Swappin' Gears - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Apex Motorsports · 08-17-2013, 04:02 PM

Warning: Installation of rear end gears should only be performed by professionals. As owners of the 5th generation Camaro continue their pursuit of more performance, many are swapping to a more aggressive set of rear end gears. While not an inexpensive modification, the bang for your buck with a rear end gear swap is hard to beat and the improvement in performance is dramatic. Making this sort of modification can be intimidating because many people don’t understand differentials and gearing. In this post I will try to provide some basic information to at least try and help get you pointed in the right direction.

How It Works

The rear differential is the device that transmits torque and rotation from the driveshaft to the rear axles which then drives the rear wheels. The rear end gears contain a ring and pinion gear that can be swapped to different ratios. The stock Camaro comes with either a 3.27 (all V6 models and the automatic SS) or a 3.45 (manual SS) rear end gear ratio. This means that for every 3.27 or 3.45 rotations of the drive shaft your rear wheels will turn once. A lower gear ratio means increased torque and increased acceleration without the engine having to create any additional power.

This all sounds great but the are some potential draw backs. A lower gear ratio means that your engine has to turn faster at cruising speeds which means fuel mileage can suffer. In the case of the 5th generation Camaro, the new six speed transmissions help mitigate the impact of this. Camaro owners that do a lot of highway miles have been reporting a loss of about 1-2 MPG, while those who drive mostly in town are reporting no change and even an increase in some cases due to the engine not having to work as hard to get up to speed.

The other potential draw back is that a lower gear ratio will shave away top end speed. This is not important to the average Joe since the Camaro is capable of speeds well beyond the speed limit right off the showroom floor, but for competitive drag racers it can be. It is possible that while the lower ratio will cause your car to accelerate faster it can also cause you to have to shift gears one more time before you cross the finish line, potentially sacrificing the gains made. Careful calculations should be made when selecting the correct ratio for these sorts of applications.

The Numbers

Camaro V6 Models

Currently, there is only one gear ratios made specifically for the 5th generation V6 Camaro. For the V6 Camaros Richmond manufacturers a 3.55 gear ratio. With the stock 3.27s the automatic (A6) equipped V6 runs 1750 RPM at 70 MPH. Swapping to the 3.55s provides an equivalent torque gain of approximately 10% or 27.3 ld.-ft. of torque and will raise 70 MPH cruising RPM to 1949.

The V6 Camaros equipped with the manual transmission (M6) come with 3.27s and run 2000 RPM at 70 MPH. Swapping to the 3.55s provides an equivalent torque gain of approximately 9% or 27.3 ld.-ft. of torque and will raise 70 MPH cruising RPM to 2167.

The rear end in the M6 equipped V6 Camaro is similar enough to the SS that their gears will also work. Apex Motorsports recently had a customer install Richmond 3.73s in his car. The result was an equivalent torque gain of approximately 15% or 40.95 lb.-ft. of torque and will raise 70 MPH cruising RPM to 2277.

Camaro SS Models

The Camaro SS models currently have three aftermarket gear ratios available for them; 3.73, 3.91, 4.11, and 4.33. When equipped the the automatic transmission (A6) the SS comes with a 3.27 rear end and cruises at 1795 RPM at 70 MPH. By upgrading the factory 3.27s in the stock A6 equipped Camaro SS to the 3.73s you will realize an equivalent torque gain of approximately 15% or 61.5 lb.-ft. of torque and cruise at 2050 RPM at 70 MPH. By upgrading the factory 3.27s in the stock A6 equipped Camaro SS to the 3.91s you will realize an equivalent torque gain of approximately 20% or 82 lb.-ft. of torque and cruise at 2150 RPM at 70 MPH. By upgrading the A6 to the 4.11s you will realize an equivalent torque gain of approximately 27% or 110.7 lb.-ft. of torque and cruise at 2250 RPM at 70 MPH. By upgrading the A6 to the 4.33s you will realize an equivalent torque gain of approximately 33% or 135.3 lb.-ft. of torque and cruise at 2377 RPM at 70 MPH. The A6 transmission is geared more aggressively than the M6 SS so we have found that 3.73 is a great gear for most A6 equipped SS applications.

