sbcbuilder

I am building a GS replica and need help with choosing gear ratios and the manufacturer of the transmission. This will be a track day car and see limited street use. Track speeds vary from 30 mph to 160 mph. Track length is 1 to 1.5 miles.

Engine specs: 358, 9.5:1, Kinsler EFI, aluminium block and heads, approx 700 hp and 550 lbs torque. Power band 4500 - 8500 rpm. Holley EFI management system.

Car weight 2400 - 2650 lbs
Final drive 4.11
Tire size 335/30ZR18
Diameter 25.9"
Width 13.5"


Gear ratios:
1st 3.54 = 45 mph
2nd 2.14 = 74 mph
3rd 1.51 = 105 mph
4th 1.23 = 129 mph
5th 1.00 = 159 mph
6th 0.85 = 187 mph

Range of gear
1st -- 0 mph to 45 mph
2nd -- 45 mph to 74 mph
3rd -- 74 mph to 105 mph
4th -- 105 mph to 129 mph
5th -- 129 mph to 159 mph
6th -- 159 mph to 157 mph

RPM Drops
1st to 2nd = 3362
2nd to 3rd = 2502
3rd to 4th = 1576
4th to 5th = 1589
5th to 6th = 1275

Thanks for your help.

briannutter1

That first gear will be pretty much worthless. Can you get something in the 2.4 range?

sbcbuilder

I am waiting for available gear ratios from the trans manufacturer. I was just trying some different combos out. Will post some new combos when I get the chart. Some people say that if you gear the car right set up you pnly need to use like 2-3-4. Ever heard of this?