BDoc

I have an opportunity to buy a complete soup-to-nuts C4 L98 TPI EFI setup for $1000. Includes intake manifold, fuel rails, ECU, all EFI parts, TPI throttle body, etc etc.

I was wondering if anyone with more experience than myself could chime in on the viability of this on my 396 sbc stroker? Having gone through hell with an aftermarket EFI kit in the past, I'm pretty burnt out on them and thought this might be a good, tunable option.

Would love some opinions on viability, install effort, and price. I believe it would hopefully fit since I have the L88 hood.

Thanks!!

kanvasman

I am in the process of putting a 1986 L98 into my C3. It will easily fit under the hood. The price seems a little high, but when you figure out all the time you would spend gathering it all up, not that bad a deal. I believe you need the distributor that goes with the set up also. If you already had an EFI setup you already have the fuel pump issue taken care of. Those engines had a reverse rotation water pump and had a small cooling line coming out of the intake near the distributor, but I don't know if you will need it on your set up. Go for it and keep us updated on any issues you come across. Good luck.

Ronaldo

MAF or MAP? I have put a 383 with AFR 195 heads and roller cam in my 1987 C4 (MAF TPI). The ECU will work but requires some extra hardware (depending on TPI version) to be really functional IMO, this would be an Ostrich 2.0 emulator (tuning without burning new chips for each change to the tune), maybe a upgraded MAF from Blowerworks and a adjustable fuelpressure regulator + new injectors if the other are stock 22's. This will cost about $600-800. The stock TPI intake manifold is too limited to support a 396 properly. I went with a FIRST aftermarked TPI manifold (because of the stock look) capable of supporting much more than the stock TPI manifold but this cost about $1000 by itself. So for a 396 in a C3 I would look for a system better suited out of the box... The stock TPI corvette engine was generally all done by 4000-4500 rpm on a 350 cui with about 240-245 hp.

BDoc

Thanks a lot for the info. Very good points and exactly the advice I needed. Yeah at that price I'd be better off just buying the $3000 holley setup

lionelhutz

It won't support your engine without replacing most of the intake parts.

Maybe a TPIS MiniRam would be a better starting intake?

If you're willing to put together parts then find a '7730 or '7727 ECU, a TPI wiring harness and a small cap HEI distributor/coil. Finding these parts shouldn't cost too much at all. Then $300-$400 extra will make it so you can emulate or flash the ECU.

Going really nuts, start with a '0411 PCM and a 24X conversion kit from EFI COnnection. Then, anyone who tunes stock ODBII GM stuff could tune it. You can do coil per plug too with no distributor.

cv67

Dont put that system on your 396 it was designed for a 305 total waste of time
If you HAVE to have TPI look into the FIRST injection system
300cfm king sizedTPI. Personally Id look into a converted LT1 intake or Miniram. David Frederick in the C4 parts for sale section converts these reasonable ready to go.

Ronaldo

but I would only do it if the savings are substantiel compared to a more modern system. I don't know how it is in the US but can be difficult to find someone to tune the old systems overhere in Europe.

Ostrich 2.0 by itself cost about $175

The FIRST TPI is optimized for middelrange efficiency (done by 5500-6000 rpm) whereas the miniram is top range (if I remember correct), so it all depends on what you want to do and how your engine/driveline is configured.

diehrd

Go Holley Multi Port Sequential , coil on plug injection ..

mrvette

Back in '95 I got the parts from a wrecked C4 and made it all work, MAP setup, still on the car....put it on the L48 OEM engine in my '72, moved to Florida in '97 and later that year I put in a roller engine, and a cam from TPIS was recommended...NEVER AGAIN!!! it was called a ZZ9 and it's a POS......

put in a stock cam L98 style....in finally finding that crappy cam, it came to changing the intake, so with help from a welder buddy I have the only LT1 induction 53? mm t-body...and kept the HEI in back, the way God intended, not that silly opticrap down lo in front....

I bet I have the only FI setup like mine in the entire world.....

cv67

Lots of converted LT1 intakes on L98s running around
Nice conversion easier to work on, run well and have lots of room for improvement if youre good with die grinder.
Similar to a minram...not quite as nice but good for most performance apps

jim2527

How do you get the distributor to 'talk' to the injectors? I've been reading about this type of swap and haven't figured it out yet.

Shark Racer

Distributorless is a better setup - look up rotor phasing and you'll find out that it's a bandaid for a problem that can't really be solved w/ a distributor.

That said, here's a simplification of the process:

The ECM figures out position by getting a reference from the cam or crank position sensor, then has a wire that tells the coil to fire when the commanded advance is at the right spot.

A GM "ESC" distributor (electronic spark control) will not have an ignition module - the ECM handles this duty.

I just got done adding ignition timing control to my Atomic EFI 78 - this was definitely the missing link. Mechanical timing and electronic fuel control don't play nicely together!

lionelhutz

NOPE. TONS of people are running converted LT1 intakes with distributors.



Distributors never "talk" to injectors. On the older fuel injection systems the distributor sends signals to the PCM and the PCM controls the injectors.

Then, the newer systems have a cam and crank sensor the PCM reads and then the PCM controls both a coil and injector for each cylinder. The 24X first appeared on the LS1 and also on some big blocks. EFI Connection sells conversion kits for the various small blocks. They also sell a book for about $25 on how to convert to these systems. I have no idea how good it is.

cv67

Yes the crank trigger systems are nice


Replaces the stock HEI you have

http://www.wongsperformance.com/

stock injectors will be way too small for your motor may need a Walbro pump, too. Pass on the TPI...thats too much coin for one anyway

lionelhutz

ALL the GM ODBI V8 EFI systems with timing control had an ESC distributor and they ALL had an ignition module. I also believe all of them were HEI based.

Some I4 and V6 ODBI stuff started appearing with multiple coils and waste spark.

Shark Racer

You're right. They don't have mech advance, but they do have an ignition module and look very much like an HEI system. The TPI Corvette distributors look very much like the C3 Corvette HEI distributors. More wires to hook up though. A mechanical HEI distributor only needs a 12V input, the ESC systems have 12V in, reference high and low outputs from the magnetic pickup and a signal from the ESC to fire the distributor (amongst other things).

I conflated my aftermarket setup (uses MSD box) with the ESC setups.