[M.P. Cobra Fan]

I know man. I have not drank the kool aid yet. It is just so damn tempting though. Plus the weight savings. Damn.

[Lefty]

I honestly don't care about the weight lol. I had an SRA in my GT and once I got the Cobra I was hooked on IRS. Plus I love the twisties any ways

[M.P. Cobra Fan]

I love the IRS myself. Not really worried about weight either. I just get bit by the bug KWIM. I am considering doing full bushings this summer.

[Lefty]

Do full bushings first. Then see if you still wanna swap

[M.P. Cobra Fan]

so spend another $600?

[mustang_gtr_99]

Originally Posted by Lefty I honestly don't care about the weight lol. I had an SRA in my GT and once I got the Cobra I was hooked on IRS. Plus I love the twisties any ways

I love the twisties as well. I am just trying to reduce weight to obtain a higher lateral G. So far the steeda 5 link has surpassed my expectations. I had a few chance for an IRS but decided against it. Not saying the IRS isnt a great piece of engineering.

[99mustanggtman]

Originally Posted by mustang_gtr_99 I love the twisties as well. I am just trying to reduce weight to obtain a higher lateral G. So far the steeda 5 link has surpassed my expectations. I had a few chance for an IRS but decided against it. Not saying the IRS isnt a great piece of engineering.

As far as IRS' go, Ford showed a mediocre attempt at it. If they would have engineered the IRS better we wouldn't have to spend so much on the 03/04 IRS to perform the way it should.

[M.P. Cobra Fan]

It would be a great system if the SVT engineers would have stopped listening to the Ford guys about road noise and vibration. Its a fucking sports car. They should have just gone with at the very least a polyurethane bushing setup.

[SS Ball3r]

well, if your doing a swap then you might as well put all poly bishings in. But yeah, they should have just gone for the whole package when designing it.

[M.P. Cobra Fan]

Agreed. If you are going to swap in an IRS get all the bushings first and put them in while you have the IRS out.
If you are going SRA, then go ahead and buy control arms and all that good shit. That is my plan if and when I do a SRA.

[dcook_14]

MM really advocates the IRS from the 03/04 Cobras. They said in thier road course testing their built IRS was like 3 seconds faster than their built SRA in the same car. Here's what Chuck said in an interview about it


NASA Pro Racing – Interview with Chuck Schwynoch, CEO
Maximum Motorsports, Inc.
June 28, 2006
By Andy Bowman

Q. The #91 MM Mustang is using an IRS rear suspension, what drove you to this decision, how has the effort been going so far?

A. We had a growing number of customers who called us and said that they were not happy with their IRS, and asked us if they should swap in the proven MM Torque-arm/Panhard Bar rear suspension. We couldn't give them a truthful answer until we had done our own testing to directly compare the Ford IRS to a well-sorted Torque-arm/Panhard bar system. Our AI race car had won races, and set track records, so it was the perfect candidate for comparison. We swapped the rear end over to the IRS, with all of the parts we had developed over the previous year on a street-driven 2003 Cobra. We left the front of the car exactly as it was with the Torque arm suspension. We maintained the exact same rear track width, and even swapped over the same brakes, rotors, calipers, and pads, from the solid axle. We then hit the track for testing. By the end of the first day of testing we were 3 seconds under the AI track record at Buttonwillow. With the IRS we had to learn what alignment and bumpsteer settings worked best. That's what testing told us. Without track testing, we really could not have given our customers an honest answer to their questions about the IRS. Even if our testing had shown the IRS to be grossly inferior to a solid axle, we at least would then be able to help our customers make an informed decision about modifying their car. As it turned out, the IRS is superior to a solid axle fitted with a Torque-arm and Panhard bar, in most aspects.



An IRS seems cheaper to build up too. You already have a 31 spline diff, strong half shafts, bilstien shocks, and 600 lb springs with the 03/04 cobra. Get a complete bushing kit, IRS brace, and diff case brace and you're probably good to go. With an SRA you have to dick around doing axles, 31 spline carrier, springs, shocks, panhard bar, torque arm, lower control arms... basically replace everything except the axle housing and add phb/ta. Plus from what I've gathered it's much easier to put in the bushings and braces on an IRS rather than put all the stuff onto an SRA

[weems]

Originally Posted by dcook_14 MM really advocates the IRS from the 03/04 Cobras. They said in thier road course testing their built IRS was like 3 seconds faster than their built SRA in the same car. Here's what Chuck said in an interview about it NASA Pro Racing – Interview with Chuck Schwynoch, CEO Maximum Motorsports, Inc. June 28, 2006 By Andy Bowman Q. The #91 MM Mustang is using an IRS rear suspension, what drove you to this decision, how has the effort been going so far? A. We had a growing number of customers who called us and said that they were not happy with their IRS, and asked us if they should swap in the proven MM Torque-arm/Panhard Bar rear suspension. We couldn't give them a truthful answer until we had done our own testing to directly compare the Ford IRS to a well-sorted Torque-arm/Panhard bar system. Our AI race car had won races, and set track records, so it was the perfect candidate for comparison. We swapped the rear end over to the IRS, with all of the parts we had developed over the previous year on a street-driven 2003 Cobra. We left the front of the car exactly as it was with the Torque arm suspension. We maintained the exact same rear track width, and even swapped over the same brakes, rotors, calipers, and pads, from the solid axle. We then hit the track for testing. By the end of the first day of testing we were 3 seconds under the AI track record at Buttonwillow. With the IRS we had to learn what alignment and bumpsteer settings worked best. That's what testing told us. Without track testing, we really could not have given our customers an honest answer to their questions about the IRS. Even if our testing had shown the IRS to be grossly inferior to a solid axle, we at least would then be able to help our customers make an informed decision about modifying their car. As it turned out, the IRS is superior to a solid axle fitted with a Torque-arm and Panhard bar, in most aspects. An IRS seems cheaper to build up too. You already have a 31 spline diff, strong half shafts, bilstien shocks, and 600 lb springs with the 03/04 cobra. Get a complete bushing kit, IRS brace, and diff case brace and you're probably good to go. With an SRA you have to dick around doing axles, 31 spline carrier, springs, shocks, panhard bar, torque arm, lower control arms... basically replace everything except the axle housing and add phb/ta. Plus from what I've gathered it's much easier to put in the bushings and braces on an IRS rather than put all the stuff onto an SRA

That's only for the twisties though.

[M.P. Cobra Fan]

Good point weems. That interview is very interesting though.

The main advantages I see with the SRA are weight, and wheel hop. If you are running straight lines, then SRA is hands down the way to go. Twisties, IRS and SRA both have advantages.


Good find D.

[SS Ball3r]

Originally Posted by weems That's only for the twisties though.

Thats because drag racing sucks.

[dcook_14]

Originally Posted by weems That's only for the twisties though.

Yeah but I thought that's what we were talking about. If we're talking straight line then it's not even a discussion, it's SRA all the way.

Originally Posted by M.P. Cobra Fan Good point weems. That interview is very interesting though. The main advantages I see with the SRA are weight, and wheel hop. If you are running straight lines, then SRA is hands down the way to go. Twisties, IRS and SRA both have advantages. Good find D.

Thanks. MM is basically saying that for twisties, IRS is the way to go.
Plus I think it'd be cheaper. A MM PHB/TA is at least $800. The best IRS bushing kit on the market is $600 and an IRS bracket is $50. You're going to have a hard time getting the wheels to hop if you have the Full Tilt Boogie bushings.