l99, 3.91 or 3.73 gears? - Page 2 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Apex Motorsports · 02-25-2014, 06:34 AM

Quote:

Originally Posted by Padre

Consensus is that 3.73 is best for an L99 bolt-on car. First gear in an auto is pretty short, which would make it mostly useless with 3.91's (spin).

If you ever plan to used forced induction, then go with 3.45's.

Padre

This pretty well nails it.

Pro Stock John · 02-25-2014, 09:50 AM

Shady, I think moving to 3.91's bump the rpms in every gear a noticeable amount, Jbrown and some others posted some info another thread (thanks again guys).

I'm not sure if Speed Inc. does gear swaps but you could ask them and they are a sponsor on here too. tom@speedinc.com

FRANK121 · 02-28-2014, 01:53 PM

I have a L99 whippled with LT headers and a 2800 stall daily driver that occasionally goes down the strip. What gears do you recommend?

FRANK121 · 03-10-2014, 01:50 PM

OK, where can I find 3.45 gears for My Supercharged L99

Snidely Whiplash · 07-24-2014, 02:05 AM

Quote:

Originally Posted by jbrown13

I'm not an experienced drag racer, having taken it up at 67 years of age, so my numbers may not be indicative of what can be had. My PB to date has been 11.362 - 1/4 and 1.623 - 60'. My tuner thinks I should be able to get into the 1.5x - 60', but I haven't been able to accomplish that yet.

Howdy fellow geezer. I'm soon to turn 60 years of age, but have HUNDREDS of passes at the dragstrip and on the street. I've run both 1/4 mile tracks (Texas Motorplex and Green Valley Raceway) and a 1/8 mile track (Kennedale Raceway).

If you ever have a question or seek to understand something about drag racing and the various things about it, please do not hesitate to PM me. I should be able to answer most any racing related question. If I cannot answer a question, I know whom I should ask.

At one time I had my NHRA license to run a full bodied car to 7.99. A friend let me borrow his car to make al the runs to get licensed. I never had the money to build a car quicker than my homebuilt small block 9 second 1962 Chevy II.

Have fun and be safe!
Remember: It's better to abort a run than have an unfriendly meeting with the retaining wall...or worse, your competitors car.

Snidely Whiplash · 07-24-2014, 02:09 AM

Quote:

Originally Posted by FRANK121

OK, where can I find 3.45 gears for My Supercharged L99

An M6 differential would be just the ticket running 540 LB/FT of torque. The guys going way up the torque values are the ones having to upgrade. Keep an eye on the classifieds.

If I was not having to save property tax money, I'd sell you my gears. I've only got 1500 miles on the clock. Too bad I cannot afford to buy and have installed, the 3.73s I'd like to have

Pro Stock John · 07-24-2014, 09:05 AM

I did 3.91's. I don't think I'd do them if I had a supercharger.

But I plan to do heads and cam.

hammdo · 07-24-2014, 09:42 AM

Quote:

Originally Posted by Pro Stock John

I did 3.91's. I don't think I'd do them if I had a supercharger.

But I plan to do heads and cam.

Same here in my L99 -- I'm doing similar mods Pro Stock John is doing -- no FI in my plans either.

-Don

Pro Stock John · 07-24-2014, 12:27 PM

If I was going the power adder route, I would not do gears until later.

Gofastson · 08-30-2019, 12:11 AM

Quote:

Originally Posted by Pro Stock John

Shady, I think moving to 3.91's bump the rpms in every gear a noticeable amount, Jbrown and some others posted some info another thread (thanks again guys).

I'm not sure if Speed Inc. does gear swaps but you could ask them and they are a sponsor on here too. tom@speedinc.com

Can you daily drive 3.91 and how is it on the freeway

dino2012ls3 · 09-09-2019, 10:05 PM

I did 410s and so far and love them, but did clutch at same the same time so cant really get after yet (break of clutch 500 miles). I'm just basic bolt ons and cammed (.236/.242) and don't plan on FI, if so I'll probably regret the 410s and have to down size..

Pro Stock John · 09-10-2019, 02:31 PM

Quote:

Originally Posted by Gofastson

Can you daily drive 3.91 and how is it on the freeway

Yes, I do, and it's about 2200 rpms at 70. car is beast from a roll too, but she is a heavy drinker.

Dirtmod66 · 09-16-2019, 01:48 PM

Have a 2010 SS Automatic that I drive only on weekends granted weather is good (no rain); Burnt rear up at track, so time to do new locker and gear; what would be the disadvantage of the 3.91? Not worried about fuel mileage, Trans is already turned for shift points along with car. I don't see 150rpms being a big deal!! Help an old circle tracker out... LOL

Dirtmod66 · 09-30-2019, 12:51 PM

Had the 3.91's installed Friday nite, drove the car Saturday and love the gears. Now just to get the tranny set right (@67 I'm doing 55), Hit the interstate and doing 70-75; rpm's where around 2100 (give or take); gas mileage went down some, but I didn't buy the car to save money on gas..

