Putting 9 inches in

Jerry Clayton · #1 (**permalink**) 10-20-2009, 10:38 AM

Gunner---I am probably the last person you want to preach weight and strength issues to on performance or race vehicles---The only draw back to the Ford 9 inch is it takes a little more power to turn because the pinion is low on the ring gear( of course the 8 and 8.8 are low also)

Generally when you see a car being towed off the track because of a broken rear, it is something other than a Ford 9!!!

And as for your referance to 100 lbs------totally out to lunch and if you are weight concerned the Ford 9 has more light weight components to use than any other rear out there--

Chaplain · #2 (**permalink**) 10-20-2009, 10:51 AM

Isn't it an over simplification to just toss out different rear end sizes and say one is better than the other? Shouldn't things like horsepower, vehicle weight, tire grip, just to name a few all be considered to determine what might be the correct choice?

Gunner · #3 (**permalink**) 10-20-2009, 01:05 PM

Quote:

Originally Posted by Jerry Clayton

And as for your referance to 100 lbs------totally out to lunch

You're right, I'm wrong. I was referencing the usual change from a C4/8 inch to a C6/9 inch which does get into triple digits.

Depending on a number of factors, the weight difference can be 25-35 pounds. Not insignificant for unsprung weight in a ~2300 pound car. Addendum: This page says 45, which is closer to my experience, and also makes a good case for the 8-inch.

When I selected components for my Mustang, I had a free hand and an open checkbook - and after a lot of careful investigation, decided against both a C6 and a 9-inch. I am using components (roller/teflon C4, Randy's 8-inch Traction-Lok) identical to several local racers who have had everything fail but their drivelines.

Unless you're running a true monster-motor (600HP+) and are going to be putting a lot of quarter-mile time on your Cobra, I'd argue strongly for a well-set-up 8-inch; plenty strong enough and at least 25 pounds lighter where it counts. (Actually, I'd argue that a solid rear axle has no place in a short-wheelbase performance car, but let's not go there...

)