When equipped with the manual transmission (M6) the SS comes with a 3.45 rear end and cruises at 1612 RPM at 70 MPH. By upgrading the factory 3.45s in the stock M6 equipped Camaro SS to the 3.73s you will realize an equivalent torque gain of approximately 10% or 42 lb.-ft. of torque and cruise at 1750 RPM at 70 MPH. 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. By upgrading the stock M6 equipped Camaro SS to 4.11s you will realize an equivalent torque gain of approximately 20% or 84 lb.-ft. of torque and cruise at 1915 RPM at 70 MPH. By upgrading the stock M6 equipped Camaro SS to 4.33s you will realize an equivalent torque gain of approximately 25% or 105 lb.-ft. of torque and cruise at 2025 RPM at 70 MPH. We have found that the 3.91s and 4.11s are great gear options for most M6 equipped SS street applications. Once the 550-600 rear wheel horsepower range is reached we recommend dialing back to 3.73 unless the vehicle has a very solid suspension package and a very competent driver.

Make It Happen

Hopefully, the information in this post has helped you better understand gear swaps. If you think a gear swap may be right for your project be sure to consult a professional, like the experts at Apex Motorsports, during your decision making process.

MikeMoach · 08-17-2013, 05:30 PM

Great info like always Chase

Ron66Vette&10SS · 08-17-2013, 09:07 PM

I'm no math wiz, but I'm guessing that in an M6 car going to 3.91's over the stock 3.45's would be around 15% gain for approximately 63 more lbs.tq......right?

Apex Motorsports · 08-18-2013, 10:45 AM

Quote:

Originally Posted by MikeMoach

Great info like always Chase

Thanks!

Quote:

Originally Posted by Ron66Vette&10SS

I'm no math wiz, but I'm guessing that in an M6 car going to 3.91's over the stock 3.45's would be around 15% gain for approximately 63 more lbs.tq......right?

It is the weekend and I can't force myself to do the math right now but that is about right.

grocerygetter · 08-18-2013, 05:27 PM

4.33 would rock on a track if u can hook it. Fat car likes gears.

13BlackCamaroSS · 08-18-2013, 08:42 PM

Good info as I am thinking of switching gears. Thanks

Apex Motorsports · 08-19-2013, 07:13 PM

Quote:

Originally Posted by 13BlackCamaroSS

Good info as I am thinking of switching gears. Thanks

Great timing then! Feel free to hit me up if you have any questions.

Stingraye · 08-19-2013, 08:40 PM

Love my 3.91's, they're a great set in an M6 SS

Jason@JacFab · 08-19-2013, 10:27 PM

Nice write up! Should add info about the 2.92 ratio in the 2ls automatic, and perhaps show the mathematical benefit of swapping to even the 3.27 auto v6 gears or the 3.55.

hunterv6 · 08-19-2013, 10:48 PM

Great info

sent form my mini computer note 2

msp2887 · 08-20-2013, 08:09 AM

What do you think of the 3.73 vs. the 3.91 for the A6?

13blackLS · 08-20-2013, 10:06 AM

Quote:

Originally Posted by RacnJsn95

Nice write up! Should add info about the 2.92 ratio in the 2ls automatic, and perhaps show the mathematical benefit of swapping to even the 3.27 auto v6 gears or the 3.55.

Where can i find more info on this? As i have a 2ls...any help or info on where to rwad up on this is greatly appreciated...thanks!

IneedAZ · 08-20-2013, 10:12 AM

Quote:

Originally Posted by msp2887

What do you think of the 3.73 vs. the 3.91 for the A6?

I know yours is a SS and mine is the RS, but i will have a good answer for you tomorrow. I stepped up to 3.73 from 3.27 a few months ago and tomorrow we needed to do a gear swap and only thing on hand is a set of 3.91's. I will post back if i see much of a difference in performance, regular driving, and mpg.

msp2887 · 08-20-2013, 10:21 AM

Quote:

Originally Posted by IneedAZ

I know yours is a SS and mine is the RS, but i will have a good answer for you tomorrow. I stepped up to 3.73 from 3.27 a few months ago and tomorrow we needed to do a gear swap and only thing on hand is a set of 3.91's. I will post back if i see much of a difference in performance, regular driving, and mpg.

Needed to do a gear swap? Were there issues w/ the 3.73s?

