[thompstl1]

Originally Posted by dickh

We were running in about 60 degrees and the runway has improved slightly traction wise according to the folks who were there in Oct. The only time I got slightly sideways was with all the controls off, but again, that's on me. The 1-2 and 2-3 shifts were solid, but I was following the mile method of slow initial takeoff, which I have used for the last four times I've run. Real reason for that is several folks took me aside on my first visit and explained why. As they were all running over 200, I thanked them and followed the suggestions. Now I'm trying my wife's patience considering Arkansas...

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.

[wnta1ss]

Originally Posted by rjacobs

There is a mile event first weekend of May in Blytheville, AR, that the group I run with here in Dallas is putting on. Will be a small event with lots of runs. They are estimating 15 runs a day if you want to as they are limiting the amount of cars that can show up.

Very cool! I've talked to someone who'd run at the Arkansas Mile and he'd said the surface was in decent condition as I recall. Are all the Arkansas events at the same place, ie doesn't move around like Texas Mile has (Goliad, Beeville, Victoria)?

[rjacobs]

Originally Posted by wnta1ss

Very cool! I've talked to someone who'd run at the Arkansas Mile and he'd said the surface was in decent condition as I recall. Are all the Arkansas events at the same place, ie doesn't move around like Texas Mile has (Goliad, Beeville, Victoria)?

yea, Blytheville. Its a mostly closed air force base from what I know.

[17CamaroZL1]

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.

That's exactly what mine did when the trans was cold. I never lifted and it shifted in about the same amount of time as yours. I'd bet money your trans was on the cool side as well during that run. I've never had that issue again since making sure the trans temp is at least 150.

The very first run on this video was when it happened to me.
https://youtu.be/e_X_LcpFp50

[wnta1ss]

Originally Posted by rjacobs

yea, Blytheville. Its a mostly closed air force base from what I know.

That's where our track up here, Loring, came from as well. It was Loring AFB until the mid-90s.

[dickh]

Looks familiar. And I tried to duplicate the time spent idling in relation to transmission temp, and I never got to 150 and it was warmer when I tried. Hope this is the solution.
Talked with a great guy from the Blytheville run and unfortunately will miss the May event. However I plan to stay in touch and try the next event.
This site couldn't be better - thanks to all.

[BMWM.D.]

Originally Posted by 17CamaroZL1

That's exactly what mine did when the trans was cold. I never lifted and it shifted in about the same amount of time as yours. I'd bet money your trans was on the cool side as well during that run. I've never had that issue again since making sure the trans temp is at least 150.

The very first run on this video was when it happened to me.
https://youtu.be/e_X_LcpFp50

Sorry to bump an older thread, but I’m pretty sure my car did this last night. I wasn’t logging or recording on the PDR, but it felt like it hit the limiter before it shifted. As I had the TC turned off, this is my best guess.

My car is lightly modified, but it sounds like guys are seeing this on totally stock cars. Thoughts anyone?

[17CamaroZL1]

Originally Posted by BMWM.D.

Sorry to bump an older thread, but I’m pretty sure my car did this last night. I wasn’t logging or recording on the PDR, but it felt like it hit the limiter before it shifted. As I had the TC turned off, this is my best guess.

My car is lightly modified, but it sounds like guys are seeing this on totally stock cars. Thoughts anyone?

If it wasn't related to the trans temp, it could be the increase in power. I've seen many A8 Vettes and Camaros have this issue after a good increase in power. It requires either increased trans pressure to firm up/speed up the shifts and/or a RPM decrease for the shift point. Some raise the rev limiter to avoid it as well.

[SteveV]

I apologize in advance if this seems like a stupid question.

Since the goal here seems to be top speed and not a drag race, why not put it in manual mode and utilize the paddles instead of relying on the computer to shift for you? Might that not get rid of the lag/delay in shifting?

Just curious...

[BMWM.D.]

Originally Posted by 17CamaroZL1

If it wasn't related to the trans temp, it could be the increase in power. I've seen many A8 Vettes and Camaros have this issue after a good increase in power. It requires either increased trans pressure to firm up/speed up the shifts and/or a RPM decrease for the shift point. Some raise the rev limiter to avoid it as well.

Thanks. I’ve been thinking about bumping the limiter a hair and doing some testing. My car has been set up this way for quite a while, and this is the first time I’ve noticed this. Could be temp related, as it definitely wasn’t fully warmed up.

I’ll probably eventually pull the TCU to get it unlocked. That really seems like the best way to deal with the torque limits and such.

[BMWM.D.]

Originally Posted by SteveV

I apologize in advance if this seems like a stupid question.

Since the goal here seems to be top speed and not a drag race, why not put it in manual mode and utilize the paddles instead of relying on the computer to shift for you? Might that not get rid of the lag/delay in shifting?

Just curious...

In my case, this just happened making a pull on the street. Sure, an early manual upshift could avoid it, but my personal opinion is that this transmission is best when it’s upshifting on its own. It could just as easily happen at the drag strip or roll racing. I’d rather fix it vs working around it.

[17CamaroZL1]

Originally Posted by BMWM.D.

Thanks. I’ve been thinking about bumping the limiter a hair and doing some testing. My car has been set up this way for quite a while, and this is the first time I’ve noticed this. Could be temp related, as it definitely wasn’t fully warmed up.

I’ll probably eventually pull the TCU to get it unlocked. That really seems like the best way to deal with the torque limits and such.

Definitely sounds like it was on the cool side then and most likely why it was slow to shift.

[dickh]

My apologies, I should have posted this earlier. Due to all the excellent input, I made sure the trans temp was over 150 and made several pulls from 50 mph on my favorite road. Shift from 3-4 went off without any hesitation. As did all the other shifts. Not that I would go to the 4-5 shift here. Ever. Honest.
Thanks again to everybody.
And my wife just walked in my office, saw what site I was on, and reminded me about the night at the Texas Mile she had to crawl through the backseat to unlock the trunk. Just heard laughing as she reiterated "Nice going Mr. Race Mechanic!"

[NicD]

Wait, you added power mods, tuned the ECM, DIDN'T tune the 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 with no issues what so ever, it needs to be tuned properly that's all.
https://www.instagram.com/p/BfzUKt5F...ormance_racing