Gear question - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

gunchamp · 10-29-2018, 12:12 PM

Hi guys. Looking at doing gears on my 15 SS L99.
Curious what seems to be the best set of gears as far as noise and strength for these cars? Thanks for any help

Pro-tuned · 10-29-2018, 02:57 PM

Need more information driving habits, mods, expectations... noise is another issue not related to gear size.

acammer · 10-29-2018, 05:58 PM

Quote:

Originally Posted by Pro-tuned

Need more information driving habits, mods, expectations... noise is another issue not related to gear size.

Agree - really depends. Typically, for a bolt on L99 car, the 3.91 is the way to go from a quarter mile perspective. But a lot of things could impact that.

Also agree, gear choice and noise aren't necessarily related. A well setup rear should be silent in OE bushings. When you go with aggressive bushings, and a reinforced diff cover you've given the noise a MUCH more direct path into the car, and some noise transmission into the cabin would be expected.

gunchamp · 10-29-2018, 05:59 PM

Mostly street, but a couple yearly visits to the track. Planning all motor, but may end up supercharging, so a little wishy washy there as of now. Have ran everything from 273 to 410s in the various cars I've owned in the past. Looking for probably a 390ish gear. Would prefer a GM gear if they make a set due to the fact they are generally a quieter gear set in my experience. This is my first 5th gen, but I've been around and have built more than a few cars in the past. Thanks

acammer · 10-29-2018, 06:07 PM

Quote:

Originally Posted by gunchamp

Mostly street, but a couple yearly visits to the track. Planning all motor, but may end up supercharging, so a little wishy washy there as of now. Have ran everything from 273 to 410s in the various cars I've owned in the past. Looking for probably a 390ish gear. Would prefer a GM gear if they make a set due to the fact they are generally a quieter gear set in my experience. This is my first 5th gen, but I've been around and have built more than a few cars in the past. Thanks

So, keep in mind that with a 6L80 car 4th gear is 1.152:1. A 3.91 works well in a bolt on car, it puts the car right around 5750rpm @ 110mph (on a stock sized tire and locked converter). A 4.10 is a little too deep for the stock cam-shaft, but with something aggressive it might be appropriate, again, depending on tire and converter, intake, etc. Gotta work backwards from goals and other equipment to pick a ratio. Supercharging changes a lot because then you start having to consider how you manage to keeping 1st gear usable.

3.91 is the usual go-to for the L99.

krisprz2010camaross · 10-29-2018, 09:33 PM

I would go with the oem 3.91’s. Went with those because they are factory and I knew there wouldn’t be any problems. I used to daily drive with FBO and gears and it was perfectly fine. Woke up the Auto trans

gunchamp · 10-30-2018, 01:26 PM

Thanks guys for the answers so far. So what seems to be the best way to improve strength with these? I see that the ZL1 conversion seems popular and the better priced option. Would just a few mods to the factory rear help gain strength for running in the say 550 rwhp range? I know anything can fail at any point and alot depends on the launch so this can be a tough question to accurately answer. Thanks

WoodBoss · 10-30-2018, 01:31 PM

If you are going to go forced induction like a supercharger, turbo charger or Nitrous just leave your gears alone unless you plan on staying Naturally Aspirated.

acammer · 10-30-2018, 07:56 PM

Quote:

Originally Posted by gunchamp

Thanks guys for the answers so far. So what seems to be the best way to improve strength with these? I see that the ZL1 conversion seems popular and the better priced option. Would just a few mods to the factory rear help gain strength for running in the say 550 rwhp range? I know anything can fail at any point and alot depends on the launch so this can be a tough question to accurately answer. Thanks

LPW diff cover helps keep the case from distorting, and it has load bolts to help keep the ring gear in place under load. That's the best step you can take.

Jannetty also makes some billet ring gear caps that are much stronger than the OE pieces - but for the money the LPW cover gives those stock caps plenty of support and girdles the rest of the diff as well. Only problem is getting LPW covers can be tricky, they go in and out of production every couple of years. They should be available right now, they were tooling up this summer to do a run of them.

The other thing that really helps keep the rear end alive is making sure any wheel hop issues are eliminated. The biggest single contributor to wheel hop is the factory rubber rear sub frame bushings and differential bushings. They make inserts, solid poly, and full solid aluminum bushings for the rear sub frame - I'm a fan of the solids as it really firms up the whole back of the car and the driveline. I run fairly hard poly bushings in the differential. That combination, along with an LPW cover (which is directly physically connected to the gear set) can make for some gear noise if the rear end is not set up perfectly. Sort of the price you pay for bullet-proofing.

Usually, the best way to ensure that the rear end stays alive is to not upgrade axles - those will usually break before the rear end gives. Consider them an expensive fuse to protect more expensive components.

Fortunately, you have an auto, and they are FAR kinder to their rear-ends than stick shift cars. Just don't abuse it and it'll take 550 whp all day long.

acammer · 10-30-2018, 07:57 PM

Also - if you're going to rebuild the diff, consider either upgrading the OE posi (Jannetty sells a posi-mod kit that many people report good success with) or adding an Eaton TruTrac, which is a worm gear based posi. The OE posi will eventually lose tension and become weak, and you'll end up with one tire fires!