08-17-2013, 04:02 PM	#1
Apex Motorsports Drives: 2000 Camaro SS Join Date: Feb 2010 Location: Louisville, Ky. Posts: 25,179	Swappin' Gears Warning: Installation of rear end gears should only be performed by professionals. As owners of the 5th generation Camaro continue their pursuit of more performance, many are swapping to a more aggressive set of rear end gears. While not an inexpensive modification, the bang for your buck with a rear end gear swap is hard to beat and the improvement in performance is dramatic. Making this sort of modification can be intimidating because many people don’t understand differentials and gearing. In this post I will try to provide some basic information to at least try and help get you pointed in the right direction. How It Works The rear differential is the device that transmits torque and rotation from the driveshaft to the rear axles which then drives the rear wheels. The rear end gears contain a ring and pinion gear that can be swapped to different ratios. The stock Camaro comes with either a 3.27 (all V6 models and the automatic SS) or a 3.45 (manual SS) rear end gear ratio. This means that for every 3.27 or 3.45 rotations of the drive shaft your rear wheels will turn once. A lower gear ratio means increased torque and increased acceleration without the engine having to create any additional power. This all sounds great but the are some potential draw backs. A lower gear ratio means that your engine has to turn faster at cruising speeds which means fuel mileage can suffer. In the case of the 5th generation Camaro, the new six speed transmissions help mitigate the impact of this. Camaro owners that do a lot of highway miles have been reporting a loss of about 1-2 MPG, while those who drive mostly in town are reporting no change and even an increase in some cases due to the engine not having to work as hard to get up to speed. The other potential draw back is that a lower gear ratio will shave away top end speed. This is not important to the average Joe since the Camaro is capable of speeds well beyond the speed limit right off the showroom floor, but for competitive drag racers it can be. It is possible that while the lower ratio will cause your car to accelerate faster it can also cause you to have to shift gears one more time before you cross the finish line, potentially sacrificing the gains made. Careful calculations should be made when selecting the correct ratio for these sorts of applications. The Numbers Camaro V6 Models Currently, there is only one gear ratios made specifically for the 5th generation V6 Camaro. For the V6 Camaros Richmond manufacturers a 3.55 gear ratio. With the stock 3.27s the automatic (A6) equipped V6 runs 1750 RPM at 70 MPH. Swapping to the 3.55s provides an equivalent torque gain of approximately 10% or 27.3 ld.-ft. of torque and will raise 70 MPH cruising RPM to 1949. The V6 Camaros equipped with the manual transmission (M6) come with 3.27s and run 2000 RPM at 70 MPH. Swapping to the 3.55s provides an equivalent torque gain of approximately 9% or 27.3 ld.-ft. of torque and will raise 70 MPH cruising RPM to 2167. The rear end in the M6 equipped V6 Camaro is similar enough to the SS that their gears will also work. Apex Motorsports recently had a customer install Richmond 3.73s in his car. The result was an equivalent torque gain of approximately 15% or 40.95 lb.-ft. of torque and will raise 70 MPH cruising RPM to 2277. Camaro SS Models The Camaro SS models currently have three aftermarket gear ratios available for them; 3.73, 3.91, 4.11, and 4.33. When equipped the the automatic transmission (A6) the SS comes with a 3.27 rear end and cruises at 1795 RPM at 70 MPH. By upgrading the factory 3.27s in the stock A6 equipped Camaro SS to the 3.73s you will realize an equivalent torque gain of approximately 15% or 61.5 lb.-ft. of torque and cruise at 2050 RPM at 70 MPH. By upgrading the factory 3.27s in the stock A6 equipped Camaro SS to the 3.91s you will realize an equivalent torque gain of approximately 20% or 82 lb.-ft. of torque and cruise at 2150 RPM at 70 MPH. By upgrading the A6 to the 4.11s you will realize an equivalent torque gain of approximately 27% or 110.7 lb.-ft. of torque and cruise at 2250 RPM at 70 MPH. By upgrading the A6 to the 4.33s you will realize an equivalent torque gain of approximately 33% or 135.3 lb.-ft. of torque and cruise at 2377 RPM at 70 MPH. The A6 transmission is geared more aggressively than the M6 SS so we have found that 3.73 is a great gear for most A6 equipped SS applications. When equipped with the manual transmission (M6) the SS comes with a 3.45 rear end and cruises at 1612 RPM at 70 MPH. By upgrading the factory 3.45s in the stock M6 equipped Camaro SS to the 3.73s you will realize an equivalent torque gain of approximately 10% or 42 lb.-ft. of torque and cruise at 1750 RPM at 70 MPH. 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. By upgrading the stock M6 equipped Camaro SS to 4.11s you will realize an equivalent torque gain of approximately 20% or 84 lb.-ft. of torque and cruise at 1915 RPM at 70 MPH. By upgrading the stock M6 equipped Camaro SS to 4.33s you will realize an equivalent torque gain of approximately 25% or 105 lb.-ft. of torque and cruise at 2025 RPM at 70 MPH. We have found that the 3.91s and 4.11s are great gear options for most M6 equipped SS street applications. Once the 550-600 rear wheel horsepower range is reached we recommend dialing back to 3.73 unless the vehicle has a very solid suspension package and a very competent driver. Make It Happen Hopefully, the information in this post has helped you better understand gear swaps. If you think a gear swap may be right for your project be sure to consult a professional, like the experts at Apex Motorsports, during your decision making process. Last edited by Apex Motorsports; 10-02-2013 at 10:45 AM.

