Not Ranked
Hi,
I'm currently running a 428, Toploader 3.31 on 295/50R15 Cooper Cobras and get about 3100rpm at 75mph
On my calcs you should be doing about 3350 - 3400rpm for your dif at 75
I'd guess ether your speedo or rev counter is a bit out or your 295/50R15 tyres are quite a lot smaller than mine (unlikly as they would have to be LOTS smaller!!)
A quick way I found of checking your speedo to within 5% is use a daily driver and drive a known route recording the distance then use your cob on the same route. It will not be brilliantly accurate but at least its in the same ball park as the real distance.
Hope that helps
Paul
|