6 Speed Tranny a weak link?
Originally Posted by Warrtalon
Whoa, show us this MR. The fastest known USMD 6spd MR has only hit 11.5 or so. The only ones in the 10s have switched to 5spds, and some of the faster ones in the 11s have 5spds, too. I haven't seen a USDM 6spd MR go 10s yet, much less 9s. Were you referring to some Australian or JDM one?
Originally Posted by Top_End_EVO
yes I would love to see this 9.8 second 6 speed evo... searching evo forums right now and typing in 9.8@141mph on the search and see nothing from an MR.... please show me where you see a 9.8 sec 6 speed..
https://www.evolutionm.net/forums/sh...ht=autoplus+MR
Last edited by Jhero23; Nov 4, 2006 at 01:13 AM.
btw guys there are two completely different failures happening to the 6-speeds.
one is failure of the 4th gear itself as in bryan's case. shearing teeth right off the gear. this is obviously mainly torque based.
the second is something that jon(gears) touched on, excessive heat causing the 3-4 syncro to warp and bind. thus making it hard to shift into 3rd and 4th. the problem is the wall thickness of the slider is about half of what the 5-speed is. here's an image i found from another thread over on evomr but the bad part looked exactly like mine did when they pulled it apart.
the one on the left is a 5-speed for comparison and the one on the right is the overheated 6-speed part.
it looks like as the slider starts to get hot and warp it starts to bind up and then the shift fork starts to wear since it has to push on the slider even harder to get the gear to change. this causes even more friction and heat and adds to the problem in a vicious cycle.
one is failure of the 4th gear itself as in bryan's case. shearing teeth right off the gear. this is obviously mainly torque based.
the second is something that jon(gears) touched on, excessive heat causing the 3-4 syncro to warp and bind. thus making it hard to shift into 3rd and 4th. the problem is the wall thickness of the slider is about half of what the 5-speed is. here's an image i found from another thread over on evomr but the bad part looked exactly like mine did when they pulled it apart.
the one on the left is a 5-speed for comparison and the one on the right is the overheated 6-speed part.
it looks like as the slider starts to get hot and warp it starts to bind up and then the shift fork starts to wear since it has to push on the slider even harder to get the gear to change. this causes even more friction and heat and adds to the problem in a vicious cycle.
Last edited by smack_evo; Nov 4, 2006 at 01:58 AM.
Evolving Member
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From: Gainesville, VA
Originally Posted by mrfred
I've read that the stack style are much more efficient at cooling.
Yes, if I had a choice I would use one, like I do on my GVR-4, but SCCA only allows the use of this part number so unless I want to be disqualified after a race for unauthorized parts I'm stuck with this thing.
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From: Tri-Cities, WA // Portland, OR
Originally Posted by VR4orceCJ
Yes, if I had a choice I would use one, like I do on my GVR-4, but SCCA only allows the use of this part number so unless I want to be disqualified after a race for unauthorized parts I'm stuck with this thing.
Originally Posted by Fireball
Where can I locate a pump if I wanted to make my own? It really shouldn't be too hard to make one.
http://store.summitracing.com/partde...5&autoview=sku
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From: Tri-Cities, WA // Portland, OR
Originally Posted by hondafan
does anyone know if cryotreating 6-speed internals helps any and if so, to what extent? how much more torque or heat could a crytreated gear take than factory?
TooMuchBoost: I used to own a WRX, that my brother now drives. It's still on the original tranny. The reason the WRX tranny's gave up has nothing to do with case flex, and everything to do with gear width and tiny teeth, this has been discussed several times in countless WRX forums, those who though case flex was the issue are wrong. The RA gearset helped a little by improving the tooth profile. Put too much power and the gears would start to fatigue. BTW, I never called myself a GURU. I'm here just like anyone else trying to get to truth about how much powerlevel the 6 speed can hold. If you own a 5 speed then the issues with the 6 speed don't even concern you, please stop cluttering this thread with your opinion as you aren't adding anything factual to help.
smack evo: The pic you posted is of Voidhawk's tranny, his sychro got fried because his wife kept resting her hand on the shifter the entire time she was driving. I haven't had a single issue with it being hard to shift (only when its really cold out). If anything shifting gets easier and smoother as the tranny fluid warms up at the track.
smack evo: The pic you posted is of Voidhawk's tranny, his sychro got fried because his wife kept resting her hand on the shifter the entire time she was driving. I haven't had a single issue with it being hard to shift (only when its really cold out). If anything shifting gets easier and smoother as the tranny fluid warms up at the track.
Last edited by DaWorstPlaya; Nov 6, 2006 at 07:45 AM. Reason: Names corrected