Gear Ratios
Thread Starter
Burning Brakes
Joined: Mar 2010
Posts: 921
Likes: 134
From: Chicago Illinois
Gear Ratios
Sorry for the noob question but after reading many posts, I see references to gear ratios. Don't really need a super detailed explanation but I want to know what effect it has on performance.
I was looking at the build sheet for my 03 AE 6sp Vert and it said it had a rear axle 3.42. Is that good, bad?
Just trying to get in touch with my inner vette-ness and not sound like a total dweeb when talking to friends about my newly acquired baby.
Thanks,
Les
I was looking at the build sheet for my 03 AE 6sp Vert and it said it had a rear axle 3.42. Is that good, bad?
Just trying to get in touch with my inner vette-ness and not sound like a total dweeb when talking to friends about my newly acquired baby.
Thanks,
Les
Le Mans Master
Joined: Feb 2007
Posts: 9,296
Likes: 1,531
From: Oviedo Florida
2024 C5 of the Year Finalist - Modified
2024 C2 of the Year Finalist - Modified
2023 C2 of the Year Finalist - Modified
2021 C2 of the Year Finalist - Modified
2016 C5 of Year Finalist
Sorry for the noob question but after reading many posts, I see references to gear ratios. Don't really need a super detailed explanation but I want to know what effect it has on performance.
I was looking at the build sheet for my 03 AE 6sp Vert and it said it had a rear axle 3.42. Is that good, bad?
Just trying to get in touch with my inner vette-ness and not sound like a total dweeb when talking to friends about my newly acquired baby.
Thanks,
Les
I was looking at the build sheet for my 03 AE 6sp Vert and it said it had a rear axle 3.42. Is that good, bad?
Just trying to get in touch with my inner vette-ness and not sound like a total dweeb when talking to friends about my newly acquired baby.
Thanks,
Les
the mpg will be less. If you had a 273 your mpg would be better.
Higher numbers are really for 1/4 mile folks and dont worry about
that. If you are interested in this there is lots of reading material.
Use your computer or library and you will learn all about how to be a
1/4 mile (or 1/8) racer. Good luck.
I am sure some else will help me out trying to explain this
complicated subject in a couple of sentences. Sometimes I know
to much for my own good.
Melting Slicks
Joined: Jan 2004
Posts: 3,012
Likes: 15
From: Jensen Beach FL
Your 3:42 is the standard gear ratio for a 6 speed transmission. It is great for fuel consumption but leaves a lot to be desired for performance. C5's with the Z51 performance option has a different transmission gear ratio but the rear is still a 3:42. That gearing is better in gears 1 and 2 and maybe 3 (not sure) but about the same as non Z51 in other gears. Many C5 owners change the differential to 3:90 or 4:10's for better performance. The cost in fuel consumption is about 2 mpg but the performance gain is about 1/2 second in the 1/4 mile. It is also much nicer to drive with the performance gears. There is no bogging, or clutch noise when taking off and the power is immediate. You also use 6th gear in everyday driving. I usually use 1, 3 and 5th or 6th in normal driving with my 4:10's. Also I take off from 2nd if not completely stopped.
Safety Car
Joined: Nov 2000
Posts: 4,419
Likes: 6
From: Arroyo Grande CA
Your 3:42 is the standard gear ratio for a 6 speed transmission. It is great for fuel consumption but leaves a lot to be desired for performance. C5's with the Z51 performance option has a different transmission gear ratio but the rear is still a 3:42. That gearing is better in gears 1 and 2 and maybe 3 (not sure) but about the same as non Z51 in other gears. Many C5 owners change the differential to 3:90 or 4:10's for better performance. The cost in fuel consumption is about 2 mpg but the performance gain is about 1/2 second in the 1/4 mile. It is also much nicer to drive with the performance gears. There is no bogging, or clutch noise when taking off and the power is immediate. You also use 6th gear in everyday driving. I usually use 1, 3 and 5th or 6th in normal driving with my 4:10's. Also I take off from 2nd if not completely stopped.
I thought the Z51 with the manual has the same transmission ratios as the non-Z51 manual. It's the Z06 that has the different tranny ratios.
The Z51 with the auto comes with the 3.15 RE vs the standard 2.73 RE on the non Z51 autos.
