[Oil Man]

Originally Posted by thompstl1

I uploaded the PDR of my 1st run to Utube. Take a look and see if this is what you experienced. Keep in mind the temperature is in the 40's, my first run and a 22 mph head wind! I was scrambling for any traction I could get!

Actually had to let off the throttle to get the car to shift into 4th.

Wow, that's extreme.

My 3-4 shifts do a milder version of this on the street, and as others have noted, it goes almost completely away once the trans is fully up to temperature.

Mine's simply annoying, but what you're experiencing in this video would be intolerable.

Looks like GM has some more transmission tuning to do.

[Rumer10]

My car has been doing this exact same thing on the 3-4 shift. Hangs up for a second or two but usually when I have been making nitrous passes (775whp). However I am starting to notice it happen more and more just driving around on the road at 650whp. It has been happening in all weather types too. Cool mornings/evenings or blistering hot days doesn't seem to matter. I feel relieved to a degree that it's not just me but also upset this is an issue for others as well.

[BMWM.D.]

Originally Posted by NicD

Wait, you added power mods, tuned the ECM, DIDN't tune TCM, and wonder why it's not shifting correctly afterwards? It's very easy to come up on the torque limit of the factory TCM when you start adding horsepower. It's either that or your tuner lowered your reported torque model to try to keep the throttle body open and caused your problems. Either way the solution is simple.

Here is a video showing the A10 shifting at ~1000 rwhp through 8 gears on the dyno.
https://www.instagram.com/p/BfzUKt5F...ormance_racing

My car only has headers and an intake, so not much more power than stock. But there’s guys posting here that are totally stock with this issue.

I was told by a few shops that I considered credible that tuning the TCM wasn’t necessary for a basic header/intake/pulley build, but it seems like messing with the torque coefficients is the work around they’re doing. That never seemed like a great solution to me, but I’m not an expert here. Correcting my airflow model seemed to get rid of my throttle closure issues, but again I’m close to stock.

You do remote tuning, right?

[NicD]

Originally Posted by BMWM.D.

My car only has headers and an intake, so not much more power than stock. But there’s guys posting here that are totally stock with this issue.

I was told by a few shops that I considered credible that tuning the TCM wasn’t necessary for a basic header/intake/pulley build, but it seems like messing with the torque coefficients is the work around they’re doing. That never seemed like a great solution to me, but I’m not an expert here. Correcting my airflow model seemed to get rid of my throttle closure issues, but again I’m close to stock.

You do remote tuning, right?

I have never seen one have a problem if it's 100% stock and if they do they should be bringing it in for warranty because that means there is a problem. I've seen plenty have problems with bad tunes, etc though.

The torque limits are relatively close even when stock in the ECM/TCM, and if they are dropping your torque model to get around the limits with an auto then they are doing it wrong. This also means that if you got around your throttle closures by altering the torque model with simple bolt ons you are doing it wrong as well.

I do not do remote tuning, never will. Too many things that you can't hear and see with my own eyes and ears to do that IMO and it takes 10x as long sending shit back and forth.

[17CamaroZL1]

Originally Posted by NicD

I have never seen one have a problem if it's 100% stock and if they do they should be bringing it in for warranty because that means there is a problem. I've seen plenty have problems with bad tunes, etc though.

The torque limits are relatively close even when stock in the ECM/TCM, and if they are dropping your torque model to get around the limits with an auto then they are doing it wrong. This also means that if you got around your throttle closures by altering the torque model with simple bolt ons you are doing it wrong as well.

I do not do remote tuning, never will. Too many things that you can't hear and see with my own eyes and ears to do that IMO and it takes 10x as long sending shit back and forth.

It appears those of us that have had this issue on stock cars, and even lightly modded ones, have all came down to lower than normal trans temps. My car did it one time after I let the car sit and cool for several hours. After looking through all the gauges on the car after that run, I saw that the trans temp was only at 150 instead of it's normal 200 or so. I made a second pass while the trans was still showing 150 and it shifted perfect. Ever since, I've made sure the trans was at least 150, and it's never happened again. I may download the Cosworth toolbox and see if I can see what the trans temp was when I had the slow shift, just out of curiosity.

