I have the tpi and computer off an 87 trans am. I would like to put it on my 377 which when complete should be putting out around 580 hp. I am pretty sure that I need to upgrade the computer and injectors, for this to work. Anybody know of a place I can get a new chip or have my computer upgraded and what sixe injectors I should run. I would really like to make this a TPI motor but will carb it if necessary.

 

for injectors i'd say like 30# would be good....pcmforless will burn you a chip, they are a supporting member too...

 

Are you sure thats enough? I have a .640 lift and 305 degree solid roller cam, with 220cc heads with 2.100 intake and 1.6 exhaust aluminum heads. The compression is 10.7-1 and the motor is a 377 (400 block 350 crank). They sell injectors up to 48 # and I kinda thought I'd be about topping out what TPI is capable of handling.

 

tell ya one thing, put a TPI on that beast, and your gonna have a lower RPM/lower HP motor, but its gonna be torque crazy....they make injectors that big for turbo/supercharger/dry nitrous applications...you can go with like a 36 or bigger if you wanna be safe, just make sure you tell them when they burn you the chip...

also as far as the TPI goes, i'd toss that idea and go with like a HSR or something...your gonna sufficate alot of power with TPI i think...

 

I would not get a company a million miles away to burn you a custom e-prom. Talk to the car nuts in your area im sure there are some local forums. The only way to accurately burn a chip for your car is to put the thing on a dyno and do it in real time.

No idea as to what injectors you need. Talk to jack at www.racetronix.com you probably need a full fuel system upgrade and he knows his stuff.

Out of curiosity what benefit is there to destroking a 400? why not stroke it out to a 427.

BTW that is an awful lot of head for that motor. The 195's they used to make eeasily supported a stroked 350 motor (383) on a 427 the 220's would prolly be okay not sure if youre going to have too much airflow for the engine.

You also have the worst head intake combo imagineable. 220 AFR's with an intake that cant flow enough air to truly support stock L98 heads?! Even a HSR will probably hold that combo back.

Having an intake that supports low air flow, high air speed combined with heads that have massive air flow capability. You will have no air volume coming through that tpi, and then as soon as it gets to the heads youll lose all of the speed as it hits the massive volume. You will have no air enteringt he motor at a very low speed.

 

I really hope that you are not planning on sticking a stock TPI intake on that motor - it will destroy the topend (unless you're boosting it). What RPM do you plan of shifting that motor?

(For those not familiar - destroking the 400 block with the 350 crank allows the motor to rev up easier....makes for a real screamer, similar concept to the 302 in first gen Camaros)

- Justin

 

I think you'd be better off with a converted carb intake. As for injectors, find someone in your area to burn you a chip and they'll be able to tell you the best injectors for your app. (as well as being able to tune it well).

 

Yeah the Idea of a destroked 400 is to get high rpm, high hp and lower torque, so on that note it really sounds like tpi is not suitable for my motor. I don't know much about Fuel injection so this is a real eye opener to me. The cams power band is 3,800-7,800 rpm, which really is perfect for a 377 and I am pretty sure that those heads are just about perfect for the cam. So anybody have any Ideas on what Fuel injection or carb setup would work well?

 

your gonna need a helluva FI setup to breathe that high...miniram/HSR/TPI will not go far past 6 grand...i know there is like holley projection and stuff, but i don't know much about it...i think your gonna need a carb setup, and your gonna need a a nice big hirise intake, because an airgap and performer RPM's won't even breathe past 6500-7000...

 

I know there's a following behind that TBI projection stuff but I just don't see why someone would use that. It just seems to me like you're halfassing an FI setup. It's FI but it's still just a carbstyle injector.

I'd look into getting a real high flowing carb intake and have some bungs welded into it for injectors. Then you could run a cheap TPI SD computer and tune it yourself if ya like.

 

Wow thats a high powerband for a street motor. And ya i guess if youre going to be revving to 7500+ youll need heads that flow that well. TPI falls flat on its face around 4500 rpms so thats a definite no and as stated previously all other FI intakes die a little over 6. Ill never be able to find the link but i know there are places where you can use more or less any lower plenum you want and then they build just like a box basically as your upper plenum. That sounds like what you need if you want fuel injection.