Ph1berOpt1k

iTrader: (1)

i have my vette on the dyno right now and we have a problem with the car, its making 438rwhp @ 6000 in 4th gear and i want to take the ms4 up to 65-6800rpm, but i keep getting a sharp drop off at 6000 rpm like it's hitting the limiter. we have tried pulls in 3rd thinking maybe the dyno didn't like the speed and it would pull to 6800 no problem in 3rd. is there another table for 4th gear limiter or speed limiting? it's doing 124mph at 6000 in 4th.... perhaps a frequency limit of the slp 85mm maf?

James Linder

You are probably hitting the top speed limiter not the rev limiter. Its another setting inthe pCM.

Ph1berOpt1k

iTrader: (1)

We are pretty sure it was the dyno not the tune, we tried a pull in 5th and it cut out at the same mph as it cut out in 4th, would a stock C5 have a 125mph speed limiter?

i'm pretty sure the tuner changed the speed limiter but can you remind me where it is (hp tuners) so I can check to be sure it has been changed?

2xLS1

iTrader: (25)

Stock C5 speed limiter is 255. What kind of dyno is it?

Ph1berOpt1k

iTrader: (1)

dyno dynamics, they have had cars do 155mph on the dyno, but they just updated the software and need the maintenance password to adjust the speed setting

still 438 rwhp @ 6000rpm with ms4 and factory 853 heads (with extreme springs) isn't bad, torque was 410rw and flat from 3500 to 6000! can't wait to see what the power is at 6800rpm, we calculated it should be around 460ish