I'm kinda new at this TPI stuff but it just looks so neat under the hood. I want a daily driver if possible a pavement breaker come sunday with the bottle. I asked and asked everywhere else on the net and no replies. I heard alot of great things about this site, I know what I'm asking is alot but if your true to the f-body i know I can get some help out there so please do your homework and show me what this Thirdgen.org is all about. Thanks for any replies

88 Formula--Bone Stock 62,249mi on the od

 

400 HP OUT OF A TPI 5.7?????

I may be wrong but I don't think you could get that out of a TPI 5.7 engine.
But if you made it into a 383 then you could possible get that with mods to the intake, exhaust, suspension, tranny and ALOT of custom chip programming.
Obviously new cam, heads, AFR's, headers, SLP's, and if it is a auto a good torque convertor like YANK or VIGILANTE.

You have to read alot! Alot of guys here have started to do new mods to the intakes like Madmax siamesing the intake. This mod showed good gains to about 6000rpms. But would it give you 400 HP with the right cam, heads and other stuff, just don't know.

Also John Millican has done a LT1 intake to a L98 motor. Very nice but then again how much HP could it give?
But the MOST important thing with these cars is the tuning of the chip. There is and article, very good by Traxion, that explains what is needed and where to buy the stuff.
I know this does not answer your question but IMHO it just seems impossible to accomplish this with a TPI 5.7L motor. But with guys like madmax and John Millican and Traxion and others here, that I failed to memtion, that try new things it may be possible.
Good Luck.

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89 IROC 350 Auto
MSD 6AL
Custom DUAL Exhaust
Edelbrock Performer 6085 Aluminum Heads
ZZ9 Cam
TPIS Level 5 Chip
And Free mods.
(stock intake, runners and suspension)

13.879 @ 98.90 mph (with 2.77 gears!)


Moderator of http://www.iroczone.com

 

The weakest link in the L98 is the Intake setup... If you can replace it with an aftermarket setup which breaths better at high RPM, then it is possible, especially with Nitrous. Then again.... if you want to push more power like that, I think it would be safe to assume a bottem end upgrade for reliability issues. Arizona Speed and Marine offer a killer Nitrous set up that has bosses in the runners for theultimate nitrous injection... this would be the way to go for a 400horse TPI. but, it'll dip into the bank account quite a bit.

As for the 383 option discussed... this will definately get you 400horse. I have worked it out on desktop dyno. You will not do it with a stock TPI setup though... you will have to upgrade your intake no matter what.

What do you look on doing or spending?

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1988 Pontiac Trans Am GTA L98 5.7L, Black on Black with 114,000kms.

Best ET 14.559 @ 95.25MPH
Custom 3" Stainless Exhaust Y-Pipe back (High flow Cat and Flowmaster Mufler)

 

When talking about horsepower you need to make clear whether you are talking about Rear Wheel Horsepower (RWHP) or flywheel horsepower. 400 flywheel horsepower (which is about 320 rwhp) is very easy. 400 RWHP isn't easy but it can be done. If you want 400 RWHP (which is about 480 flywheel horsepower) you will most definitely need to ditch the TPI intake and use something similar to the LT1 intake (or MiniRam). Many 5.7 LT1 guys are pushing 400 RWHP but you'll need a VERY good set of heads and a big cam (like the CC306) along with all the other stuff like long tube headers, 3.5" catback, bla bla bla. If you have an automatic you will need a good torque converter. No matter what - you will need the little stuff like gears, 58mm TB, etc. Furthermore, you will need to learn to program your own PROMs - there's no other way. The 400 RWHP setup will require A LOT of money. This setup can be daily driven ... but, that is a matter of opinion and learning to program your own PROMs will be the difference that will make the car a daily driver due to all the extra driveability that you can reclaim.

I am hoping to be close to 400 RWHP with my setup as soon as I get the most recent round of mods done. Check out my page.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org