differental number
Drifting
Joined: Sep 2004
Posts: 1,638
Likes: 3
Originally Posted by pwrful c4
It looks like my diff. was changed but I do not know the ratio 80 mph is about 2000 rpm. can anyone give me an idea. 
80 MPH calculates out to 7040 ft / min
If your tires are standard - I think they are 28"tall - so their circumfrence would be about 88 inches or 7. 3 feet per revolution
So the axles would be spinning at 960 times per minute (960 RPM)
You say the engine is spinning at 2000 RPM - so the speed would be reduced at a ratio of .48 - or the engine is turning 2.08 times for every wheel turn.
I have no idea if this is the correct approach - I'm thinking I would need the tranny gear ratio to go any further - because using this approach I still have 2 unknowns - the diff gear and the trans gear
Carl "I'm a biologist for a reason" Johansson
Elite Torch Red Member
Joined: Sep 1999
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From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
Cental/South NJ Events Coordinator
CI 1-2-3-4-5-6-7-8-9-10-11-12 Vet
CI-II Burnout & Drag Champ
St. Jude Donor '03-'04-'05-'06-'07
Stock tires are closer to 26" in diameter.
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
I did some figuring for another member only a couple of days ago. With a 26" (very close to our stock tires) tires, his car should have gone 81 mph @ 2000 rpms with his 2.73 gears.
RACE ON!!!
RACE ON!!!
