bob

Hah, a lighter rear suspension counts from stop light to stop light, 0-60 and at the end of the quarter

Man if Ford only had a sweet pushrod motor to put in there.

Jack Frost

Too true. It's just more 'market speak'.

Lies, lies and more lies. Statistics, surveys & polls will tell you whatever you want them too...it all depends on how you 'present' the numbers.

I bet the chief engineer had his fingers crossed behind his back when he was toeing the "our customers demanded a solid rear axle" corporate line.

danazar

Too true. It's just more 'market speak'.

Lies, lies and more lies. Statistics, surveys & polls will tell you whatever you want them too...it all depends on how you 'present' the numbers.

I bet the chief engineer had his fingers crossed behind his back when he was toeing the "our customers demanded a solid rear axle" corporate line. [/b][/quote]
Just what makes you two think you speak for all of the Mustang fanbase?

Sure, maybe you individually would prefer an IRS. You've both made that clear. But it also seems obvious that there are a lot of people who wanted a solid rear axle in the Mustang.

Besides the obvious benefits mentioned by other people, there's also the fact that a solid rear axle is cheap enough to design and include to handle even more horsepower than the 300hp the engine's rated for, so enthusiasts can soup up their 'stang to their heart's content and not worry about whether they're gonna reach a torque limit and tear up their rear end. You know people are gonna gonna put not only basic intake and exhaust mods but seriously enlarge the throttle body, the fuel injectors, the manifolds, and some will throw a blower on there with some serious boost. I'm sure there are people out there who'll be dropping cash left and right to get another 100HP or more (sometimes much more) out of their Mustang, and they know that solid, reliable rear axle is gonna take it.

And Ford has to design the Mustang for the enthusiast, or the enthusiast simply won't buy it, not in the volumes Ford needs to sell.

It's not that an IRS wouldn't necessarily take it, but 1) it'd be expensive to design with that high a design threshold, and 2) since the rear suspension isn't warrantied at anything above the factory specs, the enthusiasts would be the ones that lost out if their rear axles started failing on them--and they'd blame Ford, and Ford would lose sales.

People wanted a solid axle. Maybe you didn't. But you don't speak for everyone.

You want an IRS? Buy a Cobra. Case closed.

PeterPienaar

I don't get the complaint about ride refinement. Granted, I drive a ten-year-old truck, but is a miniscule degree of comfort really worth missing? Anybody tough left out there? :-)

max2000jp

Just what makes you two think you speak for all of the Mustang fanbase?

Sure, maybe you individually would prefer an IRS. You've both made that clear. But it also seems obvious that there are a lot of people who wanted a solid rear axle in the Mustang.

Besides the obvious benefits mentioned by other people, there's also the fact that a solid rear axle is cheap enough to design and include to handle even more horsepower than the 300hp the engine's rated for, so enthusiasts can soup up their 'stang to their heart's content and not worry about whether they're gonna reach a torque limit and tear up their rear end. You know people are gonna gonna put not only basic intake and exhaust mods but seriously enlarge the throttle body, the fuel injectors, the manifolds, and some will throw a blower on there with some serious boost. I'm sure there are people out there who'll be dropping cash left and right to get another 100HP or more (sometimes much more) out of their Mustang, and they know that solid, reliable rear axle is gonna take it.

And Ford has to design the Mustang for the enthusiast, or the enthusiast simply won't buy it, not in the volumes Ford needs to sell.

It's not that an IRS wouldn't necessarily take it, but 1) it'd be expensive to design with that high a design threshold, and 2) since the rear suspension isn't warrantied at anything above the factory specs, the enthusiasts would be the ones that lost out if their rear axles started failing on them--and they'd blame Ford, and Ford would lose sales.

People wanted a solid axle. Maybe you didn't. But you don't speak for everyone.

You want an IRS? Buy a Cobra. Case closed. [/b][/quote]
The market demands a IRS. Look at every car in our price range, the Stang is the only vehicle with an archiac solid rear. The 350Z, RX8, GTO etc. all have sophisticated suspensions that the 05 lacks. Ford started with an all new modern platform and in the beginning I heard rumors of a standard IRS suspension. I am sure the engineers wanted it, but the bean counters within Ford vetoed it. You can make a lot of power with an IRS suspension. A factory rear end is only good for so much power, this is a risk you take when modifying your car. If you add another 100 hp to an IRS suspension and it fails because of that, IT'S YOUR FAULT. I can name quite a few cars that are running a lot more hp thru the stock IRS suspension and it takes it. The C5, Supra, and 350Z pop into my head immediately. I don't care how well the car rides, which is an advantage an IRS suspension has. Rather, I care more about the balance of the car. The fact of the matter is that a properly setup IRS suspension is more stable and predictable in hard cornering. Again, most people don't track their cars so this might not be a concern of theirs. I bought my GT with the mindset of keeping the car until the new Cobra comes out and I can get everything I want in the total package. Mustang owners should have demanded a IRS suspension, otherwise they are settling for second best.

