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

[01SVTSnake]

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!

Odd, because most of my friends (some who aren't car people and some that are) noted how unplanted the rear end of the car seemed under any sort of power through less than perfect roads. They wouldn't be in the market for a sports/muscle car anyway but they still noticed. I believe Ford left a lot of room in the S550 IRS as they did with the 03-04 Cobras. They probably missed where it should be in terms of NVH for the enthusiast, but to people with the V6, EB, and a few 5.0s the ride is perfect and they probably will never see wheel hop.

Performance pack should really include better bushings/subframes/halfshafts or whatever it takes to eliminate most or all wheelhop. Most people in this segment won't care about a little NVH considering many are going to upgrade exhausts, lower the cars etc.

I went from my 11 Shelby to an 06 Viper and even though its a different type of car, the IRS in the viper is amazing to drive on the streets compared to a SRA car. I have very high hopes that the GT350 takes on the IRS issues and makes a hell of a car.

 

[mobeydick]

Odd, because most of my friends (some who aren't car people and some that are) noted how unplanted the rear end of the car seemed under any sort of power through less than perfect roads. They wouldn't be in the market for a sports/muscle car anyway but they still noticed. I believe Ford left a lot of room in the S550 IRS as they did with the 03-04 Cobras. They probably missed where it should be in terms of NVH for the enthusiast, but to people with the V6, EB, and a few 5.0s the ride is perfect and they probably will never see wheel hop.

Performance pack should really include better bushings/subframes/halfshafts or whatever it takes to eliminate most or all wheelhop. Most people in this segment won't care about a little NVH considering many are going to upgrade exhausts, lower the cars etc.

I went from my 11 Shelby to an 06 Viper and even though its a different type of car, the IRS in the viper is amazing to drive on the streets compared to a SRA car. I have very high hopes that the GT350 takes on the IRS issues and makes a hell of a car.

That's funny, yesterday, I asked a salesman at Mike Davison Ford what does the IRS actually do different then an SRA and he had no clue. He knew the IRS was supposed to be better. Mind you that was from someone who when I pulled up in my Superduty started making claims about he was a diesel guy also and his truck made 800hp and such. I also asked the Finance manager the same question because he bought the first 2015 5.0 Mustang that was delivered to the dealership and he had no clue either!

 

[Tob]

I have very high hopes that the GT350 takes on the IRS issues and makes a hell of a car.

I'm quite sure the vehicle dynamics people in the Mustang group could have delivered a setup that would have knocked your socks off on any '15 mustang. Product planning is holding them back (as they always do) with a plan to introduce mild improvements (in terms of performance) as the S550 ages. Hopefully, FRPP can get their act together and be in a position to offer the hardware that was deemed too harsh for the entire '15 target market - soon.

That's funny, yesterday, I asked a salesman at Mike Davison Ford what does the IRS actually do different then an SRA and he had no clue. He knew the IRS was supposed to be better. I also asked the Finance manager the same question because he bought the first 2015 5.0 Mustang that was delivered to the dealership and he had no clue either!

Asking anyone at the dealer level for technical information is akin to asking a fish to explain the quadratic formula.

 

[01SVTSnake]

That's funny, yesterday, I asked a salesman at Mike Davison Ford what does the IRS actually do different then an SRA and he had no clue. He knew the IRS was supposed to be better. Mind you that was from someone who when I pulled up in my Superduty started making claims about he was a diesel guy also and his truck made 800hp and such. I also asked the Finance manager the same question because he bought the first 2015 5.0 Mustang that was delivered to the dealership and he had no clue either!

Knowing and feeling are 2 completely different things. Hell comparing the ride and handling on a Mustang vs a Disel is comparing apples to vacuum cleaners. Its completely different. The SRA in my raptor does its job just fine. Im also not expecting is to pull near 1g on a skid pad or do a slalom at 65+ MPH. Hell taking turns at high speed I feel like im listing on the top of a boat. My friends who noticed the unsteadiness while riding in my GT500 on rough roads couldn't explain the difference between the two aside from their names and how it rides but they could feel the car was more planted and I was fighting it less during driving. Most dealership employees are pretty worthless in terms of technical details (Not all though). When I got my raptor the salesman tried to tell me the HID lights had to do with the computer system in the truck.

