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Old 09-07-2014, 02:32 AM   #21 (permalink)
sqidd
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Location: Ann Arbor, MI
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Mr. Scary - '07 Ford Mustang GT Race Car

The Truck - '12 Ford F-150 Scab EcoBoost FX4

The 5.0 - '12 Ford Mustang GT Vert Brembo Premium

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Quote:
Originally Posted by johnlvs2run View Post
It's a coupe. Altimax 175/70 R14 84 T
Quote:
Originally Posted by johnlvs2run View Post
Thank you! That doesn't seem very high.
I guessed high on that tire. It is 23.65".

So in 3rd @ 55mph you are at 4,150rpm

4th @ 55mph you are at 3,025rpm

I highly doubt you will see any ill effects from compression braking at 4,100rpm. But depending on how your ECU is set up you may be using more fuel at 4,100 than 3,000 so running it in 4th and using the brakes a little could be a better method. That all depends on your "tune" though and I wouldn't know where to find that info at.

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