NA vs FI - "Are you serious?"

[Ish_]

This arrose today from a recent article a friend was discussing.

The setup... "Can a ~251 hp N/A [350z] car outperform a ~400 hp [350z] FI car"

At first the answer is obvious. "Are you serious?... NO WAY STUPID!!"

Now I am wanting this post to be a technical discussion on the differences, advantages, disadvantages and so on... NOT A "My car is better/can beat your car"... not my intention!!

Now... people are going to wonder which two cars... so it was myself and Fred having the discussion. Our two cars are completely different in intention, but PERFECT for this discussion... his is built much more as a performance oriented street/track car... where as mine is a tamer streetable driver with near 150 lbs of audio equip and so on http://forums.freshalloy.com/images/graemlins/smile.gif, which will not see a track for a long time.

I want to leave this open not to these two cars specifically... but as a general discussion, but the two just work as good examples.

The NA 350 ~250 hp: Full breathing mods (minus down pipes) including spacer... Full underive pulley set. I want to ignore certain things on my car though which may affect the discussion (for those who know my car)... Ignore: Brembo brakes, Sway Bars, Wheels and of course the Audio stuff.

The FI 350 ~400 hp: ATI Supercharger, Plenum spacer, down pipes... Ignore shocks and wheels on this one.

AGAIN!... I am not looking to specifically spout my car vs Fred's car, but really our cars are just Perfect for this discussion. One being a modified NA car, the other being the horsepower king.


Ok, The Obvious... Drag stip, highways, straight aways, large open tracks, etc: the Supercharged or any FI car with more HP and torque will win hands down every time. No questions here.

All being equal now other than the true power mods, can the NA car compete with the FI car... specifically on tighter tracks, autocrosses etc?



Now since I started the discussion I'll give my opinons. Me and Fred disagreed on this one... unfortunetly Im a sissy and won't take my car on the track for a "real world" test http://forums.freshalloy.com/images/graemlins/smile.gif Again mine is a street GT/Tuner directed car. Don't want to beat the hell out of it So you can make fun of me now :P

On a tighter track I feel the parasitic loss of the supercharger, AND the added weight might just be enough to give the upper hand to the NA car. The NA car is also more predictable and easier to drive. (Also this would have to account 100% equal driving skill and identical track conditions, tires etc)

Others? And I say again... I'm not looking for a My Car/Your car battle hear. I really thought that this just made for a VERY interesting discussion. Fred and I [IMO at least:)] are good friends and I don't see him in any way as some sort of competition. In fact he has really helped me out with my car and in welcoming me into the Nissan/Infiniti community in the area. I would have never taken the tuning to the next level and of had so much fun with the Z if it wasn't for him (and of course some others) to enjoy the car with. http://forums.freshalloy.com/images/graemlins/grin.gif

So with that said... Let the discussion/debate begin! http://forums.freshalloy.com/images/graemlins/smash.gif

[palmerwmd]

Don't forget my Koni adjustables.. http://forums.freshalloy.com/images/graemlins/wink.gif

I admit,I <do> need sway bars tho.

Even tho my brakes are stock, they stop in same feet as the Track ones and onutoX so far,I have not seen fade..

Dan Wu (Freshalloy ProjectZ) and myself were gonna meet at a track to see. http://forums.freshalloy.com/images/graemlins/auto.gif


But you are right we shouldnt bog down ,in our specific cars..

