+1 Sh** happens and things break, doesn't matter if its a 5 spd or 6, especially if your putting more that 100whp over stock. I just think that if you don't have the means to fix something that breaks and mitsu decides to not cover it, then dont race.

 

Poor MR's lol ...

 

Good question. So What is the power limit of the 6sp before you start breaking things vs the 5 sp?

 

Evo-E, no one knows the answer to that question. The basic answer is you won't ever be anywhere near the point at which you are overpowering the 6spd unless you put more than 30k into it.

Look at myself and Scott, for example. We race the living hell out of our MRs. He busted his eventually, but that was at least 150 drag runs and maybe closer to 200? He didn't bust it until he was in the mid-11s and says it may have been a defect instead of just the tranny giving way.

In my case, I have over 160 drag passes with more than half being in the low 12s, and I am able to currently no-lift shift every single gear with unbelievable ease. I also road race and autocross frequently, so I'm beating the hell out of my tranny. I challenge you to beat on yours as much as we have on ours. It is certainly not a decision point between the MR and IX/RS. Gearing is also no longer an issue - if anything, it favors the MR - because 1st through 4th are relatively the same, but then the 5spd has 1 gear for 100-160 while the MR has one for 100-130 and one for 130-160 basically.

 

Thanks for all your responses so far.

 

The tranny itself is fairly stout. However, it is susceptible to heat. There are more moving parts, but less fluid to help dissipate heat. The T2 MR we sponsor has been through 3 6-speed transmission in a little over one season (about 6,000 miles on the odometer) with the fourth being built right now. Obviously, it sees a little more abuse

 

Do you think the T2 MR would go thru 5-speeds under the same conditions?

 

the MR 6-speed is not weak and no one can prove that it is. just because gears are smaller doesn't neccessarily make them weaker. the 5-speed is made by mitsu, 6-speed by nisie(maybe spelled wrong), but does anyone know what materials the gearsets of either are made of? i don't. what if the smaller gears are made out of a stronger material? also, even though the 6 holds a tad less fluid, it does have external cooling fins on the case to aid in transfering heat out of the tranny that the 5-speed doesn't have. IMO they are both stout for what the majority of us will throw at them. also, why would mitsu put this "weak"6-speed in the FQ-400 with a warranty instead of the 5-speed? i just wish instead of people assuming that one is weaker than the other, they could provide some links with factual data. they both have certain advantages and disadvantages.

 

+1

 

My evo7 5gears was grinding at 2-3-4 shifts and i developped the habbit of waiting before plugging it into those gears.. It's coz i really wasted the gear in upper shifting.. I learned my lesson and i am controlling the gear changes on the new 9 very smoothly..

I guess it's how u treat them..

Wael

 

Minor point: FQ400 is an aftermarket product from Owen Developments. It really has nothing to do with Mitsubishi.

 

The input shaft and first gear are better built, first gear is wider and the input shaft is thicker and nitride hardened. Jon from TRE had the parts on his bench last year to compare the 5 to the 6 speed. As for the rest of the trans I really don't know.

It does seem like the 5 gears were a little straighter cut, helping out with the gear and bearing loading. Might be why the 6 speed is running hotter. Just a thought

 

Mitsu uses the 5spd in their rally car for a reason.

 

Pure speculation, but I'm sure he would have gone through at least one if not more

 

maybe it could be a more optimal gear ratio, same reason many drag racers prefer the 5-speed, although i doubt that the rally car has a stock gearset in it. don't know for sure, just assuming. i would also assume that rally racing you would prefer to shift as little as possible so the 5-speed has that advantage. i thought they used sequentials in the rally cars? i don't know much about the inner workings of 's rally cars so i'm not going to sit here and act like i do, please enlighten me with a link to some factual info on 's rally car drivetrain, i'd appreciate it. i know from driving both i prefer the smoother shifting in the 6 and i do alot of highway driving to/from work so the 6th gear is a plus. since i'm not planning on producing 900 whp any time soon, i'm not too worried about the fragility of my 6-speed.