what is the big deal with IRS???

[Serpentor]

serpenoir: you got pm

 

[Joes66Pony]

You know....this whole argument sort of reminds me of the whole EFI vs. carb thing back in 1987 or 5.0 pushrod vs. 4.6 OHC in 1996, except this time they caved to traditionalists.

I'm just dissappointed that Ford decided take a step backwards in overall performance instead of forward.

 

[earl lee]

You people saying an IRS cant handle 550 ft lbs of torque are on crack. Please tell me why the old ass 4th gen supra can handle however much torque the engine cranks out without major upgrades and "snapping" half shafts? Ive never read about a supra putting out 700rwtq snapping its IRS.

This is really an engineering problem and a poor one at that.

 

[BillyGman]

I'm just dissappointed that Ford decided take a step backwards in overall performance instead of forward.

That's a very opinionated statement on your part. Whether someone views it as a "step backwards" or one forward is very dependent on whether they favour drag racing, or roadcourse/circle track racing. Most of us drag racer and traffic light racers will always favour the traditional live axles. And it's as simple as that.

 

[SGL]

That's a very opinionated statement on your part. Whether someone views it as a "step backwards" or one forward is very dependent on whether they favour drag racing, or roadcourse/circle track racing. Most of us drag racer and traffic light racers will always favour the traditional live axles. And it's as simple as that.

Using an IRS has nothing to do with road course/circle track racing. Absolutely NOTHING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[BillyGman]

Using an IRS has nothing to do with road course/circle track racing. Absolutely NOTHING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

So then what's the benefit? because it only presents problems in a high torque enviroment at the dragstrip and at a traffic light take-off. There are too many weak links with the IRS set-up since you have 6 U-joints instead of two like the traditional axle set-up. There have been guys who've built up the engines on older Vettes, who have banged second gear, only to have a half-shaft come right up through the fibrerglass floor on thise cars. And that's what having 6 U-joints can do. So what's your point?

 

[Serpentor]

sure solid axle is great for drag racing, but alot of people were expecting a more well rounded car...and there are IRS cars like the Viper (and the 4th gen supra like Earl said) can handle 500+hp without breakage or wheel hop problems.

 

[code918]

Well, I am a fan of the IRS. I wonder if the current IRS setup could be put on the GT500?

 

[SGL]

So then what's the benefit? because it only presents problems in a high torque enviroment at the dragstrip and at a traffic light take-off. There are too many weak links with the IRS set-up since you have 6 U-joints instead of two like the traditional axle set-up. There have been guys who've built up the engines on older Vettes, who have banged second gear, only to have a half-shaft come right up through the fibrerglass floor on thise cars. And that's what having 6 U-joints can do. So what's your point?

I love it when people use old cars as an example. Maybe you haven't noticed that it is 2005. People now use personal computers. We also have the microwave oven, cellular phones, artificial heart, genetics, DNA, LCD and plasma TV, fuel injection, emmisons control, wireless mouse, Internet, etc..........

So leave the old vettes alone. They were designed by people old enough to participate in WWII. Technology has actually advanced while you were sleeping or whatever else you were doing.

Here's some reading material for you: http://www.svtperformance.com/forums/showthread.php?t=174226&page=2

That's just the tip of the iceberg for suspension design.

 

[GTSpartan]

IRS can easily be made to handle very high hp. I run the stock IRS in my car (probably not a good idea) and when I get my new numbers laid down I'll have 850rwtq. The Chad who has the super fast yellow TT viper that went 8.28 @~176 has IRS with upgraded half shafts and he is putting down in the area of 1700rwhp. It can be done

 

[Jpjr]

People arguing against IRS or cutting Ford engineers slack are quite frankly contributing to the demise of the Big 3. I've said it 100 times, a solid axle belongs on an F-150 not a world class muscle/sports car. The IRS can be easily made to handle high HP, that is a NON issue. And its been done right so many times in the past that even copying another design should not be entirely difficult.

I'm disappointed in SVT. They have sunk the whole car just to put a big motor in it. But that is the very nature of lazy American half-arse thinking that has the Japanese and Germans running laps around us right now. As long as we have big motors and a loud exhuast that is all that matters though right..

 

[Joes66Pony]

People arguing against IRS or cutting Ford engineers slack are quite frankly contributing to the demise of the Big 3. I've said it 100 times, a solid axle belongs on an F-150 not a world class muscle/sports car. The IRS can be easily made to handle high HP, that is a NON issue. And its been done right so many times in the past that even copying another design should not be entirely difficult.

I'm disappointed in SVT. They have sunk the whole car just to put a big motor in it. But that is the very nature of lazy American half-arse thinking that has the Japanese and Germans running laps around us right now. As long as we have big motors and a loud exhuast that is all that matters though right..

I have to agree with you. I'm dissappointed that SVT went into headlining grabbing horsepower instead of building an all around performance machine. I mean honestly....would any of you have been dissappointed if SVT released the GT500 as a lightweight, 400 to 430 hp, N/A, IRS equipped car for under 40 grand. I don't think so.

