Go Back   Corvette Forum > C5 Corvettes, 1997 - 2004 > C5 Tech
Sign in using an external account
Register Forgot Password?
Register Search Today's Posts Mark Forums Read FAQ Vendor Directory
Search
C5 Tech
Corvette Tech/Performance: LS1 Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace Sponsored by
Karl Chevrolet

Welcome to Corvetteforum.com!
Welcome to Corvetteforum.com.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join Corvetteforum.com today!


Corvette Store
 
 
C7 Parts & Accessories
C6 Parts & Accessories
C5 Parts & Accessories
C4 Parts & Accessories
C3 Parts & Accessories
C2 Parts & Accessories
C1 Parts & Accessories
Wheels & Tires
Sponsored Ads
 
 
Vendor Directory
  
Reply
 
 
 
 
Thread Tools Search this Thread
Old 04-22-2012, 10:23 PM   #1
fotoboy
CF Senior Member
 
fotoboy's Avatar
 
Member Since: Oct 2004
Default Converting to a mn6 from a mn12

I have a buddy w a c5zo6 w a 441 ci putting down around 580 to the wheels. He is looking to convert to a mn6 for road racing. What all is involved with converting to a mn6 from a mn12?
fotoboy is offline   Reply With Quote
Old 04-22-2012, 10:39 PM   #2
8VETTE7
CF Senior Member
 
8VETTE7's Avatar
 
Member Since: Jul 2007
Default

Quote:
Originally Posted by fotoboy View Post
I have a buddy w a c5zo6 w a 441 ci putting down around 580 to the wheels. He is looking to convert to a mn6 for road racing. What all is involved with converting to a mn6 from a mn12?
The ONLY difference is the gear ratio's. If you have access to a good Mn6 just swap tranny's. It's a simple swap. If you want to just swap gear then it gets to be fun since you get to disassemble the box.

Here 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...............0.56
Rev....1.91...............3.28
8VETTE7 is offline   Reply With Quote
Old 04-23-2012, 07:49 AM   #3
AU N EGL
CF Senior Member
 
AU N EGL's Avatar
 
Member Since: Sep 2003
Location: Raleigh / Rolesville NC
Default

Not a big deal. many guys take out the MN12 for an MN6 or have it rebuilt
RPM trans can do it.

But use a .84 5th gear and a .75 or .6 for 6th gear

Dog rings are nice too, no lift shift
AU N EGL is offline   Reply With Quote
Old 04-23-2012, 11:09 AM   #4
jjtoma
CF Senior Member
Support Corvetteforum!
 
jjtoma's Avatar
 
Member Since: Jul 2009
Location: Sarasota,FL & NW Indiana
Default

Quote:
Originally Posted by fotoboy View Post
I have a buddy w a c5zo6 w a 441 ci putting down around 580 to the wheels. He is looking to convert to a mn6 for road racing.
For a road racer, should look at the ZR1 gear ratios also:

ME2 --------2012 stock
1st - 2.26
2nd - 1.58
3rd - 1.18
4th - 1.00
5th - 0.71
6th - 0.50

MH3----------2009-2011(2012 w/ PDE)
1st - 2.29
2nd- 1.61
3rd - 1.21
4th - 1.00
5th - 0.81
6th - 0.67

I think these are correct, best to call RPM Transmissions for answers

IMHO

Jim

Last edited by jjtoma; 04-23-2012 at 11:28 AM.
jjtoma is offline   Reply With Quote
Old 04-23-2012, 11:27 AM   #5
ysb02
CF Senior Member
 
Member Since: Aug 2008
Location: Austin TX
Default

Quote:
Originally Posted by AU N EGL View Post
Not a big deal. many guys take out the MN12 for an MN6 or have it rebuilt
RPM trans can do it.

