[Camaro1973]

Originally Posted by RabbitZL1

Then “tcm tune” actually happens in the pcm. Lots of misinformation out there. Shift speed/firmness is all in the virtual tq tables. Shift points are tcm.

LOL!

[radz28]

Originally Posted by Z OH 6

Its my understanding that they work together. I don't think you can adjust the transmission parameters in the ECM, I think the TCM references the ECM torque tables though.

That's what I thought, too. I guess seeing information from people with experience from, PRAY, for example, that show great gains on essentially a stock car (I'll include minor bolt-ons, like CAI and LTs - no pulleys), and then opposite comments from Sponsors here, and it leaves me wondering what all is in the TCM, and that's mostly because I haven't seen any TCM files yet. I think I'm following along...

Originally Posted by KingLT1

Yes the virtual torque table plays a big role in how the trans shifts but shift speed/firmness/inertia/scheduling/torque reduction/torque management all are addressed in the TCM. FYI there is no PCM in these cars.

You can alter the minimum spark table so the ECM does not pull as much timing on the shifts. And when you make more power then stock you need to let the ECM know by adding more torque value in the VT tables so the trans will shift right but the TCM still needs addressed regardless in order to get the throttle open all the way in first gear. Also needs addressed so some Torque management can be reduced. The only way to get full torque shifts is through the TCM. The only way to get immediate shift torque recovery is through the TCM. The factory tune ramps it back in.

Moral of the story there is a lot more to the TCM tune then shift points.

That's what I was thinking, too. Again - I'm not even close to an intermediate, but feel like I have enough theory down that I could make a little sense of balancing. My buddy's car (a T93) wasn't responding to changing VTT like we expected it should, hence why we were thinking along similar lines as what you state, King'.

Thank you for commenting.

Originally Posted by Z OH 6

That was my understanding as well.

[JSH]

KingLT1 was nice enough to post the best I've seen on this topic 2 years ago.

https://www.camaro6.com/forums/showt...ght=TUTD+edits

And he posted a video last week of a Houston guy picking up .30 via a TCM tune, so...

[RabbitZL1]

Originally Posted by KingLT1

Yes the virtual torque table plays a big role in how the trans shifts but shift speed/firmness/inertia/scheduling/torque reduction/torque management all are addressed in the TCM. FYI there is no PCM in these cars.

You can alter the minimum spark table so the ECM does not pull as much timing on the shifts. And when you make more power then stock you need to let the ECM know by adding more torque value in the VT tables so the trans will shift right but the TCM still needs addressed regardless in order to get the throttle open all the way in first gear. Also needs addressed so some Torque management can be reduced. The only way to get full torque shifts is through the TCM. The only way to get immediate shift torque recovery is through the TCM. The factory tune ramps it back in.

Moral of the story there is a lot more to the TCM tune then shift points.

wrong acronym sorry. just going by what ive discovered messing with it. the difference between my 9.52 and .36 was tq tables. But like you said they all work together.

[jorgesvlog]

All, The ZL1s TCM needs to be unlocked to remove the torque management limiter for 1st gear..... ON the ZL1 the 1st gear has a very low torque limit and if you log your car using hptuners you will notice that the the tb and Power Enrichment does not activate until the tb opens up 100%. THe torque limit in 1st gear does not allow the car to open the tb 100% because it would exceed the tq limit thats why my 60' stock was 1.66s best even with tuned ECM, once i tuned the tcm and removed the tq limit in 1st gear, that one change dropped my 60' to a 1.50! and allowed the car to open up 100% tb from the hit and go into PE mode much quicker!

[Z OH 6]

Originally Posted by jorgesvlog

All, The ZL1s TCM needs to be unlocked to remove the torque management limiter for 1st gear..... ON the ZL1 the 1st gear has a very low torque limit and if you log your car using hptuners you will notice that the the tb and Power Enrichment does not activate until the tb opens up 100%. THe torque limit in 1st gear does not allow the car to open the tb 100% because it would exceed the tq limit thats why my 60' stock was 1.66s best even with tuned ECM, once i tuned the tcm and removed the tq limit in 1st gear, that one change dropped my 60' to a 1.50! and allowed the car to open up 100% tb from the hit and go into PE mode much quicker!

