Well for the past 2 years i've been building my car to compete in time attacks. willow springs, watkins, midohio, etc

the setup is a full built d16z6, i have a y8 tranny already apart, well the casing off.

this is actualy a 2 part question.. 1.. what turbo should i run, and 2.. what gearing should i run...

i know its vague and so many factors, factor in.. but how do we start to narrow it down

 

what it all boils down to, is what speed you'll be getting up to.

figure that out and we can go from there

 

you also need to figure out if you want the most out of the car at the track or on the street. is MPG important, etc, etc.... slight gearing differances can be solved by differant size tires ie: use a set of street tires, and a differant sized track tire.... ultimately, the more gear, the faster it will accelerate, which is im guessing, what you want.

 

140mph, basicly i don't care much for mpg, and i don't care for easy driving, i'd like it as flat out insane as posible.. lol

 

what's your redline? and what size tires?

 

infinitude 3/5 gears and a 3.722 final drive with 23" tires and 7700rpm redline.
I have a 3.7222 final drive from a hx, 50 shipped.

1st = 3.250
2nd = 1.909
3rd = 1.565
4th = 1.259
5th = 1.000
final = 3.7222

5th gear tops out at 142mph.
still very daily drivable, but longer gears for 140mph high speed. closer ratio gears keep you in the upper rpms, but the lower final drive increases your top speed.

or maybe a 4.058 with zc gears? who knows, but the infinitude 3/5 is a good buy IMO

 

well with a 4.058 that would be fun but only 130-131 mph top speed..

i'm very intrested in the hx final gear, just still trying to decide with what to go with. I check out the 3rd/5th from infituide at $525.. steep.. but if it has to be, cost is just more time saving paychecks

what about the zc gear route.. and using a gearspeed calculator, how do i tell my rpms.. say i wanted to stay above 400 rpm drop, i don't really know how to word it.

 

it's all in my tranny page

4th gear / 3rd gear = J (J * redline = F) F = number that the rpms fall to
redline - F = rpm's dropped


1.259 / 1.565 = 0.804 (0.804 * 7700 = 6194.44) when shifting from 7700rpm in3rd into 4th, you'll drop to 6194.44 rpm.

7700 - 6194rpm = 1506


80% drop is ideal in my opinion.

 

yea, been going over it.. any videos of a close ratio honda d series tranny, i guess b series too.. but a dseries would be ideal

 

hmm i'd say drive the track get a feel for it and adjust as neccessary