Please clairify this test for me
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 7,825
Likes: 221
From: Hillsboro OR
Please clairify this test for me
I have read that the RPM @ 70 MPH (third gear) should equal the rear gear ratio you have? Is that correct? I have an A4 with a 2800 stall. The converter is not locked in third gear. How do I verify the rear gear ratio I have? Thanks
Resident moron
Joined: Jun 2003
Posts: 4,746
Likes: 20
From: Assachusetts
What size rear tires do you have? Assuming stock 275/40/18 or 26.7" tall, you'd have to be driving roughly 80mph in 3rd gear (or 4th with a T56) to "equal" your gear ratio with RPMs. Close enough to get a good idea anyway, for example if you had 3.42s you'd be at 3445rpm with a 26.7" tire and 80mph exactly. 3757rpm for 3.73s....etc.
The only way to REALLY check is to count the teeth on the ring and pinion but that is a lot harder to do
Dope
The only way to REALLY check is to count the teeth on the ring and pinion but that is a lot harder to do
Dope
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 7,825
Likes: 221
From: Hillsboro OR
Thank you for the replies. This makes me feel better. I thought the speed was supposed to be 70. There I was running ~ 3100 rpms. It made me wonder if I really got 3:15 gears. I also knew my converter wasn't locked in 3rd. I have to believe that at 80 MPH the RPM's would be a lot closer to 3400 than 3100, even with the converter unlocked.
Thanks again everyone.
Thanks again everyone.
