View Single Post
911st 911st is offline
Registered User
Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
It seems none if us here have really done gears except Don though we know it can help and have thoughts on how to approach it.

My two cents is I would get the motor/car built first. Dive it some to see where you want to see improvement like off the line and/or see if first is to short. Make note of what RPM you can live with on the freeway as this is often what keeps one from going with a lower final gear. Also, your Dyno plots will come in handy. Might note if you have enough power at the beginning of 2nd to spin the tires at will. If you do there is not as much reason to narrow the rpm drop into 2nd.

Cheaper improvements could be a lower R&P but from what I am hearing from Don and others that have gone there with big HP motors, this can make first to short and you end up with a weaker rear end on top of that.

Another could be to just move first up to reduce the 1-2 split but that would make your off the line pre-boost potentially slow.

The 2-3 and 3-4 gear splits are about 1800 - 1900rpm which not bad for a turbo. For a race car they could be shortened some to make an incremental improvement.

The best.
Old 05-17-2010, 08:00 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #20 (permalink)