But use a .84 5th gear and a .75 or .6 for 6th gear

Dog rings are nice too, no lift shift


If I get my MN12 refreshed I'm going with MN6 1-4 and MN12 5-6 gears. Not interested in pulling 200mph in 5th, I'd rather have useability.
ysb02 is offline   Reply With Quote
Old 04-23-2012, 12:54 PM   #6
AU N EGL
CF Senior Member
 
AU N EGL's Avatar
 
Member Since: Sep 2003
Location: Raleigh / Rolesville NC
Default

ZR1 gear ratio is too close together for that much HP
AU N EGL is offline   Reply With Quote
Old 04-23-2012, 01:10 PM   #7
Tech
CF Senior Member
 
Tech's Avatar
 
Member Since: Jun 2005
Location: St. Louis Missouri
Default

Quote:
Originally Posted by AU N EGL View Post
Not a big deal. many guys take out the MN12 for an MN6 or have it rebuilt
RPM trans can do it.

But use a .84 5th gear and a .75 or .6 for 6th gear

Dog rings are nice too, no lift shift
Funny that GM put the MN12 in there to make the car seem more like a track car. Then, the track guys take it out in favor of the Coupe transmission. Are the guys doing the swap still around the same power level as stock?
Tech is offline   Reply With Quote
Old 04-23-2012, 01:59 PM   #8
Rick@RKT56
Supporting Vendor
St. Jude Donor '08-'09-'10-'11-'12, '14
 
Rick@RKT56's Avatar
 
Member Since: Apr 2011
Location: Frederick Maryland
pages/RKT56/244463478927497 rktperformance
Default

First of all, let's get the RPO's right.

MN6 is the code for the manual transmission option.
MM6 is the 2.66 first gear T56.
M12 is the Z06 2.97 first gear T56.

Quote:
Originally Posted by ysb02 View Post


If I get my MN12 refreshed I'm going with MN6 1-4 and MN12 5-6 gears. Not interested in pulling 200mph in 5th, I'd rather have useability.
The M12 AND MM6 share the EXACT same 5/6 gears. The difference in ratio is the head gear reduction and NOT the 5/6 gears.

TR6060 transmissions can be set up for any combinations on the overdrive.
__________________

Rick@RKT56 is offline   Reply With Quote
Old 04-23-2012, 02:10 PM   #9
AU N EGL
CF Senior Member
 
AU N EGL's Avatar
 
Member Since: Sep 2003
Location: Raleigh / Rolesville NC
Default

Quote:
Originally Posted by Tech View Post
Funny that GM put the MN12 in there to make the car seem more like a track car. Then, the track guys take it out in favor of the Coupe transmission. Are the guys doing the swap still around the same power level as stock?
YES. the Zr1 gear ratio ( modeled after the GM Motorsports gear box) would be the ideal choice for a road course with a 3.73 or 3.90 gear.

On the ZR1 it is also very good, but north of 580 to the ground, that is wheel speed or could be in each gear

Hell I only run 400 to the ground and I can wheel speed in 3 gears.

the MN12 was to get better Zero to 60 times, the MN12 3-4 is a great combo, but the 2-3 is too much of a jump.

part of the other challenge is with the MN12, 3rd is too high for many low speed corners,but 2nd is too low, where the mn6 3rd is just a better gear for many corners.
AU N EGL is offline   Reply With Quote
Old 04-23-2012, 02:10 PM
 
Go Back   Corvette Forum > C5 Corvettes, 1997 - 2004 > C5 Tech
Reload this Page Converting to a mn6 from a mn12
 
 
 
Reply

Tags
2003, 373, drag, gear, mn12, speed


Thread Tools Search this Thread
Search this Thread:

Click for Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB: MN6 MN12 mainshaft Formulized94 C5 Parts for Sale/Wanted 4 05-21-2013 08:44 PM
WTB- MN6 or MN12 Transmission 99SoCalFRC C5 Parts for Sale/Wanted 0 10-29-2007 02:11 AM
MN6 vs MN12 Questions DRR C5 Tech 19 05-03-2005 10:26 AM
Different CAGS defeat for MN6/MN12? JasonS C5 Tech 2 11-17-2004 09:00 AM


All times are GMT -4. The time now is 08:26 AM.


Emails & Password Backup