After some track use the transmission starting getting difficult to move the shifter between 3rd and 4th gear.

 

Nice discussion. 290 ft-lb number is very surprising considering the "MR" tag. Is that number specifically due to the relatively wimpy 4th gear? If so, I'm wondering what's next weakest link and its torque rating.

Is there any room to stuff in a wider 4th gear?

 

Why couldn't someone make a stronger gearset for the MR? I wouldn't think it would be all that difficult. Especially for someone who already makes gearsets for other cars.

 

Obviously, everyone should realize that these cars are not primarily designed to withstand significant modifications, although the factory did provide enough to absorb moderate abuse. Be thankful the powertrain and drivetrain components hold up as well as they do, given the moderate price of admission.

Where the 6spd tranny is concerned, this unit is better suited to mildly modified cars for the reasons discussed ad nauseum here. Furthermore, as more power is being produced, the less useful an extra gear becomes. One reason why gears 1-3 are beefier because the factory figures these gears will take the brunt of the power most often. Keep in mind that the national speed limit of Japan is 60mph. The other gears are not only smaller, but are subjected to the counter forces of wind resistance at speed (which becomes tremendous), so these gears are subjected to considerable pressure. The failure of these gears is a function of stress and time.

I was skeptical of buying an MR because of the 6-spd. For those who have it, be prepared to need a rebuild at some point sooner or later - sooner with more power, later without.

 

PPG will probably end up doing it. Quaife will also probably follow suit. Now what would be trick is a 5 speed conversion inside the 6 speed case with ALOT bigger gears.

EDIT- It appears both of our questions have already been considered and answered:

http://www.ricardo.com/general/latestnews.aspx?id=11

 

I thought about that but it seems that is the most expensive solution ... it's cheaper to rebuild your 6 speed or swap to a 5 speed.

Since 4, 5 & 6 are the same width 14mm. I'ld venture to guess it would be 5th and then 6th

 

Who wants to put a dog box in a street car though. Would be nice if someone could come up with a revised set of helical gears with syncros for the 6MT. I suppose that with the prices of aftermarket gears, using a 5MT is probably the least expensive solution to the problem.

 

That probably costs $10k.

 

Well maybe the Ricardo. There is another british company that offers gear sets for 3100 pounds in all accepted group N ratios. Now I have seen alot of VIII MR failures mentioned, but what about IX's? Without disclosing too much, I have been informed that they arent exactly the same. I dont know that the gears are any wider (I'd highly doubt it) but there are apparently some internal differences.

http://www.stationgaragearnside.co.u...php?p=10&pno=0

Hollinger apparently also has a gear set listed for 650K yen at another site.

 

Those are 5spd gearsets.

 

I dont know why everyone is talking so much crap about the MR 6speed .. First of all no one knows how much hp the 6 speed can take. And if there is some high hp limit lets say 600whp that wont apply to 99% of the people. And at 600whp i doubt the 5speed will do any better with stock gears.

The one fact that is true that has been stated is the 6 speed cant handle road racing. Hmm soo unless your a road racer the 6 speed is just as good as the 5. Did any of you read warrtalon's post? 250+ drag launches power shifting ect and it still held up fine untill the road racing.

Ill say that if i ever get into road racing i will swap in a 5 speed. But for drag racing and romping around on the street ill keep my 6 speed thank you. Funny thing is there are more threads about bad 5 speeds then there are about bad 6 speeds.. and notice the 6 speeds that broke where abused alot. sorry i cant say the same for my friends 5 speed which grinds 2nd and 3rd .. and my other friend with a 5 speed's 3rd gear is starting to grind now.. both cars just have turbo backs.

Soo the answer to the title of this thread is yes the 6 speed is a weak link for "ROAD RACING". Not drag racing, not street racing, not auto X..

 

TTP broke 4th drag racing so there goes your theory.

 

Correct! Now he runs a 5sp

 

If I recall TTP said it might have been a defective gear.

 

Uhm, yes, they are all defective.