7k RPM 3rd gear speed

[GregP27]

Makes you sign in ... but thanks anyway. :-)

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[frank s]

Makes you sign in ... but thanks anyway. :-)

Darn! back to the drawing board.

Edit:__This one almost worked without a sign-in:

 

[GregP27]

I appreciate the effort, though. Cheers.

 

[frank s]

I appreciate the effort, though. Cheers.

Go to this page: http://0398ca9.netsolhost.com/

 

[DickR]

I cannot share the spread sheet since it isn't mine or openly available on the internet but here are gearing charts for 2018 GT PP automatic and manual on 275/35x19 RE71R's. Tire rpm per mile is from the Tire Rack specs table. You can easily do the arithmetic for different size tires or different gear ratios.

Note that for autocross with a 10A on most sites/courses it is best to get to 3rd in the 10A ASAP. For many courses either due to course configuration or lack of off the line traction it appears best to start in 2nd with the 10A. Automatic shifting, even in S and Track mode results in too many unneeded and unwanted up and down shifts at autocross speeds on typical "national level" size courses/sites.

 

[Condor1970]

nnn

 

[AC53]

You guys are making it harder than it needs to be.

The only things you need to know are:
1) RPM = 7,000
2) Tire diameter = PP1 is a 275/40/19 Pilot Sport 4S and its diameter is 27.7"
3) FD ratio = 3.15 and 3.55
4) 3rd gear A10 ratio = 2.15

That gives a speed of 73.95 for the 3.55 rear and 83.34 for the 3.15 diff.

The discrepancy between the 83.34 and your car showing ~90 is the inaccuracy of the speedo.

 

[Mustang_GT]

OK, here it is. Sorry, I didn't design this for public consumption. I originally did it just for me.

1) The 2019 diff ratios and transmission ratios are shown to the left.
2) You enter you Diff ratio and the gears you are interested in.
3) To the left below the gear stuff, enter the driven tire size (where it says 275 / 40 - 19).
4) You enter an rpm or a mph you are interested in and it calculates: 1) the mph for rpm of interest and 2) rpm for mph of interest.

I could dress this up and make it for more public consumption, but you get the idea.

This stuff is fun! Cheers!

Thank you for sharing!

 

[PUNISHER7772]

Don't have the exact speed on mine (I know it's close) but with the 6 speed and 3.73 gears.

1st@7k is around 50, 2nd@7k is around 75, 3rd@7k is around 105. I know I have hit 110 in 3rd but think it was over 7k.

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