🔧 BUILD ZX's 2021 Camaro ZL1

[ZXMustang]

After looking at the logs and having my tuner take a look, we believe the slow time/low mph is simply because of the TCM stepping in and telling the car to short shift. On the 1-2 it shifts at 5800, 1k rpm lower than where it should. And every gear after that it shifts at 6300. I didnt even make peak HP until 6400 and it carried to 6800 when we dynoed it.

So long story short looks like the TCM/trans tune is in order. initially my tuner said I "probably" wouldnt need it at this power level, but it looks like we are hitting the tq table limits in the TCM and its not happy.

One thing about these ZL1s, they are so well tuned from the factory to not only run the stock number, but protect themselves, there are basically no mods you can do without a normal tune that will do anything to make more power. Once you run to the limits of the PCM tuning, then you have to contend with the TCM's tq management parameters. The TCM can command the shift and also to close the throttle. We are not there yet where its closing the throttle, but its killing the power by short shifting. And on top of that its dropping me well below peak tq into the next gear as a byproduct. Look at the RPM it shifts at in the log on the 1-2.

 

[Jimy Bilmo]

After looking at the logs and having my tuner take a look, we believe the slow time/low mph is simply because of the TCM stepping in and telling the car to short shift. On the 1-2 it shifts at 5800, 1k rpm lower than where it should. And every gear after that it shifts at 6300. I didnt even make peak HP until 6400 and it carried to 6800 when we dynoed it.

So long story short looks like the TCM/trans tune is in order. initially my tuner said I "probably" wouldnt need it at this power level, but it looks like we re hitting the tq table limits in the TCM and its not happy.

One thing about these ZL1s, they are so well tuned from the factory to not only run the stock number, but protect themselves, there are basically no mods you can do without a normal tune that will do anything to make more power. Once you run to the limits of the PCM tuning, then you have to contend with the TCM's tq management parameters. The TCM can command the shift and also to close the throttle. We are not there yet where its closing the throttle, but its killing the power by short shifting. And on top of that its dropping me well below peak tq into the next gear as a byproduct. Look at the RPM it shifts at in the log on the 1-2.

View attachment 137325

No cam, no care ?

 

[Pro Stock John]

Have to mail the ecu in to HPT to unlock it?

 

[ZXMustang]

Have to mail the ecu in to HPT to unlock it?

Nah with this car I have to buy a specially unlocked TCM from this shop in Tx. They took the time to get it unlocked and sell one. My stock one wont work, I have to use the TCM from the 17-19 cars. The 2020+ TCM is different and unable to be unlocked.

 

[Pro Stock John]

Cool keep us posted

 

[Marko]

Awesome man! I’m with the above, cooler temps and I’d bet you’re sitting around 10.5-10.6! Badass machine and sounds so good.

I was thinking the same. And lower humidity

Congrats on the 10 second runs man.

 

[1quick]

Get an ice box da means a lot less with 50* blower outlet temp, 0 da would probably knock .2-.3 off that time

 

[1quick]

Nice runs though

 

[Marko]

Intake only GT500? Damn. I didn’t realize those are so fast in the 1/4. Those cars are heavy too weighing in at almost 4200 Lbs.

 

[ZXMustang]

So far my best times with the maggie ZL1. Im TCM limited. Off the hit, Tq management pulls 18* of timing and closes the throttle then short shifts at 5100 1st now. Then all the rest of the gears it short shifts at 6100 vs 6800 when it should. I ran 10.6@132 in 2500 DA on 93 as well as on e30 in -500 DA. Car has a flex fuel sensor now and AEM wideband setup. TCM is on the way and car will be retuned completely by the vengeance racing guys here in St Pete. Should run 9's pretty easily on e30 as it sits when they can turn off tq management and actually tune the trans. Super excited to run it again.

 

[Mook]

What's the theoretical bottom for this setup? Low 10?

 

[Mook]

Oh, high 9. Nice!

 

[ZXMustang]

 

[ZXMustang]

Oh, high 9. Nice!

9.80s is what they are telling me. They are guessing on 93 it makes 690s to the wheel and on e30 close to 740 to the tire.

 

[Mook]

Guessing the 60 needs to come down some more or nah?

 

[ZXMustang]

From a roll without the tq management stepping in, this car is an absolute missile. I raced a stock charger RE on the highway and from 60 put a few bus lengths on him quite quickly.

 

[ZXMustang]

Guessing the 60 needs to come down some more or nah?

Yeah the trans tune is going to take care of that. 1.4x should be easy when its not closing the throttle at the hit and pulling all the timing.

 

[IDAFC21]

Damn, nice!

 

[1quick]

18* of timing is probably 200whp nice runs that’s pretty similar to what my s550 ran on 93 with the roush

 

[ZXMustang]

Damn, nice!

Thanks man. My new Unlocked TCM will be here Saturday and when my buddy gets back from Sick week, we are going to put it in.

 

[ZXMustang]

18* of timing is probably 200whp nice runs that’s pretty similar to what my s550 ran on 93 with the roush

Yep. And the short shifting is bad too. Its shifting 400rpm lower than where it makes peak HP on the dyno. So im leaving a ton of power on the table. We are guessing it should trap 140ish in good DA when its all sorted. The Vengeance tuners are about the best in the country with LT cars, so it should be pretty spot on. They are not cheap though...

 

[ZXMustang]

Heres the log I sent the tuner last, you can see right off the hit the throttle closes a ton and it pulls timing. It was seeing -2* at that point...LOL

 

[1quick]

Do you log knock as well?

 

[ZXMustang]

Do you log knock as well?

Of course. No knock whatsoever on e30. You can see on the log I posted in red, it says 0 retard. Its a super safe tune.

And yes I have allocated funds for a full stage 5 package at the end of this summer. Car is either shipping to vengeance in GA or RPM in delaware and getting cam package, heads, full fuel system, meth, headers and some other goodies. We can then pulley it down and make 1k easy. And yes its like $25k...yay for DI LT engines...doh. #shouldhaveboughtacoyote.

 

[sktchy]

I guess this is the first time I've seen somebody outrun the e92 pcm. Never woulda thought the tcm would be clipping the throttle but I could see the short shift thing pretty easy and I know the tcm couldn't be messed with in 17 and 18 trucks either. Can usually straighten some of the weird shifting stuff in the 8 speeds out by making sure all the torque values and airflow is good in the pcm so I guess I never went much further than that