:44 AM
A friend of mine (lives in Newark) wants to keep his 240 n/a. He has a 93 hatchback 5 spd. Anyways he's convinced on staying n.a. I'm curious how rwhp could he gain with the following mods:
AEM intake
Full catback / N1 exhaust
PDM "wild" cams
Hotshot headers
Ported/polished head
Stronger pistons
and a few other things which i find a waste of money. I'm trying to convince him to just go Ka-t,SR,RB, something.. Can someone else find reasoning in building up his KA for a daily driver? I certainly can not

**DONOTDELETE**
12-12-2001, 10:31 AM
Stronger pistons won't make an N/A motor any faster.

If he gets every bolt on, including a flywheel and underdrive pulley, and 11:1 cr, the most he should expect is about 180 at the wheels.

I say go turbo, but to each his own. I am interested in building an 11:1 cr motor with piston tops ceramic coated for nitrous use, and spraying a 200 shot of nitrous on top.

Dennis

Shinsengumi_Okita
12-12-2001, 11:48 AM
How about a carbonfiber driveshaft? I read somewhere in this forum that you could gain about 5% to the wheels?
Don't forget about the ECU as well. You gain about 10hp?
... Damn it, it all costs too much.. http://www.freshalloy.com/

Oh yeah, how about boreing(sp?) to a 2.5?

NISSANSPDR
12-12-2001, 01:49 PM
The only reason to stay NA and not go turbo as your means of getting power is I think reliability. The NA more than likely will not breakdown on you as much and will require less maintenance than any turbo setup...unless you are ultra conservative on the turbo and only boost at 3 psi. Then you are dumb for turboing a KA or getting a SR and doing that! http://www.freshalloy.com/

Yours truly,
Gabriel
www.greddy240sx.nissanpower.com (http://www.greddy240sx.nissanpower.com)

**DONOTDELETE**
12-12-2001, 02:26 PM
First, why would you put an n1 on a N/A car? This will actually cause you to loose power and be very loud. (I speak from expericance as I had the n1 on my car before I did my swap)
Second, if you have talked to most people running a turbo 240sx, ka24det or sr20det, not too many people are complaining about reliability issues.

Mav1178
12-12-2001, 03:46 PM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Shinsengumi_Okita:
How about a carbonfiber driveshaft? I read somewhere in this forum that you could gain about 5% to the wheels?
Don't forget about the ECU as well. You gain about 10hp?
... Damn it, it all costs too much.. http://www.freshalloy.com/

Oh yeah, how about boreing(sp?) to a 2.5?<HR></BLOCKQUOTE>

You only gain power with a carbonfiber driveshaft when you accelerate, and the power gains can only be seen on a dynojet or equivilant dyno where you accelerate a known mass (the rollers). On a water brake dyno, it won't show up as gains.

You don't want to bore the KA out anymore. There's not much room left to bore...
http://home.earthlink.net/~mav1178/Images/Cars/Swap/DSC00022.JPG

-alex

**DONOTDELETE**
12-12-2001, 03:47 PM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Dee240sx:
Can someone else find reasoning in building up his KA for a daily driver? I certainly can not<HR></BLOCKQUOTE>

Turbo dedicated streetcars are highly impractical (why add the power if you're not going to even use it?). Not to mention these kinds (turbo street car) of people are usually uneducated about what they are even doing anyway (not hooking up the wastegate, ect.). Turbo/engine swaps are for those that have the knowledge, not for the average guy who wants to "take out a civic".

And it's not like a turbo is a bolt on and go affair, ask any of the Turbo KA guys (Dennis, Adam, TY). Many times you double your budget (of course there's really not even such a thing http://www.freshalloy.com/)/down time and you aren't even intending to build a race motor.

I say more power to him for being rational, sure he won't have 250+hp, but he's going to be reliable and he will be content long before many of these people with turbo or swap "plans".

