Tuning for Tq Convertor

[TA98]

I have HPT and am installing a 4000 rpm Yank PT convertor with a 2.2str. I was wondering what i need to change in the tuning and maybe some recommended starting points for this also.

[Firebirdjones]

The only thing I had to change in the tune with mine is the engine misfire sensitivity. I dummied it down slowly and wound up with 50% I think to stop the computer from setting the check engine light. I never had to touch anything else.

I've heard others having to change shift points and pressures etc...

[TA98]

Yea ive heard the pump does stuff at certain rpms and if its not changed to match the new convertor it will ruin a trans quickly. But im not sure what it is... thats why im here

[Firebirdjones]

I've never heard that one before. I never changed any pump or pressure settings. Drove mine for 3-4 years without problems. Maybe someone else will chime in that can elaborate on that..

[TA98]

I've never heard that one before. I never changed any pump or pressure settings. Drove mine for 3-4 years without problems. Maybe someone else will chime in that can elaborate on that..

Maybe the guy that told me that didnt know what he was talking about.

[BANDITO]

I'd like to know also. I got a 3800stall with 2.5 str. and my last tranny just neutralized it's self and I had to order a new one.

[TA98]

^^^ thats what i dont want to have happen

[Firebirdjones]

What do you mean by neutralized?

[BANDITO]

Front pump failed I guess. I put it in gear and the scanner read that it was still in park. I was driving home and all of a sudden the rpms went up like it was in neutral.

[Firebirdjones]

Ouch, that sounds like the converter wasn't locked completely into the trans. These 4L60's are funny about that. Seems like they go in, and the trans will actually bolt up with room for the converter behind the flexplate, but in reality there is still another clunk for the converter to engage. I've seen that happen to people several times, it destroys the pump and does other very bad internal damage to the trans.

[TA98]

so its installed and ive messed with the lockup speeds some in 3rd and 4th for cruising around. where do you guys seem to have yours set.

[Firebirdjones]

It's car specific. On my 4th gen I still ran the stock camshaft so I left the converter lockup stock which was roughly ~37 mph in 4th and worked fine with the stock 3.23 gears.
A car with a camshaft however may like that to be a little higher to avoid bucking and kicking issues.

My blazer which has 33's and 3.07 gears didn't like the stock lockup speeds at ~35ish mph, it was just chugging the engine too much. I found 42 mph for 4th gear to work nicely.

I never mess with 3rd gear lockup speeds, because I never drive around in 3rd gear. It's all personal preference.