Added 3.91 gears - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

TECHTURTLE · 11-03-2014, 12:54 PM

I swapped to a 1LE 3.91 differential over the weekend and WOW, what a difference.

If you are on the fence about making the change, I can now say go for it. I kept reading that the car would feel 300 lbs lighter and wondered "WTF does that mean?" well it means "Holy crap, I'm shifting already... I wasn't even getting on her." acceleration just comes.

If you swap the entire differential, DIY is a level 3 out of 10. Anyone with a jack, jack stands and a Craftsman tool set can do it. 18mm wrench and sockets, breaker bar, torque wrench, and a few other tool are all you need. BTW my 2013 needed a 36 mm socket for the rear axle nuts.

feel free to ask questions.

TECHTURTLE · 11-03-2014, 01:01 PM

BTW... I'm a 6 speed manual if you were wondering.

ChrisBlair · 11-03-2014, 06:26 PM

Only reason I'm on the fence is that I drive the car in snow. We had a few actual blizzards recently and my SS is perfectly capable as it is in snowy conditions that after 43 years in New England, I'd call "bad".

But now you know why a rear gear change has been such a popular upgrade for many years

I'm sure that the...what is it, 13% increase in torque multiplication makes the car really wake up. First thing I thought when I drove an LS3 Camaro: "Not bad. Needs 50 more lb/ft across the rev range though"

TECHTURTLE · 11-03-2014, 08:47 PM

Not enough snow down here to justify at set of snow tires, so if it snows the Camaro will stay in the garage. I found out last year that P-zeros and snow don't mix.

Another plus to the gear change is that the RPM increase got rid of the drone from the GM Performance exhaust. It was right at 70 mph.

Tenring · 11-03-2014, 09:06 PM

Oh man I really want to do this but I am stuck working on the kids cars right now.

45thCamaro · 11-03-2014, 09:44 PM

This is also on my wish list. I know I'm not in the same boat as many of you with the v8 but this should certainly make the car more interesting.

TECHTURTLE · 11-10-2014, 11:16 AM

Just had MTI Racing in Marietta re-calibrate the speedometer for the 3.91 gears. It took them less than an hour for me to be in and out... Great group of guys there, and I highly recommend them if you need any work.

Anyway, it looks like a 200 RPM increase at 70 MPH. I reset the fuel economy to see what the difference is going to be . Before resetting I was at 20.6 MPG, I'll give it a week and report back.

Josh @ Spartan LSX · 11-10-2014, 10:43 PM

The 3.91 is the ONLY gear we'll install in the 5th gen Camaro's now. All the other ratio's & brands have problems but the GM 3.91 is perfect. We've got 3 cars in the shop getting 3.91's installed as I type this, including an LLT car.

One of the best mods for the money.

Compromis/sed · 11-12-2014, 11:26 PM

Congrats on the upgrade. This is on my short list of next mods.

TECHTURTLE · 11-13-2014, 08:58 AM

Thanks, so far I'm loving them.

As of right now my average fuel economy is sitting at 19.3 MPG but I still have some highway miles to put on to get a good average. I was at 20.6 before resetting.

ATL Muscle · 11-13-2014, 10:07 AM

Where did you get the Diff from?

TECHTURTLE · 11-13-2014, 10:28 AM

I bought it from a guy here in the classified section, it came off of a 1LE he was working on. $1000.00 plus 65 shipping. Then I sold mine for 700.

ATL Muscle · 11-13-2014, 10:30 AM

Awww man! $365 upgrade. That's cheaper than buying the gears and putting it in yourself!

TECHTURTLE · 11-13-2014, 10:36 AM

Yeah, it was a pretty sweet deal... I did the swap myself but did have to pay another 200 for the speedo recal.

11-03-2014, 12:54 PM	#1
TECHTURTLE Drives: 2016 Camaro 2SS Join Date: Dec 2013 Location: OTP Atlanta Posts: 862 View My Garage	Added 3.91 gears I swapped to a 1LE 3.91 differential over the weekend and WOW, what a difference. If you are on the fence about making the change, I can now say go for it. I kept reading that the car would feel 300 lbs lighter and wondered "WTF does that mean?" well it means "Holy crap, I'm shifting already... I wasn't even getting on her." acceleration just comes. If you swap the entire differential, DIY is a level 3 out of 10. Anyone with a jack, jack stands and a Craftsman tool set can do it. 18mm wrench and sockets, breaker bar, torque wrench, and a few other tool are all you need. BTW my 2013 needed a 36 mm socket for the rear axle nuts. feel free to ask questions. __________________ 2016 2SS 6-Speed Manual... Magnetic Ride Control, Dual Mode Exhaust, Sunroof, Adrenaline Red Interior, Mylink W/Navigation Added Edelbrock E-Force Supercharger, GM 1LE Sway Bars, BMR Upper/Lower Trailing Arms, BMR Upper Control Arms. BMR Front/Rear Chassis Braces, BMR Tunnel Brace. GM Red knee Pads, GM Black Front Splitter, GM SEMA Concept Grille, GM Dark Taillights, GM Ground Effects package... Savini Di Forza BM-14 Gloss Black Wheels 9's front, 10's rear.

