Solid to IRS conversion

[LaserSVT]

Just an idea I have been toying with. Is this a hard swap or can I do it in my garage with hand tools and jackstands. Is there any cutting or welding? Also where is the best place to locate an IRS with all the parts. Can I still use the same DS? Will I have to change the whole exhaust or only the tail pipes? Thanks for the help and info guys

 

[SRT Handz]

Lots of Work....You also have to drill and tap hole, Whole new exhaust, More weight to the car, ECT

 

[Blinkstang]

This going in your 96' Cobra? For 99-04' cars, such as mine, its a direct swap. But for Pre-99 cars a few modifications have to be performed - nothing crazy. This guy has a pretty good writeup with all the little changes that need to be made, read thru the whole thread, he gives all the info you should need throughout a few of his posts - LINK.

 

[mustangkid05]

i thought you are going TT? if you are doing that, id say keep the solid because alot of termi owners switch over to solid axle for drag racing purposes

 

[LaserSVT]

Still wanting to do the TT thing down the road, it just seems for the cost of a panhard, LCA's, torque arm and all I can get a used IRS and do the few mods it takes to correct the wheelhop problem. I dont plan on going to the drags other than once ot twice (for the times the car should be able to run I would need a roll bar and dont want to do that) I just want the car to be a bad arse street car with great handling and ride. I think the IRS would work best for what I want to accomplish. Also it will make the car a little more unique. Bennyblown has an IRS and he loves it

 

[SRT Handz]

Bennyblown has had a solid, then a IRS, Then back to a Solid...Now he's on IRS #2...He never knows what he wants

 

[tiptone]

I say go for it, I swapped in an IRS last week and I love the way it rides. As far as straight line driving I don't notice much change, but driving on a bumpy road is a night and day difference from the stock SRA.

 

[BennyBlown2v]

Bennyblown has had a solid, then a IRS, Then back to a Solid...Now he's on IRS #2...He never knows what he wants

:OT:

Yes Big thing was everyone kept saying how "a fully built solid axle is just as good as a moded IRS" so I just HAD to see for myself All of that...is total IMO! Honestly if the car had started out with an IRS i would have just gone IRS-->SRA-->IRS, but it didn't so I had to do it again (not to mention the rear end that was in my car stock came pre-bent 3/4" out of toe alignment symmetrically from Ford).

IRS in a SN95 is not hard, you already have two of the holes for the brackets already so all you have to do is drill and make some brackets and bolt the brackets to the frame rail and/or floor pan of the trunk. You can also opt to remove the fuel tank and weld the brackets onto the frame rail, but that requires more that you know what you're doing.

 

[LaserSVT]

Thanks Benny and thats my point. I have heard so much how a properly set up SRA can handle just as well as an IRS but when I talk to someone who has actually done the swap they love the IRS. True a SRA is better for drag racing but I am not building my car for that (mabey a Fox notch one day ) I just want a killer street car and the IRS is the way. Blinkstangs link was perfect, the mods needed for the 94-98 are really minimal and the end result is soooo worth it. Like I said before, for the price of all the parts and labor to build the solid axle is actually higher than the IRS with all the better bushings and diff supports. Yeah I gotta get a new cat back, but that is cheep for another Flowmaster and I can sell my brand new one for $150 to offset the cost, hell my axle is freshly rebuilt with 3.73's so I am sure I can get a couple hundred for that too

 

[BennyBlown2v]

Thanks Benny and thats my point. I have heard so much how a properly set up SRA can handle just as well as an IRS but when I talk to someone who has actually done the swap they love the IRS. True a SRA is better for drag racing but I am not building my car for that (mabey a Fox notch one day ) I just want a killer street car and the IRS is the way. Blinkstangs link was perfect, the mods needed for the 94-98 are really minimal and the end result is soooo worth it. Like I said before, for the price of all the parts and labor to build the solid axle is actually higher than the IRS with all the better bushings and diff supports. Yeah I gotta get a new cat back, but that is cheep for another Flowmaster and I can sell my brand new one for $150 to offset the cost, hell my axle is freshly rebuilt with 3.73's so I am sure I can get a couple hundred for that too

Yep, for sure.

