Cortina Diff ratio's?????

[Anonymous]

I have a 6 cylinder TC cortina and have recently put on some saab pursuit rims (the only ones that fit) on my car the are 15 inch with 205/65/r15's compared from the standard 185/70r13's i had on there before.

People have told me and i have notices the reduction in the acceleration of the car due to the larger diameter of the tire/rim. I was wonder if i have a different diff ratio ( say from a 4 cylinder cortina) will it increase my acceleration again and i was wondering what the ratio's are??????

 

[Anonymous]

i dont know the tc 4cyl ratios but the te ratios are 6cyl 2.77 and 2.92 4cyl 3.5 and 3.7

tf is basically the same
im running a 3.5 diff from a tf in mine and its great for take off but crap for cruising i sit at about 3000 at 100-110kmph

im runng 15" rims with 195/65/15's and the takeoff is great

im planing to go back to a 6cyl ratio 2.92 lsd when i can afford it

the te/tf wdiff wont fit into a tc but the center will fit so thats prolly the easiest swap rather than trying to find a tc diff

cheers
pcman

 

[Anonymous]

i beleive the te-tf diff will fit i have a te diff in my td which is the same as the tc the only thing i had to do was chande the bottom braket for the shockey and drill a hole so the bolt will go thought

 

[xctasy]

If you are running a 2.92:1 diff, then target gear ratio is 2.92*1.099, or 3.21:1. This means the 3.23:1 gears are the best sellection for ya!

Note: TF diff ratios on the sixes may be the same, but it's not the same diff. Ford down graded to the same diff as the Corona, Sigma unit. The fours ran 3.42:1 ratios. Pre TF's back to post October 1972 ran the lovely 25 spline BW 7 7/8 th diff, but often the crown wheel was 7 5/8ths. It was only some ratios which were the full 7 7/8 ths (200 mm)

Ratios from things like humble Nissan Pintaras 4.11:1 right through 3.89, 3.7, 3.5, 3.45, 3,36,3.27, 3.23, 3.08, 2.92, 2.77, 2.54 are around.

The change in loaded wheel rollout is increased from 1.811 m to 1.990 meters. Thats 9.9% taller geared. Ford designed the pre TE Cortinas to run at 575 mm wheel diameter, not 633 mm as is the Saab wheel tyre combo. This isn't bad at all.

The ride will improve, and you can now get a camber eccentric kit to run negative camber to ensure the wheels are normal to the road under cornering, dump it 29 mm, and have the car handle so much better.

 

[George]

I agree with XECUTE that 3.32:1 ratio would be the best and the highest ratio I would use on a mild/stock ford 6cyl.
Years ago I had a TF cortina with a mild 6cyl ( cam, cain manifold, holley500 ect) which ran a 14.7sec 1/4 with 2.78:1 ratio. After changing the ratio to 3.55:1 the 1/4 mile time remained the same at 14.7sec but the engine was screaming its tits off.

Bye