Mav1178
12-12-2001, 04:09 PM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by niteguro:
Second, if you have talked to most people running a turbo 240sx, ka24det or sr20det, not too many people are complaining about reliability issues.<HR></BLOCKQUOTE>

It's not about reliability with turbocharged engines, it's about cost of modification, cost of maintainance, and cost of ownership.

A 150k mile KA24DE is cheaper to overhaul than a 150k mile KA24DE with a turbo.

-alex

24Dee
12-14-2001, 02:12 PM
Finally a can view this post!!! AS for the reliability of an high HP n/a motor for street use only.
In his case (he wants more revv's out the KA, about 7500 to be exact) I thought staying n/a would actually be more reliable than an SR swap or boosting the KA because the power he wants is going to be very high in the power band. Last i checked KA's weren't rev happy and revving the piss out of would actually be bad for it.
I don't know, I told him to buy a friggin honda if he wanted revv's, problem is he already had one, and won't go back again. There's much more he wants to do to the engine than what I wrote in my first post I just can't remember. How much money is he looking to spend if he wants about 200 -/+ rwhp and say 7500 rpms out of his KA.
If he has that much money I'd say import an r33...

White_240sx
12-14-2001, 03:19 PM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Dee240sx:
Finally a can view this post!!! AS for the reliability of an high HP n/a motor for street use only.
In his case (he wants more revv's out the KA, about 7500 to be exact) I thought staying n/a would actually be more reliable than an SR swap or boosting the KA because the power he wants is going to be very high in the power band. Last i checked KA's weren't rev happy and revving the piss out of would actually be bad for it.
I don't know, I told him to buy a friggin honda if he wanted revv's, problem is he already had one, and won't go back again. There's much more he wants to do to the engine than what I wrote in my first post I just can't remember. How much money is he looking to spend if he wants about 200 -/+ rwhp and say 7500 rpms out of his KA.
If he has that much money I'd say import an r33...<HR></BLOCKQUOTE>

The JWT ECU moves the rev limiter to 7300rpm, so making it revable isn't going to require much else. Maybe a KA20DE bottom end can be used if really high revs are expected. The 24 can go up to 8000rpm, it’s just the survival rate at that speed would be about the length of a circuit race. Also 200rwhp is going to require a pretty gnarly cam and make the power band fairly peaky, not street friendly.

I would say with hot street cams, head work, intake work, and some high comp slugs as well as the usual bolt ons would land a KA somewhere around 185-190rwhp. Carbs or a multi-throttle intake set up will be required for anything above that. Total cost: all said and done probably $5k-$10K on engine work, but the parts can be spread out over a period of time not like a turbo where you dump a large sum of money up front and have 3 months down time. http://www.freshalloy.com/

**DONOTDELETE**
12-14-2001, 03:26 PM
The crank is what is holding it back from 8K rpms. The valvetrain on the KA can handle it no problem. Nasport/Speedvision cars run NA SOHC KA's in that rev range all the time.

250-300hp is going to be next to impossible for a street car N/A without Nitrous. Like I said before, for that HP, you are going to need a power adder, like Nitrous or turbo, or you are going to have to swap a larger motor. A Chevy 350 should do fine with that horsepower level N/A, but you did say you wanted it to rev.

Dennis

12-14-2001, 03:37 PM
I've seen a dyno chart for a Rebello-built carbed KA24E that had something like 246 rwhp. And the powerband was nice and linear -- looked similar to a Honda hp curve.

I bet if you did a similar thing, but with an individual-throttle-body EFI setup, you could get even better low-end hp.

Asad

<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by d240t:

250-300hp is going to be next to impossible for a street car N/A without Nitrous. <HR></BLOCKQUOTE>

**DONOTDELETE**
12-14-2001, 03:38 PM
A fully built 11.1 race motor puts down 250-260 at the crank, but is not very streetable. Unfortunately, getting power like that ultimately pushes the powerband higher than what is used for everyday usage, for all out racing it would be sick, but going to work in the morning would suck. I think a reasonable number is 200 at the wheels, but that's still with a lot of work and money involved, people will always argue that the money could go towards a turbo setup and be faster. My goal is an NA motor strictly to be different, I like turbo cars and would do a swap if I ever felt like it, but I don't need 300hp all the time, 200 would be fine, then another 150 on top with nitrous if the need arises.

