Fuel injection

[spencerforhire]

If this Professional Products is the "cheap" aftermarket EFI at $2000, I'm sticking with my 1989 GTA TPI setup; I think I paid somewhere around $500- and it came bolted onto a complete good running motor.

[78spyder]

$1500 If you supply fuel pump and fuel lines. I like having direct control via laptop over the system, thats why I chose this route. Plus it will handle forced induction up to 21psi with no modifications. I'll keep ya'll updated as to how it performs.

[ColinOpseth]

Run a TPI setup with an LT1 intake. DONE.

It will make power all over the place, it extremely easy to tune, and will look great. As well, it is a VERY low system and you can run LT1 fuel rail covers on it to keep the whole works looking neat.

[78spyder]

Hey Colin, I already have my setup, so its late for me, but I'd love to learn more about this setup. Do you have pics/info? Does the LT1 intake negate the high end restriction imposed by the TPI? How do you tune it? Cmon, dont be a tease!

[Fastmax32168]

A TPI is all done by about 4500. The LT1 intake will pull hard to 7000 RPM. Any loss of torque is minimum, and at low RPM sometimes the LT1 is better.
The only place a TPI outperforms it is in the 2-4k range, and then not by much.
Also LT1 intakes can be had dirt cheap. You could sell your TPI buy an LT1 and put money in your pocket.
Roy

[78spyder]

The terminology confused me. I saw TPI with an LT1 intake, were you in reference to basicaly using the induction off of a mid 90's Camaro, or using the intake from that with a TPI? Sorry if its a stupid question . What would be used for tuning purposes? Also, are these for old style or Vortec style heads? Very interested, this is the first I've heard of using an LTI induction for performance application.

[ColinOpseth]

Heh... well, it isn't exactly plug and play.

Basically, the LT1 debuted some new technologies for the SBC. It is the first true dry-intake setup. There is no coolant that passes through the intake manifold at all, and the only thing that it flows is air. I was referring to using an LT1 intake in place of your TPI system. The LT1 intake is very similar to the TPiS Miniram and it's about 1/5th the cost. In fact, I have an intake I'd sell you. There are a few mods that need to be done to an LT1 intake so you can use it on a SBC:

Drill the hole for the distributor. The LT1 uses an Optispark so there isn't a hole on the back of the intake for a distributor. There are templates for this and it's a relatively simple process but you MUST be precise.

Drill coolant bypass holes in the intake and tap them for coolant fittings. You then use a y-block to join the coolant crossover and return it to the radiator.

I wouldn't consider any other setup for a PFI system as simple as TPI. My '93 LT1 is batch-fired just like TPI. Power increases are massive, underhood clearance is dramatically increased, and if you can get Corvette fuel rail covers that will clean it up 'big time.' Plus, you get to enjoy watching people scratch their heads over whether your engine is TPI or LT1.

Throttle bodies also interchange between the two (as far as I know). Fuel injectors are the same as TPI. You will need two fuel rail adapters because the LT1 used quick disconnects. They are about $15 a piece and they convert to AN-. Easy to go from there to your fuel line. If you're interested, watch my system. I'll be converting from LT1/carb to LT1/EFI in a few weeks. I just need to figure out how I'm going to sump the tank.

[spyderhunter]

This sounds cool, I've been trying to decide what to do with the 355 (400+hp) I'm putting in my Mirage. I need to learn more; keep the information coming!

[spyderhunter]

I haven't messed with much of the newer engine stuff, but here's a question. Are the newer heads on the fuel injection motors any better than the old double hump heads (194/202)? I know where there's a 400 that I thought about converting to EFI and didn't know if I should or could use newer heads on the block. I can't make up my mind with so many options today! I don't plan on winding up the engine too much, but I love to have the power when I want it, and the fuel injection does seem to be more fuel efficient also. Any comments?