Help me decide (M6 vs. M12)
Thread Starter
Pro
Joined: Dec 2003
Posts: 706
Likes: 46
From: Vienna VA
Help me decide (M6 vs. M12)
I need to replace my transmission (with the RPM Level V) and I’m trying to decide if I should swap with the original M6 or if I go with the M12. I have a 1997 coupe with a 4:10 rear with 420 rwhp. I turn the ¼ mile in 12 seconds (plus or minus a tenth or two) at around 117 – 120 mph.
I am most concerned about having to shift into 5th gear in the ¼ mile? I am right on the hairy edge with my current setup (4:10 rear, M6 tranny, 420 rwhp). Will going with the M12 make it more or less likely that I will need to shift into 5th?
The bottom line is which transmission (the M6 or M12) will help my ¼ mile times with my setup?
Thanks in advance for your advise
I am most concerned about having to shift into 5th gear in the ¼ mile? I am right on the hairy edge with my current setup (4:10 rear, M6 tranny, 420 rwhp). Will going with the M12 make it more or less likely that I will need to shift into 5th?
The bottom line is which transmission (the M6 or M12) will help my ¼ mile times with my setup?
Thanks in advance for your advise
Instructor
Joined: Jan 2008
Posts: 182
Likes: 0
From: mechanicsville maryland
Racer
Joined: Feb 2007
Posts: 328
Likes: 0
From: Orange County California
Instructor
Joined: Jan 2008
Posts: 182
Likes: 0
From: mechanicsville maryland
He will be shifting into every gear sooner as far as on the track..That is what he asked about.. Yes the time that he is in 4th will remain the same, but that is it.. If he shifted before into 5th lets say at the stripe now with the M12 he would be shifting before the stripe..
Instructor
Joined: Jan 2008
Posts: 182
Likes: 0
From: mechanicsville maryland
I would go with the M12 for sure... If you search posts by Robz and read what he has to say, and look at the fast list look at the 60 foots, ets, and trap speeds of the zo6s compared to the coupes with similar HP.. What tires are you using? By the trap and HP you posted you "should" be running faster than 12s, of course that is all relative.
Le Mans Master
Joined: Aug 2005
Posts: 5,130
Likes: 3
From: Winter Park FL
Like I said in my post in the performance section.......no real difference in ET. You might see a better 60' with the M12 but it will give its gains back to the M6 in 4th gear. It will pretty much be a wash.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Burning Brakes
Joined: Oct 2004
Posts: 931
Likes: 35
From: Rowlett, Texas
I agree with EGL. the M12 is geared about 12% lower in 1st, probably too low with the 4.10 diff. The MN6 is a close-ratio box, and M12 a wider ratio box. Racers of all types usually prefer a close-ratio to keep the average power under the curve higher as you go up through the gears. So, both off the line, and through the gears the MN6 seems the better of the two.
Yes, the 4th gear on both is 1.00, so the shift to 5th would occur at exactly the same place and time (assuming no advantege was gained by either tranny in 1st,2d, or 3rd).
BUT, the MN12 does have a lower (closer ratio) 5th, so it would pull a bit harder if it had to be used.
DG
Yes, the 4th gear on both is 1.00, so the shift to 5th would occur at exactly the same place and time (assuming no advantege was gained by either tranny in 1st,2d, or 3rd).
BUT, the MN12 does have a lower (closer ratio) 5th, so it would pull a bit harder if it had to be used.
DG
Racer
Joined: Feb 2007
Posts: 328
Likes: 0
From: Orange County California
Yes, the 4th gear on both is 1.00, so the shift to 5th would occur at exactly the same place and time (assuming no advantege was gained by either tranny in 1st,2d, or 3rd).
BUT, the MN12 does have a lower (closer ratio) 5th, so it would pull a bit harder if it had to be used.
DG
BUT, the MN12 does have a lower (closer ratio) 5th, so it would pull a bit harder if it had to be used.
DG
