I would like to get a set of those if they hold true to the statement on the f.c site. they say to bring down 3/10's of a second off ur quarter mile. are they alot shorter then stock, good w/mpg, and does it help out alot?
now what a lot of people NEED to understand is the focus becomes extremely unstable at sustainspeeds speeds above 140mph without serious exterior enhancements to the aerodynamics of the car and undercar aerodynamics wouldn't hurt either.so this is nothing special but i was looking around on varrious sites, found my way onto Quaife.co.uk and found a gearing calculator to figure out top speed based on your cars gearing, tire size and and redline.
here is a little taste:
stock focus gearing(1st: 3.667, 2nd: 2.136, 3rd: 1.448, 4th: 1.028, 5th: 0.767, final: 3.82)
Stock focus redline: ~ 6800rpm
tire size: 215/45/17(1961.9976mm overall rolling circumference)
=
[Gearbox:-
Tyre:- 215/45 x 17
-------------------------------------------------------------------------------------------
Top Gear gives 24.966 MPH/1000 RPM and a top speed of 169.766 MPH at 6800 RPM
Engine speeds in top gear:-
30 MPH = 1202 RPM 40 MPH = 1602 RPM 50 MPH = 2003 RPM 60 MPH = 2403 RPM
70 MPH = 2804 RPM 80 MPH = 3204 RPM 90 MPH = 3605 RPM 100 MPH = 4006 RPM
Top Speed in 1 gear = 35.509 MPH
And changes into 2 gear at 3961 RPM dropping 2839 RPM
Top Speed in 2 gear = 60.960 MPH
And changes into 3 gear at 4610 RPM dropping 2190 RPM
Top Speed in 3 gear = 89.924 MPH
And changes into 4 gear at 4828 RPM dropping 1972 RPM
Top Speed in 4 gear = 126.664 MPH
And changes into 5 gear at 5074 RPM dropping 1726 RPM
Top Speed in 5 gear = 169.766 MPH
******************************************************************************************
now with a 7200rpm redline and same specs as above....typical of what most aftermarket chips will raise the rpm limiter too
Please note that the chip usually does not completely remove the top speed limiter, it usually just bumps it up.
=
Gearbox:-
Tyre:- 215/45 x 17
-------------------------------------------------------------------------------------------
Top Gear gives 24.966 MPH/1000 RPM and a top speed of 179.752 MPH at 7200 RPM
Engine speeds in top gear:-
30 MPH = 1202 RPM 40 MPH = 1602 RPM 50 MPH = 2003 RPM 60 MPH = 2403 RPM
70 MPH = 2804 RPM 80 MPH = 3204 RPM 90 MPH = 3605 RPM 100 MPH = 4006 RPM
Top Speed in 1 gear = 37.598 MPH
And changes into 2 gear at 4194 RPM dropping 3006 RPM
Top Speed in 2 gear = 64.546 MPH
And changes into 3 gear at 4881 RPM dropping 2319 RPM
Top Speed in 3 gear = 95.214 MPH
And changes into 4 gear at 5112 RPM dropping 2088 RPM
Top Speed in 4 gear = 134.115 MPH
And changes into 5 gear at 5372 RPM dropping 1828 RPM
Top Speed in 5 gear = 179.752 MPH
******************************************************************************************
now with a 8000rpm redline and same specs as above....
=
Gearbox:-
Tyre:- 215/45 x 17
-------------------------------------------------------------------------------------------
Top Gear gives 24.966 MPH/1000 RPM and a top speed of 199.725 MPH at 8000 RPM
Engine speeds in top gear:-
30 MPH = 1202 RPM 40 MPH = 1602 RPM 50 MPH = 2003 RPM 60 MPH = 2403 RPM
70 MPH = 2804 RPM 80 MPH = 3204 RPM 90 MPH = 3605 RPM 100 MPH = 4006 RPM
Top Speed in 1 gear = 41.775 MPH
And changes into 2 gear at 4660 RPM dropping 3340 RPM
Top Speed in 2 gear = 71.718 MPH
And changes into 3 gear at 5423 RPM dropping 2577 RPM
Top Speed in 3 gear = 105.793 MPH
And changes into 4 gear at 5680 RPM dropping 2320 RPM
Top Speed in 4 gear = 149.016 MPH
And changes into 5 gear at 5969 RPM dropping 2031 RPM
Top Speed in 5 gear = 199.725 MPH
******************************************************************************************
Now compare those stats to those of the exact same car with just a 4.06 final drive conversion...
