| Calculating the optimum gear ratio for my car |
Subject: Calculating the optimum gear ratio for my car by djxib on 2011/4/20 21:43:07 (1992 C4) Assuming that all goes well with my new motor, it should be good for about 7000 RPM. It is a forged 383 and I will be upgrading the supercharger from an old S trim to a newer T (or later) model running about 14 pounds of boost. Target HP around 650. The car has stock gears (it is an MN6). My last time out to the strip I saw 12.3 at 117 with a 2.3 60'. The tach was showing around 5700 RPM across the line in 4th gear. I definitely want to see low 11's, and I'm thinking that with the new motor, a better launch, and decent tune, I should see 11.2 at 120 or better. So.. given that the motor 'could' go to 7000RPM (although I'd probably stay less than that), I'm thinking that I could also go with a lower gear ratio. I see a lot of guys run 4.10 gears but I cant find a calculator that would definitely tell me what RPM that would be at 120 MPH. Does anyone here have a calculator or real experience of 4.10 gears at the track with a MN6? Cheers! |
