Formula for chosing a gear.
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From: carol stream, il
Formula for chosing a gear. Here is a formula for those that want a gear for their car.
mph x gear ratio x 336/tire diameter. Heres and example from my car.
I trap 110 and my stock gear is a 3.23 and I run a 26 tall tire. So...
110x3.23x336/26=4591rpm's which is pretty dead on when crossing the 1/4 mile. Now I'll be switching to a 4.10 gear here shortly. So with a 4.10 I'll be at 5828rpm's crossing the line. So going with a 4.10 in my case will be perfect. Now if I install h/c in my car I'll switch to a 28in tall tire. Which will make me good for up to about 122 or so in the 1/4. You can also use it to calculate what rpm's you will be at in any given mph. Just a little somthing for people to use when considering a gear.
mph x gear ratio x 336/tire diameter. Heres and example from my car.
I trap 110 and my stock gear is a 3.23 and I run a 26 tall tire. So...
110x3.23x336/26=4591rpm's which is pretty dead on when crossing the 1/4 mile. Now I'll be switching to a 4.10 gear here shortly. So with a 4.10 I'll be at 5828rpm's crossing the line. So going with a 4.10 in my case will be perfect. Now if I install h/c in my car I'll switch to a 28in tall tire. Which will make me good for up to about 122 or so in the 1/4. You can also use it to calculate what rpm's you will be at in any given mph. Just a little somthing for people to use when considering a gear.
Shouldnt the transmission gear ratio be thrown in there somewhere?
I always liked this site for figuring this kinda stuff out: http://www.f-body.org/gears/
And isnt running 28'' tires on a H/C car kind of overkill? Only people ive seen running them are very wild H/C or power adder cars.
I always liked this site for figuring this kinda stuff out: http://www.f-body.org/gears/
And isnt running 28'' tires on a H/C car kind of overkill? Only people ive seen running them are very wild H/C or power adder cars.
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From: carol stream, il
well, the formula is based on a trans gear ratio of 1:1. I'm not sure which gear for a m6 but for an A4 its 3rd gear. If you want to find out gear ratio in any gear then mulitply the gear your in by the rear gear.
that formula works good for a manual car. it doesn't take into account torque converter slippage for autos. it's off slightly. i go through the traps shifting into 4th with mine. which puts me at least 6100 rpms just before the end.
