GT Performance Mods 2005+ Mustang GT Performance and Technical Information

Not to rehash the IRS vs SRA

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Old 2/26/06, 06:00 AM
  #41  
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<div class='quotetop'>QUOTE(thump_rrr @ February 26, 2006, 7:29 AM) Quoted post</div><div class='quotemain'>
I somehow missed this post earlier so I'll reply now.

In your reply to shifty you write "It's common knowledge on other boards that Mustang's are peices[sic] of Junk and driven by rednecks."
In the next sentence you write "Keed[sic] making generalizations, you are as bad as the people whom[sic] make that statement."

Do you see the irony in those 2 statements?

[/b][/quote]He was making the first statement to show how stupid generalizations tend to be, not claiming it as his own statement. He was being obviously over the top. There's no irony.
Old 2/26/06, 06:20 AM
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<div class='quotetop'>QUOTE(HastaLaVista @ February 26, 2006, 8:03 AM) Quoted post</div><div class='quotemain'>
He was making the first statement to show how stupid generalizations tend to be, not claiming it as his own statement. He was being obviously over the top. There's no irony.
[/b][/quote]
Then he better improve on his writing skills if he's to complete his masters degree.
Old 2/26/06, 10:18 AM
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<div class='quotetop'>QUOTE(thump_rrr @ February 26, 2006, 6:29 AM) Quoted post</div><div class='quotemain'>
I somehow missed this post earlier so I'll reply now.

In your reply to shifty you write "It's common knowledge on other boards that Mustang's are peices[sic] of Junk and driven by rednecks."
In the next sentence you write "Keed[sic] making generalizations, you are as bad as the people whom[sic] make that statement."

Do you see the irony in those 2 statements?

You state that it's common knowledge that Mustangs are a piece of junk, implying that it's a widely held view.

Generalizations such as those are usually made by people who feel threatened by the success of the S197 not by current owners.
It's more like it's common knowledge that Ford hit a home run with the new Mustang selling out their whole production run.
The car has been so successful that the Chrysler and Chevrolet camps are trying to release retro versions of their own classics.
As for the quality of the new Mustangs,it has exceeded my expectations.
The modular 4.6L engine has been around since 92 and has had a good track record.
The interior and exterior fit and finish is excellent with good panel alignment and tight body gaps.
For the price and performance nothing compares to it.
So tell me then why do people who drive GTO's, 350Z's and Subaru WRX STI's still feel the need to compare their cars to the "piece of junk" mustangs which cost far less than their cars? Do they have inferiority complexes?

As for the redneck part I could just as easily say that Corvettes are driven by people with with male sexual enhancement issues but that would force me to stoop to your level of maturity.

PS. You state that you are working toward your masters degree. I hope you put a little more effort into your spelling and grammar at school.
[/b][/quote]

No I see no irony. He stated that Supras are dyno queens, which is a generalization. I stated a typical Mustang generalization that you see on other automotive boards. That being that "Mustangs are junk and driven by rednecks". Then I stated "keep making generalizations, you are as bad as the people whom make that statement(referring to the sentence above in the original post). I was using it to point out a certain persons immaturity. You could have saved yourself 5 minutes of posting if you actually read my post. You are making the exact same point I was making, but I didn't feel like going into detail. My writing skills are perfectly fine and I admit I don't check for errors a lot on internet forums. Again, if you read my post and comprehended it like HastLaVista did, it's clear.
Old 2/26/06, 10:44 AM
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Ok boys, no mudslingling, we can all debate and discuss like men, the IRS/SRA debates happen like this all the time [img]style_emoticons/<#EMO_DIR#>/icon_mrgreen.gif[/img]

Here's my take on the IRS/SRA debate with respect to drag racing. I'll try and use my engineering knowedge, not to say I am right, any of the veterans are free to correct me.

The reason the SRA is the consensus pick with the drag racers is simplicity and adjustability. More parts = more potential for failure. All the U-joints on an IRS are under huge loads at launch, especially with slicks. A stout SRA will take a lot of abuse before it gives out. Not to say an IRS cannot be designed to hook up, but more degrees of freedom = more complexity. I haven't studied the suspension geometry of an IRS, but I am assuming there will be tradeoffs in the design with respect to having it hook up well vs. corner well. With an SRA, the ride quailty is obviously comprimised by the nature of the design, but the result is the possibility of predictable launches in a straight line. The geometry of a 3 or 4 link rear suspension is realitively simple from what I have read, and the length/angle of the control arms can change how well the car plants its tires.

As for the blown up IRS units from the vettes, it could be a variety of things, how the guy launched, the track conditions, the quality of the diff. housing. Its sad to say, but American car companies are cheaping out on everything, so the quailty of the cast iron in the rear housing could be suspect. I personally think with all the cost cutting, its the enthusiast who suffers the most. I would have gladly paid extra for a solid engine block with a forged steel crank, forged pistons, and stronger connecting rods. Additionally, from my own experience, I think that many of the design engineers working for American car companies are incompetent, so I am not surprised when things fail like this (this comment may be controversial, I apologise). Even the CTS-V is blowing up rear differentials like crazy.

