3.91 or 4.11 - Page 2 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

hammdo · 08-09-2014, 10:38 PM

I have 3.91 GM in my 2011 2SS L99 A6 -- love them.

Swacer · 08-10-2014, 07:35 AM

Quote:

Originally Posted by Comrando

First will redline ~45MPH with 4.10s.

Could you post the 3.91 table?

I am looking to do 4.11 next year

christianchevell · 08-10-2014, 08:35 AM

Have read posts from a guy who did 4.10's who later changed to 3.91's as the gears are so small in our cars that to make 4.10's the teeth are really small and he chewed his up .......... I am going 3.91 also from the price difference along with a lpw diff cover and eaton true trac

TwentyTen2SSRS · 08-10-2014, 09:41 AM

What is a typical install price for the 3.91 gears? Why are 3.91 bad if you are planning on supercharging it?

JKO · 08-10-2014, 08:34 PM

All depends if this is your daily driver and only vehicle go with 3.91 you will not be disipointed but if its a weekend crusier or toy you can go with 4.10 Just look up Gm performance for 3.91's 4.10 will have to come from Richmond or other aftermarket companies.

Cldgin2 · 08-10-2014, 10:11 PM

I was wondering the same thing... what is the install price going for? Looks like quite a job.

Quote:

Originally Posted by TwentyTen2SSRS

What is a typical install price for the 3.91 gears? Why are 3.91 bad if you are planning on supercharging it?

Jrichards73 · 08-10-2014, 11:10 PM

I did a full 1LE take off differential for $750

Josh @ Spartan LSX · 08-11-2014, 07:36 AM

We do gears in 5th gears all the time and I personally like the 3.91's the best. Due to the 5th gen trans gearing I think 4.11 is a little too much in most cases unless you're planning on using a camshaft that spins to 7K+ rpm's.

Whatever you do, stay the heck away from Richmond gears!!! We've installed 3 sets per customer request and every set broke the teeth right off within 1000 miles. We've never had a set of GM gears break. FWIW.

Mr_Draco · 08-11-2014, 09:23 AM

Quote:

Originally Posted by christianchevell

Have read posts from a guy who did 4.10's who later changed to 3.91's as the gears are so small in our cars that to make 4.10's the teeth are really small and he chewed his up

Has nothing to do with the size of the teeth and more to do with the manufacturer. Richmond is the only maker of those and they are notorious for breaking regardless of the gear or vehicle.

Taco Time · 08-11-2014, 09:32 AM

GM 3.91s.

http://www.jdpmotorsports.com/parts/...ro-ss-22813040

JDP and Apex are the cheapest.

Snidely Whiplash · 08-11-2014, 09:42 AM

Quote:

Originally Posted by Dr. Evil

Just my opinion but I think these cars are heavy and need a lot of gear to get em going. If a set of 4.30s were available for the same cost as a set of the 3.91s I wouldn't hesitate to put them in.
For the average person that doesn't see a lot of drag strip time 3.91s are a good balance of price vs performance.

Unless you go to the 9" rear, the standard SS differential pinion gear would be small and weak at a 4.30 ratio.

Dr. Evil · 08-11-2014, 08:06 PM

Quote:

Originally Posted by Snidely Whiplash

Unless you go to the 9" rear, the standard SS differential pinion gear would be small and weak at a 4.30 ratio.

I know, I just wish that was a realistic option. The tall tires diminish the returns from the deeper gears a bit.
My last car (corvette) had 4.10s and a 25.7" tall tire. In 4th gear it crossed the traps in the mid/upper teens mph. My rev limiter was set to 6700 which worked out to 125mph.

With the 3.91s and a stock 28.6" tall rear tire you're still good for 137mph (4th gear) at 6300rpm.

Swacer · 08-11-2014, 08:08 PM

Richmond is the only maker of 4.11 gears?

I was looking at Yukon ones. They said they were 4.11

hammdo · 08-11-2014, 08:25 PM

Quote:

Originally Posted by jdsblueray2013

I would love to get the 3.91 gear ratio, for my L99. That will be first mod.

Did this in my 2011 2SS L99 A6 -- just awesome...

