I have a 1995 Z28 A4 2500 stall with 3.42 gears and completely stock engine.

I just had the 2.73's replaced with 3.42's yesterday and today had the speedo recalibrated. Tonight I went for a couple of test runs and for some reason at WOT my rev limiter comes on before my car shifts. Does anyone know why?

Thank you, Corey

 

yeah, your stall converter could be letting the engine rev faster so it hits the limiter before the shift has time to take place and if your shifting wasnt reprogrammed or wasn't done correctly, then it also causes that problem. Your trans runs off the tables for rpm and mph in the pcm and they all need to be calibrated correctly when you change the gear, not just the speedo.

 

+1 on above, did the same conversion 2.73 to 3.42.. The stock 2.73 2-3 shift at TPS= above 93% is set for about 92 MPH / 5200 RPM. However with your new gears (25% more RPM per wheel MPH) the shift point (92 MPH in 2nd) is now about 6500 RPM way above the limiter. You need your transmission shift points adjusted down. EG: my 2-3 shift is now at 72 MPH. Who did your tune ? Most experienced tuners understand how to handle gear changes in an A4.. LT1 Edit and TunerCat programs have the option to correct that built into them.

 

Thank you so much for your responses and by the way I am going to purchase tunercat tonight, could you tell me where in the program the option is to fix this problem?

thank you, Corey

 

Main Menu Bar/Tools/Speed Calibration

Otherwise, go to the transmission shift tables and fix them. You can find stock pcm flashes on the internet and start from scratch if you want. You don't want to scale shift tables more than once for a gear change if you can help it. but go in there and see what the tuner did first, then make the appropriate changes. Both rpms and mph has to be met in order for it to shift at wot.