Is this feasable

[Sledgehammer]

Thinking that I would be better off racing with a solid axle, Is it feasible to consider changing the IRS in the Au to non IRS from another AU Falcon, I understand that its a straight bolt in due to all mounting points being the same, what would we need to be aware of. Just thinking that this may be a cheaper option other than goto a 9 inch rear and 4 link.

what do you guys think?

[Casper]

Originally Posted by Sledgehammer

Thinking that I would be better off racing with a solid axle, Is it feasible to consider changing the IRS in the Au to non IRS from another AU Falcon, I understand that its a straight bolt in due to all mounting points being the same, what would we need to be aware of. Just thinking that this may be a cheaper option other than goto a 9 inch rear and 4 link.

what do you guys think?

Honestly I think giving up the IRS is a mistake. I have no doubt that, with a bit of work, the rear suspension could be set up to be as good if not better than a live axle setup.
While live axle has some advantages it also has 1 very big disadvantage. As its not fixed ridgidly to the body it suffers from the torque of the driveshaft actually trying to lift one wheel off the ground while pushing the other one down. IRS doesnt suffer this as the "twist" is stopped by the diff housing being fixed to the chassis. Its a lot harder to twist a whole chassis than it is to twist a diff housing.

Have a look into what sort of changes the XR6T's and F6's are doing. Although its a control blade suspension setup its still going to point you in the right direction. There are a number of 10 second cars in there that get traction and (apart from CV's, something not as much an issue on the AU's) not blowing diff's or axles.

[stiddy]

The live axle lsd diff's are weak.. the only advantage over IRS is that they are lighter and dont have CV's to break..

[philstoj]

For drag racing, the live axle setup would be much better, but instead of using a stock Au solid diff, why not get a 9" diff cut to suit the live axle setup, it would definatly be stronger and more suited to your power levels.

The IRS is good, but definatly not up to the task of a high powered NA setup, and i believe the turbo's arent as harsh on drivelines as NA.

[MRJUCY]

I think if you went full hog with a 9 inch etc it could be an improvement but I think for the most part just bunging in the stocker setup would be a backwards step.

[T3man]

I don't think you'll improve either traction or rear axle strength by changing to a beam axle. The double-wishbone of the AU IRS is simply the best available in any mass-produced car in the world (my belief). It is streets ahead of the control blade in every respect except weight. If you feel you need a stronger diff you can now get an alloy housing for a Ford 9" to fit the AU IRS set-up. Rear axle control for racing is more a function of having the correct shock absorbers and spring rates than the axle type.

[Mark351]

Yeah, live axle is the go. Several thousand Mustang drag cars can't be wrong.

In a drag racing environment the live axle is king. From Top Fuel to pro Stock to bracket racing live axles are used because they are stronger (less parts to break) and they are tunable for weight transfer. Since many of the Mustang owners are into drag racing the IRS would offer no advantage. This is not to say that the IRS won't work on the drag strip but it certainly is at a disadvantage.

Linky link

So they are adding Watts linkage to their setups in the states. We have that on live axle Falcons!

Ok, so they are selling stuff, but what they say is generally true.

[janek]

Shane, you may be overrating the strength of the IRS axles- i managed to snap one at eastern creek, basically stock (just with the JMM extractors)... it was my fault for dropping it in gear at 2000rpm, but still... my corona survived many a 5500rpm neutral banger :S (Young and stupid lol)

That being said, i rate the IRS way better than the live axle setup