Camaro ChriSS

I haven't tried locking my TC on the dyno, but I intend to the next time. I understand how to do it thru Edit, but I want to make sure I don't hurt my tranny (unnecessarily) in the process.

I understand that after the pull you should put the A4 tranny into neutral, but at what point is the time to do it? That is, say I run it up to 6400-6500 rpm in 3rd (both locked in gear and TC) - as soon as I let off the throttle, do I put it into neutral? Or is it crucial to have to do so that quickly? Is it that important, or do you just wait till the rpms fall a bit?

Naturally don't want to put it neutral too soon or the rpms will get too high...

ls1mojo

Well as far as the TC, we locked the A4 in my dad's car by getting it in third early, around 3k. Then part throttle until the shift crossover point, not sure exactly what the rpm was. Then coasted to a roll in 3rd in between runs never did nuetral though...are you supposed to do that?

Camaro ChriSS

mojo, I am assuming that you didn't actually lock the TC unless you used software or the shop had a lock out controller (which you don't mention). Is that right? If so, what you did is fine. But it is rough on the tranny if you leave it in gear on the dyno with the TC locked.

I'm trying to find out how hard it is though.

ls1mojo

That's right we didn't have any software to do that. I did't know it could be risky to keep in gear though, hmm. We did a roll on then let off and then another roll on then off.

Camaro ChriSS

Oh, its not risky to keep it in gear - its keeping the TC locked that is the more stressful part. You can lock the tranny in 3rd, and you can lock the TC. They are two seperate things, if you follow me (and if I understand what you are saying correctly). Both can be beneficial to do on the dyno for an A4.

Camaro ChriSS

ttt

Thanks.

DanZ28

iTrader: (5)

Most dyno shops want you to put it in neutral so the dyno brake slows the wheels without having the extra inertia driving the rollers of having it in gear. It's fine to put it in neutral right after you let off the gas.

Some shops have a Tech II they use to lock the TC in third gear. I rigged my own switch that I can manually do from the center console.

Dan

12secSS

iTrader: (30)

You want to unlock the TCC first, as it is not a heavy duty clutch. After that you can do what ever you want. Our local dynos just let off the accelerator and let the engine and dyno coast down.

Camaro ChriSS

I understand that the TCC has to unlock or run risk of damage, but with edit, I don't believe I can cause it to lock the TCC and then unlock it during a dyno run (or at the end of the run). Though I don't have the software in front of my to look this up.

In my case, the shop cannot lock the TC, so I have to do so through edit. I set the TCC lock just after it shifts into 3rd gear. Is there a way to release it at the end of the run? I was just assuming that you have to pop it in neutral - my concern is how fast do you have to do that.

Can you set the TCC release at 130 mph so that it unlocks at the top end of the 3rd gear run on the dyno? I think the release has to be lower than the lock up speed, s that wouldn't work. Unless I am wrong.

DanZ28

iTrader: (5)

As soon as you put it in neatral, it goes out of lockup, obviously, your not in any gear anymore. Just put it in neautral after you let off the gas, nothing should happen if it's not done instantaneously. If your real concerned, just shift it into overdrive, it will come out of lockup, then put it in neautral..

Camaro ChriSS

Thanks Dan. That kind of addresses my concerns.

DanZ28

iTrader: (5)

No problemo

Dan