Fred

PS: I'm still calling you out, for the autoX course, me in my car, vs you in your car http://forums.freshalloy.com/images/graemlins/auto.gif

[idrive]

in the auto-x im going to say jeffs will win because its almost a quarentee that jeffs car will be in an immaculate condition mechanically etc by the time it gets in between some cones, while with freds, lets just say the future of freds car is always a mystery, j/k

but to be honest it would be a tough call, possibly a second or so between the two on a typical tight auto-x course...i nominate myself as the unbiased and controlled variable test driver for both cars for any and all future testing! http://forums.freshalloy.com/images/graemlins/car-smiley-031.gif

[rickdogg]

Way too comfusing. Too much leave this leave that out to make it any fun. Maybe a bit more organization? http://forums.freshalloy.com/images/graemlins/tongue.gif

[Ish_]

Way too comfusing. Too much leave this leave that out to make it any fun. Maybe a bit more organization? http://forums.freshalloy.com/images/graemlins/tongue.gif



As stated.. don't look at it as a comparison between those 2 cars specifically. Instead NA vs FI in general, with each having supporting Modifications for there respected builds (NA vs FI)

[bambam]

My $.02.
If EVERYTHING was equal... IE you had two track edition cars and you dropped a SC into one. I do not see how the NA would be able to keep up. Yes you are adding weight with the SC, but at the same time, given a long track, in the straight-aways he would be gaining every time... Now, maybe on a short track with only twisties, you might have the advantage in a better weight distribution...

All in all I would say with the exact same cars, but one has an SC, the SC would have the upper hand in 95% of the race cases. Just my thought anyway... no proof to back it up.
--B

[helldorado]

If the cars are completely identical in terms of brakes, wheels, tires, drivetrains and body modifictions its going to depend on the extent of airflow modifications between the two.

So if you take a NA car that has headers, plenum spacer, CAI, underdrive pulley, exhaust and put it up against a FI car with CSC, test pipes and a plenum spacer, the NA car will be lagging the FI car in just about every point of the powerband. You might keep it close on a short auto-x style track where the FI car can't make much speed, but since HP rules in a situation with identical chassis, you're not making gains to catchup.

Now, if you had two identical cars and gave each 10k to mod with, I think you could have a different story. Lets approximate what you could do with each. So say we take '06 track models so both have track ready forged wheels and Brembo's.

Say you take your 10k and focus on being NA.
CAI - $250
Plenum spacer - $250
Clutch + Flexplate - $1500
3.9 FD + LSD - $2500
Sway bars - $250
Adj. Sus + controller - $2500
Headers - $1000
Test pipes - $500
Exhaust - $1250

Then you take a the FI path.
CSC + tune - $7500
Test pipes - $500
Exhaust - $1250
Clutch - $750

Given a scenario like that, I think the NA car is going to be extremely tough to beat. I think on shorter auto-x style track and through the curves, the NA car will be much faster than the FI car. It'll be able to take the turns much more quickly as well as be able more appropriately put the power down to each wheel. The 3.9 gearing will help to make up for the loss in sheer power in acceleration. Only on long straightaway where the FI car can wind out its high HP and extend its taller gearing will it make the gains, but in the next turn, the NA car will be right there again.

Between those 2 cars, I'd take the NA car every time.

EDIT: After thinking about my later post, I swapped cams for the clutch / flexplate combo on the NA setup since it would improve driveability more than cams would. Forget these kind of things sometimes being 5AT myself. http://forums.freshalloy.com/images/graemlins/ack2.gif

[Ish_]

Helldoado
You have taken the discussion exactly where I intended it to go, a general comparison of an NA build vs an FI build. Nice Post!

[helldorado]

It brings me back to the comparison Speed Magazine did several months back. They had compared the Stillen, Vortech, JWT TT and GReddy TT. What was interesting was a sidebar they had to the entire article. They had a Z with Nismo exhaust, 8lb Tilton flywheel/clutch, 3.917 FD, Nismo LSD, Stoptech brakes, Nismo suspension and Hoosier slicks. The car was a full second faster on the track than every FI car, and 4 seconds faster than stock.

[robertp]

I think it depends entirely on the FI setup. I would think that a nicely tuned FI built for response would feel close enough to a NA machine. As long as the power isn't too much to where tires spin all the time, I don't see the lower hp NA having any advanteges. It seems the times when a lower hp NA setup is better then a FI setup, is when the car is considerably lighter. ie. stock miata vs. z06.