As for the Mustang, we all know originally it was engineered for an IRS, then re-engineered for an SRA, with the Cobra getting an IRS, which was then pulled off the table. I really believe (hope) with competition on the horizon, that Ford pulls out those old part numbers on the IRS, builds it and put its in the '09's. I think the best compromise, and perhaps one of the advantages of the Mustang, is Ford could offer both setups down the road. An IRS Boss and an SRA Mach1 for those who want to take it to the track.
Old 2/26/06, 10:47 AM
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Well said Steve.
Old 2/26/06, 11:00 AM
  #46  
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<div class='quotetop'>QUOTE(Galaxie @ February 26, 2006, 11:47 AM) Quoted post</div><div class='quotemain'>
Ok boys, no mudslingling, we can all debate and discuss like men, the IRS/SRA debates happen like this all the time [img]style_emoticons/<#EMO_DIR#>/icon_mrgreen.gif[/img]

Here's my take on the IRS/SRA debate with respect to drag racing. I'll try and use my engineering knowedge, not to say I am right, any of the veterans are free to correct me.

The reason the SRA is the consensus pick with the drag racers is simplicity and adjustability. More parts = more potential for failure. All the U-joints on an IRS are under huge loads at launch, especially with slicks. A stout SRA will take a lot of abuse before it gives out. Not to say an IRS cannot be designed to hook up, but more degrees of freedom = more complexity. I haven't studied the suspension geometry of an IRS, but I am assuming there will be tradeoffs in the design with respect to having it hook up well vs. corner well. With an SRA, the ride quailty is obviously comprimised by the nature of the design, but the result is the possibility of predictable launches in a straight line. The geometry of a 3 or 4 link rear suspension is realitively simple from what I have read, and the length/angle of the control arms can change how well the car plants its tires.

As for the blown up IRS units from the vettes, it could be a variety of things, how the guy launched, the track conditions, the quality of the diff. housing. Its sad to say, but American car companies are cheaping out on everything, so the quailty of the cast iron in the rear housing could be suspect. I personally think with all the cost cutting, its the enthusiast who suffers the most. I would have gladly paid extra for a solid engine block with a forged steel crank, forged pistons, and stronger connecting rods. Additionally, from my own experience, I think that many of the design engineers working for American car companies are incompetent, so I am not surprised when things fail like this (this comment may be controversial, I apologise). Even the CTS-V is blowing up rear differentials like crazy.

As for the Mustang, we all know originally it was engineered for an IRS, then re-engineered for an SRA, with the Cobra getting an IRS, which was then pulled off the table. I really believe (hope) with competition on the horizon, that Ford pulls out those old part numbers on the IRS, builds it and put its in the '09's. I think the best compromise, and perhaps one of the advantages of the Mustang, is Ford could offer both setups down the road. An IRS Boss and an SRA Mach1 for those who want to take it to the track.
[/b][/quote]

You used your engineering background correctly. I agree that companies are cheaping out and this means not strengthening key areas. I've spent a lot of time in the seat of a CTSV, even tracked one for a few laps. The car suffers from wheel hop pretty badly. A lot of this car be traced back to the suspension setup. The CTSV was tuned for handling. The good thing is companies like BMR and GMPP make kits to eleviate most of the wheel hop. It will be interesting to see if the GT500 with a more "handling" orientated suspension will suffer from wheel hop. Our GT's have a soft suspension condusive to drag racing. We also suffer from wheel hop too, thus we add control arms to try and combat this.

As for IRS vs SRA....The majority of miles put on a typical Mustang is on the street. On the street IRS is king. It offers a more compliant ride and better real world handling. Same goes for road racing and auto-cross. The only advantage that SRA holds is in drag racing. It's a more stout rear end and like Galaxie stated and manufacturers don't beef up IRS rears for drag racing. Again, this doesn't mean that IRS is bad for drag racing, rather not ideal. The reason why Ford chose SRA was cost and better yet profits. If Ford was to implement an IRS rear, it would obviously cost money. Either Ford could raise the base price a bit(with complaints) or eat it internally. If they ate the cost increase internally, obviously the profit margin would go down.
Old 2/26/06, 11:51 AM
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<div class='quotetop'>QUOTE(max2000jp @ February 26, 2006, 1:03 PM) Quoted post</div><div class='quotemain'>
You used your engineering background correctly. I agree that companies are cheaping out and this means not strengthening key areas. I've spent a lot of time in the seat of a CTSV, even tracked one for a few laps. The car suffers from wheel hop pretty badly. A lot of this car be traced back to the suspension setup. The CTSV was tuned for handling. The good thing is companies like BMR and GMPP make kits to eleviate most of the wheel hop. It will be interesting to see if the GT500 with a more "handling" orientated suspension will suffer from wheel hop. Our GT's have a soft suspension condusive to drag racing. We also suffer from wheel hop too, thus we add control arms to try and combat this.

