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View Full Version : Shifting Problems Solved



Zack
01-03-2007, 08:59 AM
Took me a minute to figure out why the new car isnt shifting at its programmed times. Then it hit me. The Nitto's are a different height, thus different revs/mile.
Here is the Stock Tire Calculation:
http://www.mercurymarauder.net/showcase/files/4/0/4/StockTireCalculation.jpg

Here is the Nitto Tire Calculation:
http://www.mercurymarauder.net/showcase/files/4/0/4/NittoCalculation.jpg

This different number of 730 to 700 might never get anyone's attention, but it bothers me. The speedo is a little off, as well as when the transmission is told to shift as opposed to when it REALLY shifts.
The factory value in the software is 723, maybe to account for tire wear, I dont know??

Ill change the value tonight and all will be well. :beer:

RoyLPita
01-03-2007, 09:52 AM
Isn't the stock rear size 245/55-18????

KillJoy
01-03-2007, 10:00 AM
245/55/18 comes out to 705 RPM.

KillJoy

Zack
01-03-2007, 10:07 AM
Isn't the stock rear size 245/55-18????

Yeah, im a dick.
I guess I am what steve eats! :censor:

KillJoy
01-03-2007, 10:10 AM
Yeah, im a dick.
I guess I am what steve eats! :censor:


I agree. You are a Ham Sandwich and a bowl of Chicken Noodle Soup.

;)

KillJoy

DEFYANT
01-03-2007, 10:49 AM
I alternate both OEMs w/ Nittos. I never noticed a change in the way the car shifts. Just traction :D

sailsmen
01-03-2007, 11:39 AM
The shifts will occur at different rpms. Short of redline for the Nittos.

You could load 2 different tune based on what tire.

You are giving up some time in the 1/4, assuming your tune is for the street tires.

magindat
01-03-2007, 12:20 PM
I never trust them calculators. I go with MFG specs. Maybe it's trivial, bt I figure the mfg knows better than an arbitrary calculator.

For example, here's the 555's
http://www.nittotire.com/popup_555_sizes.asp

Zack
01-03-2007, 12:48 PM
I stand corrected on this one.
The Nitto site states 722 Revs/Mile
The BFG site states 724 revs/mile.
Back to the drawing board!