Can't Decide Final Drive Ratio?
 

Guys im rebuilding my trans, can't decide on a gear. Jacks offers 4.000:1, 4.11:1, 4.928:1. My mod list is pretty basic.. boost controller set at 23psi and retune, full tbe, exhaust manifold, short ram intake. So after lurking the forums I came to the conclusion the 4.0 and 4.1 gear are really really long gears best suited for stroker 35r
motors. While the 4.9 would be more similar/ a hair shorter than stock gears wich would be a little better acceleration wise for stock turbo/motor cars.


So basically my question is do I go with the *stocker* 4.9 gear since atm im stock turbo/motor or get the 4.11 or 4.0 gear since in the future I plan on doing a 35r build? The 4.11 and 4.0 would be great for highway/road trips for the lower rpm at highway speeds.. But I cant justify the loss in acceleration/dont even know if it is that noticable? HELP PLZ!!!!!!!!!

:mitsu:

I'm interested as well too.. Come on evo transmission guru's help a brother out!!..lol

You are correct that the 4.11 and 4.0 final drives are best suited for a higher HP car. The 4.928 final drive will reduce the mph in each gear by roughly 9% while the 4.11 will increase MPH in each gear by about 9%. Hope this helps you in your decision.

Fwiw, I chose the 4.11 final drive for my car (6466, 2.4, Evo 9 1st, 2nd and 5th with Evo 8 3rd and 4th).

So would a 4.11 just be a overall bad idea on a stock motor/turbo car? In that case should I do the shorter 4.9 gear? Even though in the future I plan on doing a 35r build?

How soon and how certain are you that you will for sure do the 35r build?

Not for a year or so... Was thinking of might trying to max out the stock turbo?? would the 4.9 gear be better suited for that??

Potentially, since the 4.9 FD will give you more torque. But you also have to keep in mind that you will have to either shift to 5th or rev high in 4th, well past the efficiency range of the stock turbo, before you cross the finish line.

So what in your opinion would be better? Having more low end torque but having to shift to 5th or bouncing it at 8k in 4th gear wich would be out of the *efficiency range*? OR lose some low end torque but being able to hit speeds of 140mph in 4th eliminating the whole shift to 5th or not being in your power band ordeal?

Lets say I ran 12.6 at 115 or so with the factory gears... if it was the same setup just with the 4.11 long gears instead how much would your time suffer?

Can someone chime in on this please?

https://www.evolutionm.net/forums/ev...-1-4-time.html


Sorta Relevant

Personally, the trans is the least of your concerns since you don’t even have the power to worry about changing your FD. IF YOU’RE SERIOUS about getting a stroker motor and a 35R, then I would say sure go ahead. But you’re a long way from that ATM and getting such a low FD with your set up will only hurt you.

goood info :)

I talked to Trevor weeks ago and he told me that a 4.11 is too long of an FD for a street car, and that most people use 4.11s for drag racing. Just relaying information, I for one wanted 4.11s, I settled on Evo VIII 3rd, 4th, and 5th.

no mean to thread jack, but what would you guys recommend for road racing as far as a final drive? already planning to get the evo 8 3rd and 4th gears for my 9 trans. i also plan on doing some road trips also.

Terrence

What was the justification for the 4.11 being too long of an FD for a street car? I don't quite understand this rationale.