hi guys can anyone tell me the best ratio escort live axle for my c20xe redtop vauxhall 16v engine and type 9 gearbox before i go for a dyno !
does it matter ?
how do i find out mine ? hopefully without taking apart :-)

There is no best ratio - just the one that suits your requirements best.

You need to decide whether you want best acceleration (higher number) or relaxed cruising (lower number)

You find out what you have by counting how many revolutions of the prop it takes to turn the wheels 1 full turn - obviously you need to jack the car up and make some chalk marks on the prop and wheels then turn the prop by hand and start counting

I've been using a 3.62 LSD seirra diff and Type 9 in mine for two years now. It's spot on for the road but after using my car for more and more trackdays I've realised it's geared far too long for ideal track use.

Theorical gearing currently is 163mph top speed.

I'm changing the gearbox ratios rather than the diff (fitting a sequential) to give theoretical top of 134mph.

should give you some idea. (i'm on 13" rear wheels)

[Edited on 8/8/13 by Pat_T]

You might be pushing an escort axle to its limits with a supercharger strapped on too!

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Originally posted by Ben_Copeland
You might be pushing an escort axle to its limits with a supercharger strapped on too!

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what ratio's have you got in the type 9 ? (i.e. is it a box from a V6 or a 4cyl ford)
has it be modified to take the extra power ? (often this means different ratio's too)

also your tyre size has just as big an effect on the overall ratio as the diff...




you can use gear calc. programs to work out what effect different ratios might have, but ultimately if you feel the car could do with higher gearing (i.e are your always running out of gears before you run out of power) then try a higher ration (lower number) or bigger tyres

if your running out of power before you've maxed out the rev's in 3rd then you probably want a lower ratio diff (higher number) or smaller tyres

if it feels right then it it'll be fine as it is


[Edited on 8/8/2013 by mcerd1]

quote:

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Originally posted by Jamster1233
hi guys can anyone tell me the best ratio escort live axle for my c20xe redtop vauxhall 16v engine and type 9 gearbox before i go for a dyno !
does it matter ?

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