i just put a holley 52mm throttle body on my car (used)..already had a new IAC valve and i just left the TPS sensor that it had on it already. car shifts much softer now...when i had it tuned i had Ion adjust to make the shift a little harder and i loved it ..but now i put that holley on there and it shifts softer. Would changing the TPS sensor make it shift differently (softer)? i figure that can be the only thing that would make it do this.

 

You probably aren't pressing the gas pedal as far, because the bigger TB flows more air at the same position compared to a stock TB.

Since the transmission tables are based on TPS, the shift points and firmness are affected.

I didn't do the transmission tuning on my car, so I can't give you step by step instructions. I believe there is a transmission tuning tutorial on this site.

 

AJ52486 hit the nail on the head.

 

thx guys so if i want it firmed back up i would have to get it re-tuned correct?

 

Correct. Your tuner would have to shift the values in the transmission tables so the car behaves like it did before, but at a lower TPS value. I'm sure your tuner will know what to do. If not, maybe I can give you a better description of what needs to be changed.

 

Thx AJ

 

First thing to do is verify that your TPS is working right.

 

gonna do that tomorrow, .20-.90 acceptable right? gona shoot for .67 closed and no more than 4.9 WOT, will let u know the results.