Help with gear ratio.
Thread Starter
Melting Slicks
Joined: Sep 2008
Posts: 2,286
Likes: 4
Help with gear ratio.
I have an 05 automatic with an A4. It is the Z51 so it has the 3.15 rear now.
It has a Cow tune which helped it immensely. I have LT headers and an X-pipe as well.
I may track it soon but this is 99.9% of the time a daily driver.
Should I go with a 3.90, 3.73 or 3.42?
I have done some research and looked at the C5 forums for help as well as they have my tranny.
What say you all???
Jeff
It has a Cow tune which helped it immensely. I have LT headers and an X-pipe as well.
I may track it soon but this is 99.9% of the time a daily driver.
Should I go with a 3.90, 3.73 or 3.42?
I have done some research and looked at the C5 forums for help as well as they have my tranny.
What say you all???
Jeff
Last edited by Justasheet; Apr 3, 2010 at 09:24 AM.
Melting Slicks
Joined: Nov 2005
Posts: 2,345
Likes: 2
From: Houston 06 C6 Ysi SC 402 fgd TX
my experience with manual 06 Z51 with 3.42 going to 4.10. on the street lots more shifting in bumper to bumper driving. the handy tool for manuals though it Z51-3.90 and stock-4.10
on the road track(no autox) since I am just starting it didnt make much difference. i concentrated on the "line" more than anything and i kept it in 4th pretty much.
so IMO if you are 99.9% street, why do it?
if you are 99.9% performance then its a great mod.
on the road track(no autox) since I am just starting it didnt make much difference. i concentrated on the "line" more than anything and i kept it in 4th pretty much.
so IMO if you are 99.9% street, why do it?
if you are 99.9% performance then its a great mod.
Melting Slicks
Joined: Jan 2005
Posts: 2,326
Likes: 5
From: louisville "derby city" kentucky
save your money on the rear gear. get a yank torque converter. you won't believe the difference. best of all, your street driving will still give you great gas milage still. you will need to add a trans cooler, but that is no problem. 
Thread Starter
Melting Slicks
Joined: Sep 2008
Posts: 2,286
Likes: 4
The Z51 automatic's have a trans. cooler unless I'm mistaken.
Thanks,
Jeff
Thread Starter
Melting Slicks
Joined: Sep 2008
Posts: 2,286
Likes: 4
my experience with manual 06 Z51 with 3.42 going to 4.10. on the street lots more shifting in bumper to bumper driving. the handy tool for manuals though it Z51-3.90 and stock-4.10
on the road track(no autox) since I am just starting it didnt make much difference. i concentrated on the "line" more than anything and i kept it in 4th pretty much.
so IMO if you are 99.9% street, why do it?
if you are 99.9% performance then its a great mod.
on the road track(no autox) since I am just starting it didnt make much difference. i concentrated on the "line" more than anything and i kept it in 4th pretty much.
so IMO if you are 99.9% street, why do it?
if you are 99.9% performance then its a great mod.
Team Owner
Joined: Feb 2001
Posts: 27,254
Likes: 136
From: Short Hills, NJ
Yank, Precision Industries (aka: Vigilante), FTI, all good higher stall torque converters. 
Yes they do,
but I also believe that all automatic C6s have that same transmission cooler (located within the radiator) meaning that it's no larger or any more special on the Z51 cars than it is on the base or F55 automatics even though it's sort of listed that way when looking at the specs for the Z51 package.Either way, an aftermarket/auxiliary cooler is still recommended when installing a higher stall torque converter, especially if doing any kind of racing and/or spirited driving on very hot days.
3.42s work also but in my opinion just aren't enough of a jump up from the 3.15s to justify the cost...3.90s are great for performance and are still streetworthy but some find them to be more noisey and much less fuel efficient on longer highway trips.
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Team Owner
Joined: Feb 2001
Posts: 27,254
Likes: 136
From: Short Hills, NJ
All 2006 and 2007 automatic Corvettes came from the factory with 2.56 gears and there was no other ratio optional/available.
Thread Starter
Melting Slicks
Joined: Sep 2008
Posts: 2,286
Likes: 4
Yank, Precision Industries (aka: Vigilante), FTI, all good higher stall torque converters. Yes they do,
but I also believe that all automatic C6s have that same transmission cooler (located within the radiator) meaning that it's no larger or any more special on the Z51 cars than it is on the base or F55 automatics even though it's sort of listed that way when looking at the specs for the Z51 package.Either way, an aftermarket/auxiliary cooler is still recommended when installing a higher stall torque converter, especially if doing any kind of racing and/or spirited driving on very hot days.
But if you're still set on doing gears (and yes, they do help whether you install an aftermarket converter or not) I would recommend the 3.73s in your case, they make for an awesome combination of street and track performance machine.
3.42s work also but in my opinion just aren't enough of a jump up from the 3.15s to justify the cost...3.90s are great for performance and are still streetworthy but some find them to be more noisey and much less fuel efficient on longer highway trips.
Jeff
Thread Starter
Melting Slicks
Joined: Sep 2008
Posts: 2,286
Likes: 4
Jeff
Team Owner
Joined: Feb 2001
Posts: 27,254
Likes: 136
From: Short Hills, NJ
Thread Starter
Melting Slicks
Joined: Sep 2008
Posts: 2,286
Likes: 4
Labor was less although I still got charged for the install of the Yank. I was told that the tranny had to be partially disassembled for it. The good thing is that they're changing the tranny fluid while they're there too.
Last edited by Justasheet; Apr 5, 2010 at 06:52 PM.