Ok so this is an odd question, and I figured the C4 tech section was the place to ask it even though it's in a C3.

I'm working on ideas for a budget fuel injection setup for my car. It has a 350 with 9.5:1 compression, Brodix IK200 aluminum heads, Lunati 268 cam, and currently a Vic Jr. and Quadrajet on top.

After doing some research, I think I want to try swapping in the LT1 manifold, rail and injectors and doing the mods to the intake (drilling distributor hole, tapping coolant passages, etc...). I would most like run a Walbro in line pump to supply it for now, and a remote thermostat housing (as most do who have done this swap).

My question is on the ECU side where I have less knowledge. What do I need to run this setup? Can I pick up a TPI ECU and harness, or possibly the LT1 ECU and harness? I was planning to keep my distributor to control timing and just drilling the distributor hole, unless there is a simple way to have the computer control timing and just lock out the distributor.


Thanks for any help.

 

It would be easier and possibly less expensive to get a tunable stand alone system. Tuning will be the biggest obstacle trying to use oem efi.

 

Holley ECU will do the trick, or you could just use the Holley four injector system skipping all of the electronics hassles.

 

So the problem is, I"m seeing if I can put this together incredibly cheaply, and even the cheap systems like the Megasquirt cost $500+, at which point (after all the other parts) I'm better of just getting something like the Holley Sniper.

So to rephrase, I know how to make the LT1 manifold fit the SBC short block, and how to plumb the fuel lines, pump, and regulator. I'm mostly trying to figure out the electronics side. Plenty of people have gone from Carb to TPI, and some have gone from TPI to LT1 manifold, I'm just skipping the TPI middle ground and going to LT1.

I assume the the ECU for the LT1 is tunable (since people have done all kinds of mods from mild to wild using that ECU), so is there any reason I couldn't just get that ECU and wiring harness and then cut out everything I don't need? Or is it a total pain to tune that ECU?

Alternatively, it looks like the guys who modify the LT1 manifold for use on their TPI engines retain their stock ECU, so I presume that is an option as well?

I'm basically making some assumptions here and hoping someone with more knowledge can confirm or deny.

 

By that are you talking about their "bolt on" EFI kits like the Sniper?

 

The former is an ecu that can be used to run your LT1 based fuel system. I'm having my LT1 rebuilt on my 93, that is what my builder is using to integrate the crank/cam position sensor (58X device), implement sequential injection, and coil-on-plug modifications with the rest of the car.

Yes the Sniper in probably their best replace-the-carb-with-minimal-hassle EFI kit.

 

Ok so after some more research, here's my plan, looking to see if anyone sees any problems:

LT1 Intake (modified for coolant passages and distributor hole)
LT1 fuel rails/ injectors/ PCM/ Harness/ Sensors\
PCM tune from PCMforless
Walbro inline fuel pump
Corvette Filter/Regulator
Remote thermostat housing

Anyone see an issue with this setup?

 

You need to be sure to use the later LT1 for proper fuel rails '94+ I believe will do.

 

What PCM are you looking to use? The LT1 pcm requires the 360x and 8x signals from an optispark or else it throws codes. Having built and ran 3 MS kits I actually prefer it with the tuner studio interface ( free and really user friendly). My most recent project was MS3 + 3X board on an LT1. If you want to go for a megasquirt setup let me know and I will help in any way I can.