8.8 vs 9 inch? How to laterally locate it?

[Steven Mike]

Hi all,
My 2012 GT is about to enter a new stage of my ownership. Graduating from daily driver status to weekend warrior. And 160k miles of less than gentle driving has caught up with me. The rear end needs to be rebuilt. That said I hate to do anything twice and the car will be getting built to be an all motor or procharged setup so would like to upgrade the rear end to suit.

That said which would be superior for a car that will see weekend canyon carving and track time. An 8.8 or 9 inch rear end? Either way I intend to go with a torque arm setup. And to laterally locate the rear end would a wishbone or watts link be more favorable?

TIA for any insight

 

[xr7]

I would go with the 9" diff, tons of parts available and a diff that is easy to set up. Easy to swap in a different gear, build 2 or 3 center sections and you are ready to go.

 

[Steven Mike]

I would go with the 9" diff, tons of parts available and a diff that is easy to set up. Easy to swap in a different gear, build 2 or 3 center sections and you are ready to go.

I like the idea of a 9 inch as well especially with the aftermarket availability of brake kits etc...

I'm having trouble finding a watts link compatible with the s197 and a 9 inch. Any suggestions? Or should I go wishbone?

 

[blacksheep-1]

I like the idea of a 9 inch as well especially with the aftermarket availability of brake kits etc...

I'm having trouble finding a watts link compatible with the s197 and a 9 inch. Any suggestions? Or should I go wishbone?

Good idea on the 9 inch
Bad idea on the watts.

Why don't you just fab up the 9inch to fit the 8.8 suspension points and call it a day?

 

[Steven Mike]

Good idea on the 9 inch
Bad idea on the watts.

Why don't you just fab up the 9inch to fit the 8.8 suspension points and call it a day?

Yes. A s197 has a three link suspension. Two lower and one upper control arm with a panhard bar for lateral location. I'm converting it to a torque arm three link but still need a way to locate the rear end laterally.

 

[blacksheep-1]

Instead of that, why wouldn't you invest in a cambered diff or a set of penske coil overs?
Again, the S197 rear suspension on the Boss 302s is the high water mark for stick axles, install some decent FP trailing arms, and you can even use the stock center link, there's nothing to fix there.
With regards to the torque arm, everyone is well aware of my opinion on the watts, just use a panhard bar and keep it simple.

 

[TMSBOSS]

What BS-1 said.
Contact Cortex and see what they can do regarding a 9" cambered axel with standard suspension.

 

[Mjschneidy]

8.8 is a proven stout efficient axle, the modern “9inch”. Why all the recommendations to move away from it to a 9”? I’d refresh the 8.8 and keep the 3 link over going 9” with a torque arm. Put the money in floating hubs to eliminate the axle flange flex.

 

[navseng]

If I am building a car from scratch, I always use a 9" . In your case I probably wouldn't bother unless you plan on changing ratios often. 8.8 can be built pretty strong and handle what most people throw at them.

 

[blacksheep-1]

I think he's planning on changing ratios which would validate the 9inch, but other than that, the 8.8 is plenty stout.