[CountryTom]

This is a regular problem for me. Happening at every track day midway through - 3rd/4th/5th runs. Trans is always hot enough by that time and I’ve noticed it on the street from day one. Auto, manual, performance shift - doesn’t matter. I have a few videos I’m too lazy to post st the moment but same as your half mile run. Dealer says evidence not strong enough (& they can’t replicate obviously) for gm to open it up. I usually back off or stop the track day when it happens because speed and things not being right don’t mix well but going to drive through it this time to see what happens. Dealer suggested possibly some air bubbles in intercooler system? Does that make sense to you all? What would that cost to flush if they won’t cover under warranty?

Edit- I’m completely stock

[mariojmoe]

See, you guy's should've went M6

[BMWM.D.]

Originally Posted by CountryTom

This is a regular problem for me. Happening at every track day midway through - 3rd/4th/5th runs. Trans is always hot enough by that time and I’ve noticed it on the street from day one. Auto, manual, performance shift - doesn’t matter. I have a few videos I’m too lazy to post st the moment but same as your half mile run. Dealer says evidence not strong enough (& they can’t replicate obviously) for gm to open it up. I usually back off or stop the track day when it happens because speed and things not being right don’t mix well but going to drive through it this time to see what happens. Dealer suggested possibly some air bubbles in intercooler system? Does that make sense to you all? What would that cost to flush if they won’t cover under warranty?

Edit- I’m completely stock

It seems very much like a software calibration thing to me. Did they check for any updates?

[BMWM.D.]

Originally Posted by mariojmoe

See, you guy's should've went M6

This has happened to me a grand total of one time. I’ll take this over the M6 bog any day of the week.

[mariojmoe]

Originally Posted by BMWM.D.

This has happened to me a grand total of one time. I’ll take this over the M6 bog any day of the week.

I'm just jabbing a little man, Don't take me serious The A10 is amazing as well the M6 and both have their pluses and minuses. I just prefer a manual in a sports car (and yes I know the A10 is faster) I do more roll races anyway so it doesn't really matter to me.

[BMWM.D.]

Originally Posted by mariojmoe

I'm just jabbing a little man, Don't take me serious The A10 is amazing as well the M6 and both have their pluses and minuses. I just prefer a manual in a sports car (and yes I know the A10 is faster) I do more roll races anyway so it doesn't really matter to me.

I bumped my limiter 50 RPM in 3rd gear, and it hasn’t happened again. Ran a bunch of passes at the strip last weekend (best of 10.79 @132), and it was solid.

I was always a manual guy myself, but the times are a changing.

[Stephen12ZL1]

to me, the computer allowed the rpms to bump the rev limiter and give the stumble shown in the PDR. If you were using the paddles (recommended) for a run like this, try paddling 200rpm sooner to alleviate the "flash" when the temps are cold. If this was a run in automatic, then take over the helm as the ECU is dumbing you DOWN!

[CountryTom]

Originally Posted by BMWM.D.

It seems very much like a software calibration thing to me. Did they check for any updates?

They did. If it doesn’t go away I’m possibly selling and getting M6 or C6or7. A lot of the time I wish I was manual anyways. (But the A10 is pretty freaking awesome).

[CountryTom]

May have found the cause (for mine at least) Posted in Camaro 1LE FB group. Can anyone with access post the full TSB?

I’d like to share a little message brought to me by someone smarter than myself. LT4 guys, pay attention. If you’re anywhere near the Detroit area, let me know, we’ll be doing a bunch of them.

Alan,
FYI… ICHE purge tool bulletin which is published to dealers - 18-NA-291 TSB
You will want to perform this to all Camaro w/LT4’s. (including your car)

SO, this bulletin is put out to get air out of the stock intercooler circuit. If any aeration has occurred, intercooler temps could spike causing premature spark retardation.