what is the big deal with IRS???

[Torque]

If you want IRS, go buy a corvette. Solid live axle is where it's at. Do some of you guys prefer wheel hop or something?? I've never owned an '03 cobra, but have ridden in my friend's many times and every time he tries to light up the tires, the car hops down the road uncomfortably. So, what is the big friggin deal with IRS? Do you guys WANT to pay 50k for a friggin mustang? :shrug:

 

[Joes66Pony]

If you want IRS, go buy a corvette. Solid live axle is where it's at. Do some of you guys prefer wheel hop or something?? I've never owned an '03 cobra, but have ridden in my friend's many times and every time he tries to light up the tires, the car hops down the road uncomfortably. So, what is the big friggin deal with IRS? Do you guys WANT to pay 50k for a friggin mustang? :shrug:

Apparently, with the dealer markups being talked up.....50K seems like a bargain.

 

[Formula51]

Believe it or not, I'm not sure if you are ready for this, so take your time. Some people actually prefer to do more than go straight. Now I know thats hard to believe, so take it in slow. Easy, big deep breath, almost there! OK! Let it out. All is better. Wheel hop sucks, stick axles rule for life!


Just messin with you man. Some people preffer the superior handling characterisitcs, thats all.

 

[03Terminator]

If you want IRS, go buy a corvette. Solid live axle is where it's at. Do some of you guys prefer wheel hop or something?? I've never owned an '03 cobra, but have ridden in my friend's many times and every time he tries to light up the tires, the car hops down the road uncomfortably. So, what is the big friggin deal with IRS? Do you guys WANT to pay 50k for a friggin mustang? :shrug:

IRS greatly improves handling over the live axle set up but doesn't do so well for drag racing. Basically it comes down to what you want out of your car. If all you want is straight line performance with respectable handling then the GT500 is your car. If you want a car to road race or want the best handling you can possibly get with a little more refinement thrown in for good measure then the 03/04 Cobra's with the IRS is the way to go. Personally I don't think any one driving their Cobra on the street will be able to extract that extra bit of performance the IRS gives over the live axle in handling. If they do then they are risking getting locked up. I've had both live axle and now the IRS 03 Cobra. Biggest difference I've noticed is the ride and it tracks more smoothly around turns. No hop when hitting a bump in mid turn.

 

[Joes66Pony]

IRS greatly improves handling over the live axle set up but doesn't do so well for drag racing. Basically it comes down to what you want out of your car. If all you want is straight line performance with respectable handling then the GT500 is your car. If you want a car to road race or want the best handling you can possibly get with a little more refinement thrown in for good measure then the 03/04 Cobra's with the IRS is the way to go. Personally I don't think any one driving their Cobra on the street will be able to extract that extra bit of performance the IRS gives over the live axle in handling. If they do then they are risking getting locked up. I've had both live axle and now the IRS 03 Cobra. Biggest difference I've noticed is the ride and it tracks more smoothly around turns. No hop when hitting a bump in mid turn.

Well..I don't think it's a question of driving the car at it's limits. Even in spirited driving, the benefits of IRS greatly outweigh those of the SRA. And frankly, I'm starting to get sick of the infamous "Mustang Two Step" every time I go over an expansion joint or a bump mid corner. While the 05 GT is great....the SRA characteristics are still there (mid corner instability, vague rear end), just greatly toned down.

Essentially, it comes down to compromises. With IRS, the compromises needed for great handling are more liveable than those compromises needed for SRA.

And frankly, I call BS on Ford for saying that IRS would have cost 5K....especially considering that the S197 chassis was designed for it in the firstplace (according to HTT).

 

[03Terminator]

Well..I don't think it's a question of driving the car at it's limits. Even in spirited driving, the benefits of IRS greatly outweigh those of the SRA. And frankly, I'm starting to get sick of the infamous "Mustang Two Step" every time I go over an expansion joint or a bump mid corner. While the 05 GT is great....the SRA characteristics are still there (mid corner instability, vague rear end), just greatly toned down.

Essentially, it comes down to compromises. With IRS, the compromises needed for great handling are more liveable than those compromises needed for SRA.

And frankly, I call BS on Ford for saying that IRS would have cost 5K....especially considering that the S197 chassis was designed for it in the firstplace (according to HTT).