02-25-2014, 09:50 AM	#16
Pro Stock John Writer Drives: 2010 SS / 1967 Camaro Join Date: May 2009 Location: Chicago, IL Posts: 7,216	Shady, I think moving to 3.91's bump the rpms in every gear a noticeable amount, Jbrown and some others posted some info another thread (thanks again guys). I'm not sure if Speed Inc. does gear swaps but you could ask them and they are a sponsor on here too. tom@speedinc.com __________________ PROJECT HEAVY CHEVY Camaro Now: Mods for the Masses Part I \| Part II 13.15@106 1.95 \| 100% Stock 12.37@112 1.85 \| + Kooks Headers/Cats + 20" 555R + CAI + BW TB + UDP + Tune 12.06@113 1.70 \| + CD 3200 + 18" NT05R + RCR Intake + NE OTR + GPI Tune 11.84@115 1.59 \| + 3.91s + Race Star 17x7 Fronts 10.90@125 1.47 \| + GPI VVT Cam + BW Ported Heads + CD 3800

02-28-2014, 01:53 PM	#17
FRANK121 Drives: 2022 Camaro ZL1 Join Date: Sep 2010 Location: Sullivan, Missouri Posts: 653 View My Garage	I have a L99 whippled with LT headers and a 2800 stall daily driver that occasionally goes down the strip. What gears do you recommend? __________________ 2022 Black ZL1 RotoFab CAI, AWE Touring Edition Cat Back Exhaust. 665 Crank hp. est. and 660 Crank ft. lbs. est. Never been Dynoed

03-10-2014, 01:50 PM	#18
FRANK121 Drives: 2022 Camaro ZL1 Join Date: Sep 2010 Location: Sullivan, Missouri Posts: 653 View My Garage	3.45's OK, where can I find 3.45 gears for My Supercharged L99 __________________ 2022 Black ZL1 RotoFab CAI, AWE Touring Edition Cat Back Exhaust. 665 Crank hp. est. and 660 Crank ft. lbs. est. Never been Dynoed

07-24-2014, 09:05 AM	#21
Pro Stock John Writer Drives: 2010 SS / 1967 Camaro Join Date: May 2009 Location: Chicago, IL Posts: 7,216	I did 3.91's. I don't think I'd do them if I had a supercharger. But I plan to do heads and cam. __________________ PROJECT HEAVY CHEVY Camaro Now: Mods for the Masses Part I \| Part II 13.15@106 1.95 \| 100% Stock 12.37@112 1.85 \| + Kooks Headers/Cats + 20" 555R + CAI + BW TB + UDP + Tune 12.06@113 1.70 \| + CD 3200 + 18" NT05R + RCR Intake + NE OTR + GPI Tune 11.84@115 1.59 \| + 3.91s + Race Star 17x7 Fronts 10.90@125 1.47 \| + GPI VVT Cam + BW Ported Heads + CD 3800

07-24-2014, 12:27 PM	#23
Pro Stock John Writer Drives: 2010 SS / 1967 Camaro Join Date: May 2009 Location: Chicago, IL Posts: 7,216	If I was going the power adder route, I would not do gears until later. __________________ PROJECT HEAVY CHEVY Camaro Now: Mods for the Masses Part I \| Part II 13.15@106 1.95 \| 100% Stock 12.37@112 1.85 \| + Kooks Headers/Cats + 20" 555R + CAI + BW TB + UDP + Tune 12.06@113 1.70 \| + CD 3200 + 18" NT05R + RCR Intake + NE OTR + GPI Tune 11.84@115 1.59 \| + 3.91s + Race Star 17x7 Fronts 10.90@125 1.47 \| + GPI VVT Cam + BW Ported Heads + CD 3800

09-09-2019, 10:05 PM	#25
dino2012ls3 Drives: 2012 ls3 Join Date: Feb 2014 Location: humble Posts: 113	I did 410s and so far and love them, but did clutch at same the same time so cant really get after yet (break of clutch 500 miles). I'm just basic bolt ons and cammed (.236/.242) and don't plan on FI, if so I'll probably regret the 410s and have to down size..

09-16-2019, 01:48 PM	#27
Dirtmod66 Drives: 2010 Camaro SS Join Date: May 2018 Location: Central Virginia Posts: 86	Weekend Warrior Have a 2010 SS Automatic that I drive only on weekends granted weather is good (no rain); Burnt rear up at track, so time to do new locker and gear; what would be the disadvantage of the 3.91? Not worried about fuel mileage, Trans is already turned for shift points along with car. I don't see 150rpms being a big deal!! Help an old circle tracker out... LOL

09-30-2019, 12:51 PM	#28
Dirtmod66 Drives: 2010 Camaro SS Join Date: May 2018 Location: Central Virginia Posts: 86	NEW GEARS Had the 3.91's installed Friday nite, drove the car Saturday and love the gears. Now just to get the tranny set right (@67 I'm doing 55), Hit the interstate and doing 70-75; rpm's where around 2100 (give or take); gas mileage went down some, but I didn't buy the car to save money on gas..