White_240sx
12-14-2001, 03:55 PM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by R240NA:
My goal is an NA motor strictly to be different, I like turbo cars and would do a swap if I ever felt like it, but I don't need 300hp all the time, 200 would be fine, then another 150 on top with nitrous if the need arises.<HR></BLOCKQUOTE>

Amen to that, consider me a fan Russ. http://www.freshalloy.com/

24Dee
12-14-2001, 04:17 PM
I'm printing this out and hammering it to his front door! It's getting very complicated and although the kid makes good money (he works for bell atlantic ... 20 something/hourly + overtime). I think a swap would be better suited...

**DONOTDELETE**
12-14-2001, 06:02 PM
I am just wondering, how could I push the red line of the KA to 7300rpm (JWT ECU for example)?? Do i need to make a new crank shaft for that?? or just balance all the crank, rods, pistons in rebuilding?? No need to modify the valve train??

12-14-2001, 06:13 PM
No, you shouldn't need a new crank for 7300 RPM...a balanced, perhaps lightened crank will be more than enough (I mean, the crank is fine for 7300 just as is, but doing some prep work will make it better). IIRC, the NASport GT3 KA's rev up to 8000 or so with a prepped stock crank.

Valve springs...possibly. Here's why: I'd guess that the stock valvesprings are fine up to 7300...with the stock cams. But, of course, the stock cams are pretty crappy past 6K, so you'd definitely want to upgrade if you actually want to make any power up there...which means you'll probably want to upgrade the valve springs as well.

Also, if you want to make power up at 7K rpm, you'll most likely need some head work and probably a custom short-runner intake manifold.

Asad

<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by wkrwu_Rick:
I am just wondering, how could I push the red line of the KA to 7300rpm (JWT ECU for example)?? Do i need to make a new crank shaft for that?? or just balance all the crank, rods, pistons in rebuilding?? No need to modify the valve train??<HR></BLOCKQUOTE>

24Dee
12-14-2001, 06:34 PM
With the addition of better cams stronger valve springs, new intake manifold, and some head work; would that add any power? Or does that make the 240 just quicker being it's making power in the top end (like the GS-R's , Si's , ITR)

12-14-2001, 07:12 PM
Yes, it will add power -- any time you make it easier for the engine to inhale, you will get more power. The drawback is that making the engine breathe better at high RPMs often means sacrificing power at low RPMs.

Asad
P.S. stronger valve springs will most likely cause you to lose a little bit of power, since the stiffer spring means there's more friction and it takes more force to open the valve...but it's a necessary evil.

<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Dee240sx:
With the addition of better cams stronger valve springs, new intake manifold, and some head work; would that add any power? Or does that make the 240 just quicker being it's making power in the top end (like the GS-R's , Si's , ITR)<HR></BLOCKQUOTE>

Mav1178
12-17-2001, 12:28 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by White240sx:


The JWT ECU moves the rev limiter to 7300rpm<HR></BLOCKQUOTE>

Actually, the standard JWT ECU only changes it up to 7100RPM.

-alex

**DONOTDELETE**
12-17-2001, 01:33 AM
heh... Ford 302. http://www.freshalloy.com/

**DONOTDELETE**
12-17-2001, 04:58 AM
dont worry about valvesprings, if you need performance springs then get em, i dont think that you or the dyno can feel the friction loss of springs and the advantage of performance springs greatly greatly out weighs the friction. when you fix up your engine, you almost always raise the rpm range....

mav11, dont really understand what your saying about the shaft... dont know about you but i dont want horsepower any other time than when im accelerating. but cost effectiveness of a graphite shaft is another story..hehehe