Trans guru's step in. TC lockup question

[Don W.]

OK here's the history. Last paring it seemed that my TC clutch was slipping. Trans guy drove it and said that was it. Pull the TC, send to builder he says no. OK fine. While he has it I have him reduce the stall from about 3200 down to 2800. (This may have been a mistake.)

Anyway, on the "old" TC lockup would be commanded around 5000 and you could see it on DM. (The RPM would start to drop immediately.) With the "new" TC lockup is commanded at 4225 and doesn't seem to actually occur until about 4500. If the command RPM is in the chip then I can have Eric fix that but why the delay? Did the builder screw up?

Here is the old converter. This was my 11.95 run from last year.

https://dl.dropboxusercontent.com/u/86797850/11secrun.uni

Here is the new converter:

https://dl.dropboxusercontent.com/u/86797850/AutoLog_104.uni

I can pull the converter if I have to but not until this winter.

Thanks for you opinions.

 

[Don W.]

Re: Trans guru's step in. TC lockup question

bump

 

[0966Sy]

Have you checked the foot brake stall speed on the new TC? What gear are you locking the TC at the strip?

 

[Eric Sy GN]

Re: Trans guru's step in. TC lockup question

Don, the WOT lockup is determined by MPH, which is currently set to 78mph in your chip.
Eric

 

[Don W.]

Re: Trans guru's step in. TC lockup question

Eric, just looked at DM. The TCC lock comes on at 79. perfect. But if you look at the DMs the RPMs don't drop until about 90. I'm quite sure it's not the chip but what is it? Because this started when I had the TC looked at last spring it's pretty obvious. I was just checking for other ideas.

Meantime I've sent you new info.

Foot brake stall is about 2800 depending on how hard I press in the brake.

Thanks all

 

[Eric Sy GN]

Re: Trans guru's step in. TC lockup question

Yes it looks like the converter lockup is happening pretty slowly. I'm not a tranny guy, but it might be the lockup solenoid, or I have seen people remove the input shaft check ball which allows the converter to exhaust the fluid much faster (faster lockup).