As for IRS vs SRA....The majority of miles put on a typical Mustang is on the street. On the street IRS is king. It offers a more compliant ride and better real world handling. Same goes for road racing and auto-cross. The only advantage that SRA holds is in drag racing. It's a more stout rear end and like Galaxie stated and manufacturers don't beef up IRS rears for drag racing. Again, this doesn't mean that IRS is bad for drag racing, rather not ideal. The reason why Ford chose SRA was cost and better yet profits. If Ford was to implement an IRS rear, it would obviously cost money. Either Ford could raise the base price a bit(with complaints) or eat it internally. If they ate the cost increase internally, obviously the profit margin would go down.
[/b][/quote]
ford actually designed this car with a IRS setup. until very late in the design process this was to be the rear suspension. after gauging interest and customer feedback they redesigned a SRA system to please guys like me,don w.,george,justin, etc. they realized that having a IRS would have hurt sales and they would have none of that. so for the shelby they could use what they already have designed and prototypes built. actually the IRS system was 50lbs. lighter than the 8.8 SRA currently used so it wasn't a cost or weight issue at all. they gave the people what they wanted. a SRA that could take some 6000rpm launches at the drags. and judging from all the noise issues they dealt with in the SRA they may be regreting that decision but i'm sure as heck not.
Old 2/26/06, 11:56 AM
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<div class='quotetop'>QUOTE(spyder7724 @ February 26, 2006, 12:54 PM) Quoted post</div><div class='quotemain'>
they gave the people what they wanted. a SRA that could take some 6000rpm launches at the drags.
[/b][/quote]

Are they really that strong? I'm just wondering.
Old 2/26/06, 12:07 PM
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<div class='quotetop'>QUOTE(spyder7724 @ February 26, 2006, 12:54 PM) Quoted post</div><div class='quotemain'>
ford actually designed this car with a IRS setup. until very late in the design process this was to be the rear suspension. after gauging interest and customer feedback they redesigned a SRA system to please guys like me,don w.,george,justin, etc. they realized that having a IRS would have hurt sales and they would have none of that. so for the shelby they could use what they already have designed and prototypes built. actually the IRS system was 50lbs. lighter than the 8.8 SRA currently used so it wasn't a cost or weight issue at all. they gave the people what they wanted. a SRA that could take some 6000rpm launches at the drags. and judging from all the noise issues they dealt with in the SRA they may be regreting that decision but i'm sure as heck not.
[/b][/quote]

You are correct that Ford had originally designed the S197 for an IRS rear. The customer feedback thing is hogwash. How do they know that it would hurt sales without releasing the vehicle to the public? The guys that you listed are the minority of Mustang owners. All the competitors to the GT have IRS rears and sell. In fact I believe the Mustang is the only passenger car still with a solid rear. Interestingly enough, the 08/09 Camaro and Challenger concepts both have IRS rears.

As for the Shelby, you are incorrect. Brad posted an article a while back where Shelby himself discussed the IRS debate. Shelby stated that an IRS would add weight and significant COST to the car. I am relying on my memory but IIRC he stated it was like $3,500 per car.
Old 2/26/06, 12:11 PM
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<div class='quotetop'>QUOTE(spyder7724 @ February 26, 2006, 1:54 PM) Quoted post</div><div class='quotemain'>
ford actually designed this car with a IRS setup. until very late in the design process this was to be the rear suspension. after gauging interest and customer feedback they redesigned a SRA system to please guys like me,don w.,george,justin, etc. they realized that having a IRS would have hurt sales and they would have none of that. so for the shelby they could use what they already have designed and prototypes built. actually the IRS system was 50lbs. lighter than the 8.8 SRA currently used so it wasn't a cost or weight issue at all. they gave the people what they wanted. a SRA that could take some 6000rpm launches at the drags. and judging from all the noise issues they dealt with in the SRA they may be regreting that decision but i'm sure as heck not.
[/b][/quote]

Ron, the reason why the solid axle went in there will be a hot topic forever. I am positive that it was dropped mainly to cut costs and the company line is that enthusiasts demanded it. I think the reasons why and debating it are played out though, no reason to rehash it.

What I do think though, is because there is an IRS designed already, and apparently was done really well based on rumors, is that at some point in the near future we can get both a SRA and IRS available. I think Ford should really consider doing this, as it will make everyone happy. The cost of the SRA setup has already been paid off, and an IRS units development costs will be offset by other cars they may be building with this chassis (rumored next Gen Falcon, Lincoln coupe)
Old 2/26/06, 12:17 PM
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<div class='quotetop'>QUOTE(Shifty @ February 26, 2006, 1:59 PM) Quoted post</div><div class='quotemain'>
Are they really that strong? I'm just wondering.
[/b][/quote]

I launch at 5000 rpm and I have over 550 runs on mine.
Old 2/26/06, 01:39 PM
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<div class='quotetop'>QUOTE(thump_rrr @ February 26, 2006, 1:20 PM) Quoted post</div><div class='quotemain'>
I launch at 5000 rpm and I have over 550 runs on mine.
[/b][/quote]

Wow cool. Me like, me like.
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