11-03-2014, 01:01 PM	#2
TECHTURTLE Drives: 2016 Camaro 2SS Join Date: Dec 2013 Location: OTP Atlanta Posts: 862 View My Garage	BTW... I'm a 6 speed manual if you were wondering. __________________ 2016 2SS 6-Speed Manual... Magnetic Ride Control, Dual Mode Exhaust, Sunroof, Adrenaline Red Interior, Mylink W/Navigation Added Edelbrock E-Force Supercharger, GM 1LE Sway Bars, BMR Upper/Lower Trailing Arms, BMR Upper Control Arms. BMR Front/Rear Chassis Braces, BMR Tunnel Brace. GM Red knee Pads, GM Black Front Splitter, GM SEMA Concept Grille, GM Dark Taillights, GM Ground Effects package... Savini Di Forza BM-14 Gloss Black Wheels 9's front, 10's rear.

11-03-2014, 06:26 PM	#3
ChrisBlair Buick 455 Fan Drives: 1970 Buick, 2012 1SS LS3 Join Date: Jun 2010 Location: Boston MA Posts: 5,957	Only reason I'm on the fence is that I drive the car in snow. We had a few actual blizzards recently and my SS is perfectly capable as it is in snowy conditions that after 43 years in New England, I'd call "bad". But now you know why a rear gear change has been such a popular upgrade for many years I'm sure that the...what is it, 13% increase in torque multiplication makes the car really wake up. First thing I thought when I drove an LS3 Camaro: "Not bad. Needs 50 more lb/ft across the rev range though" __________________

11-03-2014, 08:47 PM	#4
TECHTURTLE Drives: 2016 Camaro 2SS Join Date: Dec 2013 Location: OTP Atlanta Posts: 862 View My Garage	Not enough snow down here to justify at set of snow tires, so if it snows the Camaro will stay in the garage. I found out last year that P-zeros and snow don't mix. Another plus to the gear change is that the RPM increase got rid of the drone from the GM Performance exhaust. It was right at 70 mph. __________________ 2016 2SS 6-Speed Manual... Magnetic Ride Control, Dual Mode Exhaust, Sunroof, Adrenaline Red Interior, Mylink W/Navigation Added Edelbrock E-Force Supercharger, GM 1LE Sway Bars, BMR Upper/Lower Trailing Arms, BMR Upper Control Arms. BMR Front/Rear Chassis Braces, BMR Tunnel Brace. GM Red knee Pads, GM Black Front Splitter, GM SEMA Concept Grille, GM Dark Taillights, GM Ground Effects package... Savini Di Forza BM-14 Gloss Black Wheels 9's front, 10's rear.

11-10-2014, 11:16 AM	#7
TECHTURTLE Drives: 2016 Camaro 2SS Join Date: Dec 2013 Location: OTP Atlanta Posts: 862 View My Garage	Just had MTI Racing in Marietta re-calibrate the speedometer for the 3.91 gears. It took them less than an hour for me to be in and out... Great group of guys there, and I highly recommend them if you need any work. Anyway, it looks like a 200 RPM increase at 70 MPH. I reset the fuel economy to see what the difference is going to be . Before resetting I was at 20.6 MPG, I'll give it a week and report back. __________________ 2016 2SS 6-Speed Manual... Magnetic Ride Control, Dual Mode Exhaust, Sunroof, Adrenaline Red Interior, Mylink W/Navigation Added Edelbrock E-Force Supercharger, GM 1LE Sway Bars, BMR Upper/Lower Trailing Arms, BMR Upper Control Arms. BMR Front/Rear Chassis Braces, BMR Tunnel Brace. GM Red knee Pads, GM Black Front Splitter, GM SEMA Concept Grille, GM Dark Taillights, GM Ground Effects package... Savini Di Forza BM-14 Gloss Black Wheels 9's front, 10's rear.

