Just Picked Up A Cobra Last Night

[sonicblustreak]

I just grabbed a Red on Grey Cobra last night. This is my fourth Cobra. It has 46k miles on it, with some mods being done to it. It has some type of cam, with a decent chop to it, a Jacobs electronic box(which I assume is for the ignition), BEAR sloted rotors, bolt in roll bar, and unknown gears in the rear. This is my question-if I am doing 60 mph @2500 rpm's, anyone know what gear that would be? 4.10? 3.73? Thanks.

 

[kcp203]

Two questions. Do you have stock size tires (245/45/17)? What gear for the 60mph @ 2500 rpm?

 

[sonicblustreak]

275/40/17 is the tire size. The gear is already in the car. When I go 60 mph on the interstate, I'm turning 2500 rpm. I'm trying to determine what gear this would be in the car. thanks.

 

[93LITE]

http://www.csgnetwork.com/gearratcalc.html , this is just the first one I found, looks like maybe 3:27?????????????

 

[sonicblustreak]

If I put in the tire height @24.75-25", then it puts it right at 3.08, which would be factory. Shouldn't it be lower than 2500 rpm @60 mph?

 

[cobr96]

275/40/17 is the tire size. The gear is already in the car. When I go 60 mph on the interstate, I'm turning 2500 rpm. I'm trying to determine what gear this would be in the car. thanks.

he meant what gear is the transmission in , 1,2,3,4,or5

 

[sonicblustreak]

I can see where that might be usefull. It was in 5th gear.

 

[93LITE]

Here's another with more variables, http://www.corral.net/tech/gearcalc.html. Your speedo is probably off as-well from the speedo gear not being changed when the rear gears were changed. ?

 

[sonicblustreak]

I don't know if the speedo gear was changed or not. At this time I am just assuming it was, until I can have the car calibrated.

 

[racerbox77]

If speedo is accurate it seems like a 4:10

 

[sonicblustreak]

when I used the link that 93lite provided, the closest one that I could come up with was 4.10

 

[buddha93]

If speedo is accurate it seems like a 4:10

My thoughts exactly

 

[red95gts]

Jack the rear end of the car up and put the car in neutral. Mark the rear tire at the 12:00 position and rotate the driveshaft by hand. Count the number of times you have to turn the driveshaft to get one full revolution on the tire. The result is your gear ratio.

Good Luck

 

[cobra186]

Jack the rear end of the car up and put the car in neutral. Mark the rear tire at the 12:00 position and rotate the driveshaft by hand. Count the number of times you have to turn the driveshaft to get one full revolution on the tire. The result is your gear ratio.

Good Luck

+1.... just make sure both rear tires are off the ground.

1 complete rotation of the tire to 4 rotations of the driveshaft = 4.10
1 tire to 3 3/4 driveshaft = 3.73
1 tire to 3 1/2 driveshaft = 3.55
etc etc.

 

[sonicblustreak]

Thanks guys. I'll try to do that this weekend.