New Cobra - unknown rear

[chknhwk]

At 60 mph in fifth she's running ~ 2300 RPM where my cobra is right at 2k RPM with the stock rears. I tried figuring out the gears using just a direct ratio with that information and I came up with 3.75.
However, using the Corral gear calculator we're getting 4.22's. :shrug: Can anyone provide any input here? We have no idea what's in it at this point. (Bought it from a stealership as a trade in... :bored: )

 

[Booyah]

How big are the rims and width of tires? Also is the stock tranny in it?

 

[quick01snake]

Originally posted by hwkrcng
I tried figuring out the gears using just a direct ratio with that information and I came up with 3.75.

sounds like 3.73's to me.....

 

[red96cobra]

Jack the rear end off the ground with the tranny in neautral. Make a bright colored mark on the drive shaft. Next spin the wheels one full rotation and count the number of rotations the drive shaft makes. I would guess that if you have stock size wheels and tires that you have 3.73's. y car has 255/55's on it with 4.10's and my rpm's show about the same as you's because of the taller tires

Nick

 

[chknhwk]

Everything else except exhaust and shifter is stock. That's the only variable in the equation...

 

[Booyah]

Originally posted by hwkrcng
Everything else except exhaust and shifter is stock. That's the only variable in the equation...

Probably 4.10's or 4.30's. At 70 I would run around 2250 - 2300 with my '98 and I had 3.73's.

 

[COBRASVT]

Originally posted by red96cobra
Jack the rear end off the ground with the tranny in neautral. Make a bright colored mark on the drive shaft. Next spin the wheels one full rotation and count the number of rotations the drive shaft makes. I would guess that if you have stock size wheels and tires that you have 3.73's. y car has 255/55's on it with 4.10's and my rpm's show about the same as you's because of the taller tires

Nick

That's what I was going to suggest....I kept trying the calculators on mine and finally just jacked the rear...took 10 minutes to figure out the gears that way and you know it's accurate.

 

[chknhwk]

We tried that and we got 4.5 turns. Yeah, right. I know it doesn't have 4.56's in there!!
We'll give that a try again, I guess.
Anyone on here do road courses? We're doing a two day event this weekend at Mid-Ohio, Summit Point next month and possibly VIR in June. Would 4.11's be too much for road racing?

 

[Booyah]

Originally posted by hwkrcng
We tried that and we got 4.5 turns. Yeah, right. I know it doesn't have 4.56's in there!!
We'll give that a try again, I guess.
Anyone on here do road courses? We're doing a two day event this weekend at Mid-Ohio, Summit Point next month and possibly VIR in June. Would 4.11's be too much for road racing?

Um if you did it then there isn't a doubt about it.

 

[COBRASVT]

Originally posted by Booyah
Um if you did it then there isn't a doubt about it.

Agreed....4.5 turns is 4.5 turns...no matter how you want to view it.

Check it again...someone might have counted wrong or something. :shrug:

 

[Wylde Horses]

According to the gear ratio calculator on the corral, with the stock rim and tire size, and stock transmission, if you are at 2300 rpm at 60 mph, you are running 4.30's.

Here is the URL if you want to try it out...

http://www.corral.net/tech/gearcalc.html

 

[Wylde Horses]

Originally posted by COBRASVT
Agreed....4.5 turns is 4.5 turns...no matter how you want to view it.

Check it again...someone might have counted wrong or something. :shrug:

I'm thinking 4.3 turns can look alot like 4.5 turns... ;-)