I don't own a Z, but with my 240, I had a KA with fidanza flywheel, UO pulley, hotshot headers, intake, and different exhausts. Now I have a redtop sr w/stock t25, 256 cams, 3" downpipe, fidanza flywheel, using the same 2.5" HKS exhaust that I ended up with on my KA...and honestly, it feels near identical to my old KA, with just more pull. Response is quite similar, the powerband "feels" similar, it even runs out of breath at 6200ish, just like my old KA. heh

[350ZNV]

Given the same track conditions, tires, suspension, and a driver that knows how to drive the N/A car and the FI car to their FULL potential, then the FI car will win hands down in everything. Even autocross. The weight of the supercharger will not bridge the gap between the power of the two cars.

[robertp]

What a coincidence, sport compact car's latest mag has almost EXACTLY what we're talking about! lol

A supercharged 350z against an NA bolton's 350z. The SC'd Z looks like a showcar, SCC even called it as such! lol

The SC'd Z had 359hp, the NA had 269. The SC'd Z also had like every body piece and interior piece you could think of. I wish they would have weighed the cars, because even though the NA Z had 90 hp less, it beat the snot out of the SC'd Z, 11 seconds between the 2.

[wperdigon]

hahahaha - i saw that article and was like wtf yo?

[wperdigon]

Don't forget my Koni adjustables.. http://forums.freshalloy.com/images/graemlins/wink.gif

I admit,I <do> need sway bars tho.

Even tho my brakes are stock, they stop in same feet as the Track ones and onutoX so far,I have not seen fade..

Dan Wu (Freshalloy ProjectZ) and myself were gonna meet at a track to see. http://forums.freshalloy.com/images/graemlins/auto.gif


But you are right we shouldnt bog down ,in our specific cars..

Fred

PS: I'm still calling you out, for the autoX course, me in my car, vs you in your car http://forums.freshalloy.com/images/graemlins/auto.gif





BRING IT! smile

[helldorado]

What a coincidence, sport compact car's latest mag has almost EXACTLY what we're talking about! lol

A supercharged 350z against an NA bolton's 350z. The SC'd Z looks like a showcar, SCC even called it as such! lol

The SC'd Z had 359hp, the NA had 269. The SC'd Z also had like every body piece and interior piece you could think of. I wish they would have weighed the cars, because even though the NA Z had 90 hp less, it beat the snot out of the SC'd Z, 11 seconds between the 2.



I grabbed the magazine to check out the article. Unfortunately I feel the orange Veilside car is pretty indicative of the majority of Z owners. Throw on a supercharger, lowering springs, big rims and a body kit and they think they have a super car.

There is one thing worth noting, the NA Z, is the same one I mentioned from the Speed Magazine FI shootout and Mike Cronin (who owns the car) was the driver for that shootout at Willow Hill. There are a couple differences from when he drove the car in that comparo though. This time it wasn't wearing Hooosier's and it had a Nismo LSD listed last time, this time its a Cusco 2 way LSD.

Overall, it makes me feel better about my mod path of drivetrain and handling mods first, over going FI right away. And with this I'm still debating whether or not I want to even go FI in the end, or invest in staying strictly NA and focus on engine efficiency.

[Ish_]

What a coincidence, sport compact car's latest mag has almost EXACTLY what we're talking about! lol

A supercharged 350z against an NA bolton's 350z. The SC'd Z looks like a showcar, SCC even called it as such! lol

The SC'd Z had 359hp, the NA had 269. The SC'd Z also had like every body piece and interior piece you could think of. I wish they would have weighed the cars, because even though the NA Z had 90 hp less, it beat the snot out of the SC'd Z, 11 seconds between the 2.



I grabbed the magazine to check out the article. Unfortunately I feel the orange Veilside car is pretty indicative of the majority of Z owners. Throw on a supercharger, lowering springs, big rims and a body kit and they think they have a super car.

