1992 trans am TPI Fuel system question

[Will]

My brother has a '92 T/A and has an extra 5-600 horse small block from one of his circle track cars. The first question I have is will the factory tpi intake bolt to his small block? Also, will anything besides injectors need to be replaced in the fuel system? and last one. Where is a good place to get the prom reburned? I am from ohio. Thanks a lot, Will

[Benm109]

I'm no expert on the TPI systems, but I can answer some of your questions. You can bolt a TPI intake set-up on an 86-earlier block with some modification. I think all you have to do is elongate the 4 middle bolt holes (2 on each side) that attach the manifold to the heads.

The problem with your situation is that TPI set-ups can't really handle 500-600 HP. You can upgrade the injectors and rails, fuel pump, adjustable regulator, port the intake, runners, and plenum, or buy upgraded intake runners, and plenum, but it's not worth it. The TPI system will be the weakest link of the motor. I would look into an aftermarket fuel injection system. There are tons of them out there, Accell/Lingenfelter Super Ram and Street Ram, and Holley's Stealth Ram is very popular with 3rd gen guys, by the way.

Another reason I am suggesting an aftermarket unit is also because they come with a computer and can be upgraded easier (I think). It is always best to burn your own PROMs if you can because no one else knows your car better than you. Most mail-order chips or internet chips can only give you a ball-park figure to modify the PROM for your mods, if you understand what I mean. But, if you want someone that at least half-way knows what they're doing in PROM burning, try out www.tpichips.com . There are probably some people in Ohio that can burn PROMs for you, too, though.

One more thing, check out www.thirdgen.org . It's dedicated to 3rd gens and has tons of info available for anything you want to do to your 3rd gen. Good luck with whatever you decide!

[DeWynter]

There are a few ways to go about this question. First, 85-92 TPI from a f-body only bolts to center bolt heads(Valve covers bolted down the middle with 4 bolts) you can modifiy the two Center holes to accept pre-centerbolt heads. Corvettes that had the TPI Bolt onto pre-center bolt heads as that is what they were designed for. If you are looking for Huge HP TPI is not the way to go as It will not rev past 4500 RPM and for big Engines it will not alow enough air to pass to the heads to make HP. If you want Torque TPI is a monster. I have a 383 stroker that I have been building the last two months that was just dynoed at 322 HP @ 4212 RPM and 472 #LB Tq @ 3600 RPM and 351 #lb @ 1000 RPM. This is perfect for a street car that you want to go light to light, probably not the best for a quarter mile car. I like the feel of big power at low RPMs and I dont really rev into the 4000 RPM range that often anyways. I guess it matters most what you want to use the car for. If your after HP I here you can modify a Corvette LT5 intake to work on a regular small block, it has the best of both worlds It has Long and short runners. Long for the low RPM torque than it switches to the short runners when the RPM is High enough to give you big HP. I wish there ware more aftermarket companies that would build an intake like that.
Best thing to do with the proms is burn your own they take a little learning but once you know how you can change the prom like you change your underwear. To start out with find someone with a car running simular mods get his prom and tweak from there.

[Will]

Thanks for all the help. The reason he was wanting to keep the stock tpi is so the car looks completely stock. He also doesn't want to spend a whole lot of money. What about this LT1 intake swap i hear about? Is that worthwhile and somewhat cheap/easy? Thanks, Will

[DeWynter]

For about the same price as the TPI to LT1 swap after all modifications to wire lengths Machining of the intake and tuning fixes, It would be better and more cost efective to get a super ram or something simular to replace the TPI and you will get better Preformance. Dont get caught up in the race for HP unless your going to be driving the car where its made. Here is an example of HP and torque from 1000 RPM to 4515 RPM
RPM - HP - TQ
1000-66.4-349
1185-82.5-366
1370-97.8-375
1555-114-386
1740-129-389
1925-144-394
2110-160-399
2295-176-402
2480-189-399
2665-207-408
2850-229-421
3035-254-439
3220-282-460
3405-302-465
3590-322-472
3775-340-473
3960-349-463
4145-357-452
4330-364-441
4515-364-423
As you can see HP is really only a factor at Higher RPM. This motor can make more HP if I put a different cam and intake on, but only after the 4000 RPM mark. Which with TPI is not a factor as TPI is no good past 4200-4500 RPM. The headers I am using are also smaller 1.5"P x 15"L x 2.5"Col.(beter TQ)