2011 Mustang GT power leaked

[Kitdy]

But the Mustang has a new competitor with with an optional IRS - the Genesis Coupe.

The Coupe however doesn't have the cool factor that the Mustang does, and it's a Hyundai so even though it's a great car it may be harder for it to gain acceptance in the market.

[Ferrer]

It is selling quite well though, isn't it?

[culver]

The proof is in the pudding. In this case the pudding is reported to be pretty darn good.

For the most part the LRA in the Mustang is a handicap. I can't really think of any way save for cost and high power drag launches in which it is better than a decent IRS. With the IRS you can run some rear caster and toe. You also cut down the unsprung weight. Heck, you even gain some interior space.

Now the question is what would the Mustang be like had Ford gone IRS? How much extra would it cost the customer? How much extra would it cost Ford? I suspect the LRA cost savings was somewhat split with the customer. If Ford had to increase the cost what would it do to Mustang sales numbers? I'm certain the Mustang would handle better with IRS, the question is how much better? Would it be worth it?

Hard to say. Still, with the Mustang Ford has shown that the check boxes on a list of "correct technology" only goes so far. What often maters more is the details. Ford seems to have sweated those details quite nicely.

I also noticed the $30k price. Does anyone know what kind of increase this would be over the current V8 car? It seems to me, perhaps do to the newest round of CAFE stupidity, that Ford want's to get some of the people who might have skipped the 200hp V6 in favor of the old V8 to saddle up to a new V6. Given how fast even the V6 Mustang would be, for the first time I would actually consider a Mustang that didn't have a V8 (the 1980s Turbo Mustangs being an exception).

[Kitdy]

How much extra would it cost Ford?

98 dollars per car apparently.

[pimento]

According to that article it cost Ford $98 per car to retain the live axle.. If only there was a Ford product somewhere in the world that's built on a RWD platform that has IRS that they could have leveraged... Hmm.

[ThisBlood147]

To this day I have a hard time believing that Ford is actually spending more money to keep what is generally a cheaper alternative to IRS. There may have been costs associated with the last minute change to the SRA on the pre-build 05's back in 04......but I can't see them charging more for older tech even today. I'm sure those change over costs have long since dissipated, otherwise I see no reason why they wouldn't have changed over to IRS by now. The stigma has always been that keeping the SRA until the 2014 redesign was a matter of keeping costs and weight down on the current model.

Guess I could be wrong though.

[fpv_gtho]

The SRA was to get a lower rear floor, so that it could remain a 4 seater car. Ford US and Ford AUS were working on a common IRS to be used between Mustang, Falcon and Territory, but parts of the geometry needed to be higher for Territory and lower for Mustang to keep the necessary rear room. The program ran out of time and one of the senior bosses got fed up with it all.

[Ferrer]

I don't think the LRA detracts from the Mustang. Would it be better with IRS? Probably, but then again the point of the Mustang is to offer a bit of fun, bang for buck and this sort of thing. And I think it does it quite well right now, especially with the new engines.

[ThisBlood147]

First Drive: 2011 Ford Mustang GT changes the game — Autoblog
Sounds pretty good to me. I may have found something that I'd actually be willing to part with my hotrodded 05 for.

[wwgkd]

I don't think the LRA detracts from the Mustang. Would it be better with IRS? Probably, but then again the point of the Mustang is to offer a bit of fun, bang for buck and this sort of thing. And I think it does it quite well right now, especially with the new engines.

This. I don't believe Ford would be selling the LRA for more than IRS.

Also, to everyone who says that the mustang can't handle because of the LRA, check recent SCCA results, and I think you'll find the mustang doing quite well. For a comparison of the Genisis coupe and Mustang same day, same track totally stock check the recent lightning lap times from car and driver where the 315hp Mustang was almost 5 seconds a lap faster. Sure, it would probably be better with the IRS, but it's not like it's trying to run on one leg without.

[culver]

To this day I have a hard time believing that Ford is actually spending more money to keep what is generally a cheaper alternative to IRS. There may have been costs associated with the last minute change to the SRA on the pre-build 05's back in 04......but I can't see them charging more for older tech even today. I'm sure those change over costs have long since dissipated, otherwise I see no reason why they wouldn't have changed over to IRS by now. The stigma has always been that keeping the SRA until the 2014 redesign was a matter of keeping costs and weight down on the current model.

Guess I could be wrong though.

I would tend to agree with this.

A few more points:
-We don't really know what the facts were when Ford made this choice. In retrospect someone can say, "hey, the real cost would have been X". However, what did the company know at the time. It's possible the real cost wasn't really possible to know at the time. If the cost was based on a set of assumptions whose probability of coming true was low or unknown then perhaps it was more for the sake of project cost safety rather than cost alone that lead to the use of the solid axle.

