I have an m6 car and doing a th400 swap.

my radiator doesn't have provision for trans cooler since it came w/ manual tranny. Should I look into swapping my radiator for one out of an A4 car?

Or , should an aftermarket tranny cooler be sufficient?

 

A large aftermarket cooler should be sufficient. I have the 29,200 BTU model from B&M, and my tranny hasn't seen anything higher than 165, and that was cruising around with the TCC unlocked (misfires detected from the stall).

 

Just using the cooler alone should be fine as long as its large enough and you dont live in alaska.

 

is that why my new fuddle doesnt always lock? i keep getting the p0300 code random muiltiple missfire detected. and alot of the time ill be cruising for a few miles and it wont lock and then it willand other times its fine. idk?
im guessing my tuner needs to delete this code or something?

 

He need to raise the missfire tables , Its a common issue but easily taken care of in tuning

 

Yep, probably the most common issue for the TCC not locking.