I look at the performance division of other car companies such as M-Sport, AMG, etc...and their goals are to take the mundane mainstream models (not that any 3-Series is mundane) and turn them into tru performance cars. They look at the car as a whole and work their magic. What does SVT do....let's go for big hp and hope nobody notices that the beancounters really tied or hands behind our backs.

 

[CobraRed01]

I have to agree with you. I'm dissappointed that SVT went into headlining grabbing horsepower instead of building an all around performance machine. I mean honestly....would any of you have been dissappointed if SVT released the GT500 as a lightweight, 400 to 430 hp, N/A, IRS equipped car for under 40 grand. I don't think so.

I look at the performance division of other car companies such as M-Sport, AMG, etc...and their goals are to take the mundane mainstream models (not that any 3-Series is mundane) and turn them into tru performance cars. They look at the car as a whole and work their magic. What does SVT do....let's go for big hp and hope nobody notices that the beancounters really tied or hands behind our backs.

Exactly! 400hp, N/A, aluminum block, IRS, lightweight....build it SVT!!

 

[03reptile]

I've been reading all the comments reference IRS vs. live axle and it seems many are missing the real point. We drive these cars predominantly on the streets and roads of this country and these roads are not all smooth and well cared for as drag strips and road courses. Our every day roads have potholes, center crowns, ripples, breaks in the pavement and about anything else you can think of. In the real world, with the conditions of our roads and highways, the IRS gives you a much better opportunity to stay out of trouble if you encounter the aforemention problems. It won't chatter and kick the rear end out like live axles tend to do and affords you much better control in situations where the road is not nice and smooth. That is why almost all performance machines from Germany, Italy, England, etc. use IRS rears. I for one am disappointed that SVT has chosen to abandon the IRS. I like my IRS in the 03 Cobra and although I will probably buy the 07, I would sure have preferred to have had the option to order an IRS or a live axle. I think for all around daily street driving, SVT has dropped the ball by dropping the IRS. Ok have at me now, it's just one persons opinion.

 

[AbusiveWombat]

Exactly! 400hp, N/A, aluminum block, IRS, lightweight....build it SVT!!

I always thought an aluminum block '03-'04 engine, IRS, and lightweight would have been a monster. It's not like the '03-'04's are having trouble in the horsepower department. Sure, the 5.4 will yield bigger numbers but I think the biggest problem in the '05's is the flab.

Truth be told, I'm reserving judgement on the SRA until I read some reviews. Here in Austin the roads aren't that bad (at least the ones I drive regularly) and I rarely test the handling limits on the street...so I'm not sure if I'd really notice all the side effects of the SRA.

I do agree with the post above that the domestics are getting a little lazy. Sure we've got the imports beat on raw power but how about giving up some horsepower for a more well rounded car. But then again the Mustang is on pace for 190k sold this year, so what do I know. The IRS definitely resides in the back of my mind and I certainly hope that it's not the achilles heal of the car (which it might be, along with the weight).

I guess I'll reserve judgement until January. Maybe Ford will surprize us with IRS. Afterall, the entire automotive industry seems to be fuming over the SRA decision.

 

[BillyGman]

I love it when people use old cars as an example. Maybe you haven't noticed that it is 2005. People now use personal computers. We also have the microwave oven, cellular phones, artificial heart, genetics, DNA, LCD and plasma TV, fuel injection, emmisons control, wireless mouse, Internet, etc..........

So leave the old vettes alone. They were designed by people old enough to participate in WWII. Technology has actually advanced while you were sleeping or whatever else you were doing.

Here's some reading material for you: http://www.svtperformance.com/forums/showthread.php?t=174226&page=2

That's just the tip of the iceberg for suspension design.

You can use all the fancy and eloquent words that you want, but bottom line is, that no matter how sophisticated you think the modern IRS is, it still adds 4 more U-joints to the drivetrain, and there's no way that you can deny that U-joints are the weak links in the drivetrain. So I'd rather have two of them, than six of them thankyou.

you put so much trust and faith into modern technology when it comes to your precious IRS, but by the same token, since it IS 2005 like you've so boldy and sarcastically stated, why can't you believe that it just might be possible that the modern engineering practices of the day just might have come up with a live axle and suspension set-up for the 2007 GT500 that might come pretty close if not even match the handling characteristics of the two years old IRS that you're comparing it to from the 03 Cobras?
The bottom line is, that you're going to twist your theories about this topic in any direction that you want to lean toward. But meanwhile you and others are whining about a how a 2007 car is going to handle when you haven't even sat in one yet, let alone had the opportunity to drive one. How unrealistic is that?

Why don't you guys just wait until the car comes out, and you can test drive one before you start complaining about how it's going to handle?

