[Z06] C5 6-speed H.P. limitations
Thread Starter
Intermediate
Joined: Jan 2012
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C5 6-speed H.P. limitations
I was wondering how much horse-power the stock z-06 manual transmission will hold up to before self destruction.
And is there a significant difference from the 'base' coupe & the z-06 manual 6-speed transmission.
Thanks ,John
And is there a significant difference from the 'base' coupe & the z-06 manual 6-speed transmission.
Thanks ,John
Melting Slicks
Joined: Dec 2006
Posts: 2,186
Likes: 2
From: Woodinville WA
Mine broke at 416 whp. But others have had much more and do OK. It depends how hard you drive it or if you miss a shift. The weak points are aluminum 3-4 shift fork, plastic pads, and weak stamped syncro keys. After upgrading these parts there were no more problems.
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Mine broke at 380-390 rwhp but you need to define broke/break. Mine ate the syncros which caused 3rd gear to not engage. I would not really call this broke as in broken input/output shaft or broken gears.
Mine just got an level 4 trans and McLeod RXT Twin clutch while it was all out. I was told that the Z06 T56 (M12) will take about 800rwhp before it starts having problems (John @ 21st Century Muscle cars). AFAIK the only difference between the base trans (MM6) and the Z06 (M12) is the gearing.
MM6 M12
1st 2.66 2.97
2nd 1.78 2.07
3rd 1.30 1.43
4th 1.00 1.00
5th 0.74 0.84
6th 0.50 0.57
Mine just got an level 4 trans and McLeod RXT Twin clutch while it was all out. I was told that the Z06 T56 (M12) will take about 800rwhp before it starts having problems (John @ 21st Century Muscle cars). AFAIK the only difference between the base trans (MM6) and the Z06 (M12) is the gearing.
MM6 M12
1st 2.66 2.97
2nd 1.78 2.07
3rd 1.30 1.43
4th 1.00 1.00
5th 0.74 0.84
6th 0.50 0.57
Last edited by Millenium Z06; Jan 19, 2012 at 06:47 PM.
Burning Brakes
Joined: Feb 2011
Posts: 979
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From: millstone NJ
Mine broke at 380-390 rwhp but you need to define broke/break. Mine ate the syncros which caused 3rd gear to not engage. I would not really call this broke as in broken input/output shaft or broken gears.
Mine just got an level 4 trans from and McLeod RXT Twin clutch while it was all out. I was told that the Z06 T56 (MN12) will take about 800rwhp before it starts having problems (John @ 21st Century Muscle cars). AFAIK the only difference between the base trans (MN6) and the Z06 (MN12) is the gearing.
MN6 MN12
1st 2.66 2.97
2nd 1.78 2.07
3rd 1.30 1.43
4th 1.00 1.00
5th 0.74 0.84
6th 0.50 0.57
Mine just got an level 4 trans from and McLeod RXT Twin clutch while it was all out. I was told that the Z06 T56 (MN12) will take about 800rwhp before it starts having problems (John @ 21st Century Muscle cars). AFAIK the only difference between the base trans (MN6) and the Z06 (MN12) is the gearing.
MN6 MN12
1st 2.66 2.97
2nd 1.78 2.07
3rd 1.30 1.43
4th 1.00 1.00
5th 0.74 0.84
6th 0.50 0.57
Moderator
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Posts: 22,753
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They are close ratio to keep the LS6 in its powerband so yes, you would shift a bit sooner in 1st thru 4th but they are supposed to be better geared for the road course than the MN6.
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Joined: Jun 2004
Posts: 22,753
Likes: 943
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Burning Brakes
Joined: Feb 2011
Posts: 979
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From: millstone NJ
ok got ya. . the z has a lower top speed than the c5 right? is that cause of the trans gears? also would my car be held back from hitting 200mph cause of the way its geared?
Burning Brakes
Joined: Feb 2011
Posts: 979
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From: millstone NJ
oh btw 03 z06 706rwhp stock trans and ls7 clutch. holds great i dont drag race, but do enjoy the car. . clutch just started getting alil on/off grabby, in shop now will be right around 800rwhp. cross your fingers trans holds with new duel disk
Melting Slicks
Joined: Dec 2006
Posts: 2,186
Likes: 2
From: Woodinville WA
Good point. First time mine broke the aluminum 3-4 shift fork was bent which caused it to get stuck in 4th gear. Replaced the fork with steel. The second time I missed a shift after installing an aftermarket shifter which broke some of the weak stamped keys, afterwhich I replaced with solid billet keys and put in bronze pads. No more problems after that.
