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diff ratio

Posted: Tue Nov 04, 2008 8:21 pm
by PAYNEY05
Hi guys
I am currently doing a bit of freeway driving daily and am finding the standard diff ratio making the car work too hard.The motor is a standard 138 red with a HR three speed.Is a 3.55 or a 3.36 the best options? will a 3.08 be too tall?
Thanks,Payney

Posted: Tue Nov 04, 2008 9:06 pm
by Devilrod
I'm running 3.36 they're ok. Trev's just changed his to 3.08 I think but he's got a bigger red. Tyre height will also be a factor. Taller tyre will help on the open road too.

Posted: Tue Nov 04, 2008 11:05 pm
by FB MAD
I'm running 149 red ( bored to 167 ) standard 3 speed crash box and 3.08 diff with 13 inch rims and I'm very happy with it.

Posted: Wed Nov 05, 2008 5:22 am
by Trev
I know of a grey powered car with 3.36 center and it chews up the hwy miles, thats the ratio I'm putting in the wagon :D , Trev 8) .

Posted: Wed Nov 05, 2008 12:43 pm
by fc visitor
i run an 3.36 with 215-60x13 grey motor and crash box and a 3.08 with 235-50x13 with grey motor and box and both setups work well for me.

Posted: Wed Nov 05, 2008 1:02 pm
by Sammy
my opinion has always been to use a 3.08 for economy, and if you want the thing to get off the line better work the engine etc :)

Posted: Wed Nov 05, 2008 4:00 pm
by Devilrod
I've always gone for lower gearing and more acceleration! Screw economy :twisted: :twisted: :twisted:

Now not so :oops:

............

Posted: Wed Nov 05, 2008 4:19 pm
by DNA
I've got 3.08 in mine and Im happy with it.

The commodore I just sold I was running 4.11s, was fun to drive but crap for anything other than the quarter mile.

Posted: Wed Nov 05, 2008 10:12 pm
by retro
im normally with devilrod, but im worried that ill blow the box into the freeway if i keep doing high revs with a lower diff.

Posted: Thu Nov 06, 2008 8:30 pm
by strogger
I had a 3.36 in my EK with Grey / Hydramatic, As Tim said, on the highway absoultly brilliant, but round town especially up and down hills not so good, i had to manually select 2nd a few times and the car seemed to really lug.. Dont get me wrong still a useable option if you have a good one and arnt afraid of juggling gears.

3.55 is a good compromise if you can get one..

Easy conversion as well..

Posted: Sat Nov 08, 2008 2:57 pm
by fb cruisin
strogger wrote:I had a 3.36 in my EK with Grey / Hydramatic, As Tim said, on the highway absoultly brilliant, but round town especially up and down hills not so good, i had to manually select 2nd a few times and the car seemed to really lug.. Dont get me wrong still a useable option if you have a good one and arnt afraid of juggling gears.

3.55 is a good compromise if you can get one..

Easy conversion as well..
I agree I tried a 3.36 and found I was changing back to second alot more.
Then I went to a 3.55 and found my speedo to be fairly close with 185/70 13's

Rob