Surprised a couple of mustangs -- that's for sure...

-Don

08-10-2014, 08:35 AM	#17
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	Have read posts from a guy who did 4.10's who later changed to 3.91's as the gears are so small in our cars that to make 4.10's the teeth are really small and he chewed his up .......... I am going 3.91 also from the price difference along with a lpw diff cover and eaton true trac __________________ 2021 Wild Cherry ZL1 A10, Sunroof, Data, Carbon, Nav, RotoFab Dry CAI, Elite x2, Borla ATK, Driveshaft shop

08-10-2014, 09:41 AM	#18
TwentyTen2SSRS Drives: 2010 2SS/RS Join Date: Apr 2013 Location: Seattle, WA Posts: 3,972 View My Garage	What is a typical install price for the 3.91 gears? Why are 3.91 bad if you are planning on supercharging it? __________________ Cold Air Inductions CAI • Stainless Power LT's with HFC's • Flowmaster American Thunder Cat Back • APEX Scoop and WW Relocation Kit • VMAX Ported Throttle Body • Custom Dyno Tune • Pfadt 1.25" Lowering Springs • ZL1 Rims on 275 front 315 Rear • custome underlay vinyl wrap • Anvil Spoiler • heritage grill • APR Front Splitter • Custom Emblempros emblems • ZL1 Side Skirts • 416.5 whp 410 torque (CURRENTLY) Up Next: BTR Stage 3 Cam and supporting mods (in garage now)

08-10-2014, 08:34 PM	#19
JKO Drives: 2016 2 SS Join Date: Jun 2014 Location: South Louisiana Posts: 154	All depends if this is your daily driver and only vehicle go with 3.91 you will not be disipointed but if its a weekend crusier or toy you can go with 4.10 Just look up Gm performance for 3.91's 4.10 will have to come from Richmond or other aftermarket companies. __________________ 69 Camaro 461 BBC street car 2020 ZL1 .

08-10-2014, 11:10 PM	#21
Jrichards73 Drives: 2011 2SS/RS Victory Red Join Date: Aug 2011 Location: Virginia Posts: 921	I did a full 1LE take off differential for $750 __________________ Updates: BTR Stage 2 VVT Cam Kit w/Smith Brothers Trunnions, Fluidampr, RX catch can, B&M Trans pan mod, Kooks Black Headers, Borla S-tunes, Eibach Multi-Pro-R2 coilovers and Swaybars, BMR Full Bushing kit with Toe and Trailing arms, RB Rotors w/EBC Pads, GForce 1400 Axles (now on order). AVH-X5800BHS in Scosche GM5201AB.

08-11-2014, 08:08 PM	#27
Swacer Drives: 2018 GT350 Join Date: Nov 2011 Location: PA Posts: 2,719	Richmond is the only maker of 4.11 gears? I was looking at Yukon ones. They said they were 4.11 __________________ Off to the Dark Side Last edited by Swacer; 08-11-2014 at 08:28 PM.

08-09-2014, 10:38 PM	#15
hammdo 'It's an experiment' Drives: [COTW 2/09/15] '11 GPI LSA SC Z/LE Join Date: May 2014 Location: Dallas TX Posts: 8,694 View My Garage	I have 3.91 GM in my 2011 2SS L99 A6 -- love them.

08-11-2014, 07:36 AM	#22
Josh @ Spartan LSX Drives: A wrench Join Date: Jan 2010 Location: East Atlanta Posts: 353	We do gears in 5th gears all the time and I personally like the 3.91's the best. Due to the 5th gen trans gearing I think 4.11 is a little too much in most cases unless you're planning on using a camshaft that spins to 7K+ rpm's. Whatever you do, stay the heck away from Richmond gears!!! We've installed 3 sets per customer request and every set broke the teeth right off within 1000 miles. We've never had a set of GM gears break. FWIW.

08-11-2014, 09:32 AM	#24
Taco Time Drives: 2014 1SS Join Date: Jun 2014 Location: Angleton, TX Posts: 1,339 View My Garage	GM 3.91s. http://www.jdpmotorsports.com/parts/...ro-ss-22813040 JDP and Apex are the cheapest.