Hey Evo Community.
I'm a noob when it comes to figuring out what gears to use and what not. I've been in touch with a few major trans shops but also thought I would see if anyone has something similar to me. I have a fully built evo 8. 6870 at 46psi that i spin to 9500rpms. I have a 25" tire setup (17×10 rpf1 with 255/40/17 888s). I currently have a stock evo 8 trans with I BELIEVE a 4.11 final. I DO NOT drag the car or launch it. I do only roll racing events and want to optimize the gearing of 3rd and 4th. Basically wanting to cross the 1/4 in 4th at 160+. Was wondering what gearing options I have available.

Thank you for reading and for input. Good or bad i guess

 

There are a few gearing calculators out there for the evo trans. If 4th gear goes 140mph @8000 that should be an evo 8 4th and 4.11.


You are going to want a dog box if its going to be shifted over 8500 well. A syncro box isn't going to live/shift well.

 

Contact RRT they were a big help when i inquired about what to do with my trans. I know they make some bad *** **** and more then likely I will go with them when its time to pull my trans and t case

 

Chris from Buscher basically recommended i do an ultimate trans build with a evo 9 1st, evo 8 2, 3, and 4, and evo 8 jdm 5th with the 4.11 final drive. Also do a REM treatment. With all that he said i wouldn't have to shift out of 4th when I cross the 1/4 mile mark. Also making it ideal for a long 4th gear. I don't drive it much. It's not my dd and I drive it maybe once or twice every 2 weeks. I've contemplated saving for a dog box but everyone I've talked with including buscher said I wouldn't need it for the driving I'm doing and how little I drive. Also never drag it

 

Yeah lets just keep adding on to the price of the trans. We do rem at work and all it does is oil shed. It makes the parts really shiney and has absolutely 0 performance to the build. A stock final drive will get you past the quarter mark in 4th gear just fine. It just depends on how high you rev the engine, it will put you in the 7 to 8 mark. I know with my 2.4 at the track I would hit close to 8500 at the end of the track which was beyond my rev limit. That is with a stock trans and t case. I mean a evo9 1st would be a little longer, evo8 2,3,4 are all short gears and a jdm 5th is way taller then a usdm 5th and the 4.11 would make it even longer. I wouldn't put the 4.11 in myself. Call RRT and ask them and get a second opinion.

 

I would recommend the evo 8 first gear with the 4.11. The evo 9 first gear with 4.11 will be difficult to work with. The JDM 5th is shorter then normal but would be nice for racing .Good luck on the syncro trans and that level. Hopefully it lasts awhile.

Evo 9 first gear ratio is 2.785
Evo 8 first gear ratio is 2.928
Evo 9 fifth gear ratio is .761
Evo 8 fifth gear ratio is .720
JDM 5th ratio is .825
https://gyazo.com/b75456001f128500481769a9e1d795bf

 

Thank you for the great info and also the link. Ya I called RRT and left them a message. I don't drag my car but feel like if someone good launched it I would def be a 150+ in the 1/4 so I just wanna be able to run out 4th as far as possible. I'm also not sure why he recommended a short evo 9 for 1st. Idk. They're the pros I guess.

 

Still waiting on a few shops to reply but I went ahead and order the straight cut 3/4 gears for my 5 speed. Gear ratios are same as a ppg dogbox so 3rd a day 4th will be longer. My only concern is whether or not to get the evo 9 1st or 8. And also the final either a 4.31 or 4.11

 

I think what you wanna do is get all the imput from the shops and make your decision. I would call Jon at TRE and Shep as well and ask them being they been doing this the longest if you haven't already.