Is Independent Rear Suspension Good for Next Generation Ford Mustang?


2011_GT500-Conv02.jpgby Patrick Rall

While Ford Motor Company hasn't offered up any information about the next generation of the Ford Mustang, rumors suggest that when the "next Mustang" hits the streets in 2014, independent rear suspension (IRS) will be a standard feature.  Considering how many modern vehicles use IRS setups, it seems like a no-brainer that the classic American performance car would have this modern handling technology, but is standard IRS in the next Mustang what the American performance car segment wants?

The argument for the independent rear suspension is that it allows the wheels to respond to the surface of the road independent from each other.  When a car with a solid rear axle, such as the 2011 Shelby GT500, hits any uneven pavement the entire rear axle moves - at least a little - and that means that both rear tires are affected - at least a little.  On the other hand, an IRS setup allows one wheel to travel without any effect on the other rear wheel, so you still have ideal grip with that other tire, where a solid rear axle may cause compromised grip.  Sounds perfect, right?

Considering that Ford's highest performance Mustang of all time, the 2011 Shelby GT500, and the best handling Mustang of all time, the 2012 Boss 302, both have solid rear axles, it is harder for Ford to defend the change from a standard solid axle to a standard independent axle.  If IRS is so perfect, then why don't the Mustangs made for high performance come with IRS? 

The answer lies in the hands of the average Mustang owner.  While IRS is great for handling life's turns, be it on the open roads or private road courses, this setup is less than ideal for launching in a straight line.  When you launch with a solid rear axle, when one tire lifts due to wheel spin it can have a reverse affect on the other wheel, so it essentially improves traction for activities like drag racing.

The Ford Mustang is designed and built for performance, and even though Ford has always focused on balanced performance from their legendary pony car, far more Mustang owners take to the drag strip than they do the road course or autocross track.  A better handling Mustang is great, but when the majority of Mustangs owners who race are more worried about a good hard launch than they are the ability to get through a turn slightly faster, Mustang enthusiasts have long benefited from the solid rear axle.

2004-Cobra-SVT.jpgFord has previously offered IRS in the 2003 and 2004 SVT Cobra's, better known as "Terminators", with a vastly underrated 390hp. The Terminator is one of the fastest production cars of all time, but when it came to the drag strip, the 03-04 Cobra took a very good driver with an ideal launch to get the best drag strip times.  Some owners of the Terminators would buy IRS braces or even solid rear axle swaps to improve their launching ability. At the end of the day, the solid rear axle offers an advantage over the IRS on the drag strip.

Making IRS standard in the 2014 Ford Mustang would improve the handling of the historic pony car, but it could conceivably turn off those enthusiasts who want a good drag strip car.

What do you think? Are you for or against IRS in the next gen Stang? Voice your opinion here!

Shawn Caudill (Mon, 16 Apr 2012 16:04:00 -0700): considering the fact that the average drag racer wont pump up the Mustang to over 500 HP.... DAH! Put the darn IRS in it! Ford screwed up long ago by not doing so back in the 60s. My Dads 2003 GT has the SVT IRS in it with full polyurathane/derin bushings. Replace all the rubber and add the braces and stage 5 CV axles and the IRS is good upto nearly 1000HP. You can drag a IRS and there are those that have done so competitively.
Michael Fournier (Tue, 08 May 2012 16:52:09 -0700): OK really out of ALL the mustangs sold how many actually ever make it to a drag strip? 10% -20% All this crap that a IRS can't accelerate off the line fast is bull if that is so how can IRS sports cars get 0-60 times under 4 secs they all have IRS I do not want to bash other's sport so if you like drag racing that is ok for you build your car for that but on a street car to build it with a huge weakness in ride comfort and handling over bumpy roads is simply stupid sorry I just had to say it. I love my mustang's looks I love the sound of the V8 I love everything except when I hit a bump with the inside wheel in a turn and the whole car jumps. BUT ONE thing I do worry about is if Ford builds a BAD IRS it will be worse then what we have now I have never driven a Falcon but I have seen test drives of the Aussie fords and they seem to have the performance we will have to wait and see. A proper Independent Suspension today is one that uses electronic ride control in place of sway bars so you Keep the wheels truly Independent. But I doubt the Base Mustang will have that the GT500 with it's much higher price point could as it is already pushing super car HP it would be great to have a Mustang that has true GT car performance.
Michael Fournier (Wed, 11 Jul 2012 10:09:53 -0700): So true the real benefit to the Live axle is you can build a drag car cheaper as it is much cheaper to beaf up a Solid live axle then a IRS with half shaft U joints to worry about Also if you get into building a Strong IRS that is ALSO light it gets even more costly but like I said most Mustangs will be 500hp and below and those over that will be in the $60K plus range anyway it is not hard to build a IRS that can handle repeated lunches at 500HP at the rear wheels and I have seen plenty of 1000HP plus cars with IRS. (there also very expensive but what car putting out over 1000hp isn't)
Septimiu Mocanu (Sat, 03 Nov 2012 03:57:36 -0700): .
Prasath Pillai (Mon, 29 Apr 2013 15:08:14 -0700): IRS PLEASE, so I don't have to buy a corvette :(
Mark Ziegler (Sat, 25 May 2013 16:57:40 -0700): Ford - Please hear us! It's time for IRS!
Jeff Holmes (Sat, 25 May 2013 17:00:31 -0700): What Mark said!
Jeff Holmes (Sat, 25 May 2013 17:01:47 -0700):
Mark Ziegler (Sat, 25 May 2013 17:12:58 -0700): Oh the "gorgeous" Fox body ;) I can't wait to see part 2!


Mustang Pictures

MustangForums Fans