Tom N
Supporting Member
- 414
- 32
- Sep 27, 2002
-
Sarasota,
Florida
I have been trying to figure out why my car seems to go slower at certain rpm points than it should.
Tranny and rear end are stock for the car. I disconnected the drive shaft and manually checked the rear gear ratio and it is definitely 3.54.
Well I had noticed when cruising at 4k rpms in 5th gear I am going about 76-78 mph and according to a gear calculator I should be going closer to 87mph.
I checked my mph in other gears to see if its just 5th thats off. Its not, 3rd and 4th show me going slower than the gear calculator shows at 3k and 4k rpms.
At 3k in 3rd I'm doing 33/34 mph and 3k in 4th I'm doing 46/47 mph
3k in 3rd should be about 39mph and 3k in 4th should be about 52mph
All actual speeds the car was going were verified with a GPS which was very close to what my speedo says. 1-2mph off. Car has 225/55/15 tires
Here is the calculator that was used and has always been very accurate when checking it against other cars of mine.
http://www.f-body.org/gears/
Any ideas???
Tranny and rear end are stock for the car. I disconnected the drive shaft and manually checked the rear gear ratio and it is definitely 3.54.
Well I had noticed when cruising at 4k rpms in 5th gear I am going about 76-78 mph and according to a gear calculator I should be going closer to 87mph.
I checked my mph in other gears to see if its just 5th thats off. Its not, 3rd and 4th show me going slower than the gear calculator shows at 3k and 4k rpms.
At 3k in 3rd I'm doing 33/34 mph and 3k in 4th I'm doing 46/47 mph
3k in 3rd should be about 39mph and 3k in 4th should be about 52mph
All actual speeds the car was going were verified with a GPS which was very close to what my speedo says. 1-2mph off. Car has 225/55/15 tires
Here is the calculator that was used and has always been very accurate when checking it against other cars of mine.
http://www.f-body.org/gears/
Any ideas???
