Mitsubishi Evo Gearbox

[simonvangruber]

Hello forum users,

My current Evo 8 setup produces 260 awkw on a built 2L engine. My plan is to upgrade the turbo and the upgrade should produce around 370-380 awkw on E85.

My question is whether the standard 6 speed gearbox would be able to tolerate the above mentioned power level?

I have never launched the car and do not intend to in the future. Will the gearbox be able to cope with the power in normal everyday driving?

My preference is not to convert to a 5 speed or a dogbox.

Any advice would be appreciated.

[wildeagle44]

It will hold it but only for so long of course. They dont just magically break at a certain power its all in how you drive.

Your best bet it to contact sam from neat gearboxes. He was starting to do gearsets for the 6 speeds at a fair price. Theres also a good gearbox thread on the evo oz forums you might want to look at.

[Deza3000]

Not too sure if youve solved this issue or not, but the main reasons why the 6 speed fail was due to high oil temperatures and thinner 4th, 5th and 6th gears which resulted in premature wear. Usually caused by track days with lots of 4th gear pulls (also the reason why 3rd and 4th tend to go). I would probably get a oil cooler to start off with and do a lot of cool down runs between spirited driving sessions in order to prolong the gearbox life.

Just to put it in perspective, i know a lot of people running their evo 8MRs @ ~350awkw on stock 6 speed trans on e85 (imagine the torque) and the box is still going strong. Poor shifting, aggressive/improper launches and poor servicing are all ingredients for a dead box whether your stock or modified. Changing the oil often will also help too depending on how hard you plan on driving.

Also on a side note, bashing the gear shift hard enough in between 3rd and 5th can destroy 6th rendering 6th gear unusable. I believe this was notorious in the 9s, so id be careful and avoid doing this I put a 6 speed in my 7 and have done lots of research to see what the flaws of going to 6 speed were.