What gear ratio do i need? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

TRock · 12-03-2012, 02:34 PM

OK i have new cam and heads that puts my peak rpm at 6500, im crossing the traps at 5000 rpm. Is there a way to determine what gear will get me closer to my 6500 rpm at the traps? I am looking at the 3.91's but not sure if that will do it. What are you manual guys running and what are you crossing the tarps at?

BigMatt · 12-03-2012, 03:21 PM

I'm just at redline crossing the traps in third with stock rear

fielderLS3 · 12-03-2012, 03:32 PM

I think this formula will work for you, assuming you are looking to finish in the same transmission gear as you currently are. If I made a mistake, someone please correct it.

Ideal ratio = (6500/5000) * stock ratio * (current trap speed/final trap speed)

TRock · 12-03-2012, 04:50 PM

[I'm just at redline crossing the traps in third with stock rear]

Are you auto or manual?

TRock · 12-03-2012, 04:53 PM

Quote:

Originally Posted by fielderLS3

I think this formula will work for you, assuming you are looking to finish in the same transmission gear as you currently are. If I made a mistake, someone please correct it.

Ideal ratio = (6500/5000) * stock ratio * (current trap speed/final trap speed)

Thanks I will try that.

TRock · 12-03-2012, 05:27 PM

Quote:

Originally Posted by BigMatt

I'm just at redline crossing the traps in third with stock rear

Are you running in the 1/4 or 1/8?

VADER SS L99 · 12-03-2012, 06:27 PM

There are 2 ways you can get your desired effect. The first is to raise your rev limiter to 7000 RPM. This should allow you to cross the traps at the top of 3rd gear. Make sure your valvetrain and tune are up to the task to do this. The 2nd option is some new rear end gears. The gear that would get you closer is the 4:11 or 4:10 but I think these are not as good as the OEM 1LE 3.91 gears. The 3.91 gears would put you closer to the redline in 4th through the traps but wont get you to 6500. The good thing about them though is you have some breathing room incase you decide to get more power and go faster. The 3.91 gears will do around 130mph or so in 4th so if you ever decide on a supercharger or nitrous you wont run out of gear vs with the 4.10/4.11 you will.

TRock · 12-03-2012, 06:37 PM

Quote:

Originally Posted by VADER SS L99

There are 2 ways you can get your desired effect. The first is to raise your rev limiter to 7000 RPM. This should allow you to cross the traps at the top of 3rd gear. Make sure your valvetrain and tune are up to the task to do this. The 2nd option is some new rear end gears. The gear that would get you closer is the 4:11 or 4:10 but I think these are not as good as the OEM 1LE 3.91 gears. The 3.91 gears would put you closer to the redline in 4th through the traps but wont get you to 6500. The good thing about them though is you have some breathing room incase you decide to get more power and go faster. The 3.91 gears will do around 130mph or so in 4th so if you ever decide on a supercharger or nitrous you wont run out of gear vs with the 4.10/4.11 you will.

This is what I was looking for. I found a calculator online that confirms this. I do plan to spray in the spring and want to do gears over the winter. I was on the fence between 3.91 and 4.10, I guess i will try the 3.91's and go from there. Thanks guys

BigMatt · 12-03-2012, 07:05 PM

Quote:

Originally Posted by TRock

Are you running in the 1/4 or 1/8?

1/4 mile

Hendrix-Engineering · 12-03-2012, 08:11 PM

Theres a ton of great calculaters on wallace racing calculaters

TRock · 12-04-2012, 10:20 AM

Quote:

Originally Posted by Hendrix-Engineering

Theres a ton of great calculaters on wallace racing calculaters

Thanks guys, I wish i had the $ to go 9" but not in the budget yet.

Hendrix-Engineering · 12-05-2012, 07:51 AM

Quote:

Originally Posted by TRock

Thanks guys, I wish i had the $ to go 9" but not in the budget yet.

Understood.If we can help you out with anything just let me know

12-03-2012, 02:34 PM	#1
TRock Drives: 2011 CGM 2SS/RS Join Date: Jan 2012 Location: Memphis, TN. Posts: 80	What gear ratio do i need? OK i have new cam and heads that puts my peak rpm at 6500, im crossing the traps at 5000 rpm. Is there a way to determine what gear will get me closer to my 6500 rpm at the traps? I am looking at the 3.91's but not sure if that will do it. What are you manual guys running and what are you crossing the tarps at?

12-03-2012, 03:21 PM	#2
BigMatt 2010 Camaro 2 SS/RS M6 Drives: 2010 Camaro SS/RS Join Date: May 2009 Location: Clayton Delaware Posts: 1,218 View My Garage	I'm just at redline crossing the traps in third with stock rear __________________ Forged LS3, FED M311 heads, CAI Inc, ARH 1 7/8, Corsa Xtreme, Taylor Wires, MGW Shifter, Street slayer twin carbon clutch, Tick braided clutch line & speed bleeder, ZL1 Diff Swap, BMR Split drop, Sway Bars, Trailing Arms, Toe Rods, Pro bushing kit, Carslyle racing 15in conversion, Whipple, LPE dual fuel pumps, Rx catch can, Id1300x, Alky Control

12-03-2012, 03:32 PM	#3
fielderLS3 Drives: 2016 Mazda6, 2011 Mustang 5.0 Join Date: Mar 2010 Location: Portage, Wisconsin Posts: 4,049	I think this formula will work for you, assuming you are looking to finish in the same transmission gear as you currently are. If I made a mistake, someone please correct it. Ideal ratio = (6500/5000) * stock ratio * (current trap speed/final trap speed) __________________ 2022 1SS 1LE (Arrived 4/29/22) "The car is the closest thing we will ever create to something that is alive." . 2022 1SS 1LE (Coming Soon)

12-03-2012, 06:27 PM	#7
VADER SS L99 Drives: 2013 A6 GT 5.0 Join Date: Nov 2009 Location: Edmond, OK Posts: 2,909	There are 2 ways you can get your desired effect. The first is to raise your rev limiter to 7000 RPM. This should allow you to cross the traps at the top of 3rd gear. Make sure your valvetrain and tune are up to the task to do this. The 2nd option is some new rear end gears. The gear that would get you closer is the 4:11 or 4:10 but I think these are not as good as the OEM 1LE 3.91 gears. The 3.91 gears would put you closer to the redline in 4th through the traps but wont get you to 6500. The good thing about them though is you have some breathing room incase you decide to get more power and go faster. The 3.91 gears will do around 130mph or so in 4th so if you ever decide on a supercharger or nitrous you wont run out of gear vs with the 4.10/4.11 you will. __________________ BLK/BLK 1SS/RS Ordered 11-01-2009 Took delivery 12-22-2009. Heads/cam/converter/bolt ons. SOLD Feb 2015 to fund 6th gen LT1 SS with 8L90E.

12-03-2012, 04:50 PM	#4
TRock Drives: 2011 CGM 2SS/RS Join Date: Jan 2012 Location: Memphis, TN. Posts: 80	[I'm just at redline crossing the traps in third with stock rear] Are you auto or manual?

12-03-2012, 08:11 PM	#10
Hendrix-Engineering Account Suspended Drives: First 9 inch-12 bolt IRS Camaro Join Date: Jun 2009 Location: nc Posts: 1,835	Theres a ton of great calculaters on wallace racing calculaters