Jack Frost

Miniscule?

Picture the solid axle as it tracks around a corner. If one wheel is stressed due to uneven/imperfect pavement, then BOTH wheels are stressed.

There is no way you can engineer a serious performance car around this setup.

SurfnSoCal

Do the saleen's and roushe's have IRS?

If not....aren't those track cars? Especially the roushe...

I for one do not mind the live axle. My BMW buddies LOVE to make the rear end the achille's tendon on the new stang. But honestly. If its one of the fastest cars in the salom compared to previous mustangs...then it is an improvement and I am stoked.

Put a Maximum Motorsport kit on for $2k and be whooping vettes, beemers, and porshes if you are THAT concerned with having a live axle.

distortion

Frost and Max2000, never mind why bother!

holderca1

The market demands a IRS. Look at every car in our price range, the Stang is the only vehicle with an archiac solid rear. The 350Z, RX8, GTO etc. all have sophisticated suspensions that the 05 lacks. Ford started with an all new modern platform and in the beginning I heard rumors of a standard IRS suspension. I am sure the engineers wanted it, but the bean counters within Ford vetoed it. You can make a lot of power with an IRS suspension. A factory rear end is only good for so much power, this is a risk you take when modifying your car. If you add another 100 hp to an IRS suspension and it fails because of that, IT'S YOUR FAULT. I can name quite a few cars that are running a lot more hp thru the stock IRS suspension and it takes it. The C5, Supra, and 350Z pop into my head immediately. I don't care how well the car rides, which is an advantage an IRS suspension has. Rather, I care more about the balance of the car. The fact of the matter is that a properly setup IRS suspension is more stable and predictable in hard cornering. Again, most people don't track their cars so this might not be a concern of theirs. I bought my GT with the mindset of keeping the car until the new Cobra comes out and I can get everything I want in the total package. Mustang owners should have demanded a IRS suspension, otherwise they are settling for second best. [/b][/quote]
Here the cars that you mentioned, personally I don't think IRS is worth that much.

Mustang GT - 300 hp, 320 ft-lbs, 3450 lbs, $24,995
350Z - 287 hp, 274 ft-lbs, 3815 lbs, $27,060
RX8 - 238 hp, 159 ft-lbs, 3029 lbs, $27,420
GTO - 350 hp, 365 ft-lbs, 3725 lbs, $33,190

PeterPienaar

Miniscule?

Picture the solid axle as it tracks around a corner. If one wheel is stressed due to uneven/imperfect pavement, then BOTH wheels are stressed.

There is no way you can engineer a serious performance car around this setup. [/b][/quote]
You're right, I agree it makes for better cornering. However, the complaints I heard concerned ride comfort, not high-speed track style (which, to my limited knowledge, seems like the place where IRS will tell most).

max2000jp

Live Axles can be made to perform well. Both of those cars would be even better with a proper IRS rear suspension. Real performance cars have IRS suspensions. Real race cars have IRS suspensions. I have been around some serious race cars and ALL had highly advanced IRS suspensions. I don't think that there should be an arguement in anyones mind that the 3-link in our 05's is an inferior suspension. My main arguement is that Ford should have made an IRS suspension optional. They could have made it standard in the Cobra, which would not hurt it from a sales standpoint.

max2000jp

Here the cars that you mentioned, personally I don't think IRS is worth that much.

Mustang GT - 300 hp, 320 ft-lbs, 3450 lbs, $24,995
350Z - 287 hp, 274 ft-lbs, 3815 lbs, $27,060
RX8 - 238 hp, 159 ft-lbs, 3029 lbs, $27,420
GTO - 350 hp, 365 ft-lbs, 3725 lbs, $33,190 [/b][/quote]
All of those cars listed are better handling cars, with the exception being the GTO. The GTO is a little too portly. The 350z is a very well balanced vehicle and does quite well on the track. I haven't driven a RX8, but from the reviews I read it handles awesome. You incorrectly have the weight listed for the 350Z. It should be around 3300 lbs depending on what model you buy. All the cars listed have 6 speed manuals, so you win some and lose some when taking price into the equation.a

holderca1

All of those cars listed are better handling cars, with the exception being the GTO. The GTO is a little too portly. The 350z is a very well balanced vehicle and does quite well on the track. I haven't driven a RX8, but from the reviews I read it handles awesome. You incorrectly have the weight listed for the 350Z. It should be around 3300 lbs depending on what model you buy. All the cars listed have 6 speed manuals, so you win some and lose some when taking price into the equation.a [/b][/quote]
I got all the numbers from Edmunds. So if its wrong, they have it listed wrong.

