Sierra diff ratios

[brian richards]

Hi you all,
Anyone got any thoughts on diff. ratios. I am running a Sierra 3.62:1 in my Sumo, which relates to 26 mph/1000 revs. Alt. ratios are 3.38 - 28.6mph/1000revs or 3.13:1 - 30mph/1000revs. Problem is it goes almost anywhere in 5th gear, only got 140bhp. What does anybody else use?
brian

[kdavies3]

Brian, what you have will give you best accceleration so I guess it depends what you want?
More MPG? Or more top speed? both acheived with a lower ratio 3.13:1.
5th won't be as flexible with the lower diff. You'll find yourself in the lower gears more.

http://animatedgif.net/flags/-flags-uncat/Wales.gif

Kev Davies
Dax, 383ci Chevy Stroker, Tremec TKO
South Wales

[stevee8]

Hi Brian,

I have a stockish 3.5 Rover running a 3.38 which gives about 27mph/1000 rpm.
I find it about right - I'm happy to do some slow cruisin' in 5th, the motor's easy at motorway speeds but there's always the option to drop down the box if necessary.

[brian richards]

Thanks Steve, I'll look out for a 3.38, I don't want to loose the acceleration, but bottom gear is much too low with the 3.68. It will keep me occupied during the winter.

Brian