Science experiment - can the IRS from the S550 be transplanted into a 13/14 GT500?

[PhoenixM3]

All,

Yep, probably a crazy idea, but would it withstand the power transmitted from a stock Shelby? I wonder how much fabrication would be needed, and would this solution perform as well as a Griggs setup on my car.

Anyway, just a random thought in the middle of the night.....

Ciao,

Jeff

 

[heatsoaked12]

The 15 irs is quite a bit wider than our differentials. They also seem to have a wheel hop problem that would need to be sorted out. With some major fabrication and $ sure it can be done. would it be worth it? I would look for a doner from another car with the same width as ours to start.

 

[Robot_trainer]

All,

Yep, probably a crazy idea, but would it withstand the power transmitted from a stock Shelby? I wonder how much fabrication would be needed, and would this solution perform as well as a Griggs setup on my car.

Anyway, just a random thought in the middle of the night.....

Ciao,

Jeff

Why would you want too? I dont think you are going to see a huge difference even in at a road course. Besides, i don't know if the diff will handle the torque of that blown 5.8.

 

[Imatk]

I think this would be a big mistake. I suspect that Ford will be working on that IRS (and probably is right now) and will be changing things if they stick with it.

Right now every review has shown the suspension to be not so great.

And wheel hop would be reeeeediculous at over 600hp.

 

[Tob]

All,
Yep, probably a crazy idea, but would it withstand the power transmitted from a stock Shelby? I wonder how much fabrication would be needed, and would this solution perform as well as a Griggs setup on my car.

Jeff

Jeff, I've wondered the same thing. If I can get my hands on a takeout subframe/IRS at a reasonable price I'll make it happen.

 

[stkjock]

Jeff, I've wondered the same thing. If I can get my hands on a takeout subframe/IRS at a reasonable price I'll make it happen.

why does this not surprise me..... :beer:

 

[Tob]

If Ford Racing had their act together they'd have had a kit ready to go.

Simply trying to get the CAD files from SEMA to overlay the S197/S550 pickup points is the biggest obstruction to taking a quick and easy look.

 

[SlowSVT]

I'm sure it can be done but something tells me a sub-frame will be needed for the sub-frame to connect it to the body structure. Look where the mounting points are.

Is the S197 rear suspension mounting points similar to the SN95?

 

[Tob]

The subframe can be modified, as can anything else. Or if Total Performance would let one of their cancelled S197 IRS setups go...

 

[CodyK7]

Why would you want to? Serious question?

 

[heatsoaked12]

Why would you want to? Serious question?

I would like a ride closer to the European sport models if there weren't any down side.

 

[01SVTSnake]

Solid axles ride like ass on the street. You if hit a pavement imperfection in a turn the rear end of the car is all over the place. That was one of the biggest complaints I had on my 11 and the 13 is probably just the same.

Granted the 15+ IRS looks to be off to a rough start performance wise with wheel hop etc, the Ford Racing subframe kit & HD halfshafts and some good tires seemed to nullify almost all wheelhop in the drag videos Ford post a few months back. If the S550 IRS could be installed into a S197 frame without extreme modification, I would be sold on it. Just upgrade the bushings and halfshafts before install

 

[PhoenixM3]

Why would you want too? I dont think you are going to see a huge difference even in at a road course. Besides, i don't know if the diff will handle the torque of that blown 5.8.

Well, I don't ever plan on drag racing, and probably won't track the car on any thing more serious than an HPDE. Yep, it would be a lot pricier to do this than just modify the rear suspension. I'm betting that someone will make this transplant work, but probably NOT on a GT500.

 

[PhoenixM3]

Jeff, I've wondered the same thing. If I can get my hands on a takeout subframe/IRS at a reasonable price I'll make it happen.

Tob, most view you as someone who'd actually execute this project. I'm more of thinker, not a doer.....

 

[PhoenixM3]

Why would you want to? Serious question?

Well, for one thing I'm not crazy about the "steer from the rear" forklift steering under even half throttle conditions.

 

[Tob]

Why would you want to? Serious question?