 

[moridin2004]

You can use all the fancy and eloquent words that you want, but bottom line is, that no matter how sophisticated you think the modern IRS is, it still adds 4 more U-joints to the drivetrain, and there's no way that you can deny that U-joints are the weak links in the drivetrain. So I'd rather have two of them, than six of them thankyou.

you put so much trust and faith into modern technology when it comes to your precious IRS, but by the same token, since it IS 2005 like you've so boldy and sarcastically stated, why can't you believe that it just might be possible that the modern engineering practices of the day just might have come up with a live axle and suspension set-up for the 2007 GT500 that might come pretty close if not even match the handling characteristics of the two years old IRS that you're comparing it to from the 03 Cobras?
The bottom line is, that you're going to twist your theories about this topic in any direction that you want to lean toward. But meanwhile you and others are whining about a how a 2007 car is going to handle when you haven't even sat in one yet, let alone had the opportunity to drive one. How unrealistic is that?

Why don't you guys just wait until the car comes out, and you can test drive one before you start complaining about how it's going to handle?

Yes, it does add more flex points in the drivetrain, but the Viper and the Vettes have been running low times at the drag strip reliably. It also reduces unsprung weight in the rear compared to SRA. It may add more sprung weight, but the unsprung weight is greatly reduced, making the suspension movements in the rear more controlled. You can test this theory with your car. Drop 10lbs off each corner - easiest accomplished with wheel/tire weight - and notice how much more precise the suspension becomes.

Your right, none of us have sat in a 2007 GT500 yet, but you can still make educated guesses about the car, based on previous knowledge.

I also know the chassis that the Mustang is loosely based off of was orginally designed for an IRS setup. This would not be the compromised design that went in to the 99-03.

 

[SGL]

You can use all the fancy and eloquent words that you want, but bottom line is, that no matter how sophisticated you think the modern IRS is, it still adds 4 more U-joints to the drivetrain, and there's no way that you can deny that U-joints are the weak links in the drivetrain. So I'd rather have two of them, than six of them thankyou.

you put so much trust and faith into modern technology when it comes to your precious IRS, but by the same token, since it IS 2005 like you've so boldy and sarcastically stated, why can't you believe that it just might be possible that the modern engineering practices of the day just might have come up with a live axle and suspension set-up for the 2007 GT500 that might come pretty close if not even match the handling characteristics of the two years old IRS that you're comparing it to from the 03 Cobras?
The bottom line is, that you're going to twist your theories about this topic in any direction that you want to lean toward. But meanwhile you and others are whining about a how a 2007 car is going to handle when you haven't even sat in one yet, let alone had the opportunity to drive one. How unrealistic is that?

Why don't you guys just wait until the car comes out, and you can test drive one before you start complaining about how it's going to handle?

You know, when Columbus set sail for the Americas, some thought he would fall off the edge of the ocean into the abyss. There was no way of changing their minds regardless of how well crafted his theories were. In this case we have factual evidence supported by solid engineering that an IRS is superior to an SRA.

Let me ask you one question (for which I already know the answer): Why did it take so long for IRS to become mainstream on production cars?

Hint: it has nothing to do with the low cost of an SRA

I can't wait to see how "eloquent" your answer will be.

By the way, I don't need to smell a turd to recognize one.... So no need to drive that SRA 2007 Shelby. Hummm... I wonder if Shelby will keep a few frames in his basement and sell them as new cars 30 years from now like he did with the Cobra? :loser:

 

[Dave07997S]

You can use all the fancy and eloquent words that you want, but bottom line is, that no matter how sophisticated you think the modern IRS is, it still adds 4 more U-joints to the drivetrain, and there's no way that you can deny that U-joints are the weak links in the drivetrain. So I'd rather have two of them, than six of them thankyou.

you put so much trust and faith into modern technology when it comes to your precious IRS, but by the same token, since it IS 2005 like you've so boldy and sarcastically stated, why can't you believe that it just might be possible that the modern engineering practices of the day just might have come up with a live axle and suspension set-up for the 2007 GT500 that might come pretty close if not even match the handling characteristics of the two years old IRS that you're comparing it to from the 03 Cobras?
The bottom line is, that you're going to twist your theories about this topic in any direction that you want to lean toward. But meanwhile you and others are whining about a how a 2007 car is going to handle when you haven't even sat in one yet, let alone had the opportunity to drive one. How unrealistic is that?

Why don't you guys just wait until the car comes out, and you can test drive one before you start complaining about how it's going to handle?

Ujoints are not what breaks on IRS cars from a lot of hp and tq, its the half-shafts themselves that can be twisted like a pretzel. The fact of the matter is the IRS can be quite robust and offer much better driving dynamics than a live axle. Ford probably felt the overall benefit didn't justify the cost. I think they should let the consumer decide this by offering it as a option, or make it standard and make the live axle a option. Dave.

 

[Jpjr]

Anyone defending a solid rear axle I would really like to understand better. It's a completely inferior design that has no business dragging a sports car anywhere but on the track. So...many.. people... on this board are only concerned about straight line speed. No one cares about agility. Life is not a straight line.

This may be a moot point, but its also worth mentioning that the IRS is much SAFER. You have much more control of the rear movements of the vehicle.