Both these issues may not have been HP related.
Both these issues may not have been HP related.
Thread Starter
Intermediate
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johnsengine
Thanks guys - Im shopping for a for a daily driver ,so I dont have to drive my supercharged C6 as much. But ... as it usually goes - I will end up putting more 'crap' in its pants too. 
By the way - A lady friend of mine is wanting to part with a [Good] condition 1981 vette. Low miles [65000] on odomiter & I can tell by the brake pedal its not turned over. Its white & Ive painted black /white-silver-gold checkerboard stripes on the hood center & side coves. It looks good !!
She wants about $10,000.oo or less. Its a dog ,but a nice looking car !!
Thanks again ,John
By the way - A lady friend of mine is wanting to part with a [Good] condition 1981 vette. Low miles [65000] on odomiter & I can tell by the brake pedal its not turned over. Its white & Ive painted black /white-silver-gold checkerboard stripes on the hood center & side coves. It looks good !!
She wants about $10,000.oo or less. Its a dog ,but a nice looking car !!
Thanks again ,John
Moderator
Joined: Jun 2004
Posts: 22,753
Likes: 943
Good point. First time mine broke the aluminum 3-4 shift fork was bent which caused it to get stuck in 4th gear. Replaced the fork with steel. The second time I missed a shift after installing an aftermarket shifter which broke some of the weak stamped keys, afterwhich I replaced with solid billet keys and put in bronze pads. No more problems after that.
Both these issues may not have been HP related.
Both these issues may not have been HP related.
Moderator
Joined: Jun 2004
Posts: 22,753
Likes: 943
No, the top speed is more aero limit than gearing; the notch back rear window creates a lot of drag compared to the coupe/hatchback window.
Last edited by Millenium Z06; Jan 20, 2012 at 02:42 PM.
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
Mine broke at 26k miles.... Sheered the keys on the 3rd gear syncro... So a .25 cent part costed about $3k to repair.... Because "while youre in there" upgrades always take place. Mine broke on the street after a couple hard 3rd to 4th gear runs....Got stuck in 4th and thats all she wrote.... Never been to the track at that point...
So I fixed/upgraded the tranny....took it to the track and broke the DTE Stg 2 rear end...
$1600 later its back on the road again...
No more drag racing this car..... at least not for a while...
Truth be known, any of these trannies can break at any time...it doesnt matter how many miles or what type of abuse.... Those pot metal synchro keys are little time bombs waiting to go off...Complete $HIT design by Tremec on that...
So I fixed/upgraded the tranny....took it to the track and broke the DTE Stg 2 rear end...
$1600 later its back on the road again...No more drag racing this car..... at least not for a while...
Truth be known, any of these trannies can break at any time...it doesnt matter how many miles or what type of abuse.... Those pot metal synchro keys are little time bombs waiting to go off...Complete $HIT design by Tremec on that...
Burning Brakes
Joined: Feb 2011
Posts: 979
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From: millstone NJ
Burning Brakes
Joined: Feb 2011
Posts: 979
Likes: 0
From: millstone NJ
. . .so even mine being way over powered would it be able to break 200mph?
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Intermediate
Joined: Jan 2012
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johnsengine
My 05' C6 started life as a coupe & got ZR1 drive train w/a custom 402" motor - then a pro-charger was added w/6p.s.i. boost. [$30k invested]
Making this a scary fast car [est. 725+ rwhp] !!!
I can put it in 3rd gear ,press the gas & when it hits 3k r.p.m. ,the 12" rear tires cut loose @ 80 mph !!
Then ,3 piece 20" MHT wheels /michelin pilot tires. [another $10k]
Wrapped in LeMans blue over black - its a true "Blue Devil",capable of 1000+ hp with more boost & meth inj. !!
Hope I dont have to sell it - my bike building/custom paint business has taken a big hit w/the economy sucking.
Curious ? Im on facebook [Johns Choppers]
If something doesnt give ,Ill have to sell my dream car @ a huge loss !
Making this a scary fast car [est. 725+ rwhp] !!!
I can put it in 3rd gear ,press the gas & when it hits 3k r.p.m. ,the 12" rear tires cut loose @ 80 mph !!
Then ,3 piece 20" MHT wheels /michelin pilot tires. [another $10k]
Wrapped in LeMans blue over black - its a true "Blue Devil",capable of 1000+ hp with more boost & meth inj. !!
Hope I dont have to sell it - my bike building/custom paint business has taken a big hit w/the economy sucking.
Curious ? Im on facebook [Johns Choppers]
If something doesnt give ,Ill have to sell my dream car @ a huge loss !