Gear Ratio?
Thread Starter
Junior Member
Joined: Jun 2001
Posts: 59
Likes: 0
From: Concord, CA
Car: 89 IROC
Engine: 5.7 TPI
Transmission: A4
Gear Ratio?
I have an 89 IROC with a 5.7L and single cat.
My car's RPO sheet lists it as having a BW 2.77 rear. It has rear disc and posi for sure. The original owner was an older lady and I don't think she would have changed the rear but,...Can some one who knows how to use the RPM/Gear formula check my math and tell me what gears I have. (I come up with 3.27's). I was doing about 44MPH in drive turning about 1740RPM with 28in diameter tires (14 radius).
My car's RPO sheet lists it as having a BW 2.77 rear. It has rear disc and posi for sure. The original owner was an older lady and I don't think she would have changed the rear but,...Can some one who knows how to use the RPM/Gear formula check my math and tell me what gears I have. (I come up with 3.27's). I was doing about 44MPH in drive turning about 1740RPM with 28in diameter tires (14 radius).
Supreme Member
Joined: Jul 1999
Posts: 18,457
Likes: 16
From: Loveland, OH, US
Car: 4
Engine: 6
Transmission: 5
The easiest way is to put it in direct gear (D, not OD in a 700, or 4th in a T-5) and drive 70 MPH; your gear ratio is your RPM ÷ 1000 i.e. 2770 RPM = 2.77, etc.
------------------
"So many Mustangs, so little time..."
ICON Motorsports
------------------
"So many Mustangs, so little time..."
ICON Motorsports
Thread
Thread Starter
Forum
Replies
Last Post
Hotrodboba400
Firebirds for Sale
3
Dec 10, 2019 07:07 PM
dbrochard
Engine/Drivetrain/Suspension Parts for Sale
6
Sep 19, 2015 08:13 PM
83 Crossfire TA
Suspension and Chassis
0
Sep 8, 2015 12:06 PM
UltRoadWarrior9
Transmissions and Drivetrain
3
Sep 2, 2015 08:24 PM
