Well my stock rear end is giving way... my 410 gears and rear bearings and differential are shot. Lots of metal filings coming off and the howling is loud. Clutch packs started grabbing when turning short radius.
Looks like I will pull the trigger on:
- Eaton 31 spline Detroit TrueTrac differential
- Moser 31 spline race axles with c clip eliminator & 3" studs
- Gear & bearing install kit
- Aluminum stud girdle with stud kit
- Weld my axle tubes while they are out
Car weight (no driver) is likely just under 3,400 lbs for now - will be doing some lightening as I go. I expect to run 500-550 rwhp at the track (need to get back on the dyno after last round of mods and after the new rear end).
I run a Vortech V2 SQ SI trim blower with an 8 rib conversion kit and will be running 15 lbs of boost at the top.
So in looking to what gears to go with....
When I run the calculator and here's what I come up with if I were able to trap at 6,500 rpm in 4th...
4.30 gears + 26 slicks = 116.9 mph
4.10 gears + 26 slicks = 122.6 mph
3.90 gears + 26 slicks = 128.9 mph
3.73 gears + 26 slicks = 134.8 mph
If I bump up my RPMs or step up to 28's -
6,800 rpm + 4.30 gears + 26 slicks = 122.3 mph
6,800 rpm + 4.10 gears + 26 slicks = 128.2 mph
6,800 rpm + 3.90 gears + 26 slicks = 134.9 mph
or
6,500 rpm + 4.30 gears + 28 slicks = 125.9 mph
6,500 rpm + 4.10 gears + 28 slicks = 132.1 mph
6,500 rpm + 3.90 gears + 28 slicks = 138.9 mph
So based on this I'm leaning towards 410 Motive gears and staying with my 26" MT Drags... some have suggested the 390s. Sure appreciate your input!
Looks like I will pull the trigger on:
- Eaton 31 spline Detroit TrueTrac differential
- Moser 31 spline race axles with c clip eliminator & 3" studs
- Gear & bearing install kit
- Aluminum stud girdle with stud kit
- Weld my axle tubes while they are out
Car weight (no driver) is likely just under 3,400 lbs for now - will be doing some lightening as I go. I expect to run 500-550 rwhp at the track (need to get back on the dyno after last round of mods and after the new rear end).
I run a Vortech V2 SQ SI trim blower with an 8 rib conversion kit and will be running 15 lbs of boost at the top.
So in looking to what gears to go with....
When I run the calculator and here's what I come up with if I were able to trap at 6,500 rpm in 4th...
4.30 gears + 26 slicks = 116.9 mph
4.10 gears + 26 slicks = 122.6 mph
3.90 gears + 26 slicks = 128.9 mph
3.73 gears + 26 slicks = 134.8 mph
If I bump up my RPMs or step up to 28's -
6,800 rpm + 4.30 gears + 26 slicks = 122.3 mph
6,800 rpm + 4.10 gears + 26 slicks = 128.2 mph
6,800 rpm + 3.90 gears + 26 slicks = 134.9 mph
or
6,500 rpm + 4.30 gears + 28 slicks = 125.9 mph
6,500 rpm + 4.10 gears + 28 slicks = 132.1 mph
6,500 rpm + 3.90 gears + 28 slicks = 138.9 mph
So based on this I'm leaning towards 410 Motive gears and staying with my 26" MT Drags... some have suggested the 390s. Sure appreciate your input!
