24x conversion...
Le Mans Master
Joined: Sep 2000
Posts: 6,303
Likes: 714
From: Bartlett IL
The ICM in the C4 ZR is a critical path to keeping the motor running. Its unique to the LT5 and they are a minimum of 22 years old. Pretty stout unit but everything breaks. Without it, motor won't run full stop. So there needs to be a replacement for it. And its my opinion that CnP would benefit the LT5 particularly since the motor goes to 72-7500rpm. More dwell time for the coils, hotter spark, MUCH shorter plug wires and etc. would be nice.
Burning Brakes
Joined: May 2006
Posts: 985
Likes: 17
From: St. Louis Missouri
The ICM in the C4 ZR is a critical path to keeping the motor running. Its unique to the LT5 and they are a minimum of 22 years old. Pretty stout unit but everything breaks. Without it, motor won't run full stop. So there needs to be a replacement for it. And its my opinion that CnP would benefit the LT5 particularly since the motor goes to 72-7500rpm. More dwell time for the coils, hotter spark, MUCH shorter plug wires and etc. would be nice.
What software does a stock LT5 PCM use for tuning?
Edit: I re read your post. You are trying to do the same/similar as me.
Last edited by A95Y; May 7, 2017 at 08:46 PM.
Burning Brakes
Joined: May 2006
Posts: 985
Likes: 17
From: St. Louis Missouri
Le Mans Master
Joined: Sep 2000
Posts: 6,303
Likes: 714
From: Bartlett IL
Are there compatibilities between an LT1 and LT5? I always thought they were 2 completely different engines/systems. I've haven't done much research on a ZR1....a car I'd really like to own(a sweet C4 that will increase in value)....because I've never seen one I like that I wanted to spend the cash on. I didn't see an LT5 option when I bought my ATI damper, which the Torqhead uses for their crank trigger.
What software does a stock LT5 PCM use for tuning?
Edit: I re read your post. You are trying to do the same/similar as me.
What software does a stock LT5 PCM use for tuning?
Edit: I re read your post. You are trying to do the same/similar as me.
The LT5 ECM and calibration are an offshoot of the L98. BUT, with significant differences. Its an SD(speed density)motor. It has twice the VE and SA tables due to the motor running on 8 or 16 injectors depending on mode. As stated previously, the ICM is unique because of waste spark ignition and 4 coils. I use TunerproRT for tuning editor ($35 freeware). Its OBD1.
The LT5 is absolutely bulletproof.
Last edited by Dominic Sorresso; May 7, 2017 at 09:08 PM.
Burning Brakes
Joined: May 2006
Posts: 985
Likes: 17
From: St. Louis Missouri
What about this for a crazy idea? Ditch the opti and use the Torqhead sensor plate and reluctor. Split the signals the LS PCM needs to run the car between both PCMs, if they both need them. Wire up the coils you got from your GM mechanic friend on the cheap. Wire up the injectors and timing. We have 2 DLCs, 1 for the engine and 1 for the car. Tune car and run 10's.
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