=
Gearbox:-
Tyre:- 215/45 x 17
-------------------------------------------------------------------------------------------
Top Gear gives 23.490 MPH/1000 RPM and a top speed of 159.731 MPH at 6800 RPM
Engine speeds in top gear:-
30 MPH = 1277 RPM 40 MPH = 1703 RPM 50 MPH = 2129 RPM 60 MPH = 2554 RPM
70 MPH = 2980 RPM 80 MPH = 3406 RPM 90 MPH = 3831 RPM 100 MPH = 4257 RPM
Top Speed in 1 gear = 33.410 MPH
And changes into 2 gear at 3961 RPM dropping 2839 RPM
Top Speed in 2 gear = 57.356 MPH
And changes into 3 gear at 4610 RPM dropping 2190 RPM
Top Speed in 3 gear = 84.609 MPH
And changes into 4 gear at 4828 RPM dropping 1972 RPM
Top Speed in 4 gear = 119.176 MPH
And changes into 5 gear at 5074 RPM dropping 1726 RPM
Top Speed in 5 gear = 159.731 MPH
******************************************************************************************
Gearbox:-
Tyre:- 215/45 x 17
-------------------------------------------------------------------------------------------
Top Gear gives 23.490 MPH/1000 RPM and a top speed of 169.127 MPH at 7200 RPM
Engine speeds in top gear:-
30 MPH = 1277 RPM 40 MPH = 1703 RPM 50 MPH = 2129 RPM 60 MPH = 2554 RPM
70 MPH = 2980 RPM 80 MPH = 3406 RPM 90 MPH = 3831 RPM 100 MPH = 4257 RPM
Top Speed in 1 gear = 35.375 MPH
And changes into 2 gear at 4194 RPM dropping 3006 RPM
Top Speed in 2 gear = 60.730 MPH
And changes into 3 gear at 4881 RPM dropping 2319 RPM
Top Speed in 3 gear = 89.586 MPH
And changes into 4 gear at 5112 RPM dropping 2088 RPM
Top Speed in 4 gear = 126.187 MPH
And changes into 5 gear at 5372 RPM dropping 1828 RPM
Top Speed in 5 gear = 169.127 MPH
******************************************************************************************
Gearbox:-
Tyre:- 215/45 x 17
-------------------------------------------------------------------------------------------
Top Gear gives 23.490 MPH/1000 RPM and a top speed of 187.918 MPH at 8000 RPM
Engine speeds in top gear:-
30 MPH = 1277 RPM 40 MPH = 1703 RPM 50 MPH = 2129 RPM 60 MPH = 2554 RPM
70 MPH = 2980 RPM 80 MPH = 3406 RPM 90 MPH = 3831 RPM 100 MPH = 4257 RPM
Top Speed in 1 gear = 39.306 MPH
And changes into 2 gear at 4660 RPM dropping 3340 RPM
Top Speed in 2 gear = 67.478 MPH
And changes into 3 gear at 5423 RPM dropping 2577 RPM
Top Speed in 3 gear = 99.540 MPH
And changes into 4 gear at 5680 RPM dropping 2320 RPM
Top Speed in 4 gear = 140.208 MPH
And changes into 5 gear at 5969 RPM dropping 2031 RPM
Top Speed in 5 gear = 187.918 MPH
******************************************************************************************
this is really nothing more than some FYI from me to you. i have the calculator or you can check out here on your own...
http://www.quaife.co.uk/downloads/QSpeedCalc.exe
you'll need the specs on your tires, the manufacture website should have them for you to use. what you will need is the overall diameter of the tire, them multiply by 3.14. this will give you the overall rolling circumference needed for the calculator. if the measurement on the tire site is in inches multiply your rolling circ by 25.4... this will give you the rolling circ in MM needed by the calculator.