Tomioka Racing 4.0 Final drive 2400rpm at 60mph

Lucas English · Nov 9, 2011, 09:36 PM

My thoughts on the Tomioka Racing 4.0 final drive for Evos VII thru IX 5speed transmissions.

So a few months back we had a Tomioka rep stop by and give me a final drive to try which I thought was way cool of them. The best car I felt to try it in that we had was my 2.4 FPHTA green car since it was a low rpm high TQ motor. As far as install it went great. Had to reshim the intermediate shaft some. The factory shim was .042 and I had to move it to a .036 which for a totally different shaft is great tolerance I think.

When I installed the gear set I put one new factory bearing on the bottom of the new Tomioka Racing intermediate shaft. Trying to get the factory bearing off the old shaft can be hard to do and still have it be a reusable bearing.

I have about 1500mi on the car and it’s all positive so far. I have only pushed it to around 480whp 450ft lbs so far. No noises just a nice lower rpm cruise on the freeway

Cant wait to test it on the road course.

I did a bit of reading on here trying to find opinions. How I look at it, unless it’s made of sand it would be pretty hard to mess up the final drive. It’s one of the biggest gears in the EVO and the least likely to break. I have yet to ever see one break.Unless crap from other broken gears runs through it. So even if this part is a tad bit less quality than factory I am not worried about it. Even on a 800+ hp car. While I am not a gear expert it looks like a beefyer pitch and tooth design than stock. I will keep this thread up to date if I do run into any problems.

I am very happy about this mod. I did have a stock IX trans so for me I went to a VIII Trans with this final drive so my 60mph cruise went from 3100rpm to 2400rpm or so. Have not had any good road trips yet to see what my new MPG will be.

If I were to install this on a IX trans I would put a VIII 1st gear in. To me this final drive and the tall IX 1st gear would be pretty annoying to drive. Would be hell on clutches for launching with the amount of slip needed. Also real tall 1st gears can make even the smoothest clutches be chatter monsters.

I also like the fact that you are not rowing the gears near as fast which really lets you setup for faster shifting.

So I know here at English Racing we will be happy to sell and install these final drives for the people who want them.

Here are the speed break downs for those who care.

EVO VIII Transmission 4.0 Final drive

EVO VIII Trans Stock Drive

EVO IX Trans Stock Drive

Here is a IX trans with the 4.0 Final drive

Here are some pics of course I started good by taking pics but then never took any going back together. I suck.

Here is a little video showing how nice it is to cruse.

http://youtu.be/wHHc6KMYzmk

Also a little one beating on the car some.

http://youtu.be/MQjet5SmYsA

warmmilk · Nov 9, 2011, 10:42 PM

lol @ boost under 2k rpm...

evolutionxtac · Nov 9, 2011, 11:06 PM

Where is the Tomiokoya final drive made?

jdowd · Nov 10, 2011, 07:12 AM

good review pm sent

Lucas English · Nov 10, 2011, 12:38 PM

Added the IX trans with the 4.0 Final drive to the list above.

jdowd · Nov 10, 2011, 01:09 PM

thanks for adding the evo ix 4.0 final drive do you guys sell these on your site

JohnBradley · Nov 10, 2011, 01:22 PM

We are adding everything to our site as we test them. Right now we have limited time on the 4.0 final drive but as soon as it has been torture tested we'll list it. We can always sell it right now though if you want to go ahead and order it.

Aaron

jdowd · Nov 10, 2011, 01:30 PM

when will you be doing the torture test on it i will be building my block in december and while the engine is out i wouldnt mind doing this upgrade and refreshering everything

JohnBradley · Nov 10, 2011, 02:21 PM

As soon as there isnt snow or rain on the road courses

GotWheelHop · Nov 10, 2011, 02:34 PM

Aaron, do you know how many miles were on the oem shaft/gear? Tooth edges are kinda rough. Thanks for doing this testing. It'd be nice to have another reliable option for a taller final drive for us stroker guys.

JohnBradley · Nov 10, 2011, 03:00 PM

The OE shaft and gear had 60k total and 20k on a rebuild. During the rebuild (we didnt do it) I find it highly unlikely it had been replaced. It actually doesnt look that bad in person.

To answer the question about where these are being produced, I do not have that information. I had initially thought this was a relabeled M Factory which is apparently incorrect. It looks VERY similar however for what that is worth. Their parts are produced in Australia as far as I know. I cant say for sure though.

Aaron

Svendiesel · Nov 10, 2011, 03:49 PM

Very interesting!

l888apex · Nov 10, 2011, 04:07 PM

Damn you would be at ~3,200 rpm's on a IX trans with the tomioka final drive at 80mph

that would be awesome for cruising

definitely a future mod for me

JohnBradley · Nov 10, 2011, 06:02 PM

Confirmed it is forged in Australia for those that are curious.

Here is a link to the software I used for the gear splits also-

http://locost7.info/gearcalc.php

Aaron

TurboTim06 · Nov 11, 2011, 09:11 AM

Very interesting! I'm interested in seeing the results from the torture testing but from what I'm reading here I'll be purchasing one of these from you guys in the near future once I get my build going.