[ludbg]

whats up everyone. Ivan here from Chicago. i just bought a 2003 mustang gt! It's my second mustang i had a 2000 gt last year and i loved it so had to get another one ))

bought a 2003 gt few hours ago and it has a cobra IRS (the guy didnt even know) and exhaust rear disk brakes all that stuff
but the car is just so high and i want to lower it. on my old mustang i had H&R springs and i loved the drop.
So my question is since i have the IRS what springs do i have to get? do i need front for a GT and rears for a 2003-2004 COBRA? or are the fronts of both the same so i can just get a Cobra kit and it will fit?
also whats the max rim width i can have with this setup now i read max 17x9?

i appreciate the help guys )

[manolith]

you need to get cobra springs.. the irs has diff spring rate on rear but front is about the same.. look at here. 1999-2004 Ford Mustang Lowering Springs at AmericanMuscle.com - Free Shipping!

[ludbg]

Originally Posted by manolith you need to get cobra springs.. the irs has diff spring rate on rear but front is about the same.. look at here. 1999-2004 Ford Mustang Lowering Springs at AmericanMuscle.com - Free Shipping!

yes i was just reading about the different spring rates for the front but for the rear i thought that for the back the springs are different and not just in spring rates but in size?

[ludbg]

So i found some h&r ss front ones from a gt and im going to cut the current rears a little hope the difference in spring rate wont affect the performance

[WickedSnake00]

Yes, GT springs on the front, Cobra IRS on the rear. Any 99/01 03/04 springs should fit.

I wouldn't advise cutting your rear springs, though there is nothing wrong with it. I just would prefer the stiffer aftermarket springs, they further enhance the handling qualities of the IRS in the corners. New struts don't hurt either.

You can run up to 10.5" rear rims without modification. I believe a 315 width tire will be the widest you can get without extensive modification. Some claim to run them with no modification whatsoever, but it is highly reccommended to get low profile IRS bolts and roll your fenders.

If you have any questions let me know, I've got a 2000 "GT" with an IRS...soon to be essentially an 03 Cobra. I've got 2" lowered progressive rate springs and Bilstein shocks in the rear.

[ludbg]

Originally Posted by WickedSnake00 Yes, GT springs on the front, Cobra IRS on the rear. Any 99/01 03/04 springs should fit. I wouldn't advise cutting your rear springs, though there is nothing wrong with it. I just would prefer the stiffer aftermarket springs, they further enhance the handling qualities of the IRS in the corners. New struts don't hurt either. You can run up to 10.5" rear rims without modification. I believe a 315 width tire will be the widest you can get without extensive modification. Some claim to run them with no modification whatsoever, but it is highly reccommended to get low profile IRS bolts and roll your fenders. If you have any questions let me know, I've got a 2000 "GT" with an IRS...soon to be essentially an 03 Cobra. I've got 2" lowered progressive rate springs and Bilstein shocks in the rear.

hey thanks for the reply. yea i saw your thread on the cobra clone project i know but its hard to find just rear set of aftermarket springs. i got lucky with the front ones. ill just cut a little so the front/rear difference wouldnt be too bad(maybe 1/2 coil). also its a 1999 irs so the shocks are black ones not bilsteins so i might get some tokicos.
other than that ride is very good and the car is alot more controllable than my last gt ) but got some wheel hop so ive been looking into rear bushings so the wheels might wait a little

[WickedSnake00]

You might want to check over on SVTPerformance, I'm sure you'd be able to find a used set pretty cheap over there. Assuming you don't mind used, I certainly haven't.
There are just Cobra parts galore on that forum. That's where I got my Eaton swap and engine from.

[EscortSportage]

call up MM and order some coilovers on bilsteins

[nxcoupe]

Originally Posted by EscortSportage call up MM and order some coilovers on bilsteins

Good suggestion. Cutting one half coil probably wont' be too bad. I wouldn't personally cut more than that. I am not a fan of the irs, had an 03 cobra and Ford ended up buying it back from me, mostly over the IRS issues. But they do ride nice.

[nxcoupe]

Originally Posted by WickedSnake00 Yes, GT springs on the front, Cobra IRS on the rear. Any 99/01 03/04 springs should fit. I wouldn't advise cutting your rear springs, though there is nothing wrong with it. I just would prefer the stiffer aftermarket springs, they further enhance the handling qualities of the IRS in the corners. New struts don't hurt either. You can run up to 10.5" rear rims without modification. I believe a 315 width tire will be the widest you can get without extensive modification. Some claim to run them with no modification whatsoever, but it is highly reccommended to get low profile IRS bolts and roll your fenders. If you have any questions let me know, I've got a 2000 "GT" with an IRS...soon to be essentially an 03 Cobra. I've got 2" lowered progressive rate springs and Bilstein shocks in the rear.

If you wouldn't mind, PM me a link to your build thread, I'd be interested in reading what you are doing and watching the progress. Thanks!

[WickedSnake00]

Link to the build thread is in my sig. It'll probably get moved to the project section soon.
Just search "Project: Secondhand Snake" if it doesn't work.

It should see a little bit more activity soon, hopefully getting FR500 cams/springs, injectors and TB this week. Then I can finally get my hands dirty.

Still interested to see how the OP's turned out.

-also, bushings are a must if you start getting to higher power levels. I haven't had any wheel hop problems with my Interceptor w/boltons, but I'm sure they're going to show up real quick with a pullied/ported/cammed Cobra setup.