Originally posted by h82crash
The straight is about 150'. My carb HSN is about 5 turns out and the LSN is about 2 1/3 turns out. Funny thing is, from what I've read, the LSN is even with the end of the slide. Mine is way past the end, by like 3 mm. If I back it out to even, I think the low end will be way too fat.
My EVO2 ended up with full power, and running like the Beep-Beep Bird with 5 3/4 out on the HSN and 3 7/8 out on the LSN, and at that point it is flush with the slide end, and engine temp is between 100°C to 120°C. with air temps around 25°C to 28°C, and humidity at 80 to 85%.
Your straight is about the same as mine (155ft), and i run my Evo2 (with the internal gear ratio of my Yokomo) at 7.0 drive ratio on first gear and 5.76 drive ratio on second gear for 63mm dia. tires allround.
To calculate what combinations you need, what you have to do, is divide the number of tooth from your spur and pinion at each speed, and multiply it by the internal gear ratio of your car, and you'll have your final drive ratio for each speed. You will have to correct one tooth up or down on your spurs according to your tire diameters.
Hope this helps
AFM