***Tranny Setup: MN6 with MN12 5th Gear??
09-17-2010, 11:05 PM
#1
Le Mans Master
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Location: Port Arthur, Texas 77642
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***Tranny Setup: MN6 with MN12 5th Gear??
I seem to remember of others doing this to keep the closer ratios of the MN6 along with the better 5th and possibly 6th on the MN12. Can anyone shed some light on this for me?
05-28-2018, 05:04 PM
#6
Interested to know the feasibility for those exact ratio???
Christian
05-28-2018, 11:09 PM
#7
Racer
This is an 8 year old thread but I'll shed some light for ya Miami...
I changed over to the standard 2.66 gearing first through 4th...its expensive first off. I kept my C5 Z06 5th and 6th. The car was faster with the M12 gearing on track with the 3.42 final drive before the swap. After the swap I was 2 seconds a lap slower at my home tracks. The culprit was the combined added longer gearing and still factory 3.42 rear gear. I HAD to swap out the rear 3.42 to a 3.73 to gain my torque multiplication back...car feels great now and is faster than before.
I changed over to the standard 2.66 gearing first through 4th...its expensive first off. I kept my C5 Z06 5th and 6th. The car was faster with the M12 gearing on track with the 3.42 final drive before the swap. After the swap I was 2 seconds a lap slower at my home tracks. The culprit was the combined added longer gearing and still factory 3.42 rear gear. I HAD to swap out the rear 3.42 to a 3.73 to gain my torque multiplication back...car feels great now and is faster than before.
05-29-2018, 11:13 AM
#8
This is an 8 year old thread but I'll shed some light for ya Miami...
I changed over to the standard 2.66 gearing first through 4th...its expensive first off. I kept my C5 Z06 5th and 6th. The car was faster with the M12 gearing on track with the 3.42 final drive before the swap. After the swap I was 2 seconds a lap slower at my home tracks. The culprit was the combined added longer gearing and still factory 3.42 rear gear. I HAD to swap out the rear 3.42 to a 3.73 to gain my torque multiplication back...car feels great now and is faster than before.
I changed over to the standard 2.66 gearing first through 4th...its expensive first off. I kept my C5 Z06 5th and 6th. The car was faster with the M12 gearing on track with the 3.42 final drive before the swap. After the swap I was 2 seconds a lap slower at my home tracks. The culprit was the combined added longer gearing and still factory 3.42 rear gear. I HAD to swap out the rear 3.42 to a 3.73 to gain my torque multiplication back...car feels great now and is faster than before.
What was involved in this modification and what was making it expensive please?
Regarding my application those ratio will be exactly what my engine needs as per the RPM chart versus Powerband below:
Christian
05-29-2018, 12:00 PM
#9
Le Mans Master
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Hi Christian, although I did not undertake this project I did however establish a likely path forward. I would speak with George at Rockland standard Gear, they can put together a number of ratio sets. I don't have time at the moment to share all details however once you call George and have a discussion I'm confident you'll arrive at the same conclusion. RSG is one of several companies that put together transmissions for racers that don't sell stage X upgrade mumbo jumbo BS - they deliver customized quality and reliability. Make the call, it's worth your time.
05-29-2018, 08:38 PM
#10
Racer
Simply put, to locate nice factory Tremec gears is expensive, and they don't make that stuff anymore. It has all been replaced by the updated TR6060 stuff. The output shaft to cluster and even all the gears are all extremely expensive and difficult to locate. D&D handled my build with the carbon synchros and billet pieces. But it was a scavenger hunt for me from them to Tick performance to locate what I needed. I have the entire M12 gear set sitting in my garage in perfect condition and for some reason I can't sell it. The gear set has 29k miles on it and I have only had 1 low ball offer. Maybe there isn't a market out there anymore,IDK? Even when I was looking for low mileage MM6 gear sets it was like searching for a needle in a haystack!!!!
There are alternatives out there that are made I believe out of the country but I did not want to trust those. You can't just mix and match what you want I believe. IT's either 2.66 ratio or 2.97 ratio for the first 4 gears...no other way around it. 5th and 6th are on an entirely different shaft so you can use either or. The race boxes I am not familiar with but I assume being a RACE transmission, you can swap and change what works for you. I believe you can also delete 6th gear if you wish to save weight and rotating loss through the drive train. Hope this helps
There are alternatives out there that are made I believe out of the country but I did not want to trust those. You can't just mix and match what you want I believe. IT's either 2.66 ratio or 2.97 ratio for the first 4 gears...no other way around it. 5th and 6th are on an entirely different shaft so you can use either or. The race boxes I am not familiar with but I assume being a RACE transmission, you can swap and change what works for you. I believe you can also delete 6th gear if you wish to save weight and rotating loss through the drive train. Hope this helps
05-31-2018, 10:45 AM
#12
Drifting
Not that this will add anything to the discussion, I just spun 5th & 6th gears.(in a M12 box) When I took the cluster out the shaft that they ride on striped the splines. Also I'm not running anything other then a stock LS6.
Mark.
Mark.