AMP Racing
Joined: Aug 2006
Posts: 10,755
Likes: 589
From: Washington TWP NJ
2023 C5 of the Year Finalist - Modified
2017 C5 of Year Finalist
St. Jude Donor '09-'10-'11-'12
OP,
The only gear available in a manual trans vette is the 3.42
The auto cars had either a 2.73 or a 3.15
The higher the number the lower the gearing of the fiinal drive and the easier it is to start from a stop - this is why drag racers like 3.90 and 4.10 gears - as mentioned above.
Gas mileage will suffer from changing gears - some (like me) dont care, and just love the way the car responds on the street and the track.
Changing the gear is available in basically two ways,
buying a complete differential, or
having a set installed in your differential.
The swap can be done in a day by an experienced installer.
Good luck, welcome to the C5 vette world. Feel free to ask any questions here, as there are a lot of very smart people here
Melting Slicks
Joined: Apr 2003
Posts: 2,285
Likes: 16
From: Nashville TN
like they said the 3.42 is the stock gear with a 6speed. It is a good all around gear. However many people change to a 3.73, 3.90, or 4.10. These gears provide better acceleration with slightly worse gas mileage. Many people overlook gears when seeking better performance, yet it is arguably the one area where you can get the most gain. 3.73s or 3.90s make the car drive completely different. Its a great mod.
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Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
Other issues to consider when going lower than the stock 3.42's
Lower gears will make the car launch very hard---traction becomes an issue--often you won't pick up much ET's without getting drag radials becuase the car just spins more--
Also lower gears will "shock" the drivetrain more--at launch--things are more suspect to breaking---usually the output shafts will break and you'll have to install meaner aftermarket ones--more $$$ --- If your car is hopping when lauched you WILL break them sooner or later---tell tale sign--
Lower gears will make the car launch very hard---traction becomes an issue--often you won't pick up much ET's without getting drag radials becuase the car just spins more--
Also lower gears will "shock" the drivetrain more--at launch--things are more suspect to breaking---usually the output shafts will break and you'll have to install meaner aftermarket ones--more $$$ --- If your car is hopping when lauched you WILL break them sooner or later---tell tale sign--
Safety Car
Joined: Oct 2004
Posts: 4,816
Likes: 132
From: Plano TX
Your 3:42 is the standard gear ratio for a 6 speed transmission. It is great for fuel consumption but leaves a lot to be desired for performance. C5's with the Z51 performance option has a different transmission gear ratio but the rear is still a 3:42. That gearing is better in gears 1 and 2 and maybe 3 (not sure) but about the same as non Z51 in other gears. Many C5 owners change the differential to 3:90 or 4:10's for better performance. The cost in fuel consumption is about 2 mpg but the performance gain is about 1/2 second in the 1/4 mile. It is also much nicer to drive with the performance gears. There is no bogging, or clutch noise when taking off and the power is immediate. You also use 6th gear in everyday driving. I usually use 1, 3 and 5th or 6th in normal driving with my 4:10's. Also I take off from 2nd if not completely stopped.
The Z51 performance option does not offer a different transmission with different ratios.. The M6 manual is the same in all C5's The Z06 has an M12 transmission with a 3.42 axle ratio. This is the transmission with better (more aggresive) gearing in gears 1-3.. Again this transmission (M12) is exclusive to only the Z06 and was the only transmission available in a Z06.. The (M6) 6 speed was put in all other C5 Corvettes regardless of option packages.
Last edited by David426; Aug 29, 2010 at 04:28 PM.
Advanced
Joined: Oct 2000
Posts: 56
Likes: 0
From: Sterling, VA, USA
this is correct.
OP,
The only gear available in a manual trans vette is the 3.42
The auto cars had either a 2.73 or a 3.15
The higher the number the lower the gearing of the fiinal drive and the easier it is to start from a stop - this is why drag racers like 3.90 and 4.10 gears - as mentioned above.
Gas mileage will suffer from changing gears - some (like me) dont care, and just love the way the car responds on the street and the track.
Changing the gear is available in basically two ways,
buying a complete differential, or
having a set installed in your differential.
The swap can be done in a day by an experienced installer.
