Short ratio gears with 3:54s? Or 3:33s?

[bushido]

I plan on doing close ratio gears ( 5th and 6th ). At the moment my car has 3:54 rear gears & Tru-Trac differential, and my car is putting down 600rwhp.A head/cam 97 GTS. So would it be a good idea to change out the 3:54s for 3:33s? Thanks

 

[bushido]

I'm currently rolling on 19inch wheels.Tire size is 345/30/19s..

 

[PhoenixGTS]

I'm currently rolling on 19inch wheels.Tire size is 345/30/19s..

Then I would say definitely 3.55 if not 3.73 (perhaps 3.73 if you have a raised rev-limiter). The taller Gen III size rear tires effectively turn a 3.55 in a Gen II into 3.33 gearing, and 3.73 with the tall tires is effectively a 3.55 on a Gen II. I say don't be afraid of short gears unless you do a lot of drag racing and you calculate that that big power car of yours will run out of top end in 4th gear in the quarter mile.

That is a lot of power for just heads/cam etc. Can you describe your set-up?

 

[Mopar Boy]

I run 3.73 with the 20" rim so I am equal to a 3.45. I like it. Seems about right. Does rev a little higher on the freeway but for more of the speed limits around here are 60 MPH anyways so....

Not sure you would like a 3.73 on your car...too low.

 

[bushido]

Then I would say definitely 3.55 if not 3.73 (perhaps 3.73 if you have a raised rev-limiter). The taller Gen III size rear tires effectively turn a 3.55 in a Gen II into 3.33 gearing, and 3.73 with the tall tires is effectively a 3.55 on a Gen II. I say don't be afraid of short gears unless you do a lot of drag racing and you calculate that that big power car of yours will run out of top end in 4th gear in the quarter mile.

That is a lot of power for just heads/cam etc. Can you describe your set-up?

On my setup I have JM stage 3 ported heads ( milled for higher compression 10:5to1)LSM Cam, Ported intake manifold, American Racing 5-into-1 stepped headers,no cats, Borla exhaust system, and Crower 1.7 RRs.Last, Exotic Engine valve cover breather system. All done, and tuned by DC Performance. Stock PCM + Stock fuel system..

 

[2001 GTS]

Yo Bushido!

I'm running the 3.55s with my 19s as well and think they are perfect man!

 

[Simms]

Did you ask Dan Cragin his thoughts?

 

[SquadX]

I have 355 and will be switching back to stock. In 5th at redline I am at 148mph. *****.

 

[Brake Dust]

I have 355 and will be switching back to stock. In 5th at redline I am at 148mph. *****.

HOW ABOUT 6TH

 

[PhoenixGTS]

I have 355 and will be switching back to stock. In 5th at redline I am at 148mph. *****.

I'm thinking there is some clutch slippage at play there. Before all the good gear calulators disappeared I calculated my 3.55 car with a 0.64:1 6th and Gen II height rear tires as theoretically capable of right at 200 mph at 6,200 rpm (not enough power to really get there) which I believe would put me at 160 at fuel cut-off in 5th.

 

[Burntrubber]

I have 355 and will be switching back to stock. In 5th at redline I am at 148mph. *****.

something might be up, should be 165mph @5500rpm in a stock GTS w/ 3.55s