11-03-2014, 09:06 PM	#5
Tenring Drives: 2014 2SS/RS - SIM Join Date: Apr 2014 Location: Arizona Posts: 2,188	Oh man I really want to do this but I am stuck working on the kids cars right now.

11-03-2014, 09:44 PM	#6
45thCamaro Drives: 2012 Camaro 45th Anniversary RS Join Date: Nov 2012 Location: New York Posts: 2,421	This is also on my wish list. I know I'm not in the same boat as many of you with the v8 but this should certainly make the car more interesting.

11-10-2014, 10:43 PM	#8
Josh @ Spartan LSX Drives: A wrench Join Date: Jan 2010 Location: East Atlanta Posts: 353	The 3.91 is the ONLY gear we'll install in the 5th gen Camaro's now. All the other ratio's & brands have problems but the GM 3.91 is perfect. We've got 3 cars in the shop getting 3.91's installed as I type this, including an LLT car. One of the best mods for the money.

11-12-2014, 11:26 PM	#9
Compromis/sed Drives: 2010 Camaro SS Join Date: Feb 2012 Location: Dallas, Texas Posts: 138	Congrats on the upgrade. This is on my short list of next mods. __________________

11-13-2014, 08:58 AM	#10
TECHTURTLE Drives: 2016 Camaro 2SS Join Date: Dec 2013 Location: OTP Atlanta Posts: 862 View My Garage	Thanks, so far I'm loving them. As of right now my average fuel economy is sitting at 19.3 MPG but I still have some highway miles to put on to get a good average. I was at 20.6 before resetting. __________________ 2016 2SS 6-Speed Manual... Magnetic Ride Control, Dual Mode Exhaust, Sunroof, Adrenaline Red Interior, Mylink W/Navigation Added Edelbrock E-Force Supercharger, GM 1LE Sway Bars, BMR Upper/Lower Trailing Arms, BMR Upper Control Arms. BMR Front/Rear Chassis Braces, BMR Tunnel Brace. GM Red knee Pads, GM Black Front Splitter, GM SEMA Concept Grille, GM Dark Taillights, GM Ground Effects package... Savini Di Forza BM-14 Gloss Black Wheels 9's front, 10's rear.

11-13-2014, 10:07 AM	#11
ATL Muscle Account Suspended Drives: A Few Camaros. All V8. Join Date: Mar 2012 Location: Atlanta, Ga Posts: 667 View My Garage	Where did you get the Diff from?

11-13-2014, 10:28 AM	#12
TECHTURTLE Drives: 2016 Camaro 2SS Join Date: Dec 2013 Location: OTP Atlanta Posts: 862 View My Garage	I bought it from a guy here in the classified section, it came off of a 1LE he was working on. $1000.00 plus 65 shipping. Then I sold mine for 700. __________________ 2016 2SS 6-Speed Manual... Magnetic Ride Control, Dual Mode Exhaust, Sunroof, Adrenaline Red Interior, Mylink W/Navigation Added Edelbrock E-Force Supercharger, GM 1LE Sway Bars, BMR Upper/Lower Trailing Arms, BMR Upper Control Arms. BMR Front/Rear Chassis Braces, BMR Tunnel Brace. GM Red knee Pads, GM Black Front Splitter, GM SEMA Concept Grille, GM Dark Taillights, GM Ground Effects package... Savini Di Forza BM-14 Gloss Black Wheels 9's front, 10's rear.

11-13-2014, 10:30 AM	#13
ATL Muscle Account Suspended Drives: A Few Camaros. All V8. Join Date: Mar 2012 Location: Atlanta, Ga Posts: 667 View My Garage	Awww man! $365 upgrade. That's cheaper than buying the gears and putting it in yourself!

11-13-2014, 10:36 AM	#14
TECHTURTLE Drives: 2016 Camaro 2SS Join Date: Dec 2013 Location: OTP Atlanta Posts: 862 View My Garage	Yeah, it was a pretty sweet deal... I did the swap myself but did have to pay another 200 for the speedo recal. __________________ 2016 2SS 6-Speed Manual... Magnetic Ride Control, Dual Mode Exhaust, Sunroof, Adrenaline Red Interior, Mylink W/Navigation Added Edelbrock E-Force Supercharger, GM 1LE Sway Bars, BMR Upper/Lower Trailing Arms, BMR Upper Control Arms. BMR Front/Rear Chassis Braces, BMR Tunnel Brace. GM Red knee Pads, GM Black Front Splitter, GM SEMA Concept Grille, GM Dark Taillights, GM Ground Effects package... Savini Di Forza BM-14 Gloss Black Wheels 9's front, 10's rear.