jwenn89GTA

I have been considering doing a Pontiac 455 swap into my 89 GTA. I did a search and could not find any info on anybody using a TPI. Is there any reason that I could not use this intake http://www.edelbrock.com/automotive_..._pontiac.shtml
with a fabricated plenum and retain my TPI? Obviously the PROM would have to be reprogrammed. Is the MAF TPI able to flow enough to feed a mild 455? Is there a way to retain the Chevy HEI for the signal to the CPU?

Air_Adam

It won't work - the Pontiac engine is a completely different mamal from the Chevy motor. The intake manifolds are completely different. The '82-02 Firebirds did not use Pontiac engines, they used Chevy V8s like the Camaro. Thats why both had TPI engines.

jwenn89GTA

I know the engines and the intakes are different. That's why there is a link to a Pontiac Fuel injection intake in the post. I was just thinking that with a fabricated plenum on top of the intake, the TPI throttle body and ECM could be retained. This would be more cost effective and should eliminate hood clearance issues. So the same questions. Can the MAF TPI system flow enough to feed a 455 and is there a way to either use the chevy HEI distributor or rig something different to work with the TPI?

Fast355

iTrader: (2)

Computer control on a 455 could be pretty easy.

I am almost certain the distributer from a 301 would drop right into a 455 and function. The 1980-1981 Pontiac 301 was computer command control carbed.

I would personally pick up a 730 SD ecm, tuning stuff, and go speed density.

Air_Adam

I don't think the distributor from a 301 would work. The 301 is a short-deck Pontiac block, not a std-deck like a 455. I seem to remember the 455 even being a tall deck Pontiac block (?) compared to the 326-400ci, but thats probably wrong. Though maybe its possible to swap the CC guts from the 301 distributor to a 455 distributor?

That intake you put in a link to is just a 4bbl carb intake with injector bosses. TPI is totally different. TPI has runners on the plenum to individual ports, so theres really no way to use a TPI system on the Pontiac motor.

Why would you wany to anyway though? TPI goes face first into a brick wall at 4500rpm in just a little 350! You'd be all done by 3500rpm with an engine that big.

If you want an old Pontiac motor with EFI, best route is TBI. You could probably modify a 454 TBI system to work with the 455. Or you could go 100% aftermarket fuel injection system, but it will still be an EFI setup thats carb-based, like the manifolds you posted that link to. Those are really the only two reasonable options I know of.

five7kid

iTrader: (14)

The problem with TPI isn't that it's EFI, it's that it's "tuned" - with the bar set low.

There's no reason you couldn't use a TPI computer to run a port injected system on that manifold. Of course, you'd have to rig up a throttle body and all of the sensors. Some guys have rigged up some pretty weird stuff on SBCs, no particular reason you couldn't get weird with a Pontiac.

AlkyIROC

You can put EFI on any engine with a system like this

http://www.msefi.com/

jwenn89GTA

I was just thinking that if I could use most of the factory system, it would save some money to use in other places. My thought was to use the Edelbrock intake and build a "plenum" of sorts to mount on top of it. Instead of using a tbi type of throttle body, I could then mount the TPI throttle body to the front of the "plenum". I guess my biggest concern is the distributor signal. I don't think the rest of it would be any big deal. Even switching to an SD system instead of MAF, I think it will have to be less expensive than a holley aftermarket system.

Plus I think that should allow it to fit under the factory hood since I could use the remote air filter like TPI instead of putting it on top of the TBI.