He quotes it as being a cost cutting measure and an effort to save weight??? :shrug:

 

[Joes66Pony]

He quotes it as being a cost cutting measure and an effort to save weight??? :shrug:

From the CarConnection.com

Well, maybe not all of them. During a media preview prior to the New York Auto Show, Ford officials confirmed the new Cobra would stick with the base Mustang's solid axle, rather than going for an independent rear. North American product development czar Phil Martens told TheCarConnection.com the decision was made for two key reasons. He insisted the results of the IRS system just weren't better enough to justify adding 180 pounds to Mustang's curb weight.

Actually, Shelby revealed, there was another reason. The results also weren't good enough to justify a projected $5000 cost penalty. So we'll have to wait and see whether they're right, once Ford has a Cobra GT500 ready for the press fleet.

So the IRS would have cost 5000 grand plus an additional 180 lbs according to Ford.

But we'll never know I suppose.

 

[hitman#1]

IRS greatly improves handling over the live axle set up but doesn't do so well for drag racing. Basically it comes down to what you want out of your car. If all you want is straight line performance with respectable handling then the GT500 is your car. If you want a car to road race or want the best handling you can possibly get with a little more refinement thrown in for good measure then the 03/04 Cobra's with the IRS is the way to go. Personally I don't think any one driving their Cobra on the street will be able to extract that extra bit of performance the IRS gives over the live axle in handling. If they do then they are risking getting locked up. I've had both live axle and now the IRS 03 Cobra. Biggest difference I've noticed is the ride and it tracks more smoothly around turns. No hop when hitting a bump in mid turn.

Have you ever driven or ridden in a car with a stick axle and a CORRECTLY designed suspension? The Camaro SS I used to own tracked just as well as my '99 Cobra did, WITHOUT the wheel-hop issues. Also, most road-race courses have smooth, non-bumpy corners. The only place that the IRS is of true benefit in in a bumpy corner. Otherwise it's just an expensive way to add about 180lbs to an already porky car.

Keep this in mind: The GTO has an IRS and the '05 Mustang does not. Check out Car and Driver or Autoweek's comparos. The solid axled 'Stang kicks the GTO's butt around corners. Does that sound like a superior set-up to you? I think not...

 

[03Terminator]

Have you ever driven or ridden in a car with a stick axle and a CORRECTLY designed suspension? The Camaro SS I used to own tracked just as well as my '99 Cobra did, WITHOUT the wheel-hop issues. Also, most road-race courses have smooth, non-bumpy corners. The only place that the IRS is of true benefit in in a bumpy corner. Otherwise it's just an expensive way to add about 180lbs to an already porky car.

Keep this in mind: The GTO has an IRS and the '05 Mustang does not. Check out Car and Driver or Autoweek's comparos. The solid axled 'Stang kicks the GTO's butt around corners. Does that sound like a superior set-up to you? I think not...

All a matter of personal choice. Doesn't matter to me either way. Like I said only benefit I noticed over the live axle cars I've owned was the ride and the fact that it didn't hop in mid turn when hitting a bump. To some people that's a big deal.

 

[Torque]

ok, I'll agree, I hate the mid turn bump, say when you are comin off an exit ramp that twists around, but it is all in how the rest of the susp. is set up. It is alot easier to make the solid axle handle well, than it is to get rid of the wheel hop with an IRS. Period. :burn:

 

[03Terminator]

ok, I'll agree, I hate the mid turn bump, say when you are comin off an exit ramp that twists around, but it is all in how the rest of the susp. is set up. It is alot easier to make the solid axle handle well, than it is to get rid of the wheel hop with an IRS. Period. :burn:

See Ford gave us this half a.... explanation as to why they didn't put an IRS in it. That's why some people are pissed about it. If they just said, look with 450+ lbs of torque you would leave a trail of precious IRS parts behind you on first launch then it might make more sense. :burnout:

 

[Joes66Pony]

ok, I'll agree, I hate the mid turn bump, say when you are comin off an exit ramp that twists around, but it is all in how the rest of the susp. is set up. It is alot easier to make the solid axle handle well, than it is to get rid of the wheel hop with an IRS. Period. :burn:

The problem with bringing up the IRS system in the 99-04 Cobras is that the SN-95 chassis (or Fox-4..however you want to call it) was never designed for IRS in the first place, so it was severely compromised.

Kudos to SVT for actually making it work and making the 99-04 Cobras some of the best handling cars out there. But the wheel hops issues is more a problem from the compromises than any inherent flaw with IRS in general.

It may be easier to make an SRA handle well...but the compromises necessary are unacceptable in my view. There's a reason why I don't drive 1987 to 1993 5.0L's...they handled great...but my kidneys took a serious beating.

