Is there a good writeup on how to build the IRS on a 99 Cobra? I want to change out the 29 spline axels for 31 spline and get a better differential. What parts are needed to build the IRS? Also, what kind of power can a built IRS hold? I'm looking to twin turbo my cobra and I think the IRS would be the first thing to break.

 

The IRS bible is over at SVTPerformance.com in a sticky in the NewEdge section. A built IRS is actually cheaper and better performing than a SRA.

 

http://www.svtperformance.com/forums...d.php?t=231900

^^there you go

basically bushings, girdles and half-shafts. polyurethane subframe bushings, polyurethane UCA/LCA bushings, differential girdle, solid/poly differential bushings, solid differential mount, thicker tie rods or bumpsteer kit, level 1,2 or 5 halfshafts, springs/shocks or coil-overs. in the 99 cobras case, a new differential. other options include shms shepherical spindle upgrade, finding kenny brown UCAs/LCAs, thicker 03-04 pinion flanges (need a shorterdriveshaft) or mods such as these done to the carrier:

http://www.mustang50magazine.com/tec...ion/index.html

 

just swap in the irs out of an 03-04, might be easier but i don't know.

 

Thanks for the repilys. thats a great site.

 

swapping an entire IRS is as simple as dropping exhaust pipes, disconnecting brakes and driveshaft and pulling 4 bolts.

A STOCK IRS out of an 03/04 is only going to be marginally stronger and WILL NOT be the end-all solution to a high-horsepower application.

 

isn't the 03/04 irs pretty close the the stuff he was describing, did not sound to me like the op was really talking about going all out on it.

 

Solid Axle FTW........

 

thats what i got, i have a complete 03-04 IRS including drive shaft to sell now though.

 

he was talking about going twin turbo. Thats fairly all-out in my book.... more than what I would trust a stock 03/04 IRS with. just because it came out of a Terminator doesnt mean its indestructible.

Solid axle IS cheaper to built to handle more horsepower.