Do you know how close we were to having an S197 with an IRS? I invite you to take a few moments and read through the following article.

http://www.drivingenthusiast.net/sec-blog/?p=11329


This past summer I was lucky enough to be invited to join Rehagen Racing in the pits during the Pirelli World Challenge races in Toronto. A great weekend, including the inadvertent opportunity to discuss the Hellcat with Ralph Gilles of Chrysler (he went toe to toe and didn't miss a beat) as well as pick the brain of Filip Trojanek of Cortex (he was there in support of Rehagen that weekend). No doubt, the highlight was getting the chance to discuss a number of S197 related items with Dean Martin from Rehagen. Dean won the race in the GTS class on Saturday and Hooper West (who also took the photograph in previous link) and I were lucky enough to be asked if we wanted to go out to dinner that night to celebrate with the team. We ate at a fabulous Italian restaurant at the edge of the city limits. Sitting next to Dean, I took advantage of the opportunity to ask him a few things about our beloved S197's.

I had followed the mumblings about an ill-fated S197 IRS and seen a few photos then pretty much forgot about it. So when Dean started to talk about Coletti, '03-'04 Cobra and R development, etc, I asked about the IRS that was earmarked for the '05. He confirmed it was killed as mentioned in the above Drivingenthusiastblog link. I then asked him how it actually drove. He said he was tasked with driving one of the development cars that was equipped with the IRS. He stated that it didn't take long to realize that the car was pretty well sorted out. He said he pulled up, got out of the car and handed over the keys, and let it be known that he felt that the car was ready as is. That it was that good. I think I uttered a "you gotta be kidding me" and he looked me square in the eye and smiled. I mentioned seeing an entire prototype assembly floating around (one popped up in a post here at SVTP) the web. He then yelled over the table to his ace mechanic Jesse and asked him if he remembered the two IRS S197 cars that he bought from Ford for next to nothing. I asked him whatever happened to the IRS portions and he said something about John Vermeersch at Total Performance having a couple of them.

So I suppose in the above context, you could see why anyone might have an interest in doing what should have been done in the first place. You can argue about weight, blah blah blah, but in the end, the pig that the GT500 was would have been a heck of a car with the IRS that was killed off. The chassis rails would still have kicked up (unlike the S550) and thus allowed solid axle swaps with ease for the knuckle dragging crowd. But it sure would have been interesting with a factory IRS. And you know that the aftermarket would have made it even better.

 

[SID297]

Dean is a fan of the S-197 IRS. It would be interesting to see someone install one in a track-day car.

 

[mobeydick]

Solid axles ride like ass on the street. You if hit a pavement imperfection in a turn the rear end of the car is all over the place. That was one of the biggest complaints I had on my 11 and the 13 is probably just the same.

Granted the 15+ IRS looks to be off to a rough start performance wise with wheel hop etc, the Ford Racing subframe kit & HD halfshafts and some good tires seemed to nullify almost all wheelhop in the drag videos Ford post a few months back. If the S550 IRS could be installed into a S197 frame without extreme modification, I would be sold on it. Just upgrade the bushings and halfshafts before install

99% of Mustang buyers can't tell you the difference between a IRS and a SRA, of the 1% that can 99% of those can't tell the difference driving on the street. The only advantage IRS gives the user is that .05% difference it takes to win vs. a SRA on the track! The IRS on the S550 platform will be replaced with a SRA within two years or the whole platform will be gone in three. It cost twice as much as a SRA and gives little performance value to the vast majority of Mustang buyers (may be even more expensive then that). Ford put it in to compete in the European market. That market doesn't buy American Muscle cars. The Camaro with a IRS has been available in the European market for 5 years and they are lucky to sell 1,500 a year. Most of the Mustangs and Camaros sold in the EU are bought by Americans!

The IRS in the S550 is a failure, it needs getting rid of now, not tomorrow!

 

[2112]

In a race set up, an SRA can be made to work well. As good as an IRS? IDK

I will take an IRS over an SRA on the streets with expansion joints etc all day long. An IRS just doesn't buck and kick like an SRA does on less than perfect roads.

 

[BlownAway03]

I sure wish my 13 would've had IRS. The ride was one of my least favorite things about the car. I won't even mention sport mode.