i would try an experiment and gun it and see where it takes you, then go easy (no/low boost, easy on pedal) til redline and see what mph that takes you to. could be the amount of throttle (revving at max before trans reaches top of gear) or wheel spin i typically get 35+ mph

then again, i'm a fighter jet mechanic, not a GM Tech, so if it seems out of the norm to you, I'd have them take it in under warranty to get it looked at

 

wow it took like 8 wrong answers to get one right one! hehe...... its definately 35MPH at the rev limiter

 

sounds like your clutch is going out

 

tested mine.... 35mph

 

Same here. tonight i made it to at least 32 mph or so in first

 

I got intense stage 3 with the 7k redline

1st 37 2nd 71 3rd 113 4th 135 and 5th don't know only been 150 in 5th

Shermen

 

these are the redline speeds for the stock SS/SC:
1st - 36
2nd - 69
3rd - 104
4th - 137
5th - 175

And for the stage 2 SS/SC:
1st - 39
2nd - 75
3rd - 112
4th - 148
5th - 188

For the 2.2 5 speed at redline:
1st - 37
2nd - 65
3rd - 97
4th - 134
5th - 190

 

I've hit 41 in first! 7400 rpm in first FTW!!!

 

I never really paid attention to the speedo in first, but it certainly is more than 20 as someone else posted...