Thread: Project "Left Overs"

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Here is a site I have used in the past and it makes it very simple to figure out your rpms. All you do is plug in your gear ratio (no periods or colons), your tire size and your intended speed, and it gives you the rpms for an automatic, aod, manual, and 5 speed transmission. It is very accurate, my tires on the 27 are about 29 inches tall and it pegged my rpms at 2984 and change. On the road I was turning 3,000 at 60 mph on the gps.

http://www.reiderracing.com/rtech-engine-rpm.php

Try this with your cars info and see how it compares.


I have been considering changing to Hurst brand slicks this time on the rpu, but they are a little short, only 28.75 tall, and the Firestones I had on my 23 were 30. That 1.25 makes a little difference, and also looks better IMO.

Don

Originally Posted by Itoldyouso

Here is a site I have used in the past and it makes it very simple to figure out your rpms. All you do is plug in your gear ratio (no periods or colons), your tire size and your intended speed, and it gives you the rpms for an automatic, aod, manual, and 5 speed transmission. It is very accurate, my tires on the 27 are about 29 inches tall and it pegged my rpms at 2984 and change. On the road I was turning 3,000 at 60 mph on the gps.

http://www.reiderracing.com/rtech-engine-rpm.php

Try this with your cars info and see how it compares.


I have been considering changing to Hurst brand slicks this time on the rpu, but they are a little short, only 28.75 tall, and the Firestones I had on my 23 were 30. That 1.25 makes a little difference, and also looks better IMO.

Don

Don,
The problem with the Reider Racing calculator is you cannot plug in your actual OD ratio. Their 5speed calculation assumes a 0.80 final drive ratio in 5th which may be right for some, but not for me. My TREMEC is 0.64 in 5th, and TREMEC also has their 6 speed (used in the new Hemi Challenger) that has a final 0.50 to 1 OD ratio. Plugging in a 0.80 OD ratio into the calc I gave you yields the same answer as the Reider calculator, which it should.

That's probably true. I can't afford an overdrive transmission, so it works ok for me.

Don