Differential Gearing - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

donnieslagle · 11-08-2015, 08:16 PM

Anybody switched out the stock M6 differential ring and pinion for a 3.90:1? Curious how much difference it made. Of course, I know it will affect fuel mileage, but I rarely use 6th gear anyways. Thinking about gearing it down a little to get the RPM's up during normal cruising speeds.

Thoughts or experiences?

Thanks

olblue75 · 11-08-2015, 08:36 PM

It's a awesome MOD the 3:91s make the car feel lighter and more responsive especially coupled with each Z/28 intake. 1st gear shift is kind of quick compared to the 3:45 but 2nd and up is a blast. It only increases rpms minimally and gas mileage will suffer for awhile to you get tired of hammering on it LOL!!! I got about 500 and will be changing the fluid soon along with the tranny fluid....

donnieslagle · 11-09-2015, 06:50 AM

I was thinking about 3.91 or 4.11 but I've read where some guys have had a lot of problems with the 4.11. I thought the 4.11's would be neck snappers but they may snap something else too!

christianchevell · 11-09-2015, 07:49 AM

our differentials are not that large with our gears size being like 8.6" so the smaller the gear teeth you go the more prone to breakage .... But lots of guys on here have done 3.91's as the price is right and I may do them someday myself.... Or rather have the best rear end shop around here do it that is then get my tuner to dial in the speedometer. Many will say its a real kick in the pants, and I know gm installs and warranties the 3.91s if you want to pay them more.....

Apex Motorsports · 11-09-2015, 09:38 AM

Swapping to 3.91s in the manual SS has become extremely popular. Short of adding a supercharger it is the best bang for your buck performance upgrade you can do. By upgrading the stock M6 equipped Camaro SS to 3.91s you will realize an equivalent torque gain of approximately 13% or 54.6 lb.-ft. of torque and cruise at 1800 RPM at 70 MPH (versus 1600 stock). With these 6 speed transmission and 2 over drive gears most people only see about a 2 MPG loss, however, we have had a few customers that only use their cars for cruising in town actually see a slight improvement in fuel economy because the engine doesn't have to work as hard to get moving.

paul84043 · 11-09-2015, 07:24 PM

The lower you gear, the smaller that pinion gets.. You need a pretty good reason to take up a mod like this.. It's can get pretty involved.

Sandor · 11-10-2015, 07:02 PM

Quote:

Originally Posted by donnieslagle

I was thinking about 3.91 or 4.11 but I've read where some guys have had a lot of problems with the 4.11. I thought the 4.11's would be neck snappers but they may snap something else too!

It's a great mod, you'll definitely feel a difference. Here's the info from Chevrolet Performance:

http://www.chevrolet.com/performance...s/1le-zl1.html

11-08-2015, 08:16 PM	#1
donnieslagle Drives: 2011 Camaro SS1 Join Date: Jan 2013 Location: United States Posts: 13 View My Garage	Differential Gearing Anybody switched out the stock M6 differential ring and pinion for a 3.90:1? Curious how much difference it made. Of course, I know it will affect fuel mileage, but I rarely use 6th gear anyways. Thinking about gearing it down a little to get the RPM's up during normal cruising speeds. Thoughts or experiences? Thanks

11-09-2015, 07:49 AM	#4
christianchevell old school chevy rodder Drives: 2013 2SS/RS Manual,DM exhaust,CRT Join Date: Jul 2012 Location: Oregon Posts: 5,587 View My Garage	our differentials are not that large with our gears size being like 8.6" so the smaller the gear teeth you go the more prone to breakage .... But lots of guys on here have done 3.91's as the price is right and I may do them someday myself.... Or rather have the best rear end shop around here do it that is then get my tuner to dial in the speedometer. Many will say its a real kick in the pants, and I know gm installs and warranties the 3.91s if you want to pay them more..... __________________ 2021 Wild Cherry ZL1 A10, Sunroof, Data, Carbon, Nav, RotoFab Dry CAI, Elite x2, Borla ATK, Driveshaft shop

11-08-2015, 08:36 PM	#2
olblue75 Drives: 2010 2SS/RS Join Date: Dec 2009 Location: Clarksville Tennesse. Posts: 6,064	It's a awesome MOD the 3:91s make the car feel lighter and more responsive especially coupled with each Z/28 intake. 1st gear shift is kind of quick compared to the 3:45 but 2nd and up is a blast. It only increases rpms minimally and gas mileage will suffer for awhile to you get tired of hammering on it LOL!!! I got about 500 and will be changing the fluid soon along with the tranny fluid....

11-09-2015, 06:50 AM	#3
donnieslagle Drives: 2011 Camaro SS1 Join Date: Jan 2013 Location: United States Posts: 13 View My Garage	I was thinking about 3.91 or 4.11 but I've read where some guys have had a lot of problems with the 4.11. I thought the 4.11's would be neck snappers but they may snap something else too!

11-09-2015, 09:38 AM	#5
Apex Motorsports Drives: 2000 Camaro SS Join Date: Feb 2010 Location: Louisville, Ky. Posts: 25,179	Swapping to 3.91s in the manual SS has become extremely popular. Short of adding a supercharger it is the best bang for your buck performance upgrade you can do. By upgrading the stock M6 equipped Camaro SS to 3.91s you will realize an equivalent torque gain of approximately 13% or 54.6 lb.-ft. of torque and cruise at 1800 RPM at 70 MPH (versus 1600 stock). With these 6 speed transmission and 2 over drive gears most people only see about a 2 MPG loss, however, we have had a few customers that only use their cars for cruising in town actually see a slight improvement in fuel economy because the engine doesn't have to work as hard to get moving.

11-09-2015, 07:24 PM	#6
paul84043 Drives: 2015 Camaro 2SS RS 1LE Join Date: Nov 2011 Location: Lehi, Utah Posts: 1,349 View My Garage	The lower you gear, the smaller that pinion gets.. You need a pretty good reason to take up a mod like this.. It's can get pretty involved.