Solid axle or IRS?

[330mach1]

i'm sure there are threads about this already, i'm just too lazy to look. I have a 03 mach, i'm just finishing the 5.4 swap. My fiancee and i test drove an 01 cobra last week and with how it handled i'm really tempted to swap to an IRS in the mach. so what are the pro's and cons of having the IRS in a street car that will go to the track from time to time?

 

[buckinwild]

Both axles have their merits. Solids are preferred by drag racers where IRS's are revered by road course types. I've read alot of complaints with IRS's wheel hopping on launches and cobra owners wanting to swap for a solid axle for dragstrip use. Whereas on a road course, etc. the IRS begins to shine. Seems like I heard a simple bushing swap helps out considerably with the drag racing side of it.

 

[f8lmach]

Theres a sticky for it now:beer:

It's a tough call though... Riding in my brothers cobra is awesome but the launching in the SRA is quite nice.

 

[speedofsound]

IRS. Properly setup bumpsteer, tire choice, and better subframe bushings help a ton. I don't have any wheel hop.

 

[RcodeStang]

IRS is nice, but it's also a big pain. The factory IRS blows. You need to delrin control arm bushings, poly subframe/diff mount (or aluminum) bushings, differential brace, and bumpsteer kit to eliminate wheel hop/make it handle well. The bushings are an absolute pain in the ass to do. Changing the differential is more work. You'll now need rear alignments/bumpsteer setting. If you're interested in open track, you have to worry about overheating the differential without an expensive cooler.

A lot of people in the OT section here swear by the IRS, but everywhere else on the net condemns it. Maximum Motorsports had favorable results when they switched to IRS. All the fast American Iron cars run solid rear.

Fixing the solid rear is pretty idiot proof. Panhard bar, torque arm, LCAs. Done. Cheap, easy, proven.