 

[03Terminator]

The problem with bringing up the IRS system in the 99-04 Cobras is that the SN-95 chassis (or Fox-4..however you want to call it) was never designed for IRS in the first place, so it was severely compromised.

Kudos to SVT for actually making it work and making the 99-04 Cobras some of the best handling cars out there. But the wheel hops issues is more a problem from the compromises than any inherent flaw with IRS in general.

It may be easier to make an SRA handle well...but the compromises necessary are unacceptable in my view. There's a reason why I don't drive 1987 to 1993 5.0L's...they handled great...but my kidneys took a serious beating.

Try adding an Eibach suspension and 18X9's with 35 series tires.......... :cryying:

 

[hitman#1]

All a matter of personal choice. Doesn't matter to me either way. Like I said only benefit I noticed over the live axle cars I've owned was the ride and the fact that it didn't hop in mid turn when hitting a bump. To some people that's a big deal.

I don't know what stick axle cars you've owned, but yes, some of the older ones were atrocious. The '92 Mustang GT I owned was absolutely un-nerving in a bumpy corner. The rear-end felt like it would step out about 6" if you hit a bump at the apex of a freeway on ramp. On the otherhand, my SS exhibited none of that. My guess is that the new Cobra's suspension will be quite a bit better than that of the Camaro, so this should be even less of a problem than it was with my SS.

Do yourself a favor. Go take an '05 Mustang for a drive. Push it through some corners and then imagine a car that has better shocks and spring rates, as the new Cobra would have. My guess is that you wont be disappointed. :burnout:

 

[03Terminator]

I feel your pain with your 92 GT. I have a 90 GT Vert with an Eibach Pro kit, 18X9 Y2k Cobra R's and 35 series tires. Talk about bone jarring??!! No doubt in my mind that the 05 GT's will be light years ahead of my 90. I'm also sure that the GT500 will perform as promised and most people won't even notice that it doesn't have an IRS.

 

[Joes66Pony]

I don't know what stick axle cars you've owned, but yes, some of the older ones were atrocious. The '92 Mustang GT I owned was absolutely un-nerving in a bumpy corner. The rear-end felt like it would step out about 6" if you hit a bump at the apex of a freeway on ramp. On the otherhand, my SS exhibited none of that. My guess is that the new Cobra's suspension will be quite a bit better than that of the Camaro, so this should be even less of a problem than it was with my SS.

Do yourself a favor. Go take an '05 Mustang for a drive. Push it through some corners and then imagine a car that has better shocks and spring rates, as the new Cobra would have. My guess is that you wont be disappointed. :burnout:

I have driven an 05...several of them. And yes...it is a vast improvement over the previous 'Stangs. But the SRA tendencies are still there...just less noticeable.

My personal opinion...for the price of the GT500, I just find the SRA unacceptable.

For the most part..people probably won't notice. The SRA is good enough. But in these day and age...cheap and good enough just don't cut it anymore. Especially when you start talking about what a car like the GT500 is capable of.

 

[03Terminator]

I have driven an 05...several of them. And yes...it is a vast improvement over the previous 'Stangs. But the SRA tendencies are still there...just less noticeable.

My personal opinion...for the price of the GT500, I just find the SRA unacceptable.

For the most part..people probably won't notice. The SRA is good enough. But in these day and age...cheap and good enough just don't cut it anymore. Especially when you start talking about what a car like the GT500 is capable of.

If Ford kept the price at around 40 grand and included the IRS it would be the deal of the century. But their not so it's the live axle or nothing. :cryying:

 

[KevinB120]

You can not compare the 04 to the 05. The older stang has so many design deficiencies at its core its not a matter of what type of suspension it has. Very short wheelbase, poor f/r balance, component flex, poor roll center, and bump steer hinder the old car no matter what the setup is. I have spent tons of money trying to make an sn95 handle and the car just does not have it in it by design. It may 'feel' fast from throwing its weight around poorly, but on the clock it's not. The old car is no match for even a live axle 05, in any form. The M3s are having quite a time keeping up with the FRPP cars right now on the track.

 

[Top_Fuel]

An IRS would be fine with me as long as it's optional. For many of us it simply adds weight and expense...two things the GT500 doesn't need right now. And since Ford can't afford to engineer their IRS properly, I say leave it off. I suspect most people who want a well-balanced $45K sports car with an IRS will probably buy a Corvette anyway.

 

[KevinB120]

Funny enough, HTT says the prototype IRS units are lighter then the live axle.