Good luck, welcome to the C5 vette world. Feel free to ask any questions here, as there are a lot of very smart people here
OP,
The only gear available in a manual trans vette is the 3.42
The auto cars had either a 2.73 or a 3.15
The higher the number the lower the gearing of the fiinal drive and the easier it is to start from a stop - this is why drag racers like 3.90 and 4.10 gears - as mentioned above.
Gas mileage will suffer from changing gears - some (like me) dont care, and just love the way the car responds on the street and the track.
Changing the gear is available in basically two ways,
buying a complete differential, or
having a set installed in your differential.
The swap can be done in a day by an experienced installer.
Good luck, welcome to the C5 vette world. Feel free to ask any questions here, as there are a lot of very smart people here
AMP Racing
Joined: Aug 2006
Posts: 10,755
Likes: 589
From: Washington TWP NJ
2023 C5 of the Year Finalist - Modified
2017 C5 of Year Finalist
St. Jude Donor '09-'10-'11-'12
When changing the gear ratio in the differential on a C5 corvette, the rear cradle has to come out of the car. As does the exhaust h-pipe (or x-pipe) and the tunnel plate.
The axles slide out of the differential and the differential unbolts from the transmission. Then the shop (I hope you chose a good one) takes the diff apart and installs your new ring and pinion.
It's not really an "easy" job, but not really hard either - it just takes time. Which is why you can save a bit of money by taking the diff out yourself and bringing it to a shop to be built.
Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
Your 3:42 is the standard gear ratio for a 6 speed transmission. It is great for fuel consumption but leaves a lot to be desired for performance. C5's with the Z51 performance option has a different transmission gear ratio but the rear is still a 3:42. That gearing is better in gears 1 and 2 and maybe 3 (not sure) but about the same as non Z51 in other gears. Many C5 owners change the differential to 3:90 or 4:10's for better performance. The cost in fuel consumption is about 2 mpg but the performance gain is about 1/2 second in the 1/4 mile. It is also much nicer to drive with the performance gears. There is no bogging, or clutch noise when taking off and the power is immediate. You also use 6th gear in everyday driving. I usually use 1, 3 and 5th or 6th in normal driving with my 4:10's. Also I take off from 2nd if not completely stopped.
http://www.c5registry.com/zo6/hib/page4.htm
Melting Slicks
Joined: Mar 2008
Posts: 2,962
Likes: 254
From: Richmond, Ky
It's sometimes amazing to me that info is posted on the "tech" board that is just incorrect. To make statements on the general board where discussion is often opinion, the occasional slip of a more technical nature is not all that uncommon. But to me, if you are going to post on the tech board you should either know what you're talking about or preface your statements with, I believe, I'm pretty sure, or I could be mistaken but.....
I am far from an expert in all things Corvette and I learn more every day much of it gleaned from these forums. There is a wealth of knowledge to be shared by everyone but it behooves us to have our facts straight if we are going to present them as such. Now down from my soapbox and back to the cheap seats.
I am far from an expert in all things Corvette and I learn more every day much of it gleaned from these forums. There is a wealth of knowledge to be shared by everyone but it behooves us to have our facts straight if we are going to present them as such. Now down from my soapbox and back to the cheap seats.
Melting Slicks
Joined: Jan 2004
Posts: 3,012
Likes: 15
From: Jensen Beach FL
The M12 transmission option was only available on the Z06.
http://www.c5registry.com/zo6/hib/page4.htm
http://www.c5registry.com/zo6/hib/page4.htm
M12 transmission.
Intermediate
Joined: Jul 2011
Posts: 42
Likes: 1
From: Bonney Lake, Washington
Does the 1999 FRC have a MN6 or a M12 transmission
The Z51 performance option does not offer a different transmission with different ratios.. The M6 manual is the same in all C5's The Z06 has an M12 transmission with a 3.42 axle ratio. This is the transmission with better (more aggresive) gearing in gears 1-3.. Again this transmission (M12) is exclusive to only the Z06 and was the only transmission available in a Z06.. The (M6) 6 speed was put in all other C5 Corvettes regardless of option packages.Thanks
Don
Race Director
Joined: Dec 2006
Posts: 12,383
Likes: 2,905
From: Fort Worth, Texas
The FRC has the same trans gear ratios as the base C5, not the C5Z ratios that are also in the GTO.
