I'm in the market for a 2006 Evo MR and would love to keep the 6 speed. What would I have to do to the transmission to beef it up so that it can handle 600hp?

 

I'm thinking you would be fine. Seems like it's heat they don't like not necessarily power. I've been a very hard few thousand miles on an HTA73 Green and 6 speed but that few miles isn't necessarily a good indication.

In for info though because I broke a rod and am about to go built block and probably bigger turbo and most likely plan to keep my 6 speed as is.

 

Yea, I've been doing some reading and I notice its more heat than power. Would I need a trans cooler? I just want to reinforce it before I throw power at it, regardless of what needs to be done

 

There is a Shep 6 speed for sale in SoCal for $2k. That's a good price, and I would buy it as a spare if I weren't trying to finish up my engine build.

 

Good deal for an already built 6 speed as long as it's in good shape. I'm in the same situation with the engine build though. Shep still build the 6 speed on request? I read before that they couldn't get the gears anymore or something like that. I think my 6 speed shifts much smoother than the 5 speed.

 

there was a pretty big thread on beefing up the 6 speed and long story short it wasn't cheap at all in the end. I own an MR 06 with the six speed. My engine is fully built, transfercase is stock and I only have the ACT street light clutch with my stock flywheel, I believe I change the shifter bushings to the steel or aluminum after market ones that AMS sells, and I had the shifter shortened. I don't daily drive it as it is a garage queen, I'd say i drive it 1-2 times a month and start it once a week. When I do drive it I get on it fairly ruff, I haven't race from a dig in a long time but would hear that transfercase clunk pretty hard. So far so good, I think it just depends on the transmission shifts, changing out the trans fluid regularly and so on. I heard 3rd gear starts to grind after awhile but then again lets be real, eventually a re-build will be needed. an 06 is already 10 years old. If I had the money I'd build my 6 speed or at least look at that one in socal for 2k. Some ppl will tell you to swap it to a 5 speed but then again why did we buy the MR in the 1st place? good luck.

 

The Shep 6 speed was a one-off deal if I remember right. I somehow got my hands on one when they were making them. Basically a 3-4-5 gearset. Sounds like 3-4 are straight-cut, but I cannot comfirm that for sure, haven't had to open up the transmission yet (cross your nipples for me). Like I said, I don't think Shep is making the gears and selling the upgrade any more, but apparently there are some out there. A lot of people have done trans coolers for track stuff and it shouldn't be all that difficult to make. I looked into it, but decided to build a track car so never got around to designing it. Not much info out there on how big a heat exchanger you would need. Probably would end up being a situation where you over-size the heat exchanger and then have a sensor turn the pump on/open a valve at a certain temperature. Most people just swap to a 5 spd, and to be honest that is the easier/lighter/cheaper way to go in the long run probably. The 6 spd is nice to have for driving around town and having the option for lower rpms and fuel savings, but for a track car, I would say it would be a close tradeoff between what you are gaining with the extra gear and the time loss during the extra shifts, not to mention the extra weight, etc... Long story short, just buy a monkey.

 

How much lighter is a 5 speed? That's an added benefit I didn't think of. I'm still debating whether to sell my 6 speed and go built five speed when I have my transmission out putting in a built motor.

 

Yes you can reinforce it. Buy a 5-speed.

 

AFAIK, Shep is making them again. He definitely ran a second production run, because I literally bought the last set he had from the first. With a higher FD, 6th is a cruising gear and I am pretty sure you wouldn't use anything higher than 5th on a track. 6 speed is still much smoother shifting than the 5. For a serious track set-up, the 6th still might be heat-limited...but a cooler can help.

Not sure how much lighter the 5 speed is, but don't forget to factor in that extra .7 liters of fluid the 5 speed uses

Here's a used Shep 6 speed for sale in SoCal:

https://www.facebook.com/photo.php?f...type=1&theater

 

* I have 127k on my 6spd. Never put much more than 400whp through it, though.
* Shep is doing the 6spd again. Hopefully still will when I need one done.
* for those of us that have driven both, the 5spd is a bit notchy. It doesn't shift as nice as the 6. I prefer the ratios in the 6 as well.

All up to you, though.

If you sell the 6spd, let me know 😁

 

I have said shep 600hp 6 speed in my MR (with the longer final drive as well)

 

How do you like it? I'm still getting my car back together.

 

I have only drove it about 800 miles since september 2014.

300 of the miles were all highway.

I do like my cruising RPM with the longer gearing. The trans is noisier (which I like) partially I'm sure this is because I also did a limited slip upgrade at the same time.

It shifts better so far and I haven't had problems but it hasn't had lots of testing. I'm really glad I stretched out the final drive because now when I use e85 I have gobs of torque and the rpm climbs really fast. (I can't imaging how fast it would fly through the rpm with the original final drive - too much time shifting)

 

I know Jacks Transmissions came out with a 3rd-5th gear set for the evo 8/9 MRs not sure who has used them yet but here's the link:

http://www.jackstransmissions.com/co...set-evo-8-9-mr