If SRAs were perfect many elite sports/exotic/hyper cars would use them to save weight and be cheaper. To my knowledge the M3/M5/M6, Nissan GTR, AMG C63/SLS/E63/SL65 etc mercedes, Corvettes, and exotic cars all use the IRS to name a few. They seem to do just fine with them. They tend to go after handling more than mustangs do anyway so I trust their judgement using an IRS (properly done) They can make these cars pretty damn fast in a straight line too and have no issues with the IRS' with some work.

The Mustang isn't in the same class and is cheaper than most if not all of the cars I listed above, but the days of "muscle" cars being nothing but straight line machines are dwindling. Not to say their straight line performance has gone down hill but the market/consumer wants to have their cake and eat it too. Most US roads probably aren't stellar (I know PA isn't) so we need something to combat the crappy conditions while having a good ride and not have the back end feeling all over the place.

People are also saying with these IRS' having wheel hop that it is a total failure, but yet I see people putting in springs, LCAs and mounts, UCA + mount, panhard rods, watts link, torque arms, better tires to combat wheel hop with their SRA cars. Going back to the factory, they have to find the balance of performance and comfort as many people who drive these cars will never push them like enthusiasts and have no problem with the hop if they ever feel it more than a handful of times they own the car on either a IRS or SRA car. This leaves the aftermarket open as well (Bruce @ Full tilt im hoping you step up!) I am sure someone will also have a solid axle drop in for the people that want to drag race them more seriously.


Going back to the topic, TOB if you somehow did this or got a hold of the S197 IRS it would be wonderful. Im still not 100% on the looks of the S550 front end (hoping the aftermarket has some nice offerings) The GT350 won't be out soon and I would love the have a 13-14 662hp base car with a good IRS. Its the only reason I haven't gotten out of the viper and back into a stang. Would like to drive a S550 w/ Performance Pack to try it

 

[PhoenixM3]

Coming from a decade of driving IRS equipped M3's, I noticed that the rear end of the Shelby wasn't even close to being as confidence inspiring. I trust that Ford (and the aftermarket crowd) will get any wheel hop foibles corrected with the S550 platform, and in 5 years everyone will be saying, "why the hell didn't Ford utilize IRSs in the first place (Terminators aside).

I'm finished drinking BMW's koolaid, and am intoxicated with the power that a stock Shelby brings. I will focus on suspension tweaks and handling before upping HP and skewing the (already) out of whack power-to-handling ratio.

 

[PhoenixM3]

Knowing and feeling are 2 completely different things. Hell comparing the ride and handling on a Mustang vs a Disel is comparing apples to vacuum cleaners. Its completely different. The SRA in my raptor does its job just fine. Im also not expecting is to pull near 1g on a skid pad or do a slalom at 65+ MPH. Hell taking turns at high speed I feel like im listing on the top of a boat. My friends who noticed the unsteadiness while riding in my GT500 on rough roads couldn't explain the difference between the two aside from their names and how it rides but they could feel the car was more planted and I was fighting it less during driving. Most dealership employees are pretty worthless in terms of technical details (Not all though). When I got my raptor the salesman tried to tell me the HID lights had to do with the computer system in the truck.

If SRAs were perfect many elite sports/exotic/hyper cars would use them to save weight and be cheaper. To my knowledge the M3/M5/M6, Nissan GTR, AMG C63/SLS/E63/SL65 etc mercedes, Corvettes, and exotic cars all use the IRS to name a few. They seem to do just fine with them. They tend to go after handling more than mustangs do anyway so I trust their judgement using an IRS (properly done) They can make these cars pretty damn fast in a straight line too and have no issues with the IRS' with some work.

The Mustang isn't in the same class and is cheaper than most if not all of the cars I listed above, but the days of "muscle" cars being nothing but straight line machines are dwindling. Not to say their straight line performance has gone down hill but the market/consumer wants to have their cake and eat it too. Most US roads probably aren't stellar (I know PA isn't) so we need something to combat the crappy conditions while having a good ride and not have the back end feeling all over the place.

People are also saying with these IRS' having wheel hop that it is a total failure, but yet I see people putting in springs, LCAs and mounts, UCA + mount, panhard rods, watts link, torque arms, better tires to combat wheel hop with their SRA cars. Going back to the factory, they have to find the balance of performance and comfort as many people who drive these cars will never push them like enthusiasts and have no problem with the hop if they ever feel it more than a handful of times they own the car on either a IRS or SRA car. This leaves the aftermarket open as well (Bruce @ Full tilt im hoping you step up!) I am sure someone will also have a solid axle drop in for the people that want to drag race them more seriously.


