Having run a stock 6 spd, stock 5 spd, and ultimate ratio 5 spd, I would never go back to the 6 spd. The ultimate ratio gearing (Evo IX 1st/5th, Evo VIII 3rd/4th) is superior to the 6 spd imo, as well as substantially stronger.

I am still on stock trans and t-case 6-speed 06 IX MR...i am pushing 433whp 425tq with 56,3xx miles so far. I use the exedy HD twin clutch with OEM fluids.

Note, I do not track or autox my evo.

I'm Doing Fine With 6.
 

Bought my '06 IX-MR new and now it has 105K miles on it. Used to be a daily driver, but not any more. I'm at 390 horsepower, rarely does it get 'notchy'...I might do a Shep upgrade someday, but I'm in no rush! I won't ever switch to a 5 speed.

She's not a track car.

After 30k miles on my 6 speed, today I popped the cherry for the first time on my 5 speed swap. I always loved the torquey feel of the 6, and it held up fine w 360 ft lbs but the 5 speed feels bulletproof. Especially with this
quartermaster 8 leg race version. I'm in love.

Bought my '05 VIII MR brand new.......has 166,000 miles currently. Approx 350whp its whole life, many many track days, and I think I only changed the oil in the trans 3 or 4 times.....can't remember.

6-speed transmission still ticks like a champ. No notchy shifts. :thumbup:
Hope this helps.

Mine is weird lol. Some days it shifts like butter, no resistance at all, shifter almost falls into place. Other times it's tough to go in, maybe even a lil grind, not audible but I can feel it and sometimes pops coming out of gear. It's almost as if the trans isn't aligned to the motor, so odd.

Kind of a late response, but I did a small write up on my cooler here

I have the pump mounted in the space shared with the ACD pump. However I am thinking to move it just off of the center transmount bar. Another member had a post about it and he welded two rods onto that unit and then effectively hung the pump between them. This ended up in the gap between the radiator and the trans just above the under tray.

I used an RB pump which is all brass and supposed to be super crazy over built. however, I have found that it was probably over kill and over complex. Just using a regular Tilton trans pump of any kind is probably fine. My pump only runs during track day use anyway, so if I were doing it again I save that 300 bucks I spent on that fancy pump.

always heard the the mr 6spd is the worst transmission for evo at higher hp levels. always liked the MR but now i'm looking for RS or GSR with 5 speed trany.

Drivetrains receive stress from high torque, not high horsepower. I've had both the 5 spd and 6 spd transmissions and I miss the 6 spd.

fireroasted thanks for the info, and the link to your write up.
MIKE

I Bought my Evo 9 MR with 76k miles, and have put 12k on it, in the past 2 years, on the stock 6 speed. Its always been a little notchy, especially when its cold but it has not gotten any worse over that time.

Now When i got it, it was making 384whp and 352 tq on a FP 71 HTA turbo, held the power just fine. And for the past 5K miles I've been running an FP Red at 30 PSI making 470whp and 444wtq, from a Mustang Dyno. My transmission feels the same as before. No issues as far as performance and shifting. It does have some gear rattle and TOB rattle noise. This car is daily driven, on a ACT HD street disc.

I have also taking it to the track once, did a few passes, and ran my best of 12.38 at 121mph.

The best I've experienced to keep it running well, is to use AMSOIL MTG in it. The OEM fluid was fine for the first few thousand miles, and then i tried Pennzoil Syncromesh, which was the worst idea ever! Grinded a lot, didn't want to go in gear, and made the transmission louder. After running that for only 1k miles, i changed to AMSOIL and haven't had any of those issues since. Its still a little notchy, just like when i bought it but that AMSOIL was the best thing that transmission has seen, also its recommended by TRE.

I will be keeping my 6-speed transmission though, I will have TRE build it, and i have a Exedy Twin disk to go in with it. I plan on making over 500 when i switch to E85 and bigger cams. I guess we'll see how it holds up, but i am very confident it will. I just love going to work everyday, being able to rip through some gears and also hit 6th and cruise. And possibly see some track time. Hope this info helps!

what I heard the 5 speed is better I find one that I am going to send to jack transmission to rebuild it and change t for the 5 speed and I will keep my 6 speed.

108000plus miles depending on boost 440-over 500 daily driven
been through three clutches however

Clutches are much cheaper then the box lol

I got 103K miles 320 WHP maybe a little more. replaced clutch ar 88K and no prob yet with trany