I'd imagine all aluminum bits would come in lighter unless ford uses some crazy bulky stuff.

 

The S197 platform has run its course. Time to evolve the car into the modern era. They've got a few solid starting points in their arsenal.

 

Can I get a ?!

Just hope Ford has the sense to build it tough enough to handle drag strip launches and fight wheel hop to somewhat appease the straight line racing crowd. Would be even cooler if it can get away with utilizing the 8.8 R/P or even stepping up to a 9-in. center section ready for a wide range of aftermarket ratios - unlike the one in the current F-Body.

 

I was not disappointed Ford kept the soon to be obsolete rear end in the Mustang as long as they did. I would expect Ford to have an all new chassis to go along with the IRS. As important as drag racing is to us Mustang enthusiasts, you can bet they will have a beefed up version of the IRS for drag racing.
Secretly,I wish the 2015 Mustang had the same interior and exterior dimensions as my beloved Fox Mustangs. My 2007 Mustang just seams too spacious for a sporty car.

 

I have spent enough time under the back of my car while installing dual exhaust, mufflers and a GT rear valance to know that is the same exact platform as the current cars. The rear frame rails, floor pan and that heavy boxed skid plate protecting the charcoal canister all look familiar to me. What I see different is the IRS installed as a unit into the area that occupied the SRA. The exhaust is modified to go under the IRS with a new center support bracket with isolators.

 

We might be surprised that Ford may still leave the platform designed so that the IRS can be swapped out for a solid axle through Ford Motorsports if anyone wants it... Ford could even offer it as a factory racing option package.

 

I suspect that black mule is, indeed, the existing S197 platform being used to evaluate the IRS components. This is a very early mule, so don't read too much into what will/won't be part of the '15 platform. Once we start to see heavier camoflaged mules, that's when I'd expect it to be running the all new underpinings.

 

Not sure on these last 2.......they were in the same gallery on LNN, but it's a different setup......current car for comparison?

 

The prototype IRS that was discovered in a warehouse actually weighed less than the live axle, and it would obviously cut unsprung weight by a lot too. Even if the platform is mostly the same, there is weight savings to be had in doors, body panels, etc.

 

Perhaps, given Watchdevil's observations, the basic floorpan of the current car will be retained, perhaps stamped with lighter, high strength alloys, while the bulk of the platform/body will be all new with a focus on lightness (design, engineering and materials) to hack off the 200-250lbs of road-hugging lard rumored to be left at the fat farm.

While the IRS does look to be somewhat different than the 2005 prototype (spring perch seems to be on the lower rather than upper lateral arms on the 2015 design for example), I suspect that it will be a bolt in unit that might also allow a lively axle design for those who indulge in performance in 1/4 squirts on smooth, straight strips/streets. Perhaps a mix of either IRS or Iron Age rear suspensions might be offered, either off the showroom, or, barring excessive crash and other certification costs, at the parts counter.

As for weight, an aluminum alloy intensive IRS system can weigh nearly the same of even less than the more steel/iron based lively axle, at least per http://www.drivingenthusiast.net/sec-blog/?p=11329 in discussing the 2005 prototype IRS system:As noted above, the far more salient factor to performance is the slashed unsprung weight, which is far more critical to suspension performance than the whole system weight, as might shaving a few ounces off an engine's valve train will have much more impact on performance than shaving a few ounces off the block casting.

As for worries about some delicate, glass-jawed IRS that will shatter even coming within 300 yards of a drag strip, I think those are vastly overstated and unwarranted. The automotive field is replete with IRS systems capably and reliably handling vast amounts of power, from 600hp-class Vettes, Vipers and Ferrari up to 1,200 hp class hypercars like the Veyron. Proper design, engineering and construction are key here, as they are in making a reliable live axle for that matter.

Could Ford flub this? Of course, but this in no more or less true than for any other component and given the scrutiny the drag racers will be directing towards the IRS in this regard, I bet Ford will, if anything, over-engineer it in this regard. Pics of the 2005 prototype and from what one can discern of the upcoming system do seem to indicate pretty stout bits, hardly Miata-class componentry.

In sum, I think the IRS will greatly expand the suspension's overall capabilities and performance envelope, allowing the Mustang to put down more power in a much broader range of driving surfaces and conditions than even its currently well-sorted SLA design. The icing on the cake, beyond dead-ahead pedal stomping, will be a greatly expanded handling envelope too, all achievable with equal or better ride to basically result in a superior overall suspension and a faster, and better overall, Mustang.

By 2016, I think the grumbler's grumbles will quickly fade and the whole consternation with an IRS will sound like the keening and wailing that went on about the adoption of other new (as if IRS is new) technologies like fuel injection or ABS, perhaps even eventually sounding a bit hysterical and apocalyptic.

 

The last two pictures are of the current live axle setup.

 

Cool, thought so. Just unusual to see one thats not rusted up already

 

Finally mules!

Digging the IRS!!!!

 

Hopefully they'll take the initiative to paint the components this time. I hate the rusty axle.

 

This looks like an entirely new platform. I just looked under my Dad's Boss and it is entirely different. And, like Topnotch said look how the frame is sticking out of the rocker panels.

 

......

 

I like that Ford may use aluminum pieces for the IRS, but I do not think I will be able to use my arc welder to weld mounts for my lift bar. Setting up the IRS for the drag strip will not be so easy for us shade tree mechanics.

 

I would caution against drawing too many conclusions based on one mule, fellas. There's going to be a whole bunch of these running around for the next couple years. Other than affirming that IRS is definitely in the cars, let's steer clear of absolutes.

 

http://www.leftlanenews.com/photos/f...picture-1.html

 

My 500 axle won't rust.