I just went with my friend to pickup an IRS for his 97 Cobra, he just straight up traded his solid axle (which only had lower control arms and tokico shocks), but he kept his exhaust and everything so he has that to sell to make some cash and get a cobra exhaust and all that setup. Shouldn't be fun, especially since he has a blower and all that (he's trying to copy my setup I think, but doesn't wanna go all out and do coilovers cuz he's a puss LOL).

 

[Zax]

I have had both and I prefer the IRS by far. Much less mods to handle. I corner like Im on rails

 

[LaserSVT]

So who on here wants to trade their IRS for my SRA? It has 6 month old 3.73's and a new Trac-Loc.

BTW does the IRS use the same shocks and springs?

 

[tomustang]

:OT:

Yes Big thing was everyone kept saying how "a fully built solid axle is just as good as a moded IRS"

That is based on 'track' prospective, which is kind of true, but the IRS is a bit better since it can be more adjusted

On the street it's a no brainer

 

[BennyBlown2v]

That is based on 'track' prospective, which is kind of true, but the IRS is a bit better since it can be more adjusted

On the street it's a no brainer

Yes - but I track my car so whateva IMO the handling characteristics of the IRS (agreed, simply due in part to the adjustability of the setup, but moreover the fundamental difference in function) are better for the track, as well as the street.

The BIG reason for a solid axle on a full race car is it's simplicity and ease of fixing in the pits and at home - with a Cobra IRS is not quite as easy to say, pull and swap axles, or repair a broken diff. A simple setup that works well is often better than a complicated setup that works better, given that sort of situation.

 

[tiptone]

So who on here wants to trade their IRS for my SRA? It has 6 month old 3.73's and a new Trac-Loc.

BTW does the IRS use the same shocks and springs?

I've read of people using the IRS and SRA shocks interchangeably but I didn't. Most places that sell them sell a different set for IRS but I haven't looked close enough to see if they are actually different. Springs are for sure different and you'll need the ones from the IRS when you swap it in.

 

[BennyBlown2v]

BTW does the IRS use the same shocks and springs?

Nope! You'll need new springs, and shocks. www.stangsuspension.com use coupon code stangnet lol...good prices

 

[tomustang]

Yes - but I track my car so whateva IMO the handling characteristics of the IRS (agreed, simply due in part to the adjustability of the setup, but moreover the fundamental difference in function) are better for the track, as well as the street.

The BIG reason for a solid axle on a full race car is it's simplicity and ease of fixing in the pits and at home - with a Cobra IRS is not quite as easy to say, pull and swap axles, or repair a broken diff. A simple setup that works well is often better than a complicated setup that works better, given that sort of situation.

gotta love it, you can throw together a SRA kit in one car and an IRS kit in another, the SRA guy is making laps while the IRS guy is still tuning in his setup

the IRS weighs too damn much and it was never orginally designed for the mustang so it does take alot of work to make it run better, The weight in the rear would help f/r distro though, was in the plan with a lighter front but life keeps putting halts on the cobra project

 

[tiptone]

gotta love it, you can throw together a SRA kit in one car and an IRS kit in another, the SRA guy is making laps while the IRS guy is still tuning in his setup

the IRS weighs too damn much and it was never orginally designed for the mustang so it does take alot of work to make it run better, The weight in the rear would help f/r distro though, was in the plan with a lighter front but life keeps putting halts on the cobra project

The whole setup is heavy, and does add to the overall weight of the car. In addition to helping with the front/rear weight distribution this also removes 125lbs of unsprung weight from the car, helping to offset the addition overall weight of the piece. Hands down, my car drives better day-to-day over all road surfaces and conditions with the IRS in there.