Gen 3 Conversion Torque Management, TCS or Both?

[Ratssled]

***Edited with more details and for clarity***

What are all the possible suspects that would cause this much spark reduction?

After years of disabling Torque Management I now want to keep it yet tame it. I only want it to help the trans shift at WOT, and because 90% of the performance built 4L60e's still need some level of protection.

The car is a 95 Impala with a Gen 2 LT1 409 (NA), a 4L60e and a 3,200 stall TC.

The conversion part of this is the 24x signal kit and a converted harness connected to an 0411 PCM running a 12212156 OS for a 02 Camaro.

The car is still fitted with the stock 3-bar vac-ref fuel system. I've installed FID500 injectors with reliable injector data and tuned the VE and MAF. We took it to the track on Friday and noticed significant spark reduction that I don't see when testing on the street.

The car still has the stock standalone ABS system, and based on information in the field service manual there is ZERO communications between the PCM and the EBCM. The ABS system in this car is for brakes only, and was never intended to be used for traction control!

Attachment 161233

[RDF1]

Just for a test, give this a try.
See if all the TM being disabled will make a difference.
Also you can datalog all the spark modifiers.

Your spark table was quite high and your VE table seems like injector data is off or you have lower fuel pressure.

[Fast4.7]

What are the possible suspects that would cause this much spark reduction?
Car is a 95 Impala with a P01 running a 12212156 OS. No TCS button, and a primitive ABS system. As far as I know there isn't any connection between the PCM and the EBCM.

Attachment 161233

I do not know if the B-cars of that era had the ABS hooked to the VCM via Serial data yet but the 96+ Vortec trucks do. My 97 Express van would pull a lot of timing when the rear tires broke loose after I put an 0411 into it and I later found out it was in fact TCS retard doing it.

[2xLS1]

Your spark table was quite high

He said 95 Impala. If this is an old LT1 conversion they run that much timing.

[Ratssled]

Just for a test, give this a try...

Sorry, I should have mentioned that it's not an LS engine. I updated my initial post with more details.
I don't want to get rid of TM because the trans desperately needs it in order to complete a WOT shift. Thanks for offering though!

[Ratssled]

It's my understanding is that:

• the PCM uses this table for torque reduction during shifts...

Stock 02 Camaro
Screenshot 2025-06-08 093307.png

My own settings based on the 409 LT1
Screenshot 2025-06-08 093315.png

• then reduces spark advance based on data in these two tables...

Stock 02 Camaro:
Screenshot 2025-06-08 092554.png

My own settings based on the 409 LT1
Screenshot 2025-06-08 092534.png

If those numbers are for a stock LS1, then did GM intentionally retard Spark Advance so much that it would create engine braking?

[Alvin]

I think this is less of what you think it is and more of the flat out torque limiters.

Keep the TM but push the limiters way out of the way.. Max them out for that matter. You can still have shift TM.

[RDF1]

He said 95 Impala. If this is an old LT1 conversion they run that much timing.

Sure would have been nice to know from the beginning what we were looking at.

[Ratssled]

I think this is less of what you think it is and more of the flat out torque limiters.

Keep the TM but push the limiters way out of the way.. Max them out for that matter. You can still have shift TM.

So, the limiters and the torque model values are what's doing it?
I'll do some more research, and move the limiters around at the dyno tomorrow.

Really appreciate the help, and sorry for the confusion. I'm usually dealing with other Gen2 LT with 411 swap guys, and I forget to note all of the oddities that comes with our Frankenstein's. It would be nice if there was a Gen III for oddballs section.

[Ratssled]

The converter appears to be too loose. It stalls at round 5K! Could that be a factor?

[Ratssled]

The problem may be related to a loose TC

[Ratssled]

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