-We don't know what issues were involved with using an IRS. My assumptions about IRS having more interior space do presume some level of "good fit" between the IRS used at the car. If you look at the Fox body Mustangs with IRS you can see a system that didn't live up to the full promise of IRS due to the compromise of having to bolt onto the existing chassis. It is possible that the compromises needed to use the Falcon IRS were rather large thus Ford would have ended up with a so-so IRS vs the, forgive the term, very good live axle on the current car.

-Let's assume the $100 number is correct. So what does this number really mean? First, let's assume that this would buy a suspension that is in fact superior to the live axle. It would seem based on the Mustang vs Dodge comparison (not truly apples to apples) that the live axle of the Mustang is better than the IRS of the Dodge. So ignoring that, what cost whom $100. If this is $100 onto the sticker price of the car well that's would be worth it IMHO. But if this is $100 extra in part costs only then the customer price might be much higher. I figure the manufacturing price estimate would make for a worst case. In this case we still have to pay the extra R&D costs of the IRS system (probably not that much more than the IRS). We have to assume that the Mustang IRS ends up not being able to piggy back on the Falcon's system (it often happens when what was supposed to be common turns bespoke). We then need to ask how does $100 parts affect the price of the car. Well does the IRS cost more to assemble? If so that adds to the price (perhaps that was included). What's the multiplier between added manufacturing cost vs added MSRP. In some cases it's 10:1. Let's just assume it's 5:1 which is likely quite realistic. So now we added $500 to the price of the car. This isn't $500 worth of high margin paint protection, this is $500 of real total costs that can't really be trimmed. So now what does an added $500 in transaction price do to sales volume? Does the benefit of an IRS offset the loss in sales due to the higher price?

-Is that number even right? In general the auto press is probably better informed than most. However, I specifically argued with a MT tech editor who didn't understand how the Corvette leaf spring worked. His description of the system was flat wrong and claimed that lifting the left side would force the right side down and this act in a fashion that was opposite the way it really works. So here is someone who is supposed to understand these things getting it flat wrong. My point? Do we know if the $100 number is creditable?

-It is possible that Ford screwed up and they really could have delivered for little cost in the long run. It appears that when Europe was moved to the Mk2 Focus Ford didn't save money by keeping the North American market on the Mk1 chassis. The cost of redesigning the Mk1 was high enough that it didn't save money over using the presumably nicer Mk2. Of course this could also be untrue.

Basically in the end it's hard to say if the choice was right or wrong. At least when comparing to the Camaro and Challanger the choice seems to be right as the Mustang is reported to be the best handling car of the bunch. However, does the Mustang out handle the 370Z and Hyundai coupe? I don't know. All three are priced in the same market and I'm sure Ford wouldn't complain if the Mustang grabbed sales from both.

[Ferrer]

I'd tend to think that when evaluating a live axle over an IRS setup lap times or racing success are a moot point. As I understand, and I'm no engineer, live rear axle suffer the most in bumpy road and when the surface isn't perfect, which isn't the case in race track. So possible a very well developed live rear axle, like the Mustang apparently has, could (almost) be a match for an IRS in terms of outright performance.

Then there's the point of the car's market. Is it supposed to be a nimble sportscar? No. Is it supposed to be a dragstrip slayer? Yes. Does handling matter there? Not much. So in that case the IRS matters even less. Furthermore, despite car magazines going to great lenghts to find twisty moutain roads, are those common in North America? I can't say for sure, but I'd say that no.

So in the end this car could end with an amount of overengineering that it wouldn't put to good use, even if it could be a better car.

[culver]

Well the Pony cars were never supposed to be bad handling cars. They were always supposed to be good handling cars that could be both fun in a line and fun for a weekend drive in the hills.

Also, I've certainly seen a few race tracks were the surface wasn't exactly smooth. Also, with a rigid axle you are pretty much stuck with 0 toe and 0 camber (not as big a deal since the axle stays square to the road as the body leans).

[clutch-monkey]

-Let's assume the $100 number is correct.

i do doubt this.
ford has gone live rear axle for two reasons imo;
A) it's cheaper
B) it's what the customers want.

they've simply tried to make it as good as they can to please everyone, and have done a pretty good job.
besides.. Roush offers IRS right?

[ThisBlood147]

No, Roush reworks most of the factory suspension, but the live axle remains. As far as I know, there aren't any aftermarket tuner companies that provide a current Mustang build with a custom IRS. In the past there have been aftermarket IRS units available for the platform........but they were so ridiculously pricey that almost no one was willing to drop the coin on them.

Regardless of the reasons for Ford staying SRA, I think we can expect the 2014/15 redesign to finally usher in the age of the proper multi-linked rear suspended Mustang. It's the only thing holding the Mustang back in the court of public opinion (despite the fact that it hasn't hampered the car's performance or sales very much).