Final Drive Ratio's

[Guest Gilto]

Hi all,

Peter, just wondering if you can shine some light on a question. With a stage 2 or 3 APS kit, what final drive ratio would you say in a manual transmission car would give the best quarter mile and 0-100km times withous sacrificing highway driving??

I am keen to go either a 3.9 or 4.11

Would love to know your thoughts on this.

Thanks for all your time!

Gilto!

[Ezy10z]

Hi all,

Peter, just wondering if you can shine some light on a question. With a stage 2 or 3 APS kit, what final drive ratio would you say in a manual transmission car would give the best quarter mile and 0-100km times withous sacrificing highway driving??

I am keen to go either a 3.9 or 4.11

Would love to know your thoughts on this.

Thanks for all your time!

Gilto!

Personally I would just keep the final drive ratio standard. Judging by the times and terminal speed done by a T fitted with the stage 3 kit I dont see any purpose in changing the final drive ratio. I'd think you should be able to pull at least 125mph ++ comfortably in fourth gear especially with the taller drag tyres which seems perfect for the 1/4.

[aps]

Hi all,

Peter, just wondering if you can shine some light on a question. With a stage 2 or 3 APS kit, what final drive ratio would you say in a manual transmission car would give the best quarter mile and 0-100km times withous sacrificing highway driving??

I am keen to go either a 3.9 or 4.11

Would love to know your thoughts on this.

Thanks for all your time!

Gilto!

Good question. I think the stock final drive ratio is 3.45 to I , if you are going to the trouble of changing ratio's I would make the change to a 4.11 to I ratio this would help to offset some of the weight in the xr6t. It will also depend on what size /diameter tyre you intend using, this way you can caculate the MPH the car can run on the over all gearing. let me know what you intend to do.

PETER

APS

[100%]

Hi all,

Peter, just wondering if you can shine some light on a question. With a stage 2 or 3 APS kit, what final drive ratio would you say in a manual transmission car would give the best quarter mile and 0-100km times withous sacrificing highway driving??

I am keen to go either a 3.9 or 4.11

Would love to know your thoughts on this.

Thanks for all your time!

Gilto!

Gilto,

Have you thought about what this will do to your Hwy drivability? I'm sure you can calculate what your revs will be on the Hwy at 110km/h with a 4.11 compared to std. I don't know if I'm right but I get about 2700rpm @ 110km/h? Gonna kill your top speed!

Not good me thinks! Unless your car is just for 1/4's?

[Cobra]

I've been told that changing the rear ratio is extremely hard on these diffs ... Canadian made ???

we are doing a XR8 soon .... even worse ratio than the T ... the plan is to chuck the diff altogether and just wack in a 9" .... oh ... it's a ute

[Guest ROCKET]

greetings all

from memory to calculate the revs your car will be doing at 100Kmh all you need to know is the diff ratio that is in your car at the moment & the revs that it is doing at 100 Kms with that diif

my pursuit for instance has a 3.46:1 diff ratio & @ 100Kmh it is reving at 1800 RPM

if I was to put 3.90:1 diff gear in all you need to do is

devide the original diff ration into the new diff ratio

ie: 3.9 divided by 3.46 Equals 1.127

them multiply that number by the revs that it was doing @ 100Kmh

ie: 1.127 multiplied by 1800 equals 2028.60

there for if I was to change my diff gears from 3.45:1 & put in 3.90:1 my revs @ 100Kmh would go up from 1800Rpm to 2028Rpm

hope this helps, if anybody carnt follow this just PM. me with what diff gears you have & what RPM your car does @ 100Kmh & the ratio of the gears sets that you are thinking of fitting & I will endevoir to work it out for you

regards

rod

[Guest Gilto]

Hi 100%,

I was intending on doing this in the new T with a six speed manual. Hopefully the sixth gear will be quite long so it will compensate for the 4.11 final drive.

Sounds ok to me in theory anyway??

[bcl]

Gilto,

Do the maths. The T-56 with ratios 2.97/2.07/1.43/1/0.8/0.62 will work OKl with a 4.11 final drive. 6th in the T-56 will be close to 5th in the current T5.

Brian

[100%]

Hi 100%,

I was intending on doing this in the new T with a six speed manual.

You hope!!!! :banghead:

[WBT56]

what is the rev limit on these modded cars? With 4.11 gears in fourth, you will be doing about 176km/h at 6000rpm. To cross the line in fourth, you have to work back from your redline and rpm at 100 to get your maximum terminal speed.