08-17-2013, 09:07 PM	#3
Ron66Vette&10SS Plays with Hot Wheels Drives: '17 Jet Black ZL1 Join Date: Apr 2010 Location: Derby, Kansas Posts: 849	I'm no math wiz, but I'm guessing that in an M6 car going to 3.91's over the stock 3.45's would be around 15% gain for approximately 63 more lbs.tq......right? __________________ Previous Cars: '78 Z28, '92 Z28, '95 Z28, '85 Corvette, '01 SS, '96 Z28, '04 Z06 Corvette, '10 SS, '13 SS Hot Wheels Current Cars: '17 ZL1(daily driver), '04 Trailblazer (rain & snow), '66 Corvette (restoring)

08-18-2013, 05:27 PM	#5
grocerygetter instigator Drives: 2020 6.2 Trail Boss, 2022 XC90 Join Date: Jan 2010 Location: 72034 Posts: 3,979 View My Garage	4.33 would rock on a track if u can hook it. Fat car likes gears. __________________ -John S.

08-18-2013, 08:42 PM	#6
13BlackCamaroSS Drives: 2016 Camaro 2SS Join Date: May 2013 Location: Indiana Posts: 563 View My Garage	Good info as I am thinking of switching gears. Thanks __________________ Race what you brung, Hope you brung enough 2016 2SS, NPP, Adrenaline Red Leather and Pads, 6sp, Sunroof, Black Bowties, Upgraded Wheels, 15% Tint, Kooks Headers, MBRP Exhaust, 1LE Wheels, Badging, Ported Throttle Body, Procharged, Snow Performance Stage 2 Meth Kit Coming Soon: Custom Cam, E85, Ported Heads

08-19-2013, 10:48 PM	#10
hunterv6 Always bet on Black Drives: 2011 turbo LS, 2012 f 150, Join Date: Nov 2010 Location: Concord Nc Posts: 1,983	Great info sent form my mini computer note 2 __________________

08-17-2013, 05:30 PM	#2
MikeMoach Drives: 2010 RJT 2SS/RS Join Date: May 2012 Location: Staten Island, NY Posts: 1,354	Great info like always Chase

08-19-2013, 08:40 PM	#8
Stingraye Drives: 2011 2SS / RS M6 LS3 IBM Join Date: Apr 2011 Location: SE PA Posts: 174 View My Garage	Love my 3.91's, they're a great set in an M6 SS

08-19-2013, 10:27 PM	#9
Jason@JacFab Drives: 2016 1LT RS Camaro; 72 Chevelle Join Date: Apr 2008 Location: Central Point, OR Posts: 5,688 View My Garage	Nice write up! Should add info about the 2.92 ratio in the 2ls automatic, and perhaps show the mathematical benefit of swapping to even the 3.27 auto v6 gears or the 3.55.

08-20-2013, 08:09 AM	#11
msp2887 Drives: 2011 2SS/RS Black Join Date: Feb 2011 Location: Hillsborough, NJ Posts: 233	What do you think of the 3.73 vs. the 3.91 for the A6?