Going back to the topic, TOB if you somehow did this or got a hold of the S197 IRS it would be wonderful. Im still not 100% on the looks of the S550 front end (hoping the aftermarket has some nice offerings) The GT350 won't be out soon and I would love the have a 13-14 662hp base car with a good IRS. Its the only reason I haven't gotten out of the viper and back into a stang. Would like to drive a S550 w/ Performance Pack to try it

Couldn't agree with you more....

 

[mobeydick]

Knowing and feeling are 2 completely different things. Hell comparing the ride and handling on a Mustang vs a Disel is comparing apples to vacuum cleaners. Its completely different. The SRA in my raptor does its job just fine. Im also not expecting is to pull near 1g on a skid pad or do a slalom at 65+ MPH. Hell taking turns at high speed I feel like im listing on the top of a boat. My friends who noticed the unsteadiness while riding in my GT500 on rough roads couldn't explain the difference between the two aside from their names and how it rides but they could feel the car was more planted and I was fighting it less during driving. Most dealership employees are pretty worthless in terms of technical details (Not all though). When I got my raptor the salesman tried to tell me the HID lights had to do with the computer system in the truck.

If SRAs were perfect many elite sports/exotic/hyper cars would use them to save weight and be cheaper. To my knowledge the M3/M5/M6, Nissan GTR, AMG C63/SLS/E63/SL65 etc mercedes, Corvettes, and exotic cars all use the IRS to name a few. They seem to do just fine with them. They tend to go after handling more than mustangs do anyway so I trust their judgement using an IRS (properly done) They can make these cars pretty damn fast in a straight line too and have no issues with the IRS' with some work.

The Mustang isn't in the same class and is cheaper than most if not all of the cars I listed above, but the days of "muscle" cars being nothing but straight line machines are dwindling. Not to say their straight line performance has gone down hill but the market/consumer wants to have their cake and eat it too. Most US roads probably aren't stellar (I know PA isn't) so we need something to combat the crappy conditions while having a good ride and not have the back end feeling all over the place.

People are also saying with these IRS' having wheel hop that it is a total failure, but yet I see people putting in springs, LCAs and mounts, UCA + mount, panhard rods, watts link, torque arms, better tires to combat wheel hop with their SRA cars. Going back to the factory, they have to find the balance of performance and comfort as many people who drive these cars will never push them like enthusiasts and have no problem with the hop if they ever feel it more than a handful of times they own the car on either a IRS or SRA car. This leaves the aftermarket open as well (Bruce @ Full tilt im hoping you step up!) I am sure someone will also have a solid axle drop in for the people that want to drag race them more seriously.


Going back to the topic, TOB if you somehow did this or got a hold of the S197 IRS it would be wonderful. Im still not 100% on the looks of the S550 front end (hoping the aftermarket has some nice offerings) The GT350 won't be out soon and I would love the have a 13-14 662hp base car with a good IRS. Its the only reason I haven't gotten out of the viper and back into a stang. Would like to drive a S550 w/ Performance Pack to try it

Try Comprehending, I never, not one time said SRA was perfect or even close to that. What I'm telling you is with only 80,000 units sold a year the Mustang is GONE, FINISHED! GM knew this in 2000 and killed the Camaro in 2002. Ford is trying a last ditch effort to save the Mustang and sell the Mustang to Europeans and to do that they think Europeans will buy a Mustang an IRS. If Europeans wanted a Pony car with IRS the Camaro has be available to them for 5 years and GM sells 1,500 a year over there! Trying to please Europeans and destroying your base is NOT sound business practice!

The days of the Muscle car are almost done anyway regardless if the Mustang has an IRS! Again the bean counters have told the Marketing department at Ford either boost sales or the Mustang is gone. An IRS that cost $500 more on a vehicle that 99% of the buyers could care less what rear suspension it has is foolish!

 

[2112]

In my opinion, 90% of buyers want a smoother handling car, not 1/4 mile capability. They don't know or care how it is done.

I think they are making the right move. If $500 is the make or beak on selling volume on a car in this piece range, it is doomed either way.

Personally, I can't get past the front end esthetics so I am sticking with my 14'.

