92 LT5 ecu ignition program and control

[Theg]

Originally Posted by XfireZ51

If there’s knock, then the ECM will retard timing depending on the amount of retard defined in the calibration. Given that the ECM is calculating pulse width to control injectors, doubtful u can use the OEM ECU. A Holley Pro-Jection system may be a viable alternative.

Just a bit confused now . Im unsure if you mean I cant use the stock ecu to run just timing and ignition control when Ive no sensors for fueling returning signals to the ecm .
Basic question is if I removed all injector wiring and map sensors ,TPS, 02 sensors, coolant temp etc etc but left ignition sensors like crank sensor and knock sensor would the ecm still carry out the ignition function when over the 400rpm ?

[XfireZ51]

Ignition is controlled by the ECM and is based on RPM x MAP. Without sensors, u have a bunch of codes. Whether the motor would even start is questionable. It certainly would be in “limp home” mode. What u are describing is using an ignition control system, so that’s what u should use.

[XfireZ51]

One other point about employing carbs sitting on top of the LT5 plenum. The plenum and injector housing was designed as a dry induction system for port fuel injection. Quite a few twists and turns in the journey of air from TB to combustion chamber. Runner length is quite long. I can see quite an issue with fuel coming out of suspension in the induction tract and dumping raw fuel onto the valves. Don't mean to rain on your parade, but I don't think its a very workable configuration.

[tpepmeie]

Originally Posted by XfireZ51

One other point about employing carbs sitting on top of the LT5 plenum. The plenum and injector housing was designed as a dry induction system for port fuel injection. Quite a few twists and turns in the journey of air from TB to combustion chamber. Runner length is quite long. I can see quite an issue with fuel coming out of suspension in the induction tract and dumping raw fuel onto the valves. Don't mean to rain on your parade, but I don't think its a very workable configuration.

Easily the beacon of reality (BoR) award for this week. I agree with Dom, that setup -- carbs on top of the LT5 plenum doesn't seem ideal to me.

If you're going carbs, I'd do a custom tunnel ram fabricated manifold.

[Theg]

Originally Posted by tpepmeie

Easily the beacon of reality (BoR) award for this week. I agree with Dom, that setup -- carbs on top of the LT5 plenum doesn't seem ideal to me.

If you're going carbs, I'd do a custom tunnel ram fabricated manifold.

I havnt definitely decided to graft carby plate to the plennum and mentioned in an earlier post possibility of fabricating a manifold .
Fabricating a manifold would eliminate the necessity to plug and smooth the injector bosses but would creat some grief around what to do about the coolant tubes passing into the existing injecter manifolds.

[Mystic ZR-1]

An LT5 would look pretty good with 4 Weber DCOE 45s...
... make that DCOE 48s
It'd starve with the 45s, even if ya got it to run with carbs...

[Theg]

Originally Posted by Mystic ZR-1

An LT5 would look pretty good with 4 Weber DCOE 45s...

It is a hot rod and its all about looking cool.

[Theg]

Originally Posted by XfireZ51

Ignition is controlled by the ECM and is based on RPM x MAP. Without sensors, u have a bunch of codes. Whether the motor would even start is questionable. It certainly would be in “limp home” mode. What u are describing is using an ignition control system, so that’s what u should use.

Looked into the MSD 6010 again today as a ls coil ignition swap option with crank nose reluctor and trigger .
Does anyone know the lt5 cam sensor trigger and reluctor setup ?
The msd requires a cam signal matching the stock ls1 triggering .
Anyone know if lt5 cam signals match ls1?