But the Mustang GT is still faster than all those cars and is at least $2k cheaper than all of them. I guess if you want to sacrifice power and torque and a larger chunk out of your wallet, then go with one of those other cars. The RX-8 was not even an option for me, I couldn't drive, no leg room up front, I would have a permanent bruise on my left knee if I had one from hitting the dash on every shift.

SixtySix

And truth be told it's kind of doggy from a seat of the pants feel. I test drove one, and was not impressed or comfortable.

mgrabo

here is a bit of info. ford mostly owns mazda. so if you buy a rx8 or a mustang ford makes money.
i have owned 6 mustangs in the past 13 years. i will probley never have a car for my personal use other than a mustang. i havent driven the new mustang yet, but i bet its lightyears ahead of the older fairmont suspended mustangs. i think the mustang caters to alot of people like me. and i think thats how ford envisioned it.
yeh ford doesnt offer the gt with irs. i think its a good decision. no ford didnt ask me what i wanted and i bet they didnt ask many if any reading this. just think about it. a gt with 300 hp. a cobra with 450-500 hp. they both feel exactly the same. what am i going to but a car thats faster that runs on 92 octaine and gets 20 mpg at the best. or a car thats slower than the cobra but faster than most outthere that runs on 87 octaine and gets 26 mpg, o and its 8-10 grand cheaper. i pick the gt.
maybe it makes more sense know, maybe i just typed this out for no reason.
o and by the way my wife had a focus se and the rearend jumped around as much as some of my older mustangs.

Rampant

One thing I don't understand is if the solid rear axle is so much better for torque and power, then why does Ford choose it's most powerful motor to put the IRS on?

Price.
They can charge more for the Cobra, plain and simple. That is the only reason I can come up with.

If Ford would just come out with an IRS SE model, then everyone will be happy. The old-school pony/muscle car, hard-core draggers will have the SRA, and those that want an IRS will be able to get that without paying top dollar for the Cobra.

bob

I would say Ford put an IRS on the Cobra because most of the people spending that kinda money are like Max and Jack. They liked the mustang but had a lump in their throats about the live axle. So when it was feasible in went an IRS.

Personally I like the knuckle dragging nature of the car. No IRS, no SLA its only real nod to modern performance is the OHC engine. Does it matter to me that it won't ride as smooth or display the dynamics of a car equipped with these things? Not one bit, its all part of the car's charm to me.

In any event, at its core, this is really a bench racing discussion and thats all about one upmanship and keeping up with the joneses.

SixtySix

Kinda silly isn't it

danazar

Not price. Cost. There's a difference.

Sure, Ford can afford to make an IRS that'll take 400+hp for a fifty-thousand-dollar car. However, the base $20k V6 model doesn't need that much durability, and there's no way they could keep the costs on both the V6 and GT down to keep them at the under-$20k and under-$25k price points that they wanted while at the same time including something like that.

But like I said, Ford wanted the enthusiast to be able to keep modding upward, so they'd be happy. They could have gone with a cheaper, 'lesser' IRS for the base models, but then there'd be durability issues with the enthusiast crowd.

A solid axle is a solid axle, it's fairly cheap to build one that'll take anything reasonable. With an IRS though, you're looking at more and more cost for something that's absolutely durable as your HP/torque goes up... and come on, the last thing Ford needs to worry about right now is the new Mustang, after all the hoopla, being hit with "reliability/durability issues" on such a major component. They took the cheap road, because the Mustang's supposed to be an affordable car.

rhumb

Yeah, as Dan noted, I'm definitely in the IRS camp. As you noted, the live axle was primarily a cost-based decision though it does actually function better in a very limited subset of performance situations, namely, standing-start, straight-line, smooth-road acceleration. Other than that first second or two off the line, it suffers against a good IRS, especially, as you have noticed, when the going gets tough on less than perfect roads where the live axle gets rather lively.

Hopefully, the upcoming Cobra's IRS, which should greatly expand the Stang's handling prowess beyond the smooth and straight, will either be added to mid-range models, perhaps some neo-Boss 302 type, or readily retrofitted into the current GT. That should give you ride AND handling over all the varied roads you drive and the rest of us who drive for more than a quarter mile at a time on billiards-table smooth roads.

In the meantime, various aftermarket companies are coming out with all sorts of suspension upgrades that might improve your handling/ride balance a touch, though its hard to overcome the live axle's innate Achilles’ heel of humongous unsprung weight.