WoodBoss · 10-31-2018, 01:13 PM

I'm still on the stock rear and I had a couple 1 wheel burnout at the track in 2017, drained out the differential lube I had in there with friction modifier and only used Amsoil 75w90 Gear Oil and this has stopped the one wheeled burnouts for now anyway. No problems in the turns either with chattering.

10-29-2018, 12:12 PM	#1
gunchamp Drives: 15 Camaro SS Join Date: Oct 2018 Location: Mountains of central PA Posts: 1,442	Gear question Hi guys. Looking at doing gears on my 15 SS L99. Curious what seems to be the best set of gears as far as noise and strength for these cars? Thanks for any help

10-29-2018, 02:57 PM	#2
Pro-tuned Angewendet Ingenieur Drives: 14 Camaro ZL1 Join Date: Apr 2015 Location: USA Posts: 401	Need more information driving habits, mods, expectations... noise is another issue not related to gear size. __________________ ———— LQ9, Iron Block, Forged internals, 408CI, Jannetty custom cam, TS short block, Whipple, Hardened Jackshaft, PRC 260, 2X3 Dynatech Full Competition, HF Cats, CAI, NW 103, Chee, ID 1300, COPO Breather, MSD, Fore Dual Pump, ultratorque, E85, dual Meth, True Trac, 3:45, 1500hp axle-shafts, DSS CF, BMR, custom Pearl/Candy paint by Jaidah.

10-29-2018, 09:33 PM	#6
krisprz2010camaross Drives: 2010 Camaro 2ss/Rs Transformers Join Date: Aug 2014 Location: Yorba Linda, California Posts: 1,564	I would go with the oem 3.91’s. Went with those because they are factory and I knew there wouldn’t be any problems. I used to daily drive with FBO and gears and it was perfectly fine. Woke up the Auto trans __________________ YouTube:Krisprz garage Insta:kris__perez & krisprz_garage LS3 conversion Vararam intake(tune model) Kooks LT headers & cats delete Corsa ZL1 3" exhaust RedBarn Racing Tune CMS Stage 3 Cam AFR CNC ported heads MSD Spark plug wires LNC-2000 Launch controller NGK TR6 Spark Plugs 1le strut tower brace-TPIS spacers Nick Williams 102mm throttle body Fast lsxr 102 intake manifold Slp 25% UDP Katech Tensioner Pulley Circle D 3600-3700 multi disk Stall GM 3.91 gears DDS carbon fiber driveshaft ZL1 fuel pump & injectors Flex fuel sensor(91/E85) https://wheelwell.com/kris-perez

10-30-2018, 07:57 PM	#10
acammer GPI Sales Consultant Drives: 2011 Camaro 2SS SGM Join Date: Jul 2016 Location: Weedsport, NY Posts: 2,794 View My Garage	Also - if you're going to rebuild the diff, consider either upgrading the OE posi (Jannetty sells a posi-mod kit that many people report good success with) or adding an Eaton TruTrac, which is a worm gear based posi. The OE posi will eventually lose tension and become weak, and you'll end up with one tire fires! __________________ GPI Max Package 2.0: Brodix BR7 heads/GPI porting, MAX3 cam, ST2116LSR, BSR Max Lift rockers, LS7 LSXR with 103mm TB, Vararam OTR, Mcleod RXT, G-Force/Strange 9" IRS setup with 4.63 gear. 551whp, 11.1@124mph. *Got a question about a GPI product? Feel free to shoot me a message!*

10-29-2018, 05:59 PM	#4
gunchamp Drives: 15 Camaro SS Join Date: Oct 2018 Location: Mountains of central PA Posts: 1,442	Mostly street, but a couple yearly visits to the track. Planning all motor, but may end up supercharging, so a little wishy washy there as of now. Have ran everything from 273 to 410s in the various cars I've owned in the past. Looking for probably a 390ish gear. Would prefer a GM gear if they make a set due to the fact they are generally a quieter gear set in my experience. This is my first 5th gen, but I've been around and have built more than a few cars in the past. Thanks

10-30-2018, 01:26 PM	#7
gunchamp Drives: 15 Camaro SS Join Date: Oct 2018 Location: Mountains of central PA Posts: 1,442	Thanks guys for the answers so far. So what seems to be the best way to improve strength with these? I see that the ZL1 conversion seems popular and the better priced option. Would just a few mods to the factory rear help gain strength for running in the say 550 rwhp range? I know anything can fail at any point and alot depends on the launch so this can be a tough question to accurately answer. Thanks

10-30-2018, 01:31 PM	#8
WoodBoss "Old School" Drives: 2010 2SS L99 Join Date: Apr 2015 Location: Sherrills Ford, NC Posts: 1,295	If you are going to go forced induction like a supercharger, turbo charger or Nitrous just leave your gears alone unless you plan on staying Naturally Aspirated.

10-31-2018, 01:13 PM	#11
WoodBoss "Old School" Drives: 2010 2SS L99 Join Date: Apr 2015 Location: Sherrills Ford, NC Posts: 1,295	I'm still on the stock rear and I had a couple 1 wheel burnout at the track in 2017, drained out the differential lube I had in there with friction modifier and only used Amsoil 75w90 Gear Oil and this has stopped the one wheeled burnouts for now anyway. No problems in the turns either with chattering.