That being said, for people that drive their cars on the street or without drag radials, its probably not such a terrible thing to limit the torque in 1st gear for traction purposes. I could understand this might be an issue for those that want to drag race at the track with drag radials though and want every bit of power right off idle. This probably explains why my car with 700whp still hooks up quite well on street tires.

[jorgesvlog]

Originally Posted by Z OH 6

That being said, for people that drive their cars on the street or without drag radials, its probably not such a terrible thing to limit the torque in 1st gear for traction purposes. I could understand this might be an issue for those that want to drag race at the track with drag radials though and want every bit of power right off idle. This probably explains why my car with 700whp still hooks up quite well on street tires.

That is true, but the traction control will take care of street driving, just dont turn off the traction control completely and you should be ok.

[Z OH 6]

Originally Posted by jorgesvlog

That is true, but the traction control will take care of street driving, just dont turn off the traction control completely and you should be ok.

That would have to be tested to see which performs better on street tires. TCM tune and traction control vs no TCM tune and no traction control.

[JSH]

Originally Posted by jorgesvlog

All, The ZL1s TCM needs to be unlocked to remove the torque management limiter for 1st gear..... ON the ZL1 the 1st gear has a very low torque limit and if you log your car using hptuners you will notice that the the tb and Power Enrichment does not activate until the tb opens up 100%. THe torque limit in 1st gear does not allow the car to open the tb 100% because it would exceed the tq limit thats why my 60' stock was 1.66s best even with tuned ECM, once i tuned the tcm and removed the tq limit in 1st gear, that one change dropped my 60' to a 1.50! and allowed the car to open up 100% tb from the hit and go into PE mode much quicker!

Would you please show us some screen shots of your TCM tune?

[jorgesvlog]

Originally Posted by JSH

Would you please show us some screen shots of your TCM tune?

I dont have any but there is a table in the transmission tcm you can see when you download the 10 speed tcm tune from your unlocked trans thats basically showing a torque limit and the first gear torque limit is wayyy less than the other gears. if you watch my youtube videos the ones they linked above with the black zl1 you will see how much of a difference it makes from a launch. from a roll it probably wont matter as much since your not starting in first gear....

[JSH]

Originally Posted by jorgesvlog

Ithe first gear torque limit is wayyy less than the other gears..

I'll take your word for it, but I find it counterintuitive that removing the torque limit would not result in worse traction in 1st/2nd gear. What other edits did you make to the stock TCM tune?

[Camaro1973]

Originally Posted by JSH

I'll take your word for it, but I find it counterintuitive that removing the torque limit would not result in worse traction in 1st/2nd gear. What other edits did you make to the stock TCM tune?

No it’s not. It’s because the car was designed to run on street tires, hence the reason for the torque limits. No one looking for good numbers is going to be running a street tire at the track.

Removing the torque limit allows full power, and gets you MUCH better 60ft times.

[JSH]

Originally Posted by Camaro1973

No it’s not. It’s because the car was designed to run on street tires, hence the reason for the torque limits. No one looking for good numbers is going to be running a street tire at the track.

Removing the torque limit allows full power, and gets you MUCH better 60ft times.

Yes, it is, because full power only translates to better 60 ft. IF you can hookup the car, which is not easy with this car

[jorgesvlog]

Originally Posted by JSH

Yes, it is, because full power only translates to better 60 ft. IF you can hookup the car, which is not easy with this car

Pray Performance tuned the TCM so im not sure what else he has modified besides a couple shift points to get 1-2 to shift at 6500 not 6200, and like stated above, I run a full drag pack at the track and turn off the traction control completely off when I make my passes and the drag radials hook up under full power from a stop at the track in a prepped surface.