Are there any aftermarket kits to replace the gearsets in the front and rear differentials on the evo8? My end goal is to have reduced highway cruising rpm. any help would be appreciated. Thanks.

 

Why not just change 5th gear to something taller? That would seem like less work compared to changing the ring and pinion on both the front and rear diffs.

 

This one isn't easy.
-First thing you got to know is how much gear ratio to change. Too much and you might not enjoy the 5th gear unless you're doing 80+mph. Evo's are not V8's which can drive at low rpm's with ease like 1600rpm at 60mph.
-Second what about the 4th gear. If 5th gear is too tall than you'll need to down shift to 4th more often which could make gas milage even worse.
It would be nice if we can just add a 6th gear to the stock 5 speed tranny. It could serve as an overdrive.
BTW if you change the gear set in the Diff's to reduce rpm at crusing, your 1st gear might be too tall for normal street driving.

Best thing to do, don't go over the speed limit, wax the car, add couple psi to the tires and drive at steady speed as much as possible, changing speed faster (up and down) eats more gas.

 

I'm used to my Stealth TT with the taller gears. I'd add a six speed, but I've been informed that the final drive ratios are essentially the same. I'd add a taller 5th gear, but no one makes them.


Don't go over the speed limit

 

How would having a too tall first gear be bad for street driving? You are thinking in the opposite direction. If you put a higher gear as final drive to lower fifth, you could go a higher speed in first thus meaning you could stay in first longer. That's better for street driving.

 

There are actually a wide variety of gear sets available in Europe but they are mainly for racing applications and cost prohibitive for street users.

We will find out more if we go to the Autosport International motorsport show in the U.K. next month. Tuning over there is taken very seriously and there is a wide variety of sophisticated, well engineered products for the EVO.

 

Make sure to bring back some of the knowledge and stuff for us.

 

Thank you. It would be much appreciated.

 

In japan it looks like hks makes a 4.11 gear that sells for roughly $700-800 depending on yen rate. this should bump you final speed@7000rpm in each gear up to about 43 in 1st, 63 in 2nd, 87 in 3rd, 118 in 4th and about 160 in 5th. I'm not sure about the top speed because I'm not sure about fifth gear, I think the U.S. spec was different.maybe one of the vendors that sells jdm parts can get it for you.There is a british site that also sells a 4.11 gear they say that it will boost top speed up to 188mph at 8000rpm, their's is a little more expensive at 999LB thats like $1500-1600.Here is there site http://www.norrisdesigns.com/ . If you check out there site look under various ancillaries for it. These guys had an evo that hit 196mph in britian which is sick.

 

Thanks, but the norris group's stuff is for the evo 4 thru 7.

 

evo 7 tranny and ours is essentially the same I believe. talk to JUN EVO, he found out that the final drive out of an 02 Galant is the same part that HKS sells, I believe that ASTROEVO found the same.

 

EVO IV-VIII are all the same trannies, except of couse the 6speed in some of the 8's

-george