 

[brad65ford]

I feel the difference and hate a solid axle, we are past the 50's and 60's. WTF Ford they should have never stop with progression with the irs, this is one area Ford has failed IMO. I'd love a IRS upgrade for my 13 shelby end of story. Unfortunately i doubt the new IRS plate forum will swap into the earlier years. The 03/04 cobra irs can easily fit in any of the Fox bodys which is pretty cool IMO.

Bottom line IRS's look cool too. Love how the rear end squats on the 03/04 cobra. I hate having the solid in my 13 Shelby. Damn you Ford ! Way go backwards !!

 

[HooperWest]

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

Didn't Multi-Matic http://www.multimatic.com/index.shtml make AND sell (to some Euro Race Team) some S197 IRS set-ups?

 

[Robot_trainer]

I'm sure with a little work the solid axle's performance can be made to perform much better than it is, although for what it is it's actually pretty good.

 

[Robot_trainer]

That looks heavy! And I mean weight wise.

 

[Tob]

Didn't Multi-Matic http://www.multimatic.com/index.shtml make AND sell (to some Euro Race Team) some S197 IRS set-ups?

Roush is mentioned as the source in post #13 of the following thread.
http://www.svtperformance.com/forums/showthread.php?664427-The-rear-suspension-that-could-have-been

 

[93 347 Cobra]

The SRA in the Shelby is pretty damn good for what it is but I'd take an IRS any day over it. I do miss the ride quality and handling dynamics on my '03 Cobra, even with its compromised design. Taking a curved on-ramp at 80 and hitting a pavement transition is unnerving in the Shelby as the rear jumps right or left half a foot. Driving over undulating pavement on the interstate at 90-100 and having the suspension compress causes the car to wiggle slightly due to the rear steering effect of the SRA. Hitting pavement transitions in a straight line while accelerating causes the rear to skip and it jolts the car. There are just too many reminders of its handling drawbacks, especially when driving enthusiastically on backroads.

 

[SlowVert]

The SRA in the Shelby is pretty damn good for what it is but I'd take an IRS any day over it. I do miss the ride quality and handling dynamics on my '03 Cobra, even with its compromised design. Taking a curved on-ramp at 80 and hitting a pavement transition is unnerving in the Shelby as the rear jumps right or left half a foot. Driving over undulating pavement on the interstate at 90-100 and having the suspension compress causes the car to wiggle slightly due to the rear steering effect of the SRA. Hitting pavement transitions in a straight line while accelerating causes the rear to skip and it jolts the car. There are just too many reminders of its handling drawbacks, especially when driving enthusiastically on backroads.

I know this is a blanket statement... but SRA works if you live in areas where freezing winters aren't a concern... if you live in areas where ice destroys roads on a yearly basis - you'll really notice the difference between a SRA and IRS car.... my wifes Infinity G35S feels like I'm riding on a cloud compared to Mustang - and it's not a pure stiffness thing - it's just not anywhere near as "jumpy" in the turns or on bridges/joints/potholes/etc - and forget about roads with heavy truck wear when you add in waves in the pavement.

I can live with the SRA because I love the car - but I really debated waiting for the newer model and IRS.... on rougher roads it makes a huge difference. If I lives in the south or loved to drag race - I'm sure my opinion would change.

J.

 

[2112]

Roush is mentioned as the source in post #13 of the following thread.
http://www.svtperformance.com/forums/showthread.php?664427-The-rear-suspension-that-could-have-been

What ever happened to the Maximum Motorsport IRS mentioned in this ^^^^^thread?

 

[03 DSG Snake]

What ever happened to the Maximum Motorsport IRS mentioned in this ^^^^^thread?

+1 I recall them having a prototype years ago. Not like the factory mule either.

 

[SlowSVT]

What ever happened to the Maximum Motorsport IRS mentioned in this ^^^^^thread?

You mean this:

http://www.autoblog.com/2005/11/02/maximum-motorsports-shows-off-irs-suspension-for-mustang/

That thing made the factory IRS look "featherweight" by comparison.

 

[2112]

You mean this:

http://www.autoblog.com/2005/11/02/maximum-motorsports-shows-off-irs-suspension-for-mustang/

That thing made the factory IRS look "featherweight" by comparison.

Most of those pictures are for the front, no?

 

[SlowSVT]

Most of those pictures are for the front, no?

True, I didn't look long enough to spot this but I believe the IRS is installed on that car. Note the size of the bracketry just on the front. I could probably used for "off-road" riding.