I have a TCI SSF 3500 converter in my 99 Z28. I don't think the converter is locking up. With 3.23 gears what rpms should the car be at in overdrive at 75mph. Right now when I'm at 75mph my rpms are at about 2300. I think they should be at 2000 or less in overdrive. When this converter locks up should it be at the same rpms as the factory converter? Is there some kind of chart or something that would tell me what rpm I should be at when I'm going a certain speed when the converter is locked? Also if the converter is not locking is there a way to tell if the converter itself is the problem or something in the PCM.


Thanks

 

I'm not sure but 2300 sounds close to right for me... 75 MPH isn't remarkably slow of a speed and most cars I've driven do 75 at 3000 RPM's. My dad's Z28 did 70 MPH at 2k RPMS so I really don't see a problem at all.

 

At 2300 RPM you should be running 78 MPH in OD www.f-body.org/gears/
The TC should lock up around 40 MPH and unlock a couple MPH below that letting off the gas, or if you touch the brake.