There is one thing worth noting, the NA Z, is the same one I mentioned from the Speed Magazine FI shootout and Mike Cronin (who owns the car) was the driver for that shootout at Willow Hill. There are a couple differences from when he drove the car in that comparo though. This time it wasn't wearing Hooosier's and it had a Nismo LSD listed last time, this time its a Cusco 2 way LSD.

Overall, it makes me feel better about my mod path of drivetrain and handling mods first, over going FI right away. And with this I'm still debating whether or not I want to even go FI in the end, or invest in staying strictly NA and focus on engine efficiency.



WhooHoo! Stay NA

[helldorado]

Yeah, then I can beat both you and Fred! http://forums.freshalloy.com/images/graemlins/boxing_smiley.gif

[Ish_]

Yeah, then I can beat both you and Fred! http://forums.freshalloy.com/images/graemlins/boxing_smiley.gif



Well, I've pretty much only not done cams and downpipes :P ... so you got some modding to do http://forums.freshalloy.com/images/graemlins/smile.gif

[helldorado]

Yeah, then I can beat both you and Fred! http://forums.freshalloy.com/images/graemlins/boxing_smiley.gif



Well, I've pretty much only not done cams and downpipes :P ... so you got some modding to do http://forums.freshalloy.com/images/graemlins/smile.gif



Yeah, I've only got this measly UR pulley and a CAI / plenum spacer combo to back it up...





























Though before the end of the summer I should have a rebuilt rear-end with the 3.917 gearing and a Quaife. http://forums.freshalloy.com/images/graemlins/31.gif


If William ever gets his act together. http://forums.freshalloy.com/images/graemlins/7.gif Hahaha. http://forums.freshalloy.com/images/graemlins/tongue.gif

[Ish_]

Yeah, I've only got this measly UR pulley and a CAI / plenum spacer combo to back it up...




UR Pulley?
I Already have that... AND the UR accessory pullyes http://forums.freshalloy.com/images/graemlins/smile.gif
Plenum spacer... oh yeah Got that one too http://forums.freshalloy.com/images/graemlins/smile.gif

The UR pulleys are AWESOME!!!! Really noticed the low end kick

Plenum spacer... seemed to "enhance" my headers sound, which probably is aiding in some air flow then, but no drastic gains noticed. Though its hard to notic just a couple horsies diffrence, especially if the ECU has to take some time to compinsate.

[helldorado]

Yeah, I've only got this measly UR pulley and a CAI / plenum spacer combo to back it up...




UR Pulley?
I Already have that... AND the UR accessory pullyes http://forums.freshalloy.com/images/graemlins/smile.gif
Plenum spacer... oh yeah Got that one too http://forums.freshalloy.com/images/graemlins/smile.gif

The UR pulleys are AWESOME!!!! Really noticed the low end kick

Plenum spacer... seemed to "enhance" my headers sound, which probably is aiding in some air flow then, but no drastic gains noticed. Though its hard to notic just a couple horsies diffrence, especially if the ECU has to take some time to compinsate.



UR Pulley is pretty nice. I dyno'd after installing and it gave me 7 whp. I even have a used idler pulley I grabbed off supercharged4 for $20.

However, I would only run it on a stock engine. Once I start anything that changes the nature of the operation of the engine by either timing (cam), large power (FI or rebuild) or crank speed (ECU flash), I'm replacing it with a Fluidampr. Slightly heavier than the UR pulley because its stock sized, but its a torsional dampener too, which the UR pulley isn't. I don't think its a big deal on stock because the factory pulley only has a rubber damper on it which seems to be mostly for NVH and not actually reducing torsional vibration on the crank. But once you start pumping bigger numbers it would seem to be a wise idea.

http://www.fluidampr.com/images/rendered_parts/honda_cropped.jpg

Besides, I'm not going to need tons of power once my drivetrain is done. http://forums.freshalloy.com/images/graemlins/31.gif

[helldorado]

Which reminds me, have any of you seen the Nismo Concept RS? Rated at 350hp NA, though I'm assuming thats at the crank. Think I'll start another thread about that.