Does the Ford Mustang really have solid rear axle?
There is every indication that Ford put the old-style live axle in the non-Cobra Mustang V8s because of the drag-racing and burnout concerns. Cobra buyers, on the average (without getting too much into stereotypes), are a little more mature, and less given over to Friday-Night, high-school stuff. A live axle, however, can, under some circumstances, have an annoying trait called "axle-hop", where a simple or poorly-engineered suspension can make the axle jump up and down under hard acceleration, resulting in patchy, dashed-line tire contact. I had that happen to me a few times myself back in the late 60s, particularly with the Chrysler leaf-spring rear ends.
Live axles are used, not only for V8 Mustangs, but in many vehicles where powertrain ruggedness and durability are desired. That's why, with a couple of rare exceptions like the Honda Ridgeline, you will find them almost across-the board in pickup trucks, which are built for work.
The Ford GT would be better competition for the Z06/ZR-1 in the handling department than a Shelby Mustang.....even the Super Snake.
I once looked it up, the mustang is the only new car for sale in the united staes and england that has a solid rear axle. The previous "terminator" Cobra had a IRS , but when they are built up for serious drag racing, they switch to the solid rear axle. I still think a serious road racing mustang should come stock with a IRS setup.
Mmarshall- did not know about the burnout thing, very interesting.
Mmarshall- did not know about the burnout thing, very interesting.
If you actually use your car this way, I'm officially envious. The standard, non-tuner Mustang and other pony cars are not built for you. They are not exotic plasma-burners that run on fuels only attainable from a flux capacitor, nor do they accelerate the net rotational speed of the earth when dropping the hammer while pointed west.
An independent rear suspension may be good for bragging rights to the assembled multitudes of mouth-breathing spec racers, whose current ride is a skateboard, but if I'm going to apply some serious torque to the abuse the big rubber out back, give me a solid axle every time. I'll laugh and wave at the elitists left in a smoking heap of busted half-shafts and split U-joints.
On a road course the IRS has a lot of advantages, but if you want to pour loads of torque and heavy shock loads through a mechanical connection to the roadway, the old solid axle will outlast and outperform an independent rear end in years of trouble free service.
The concept of the muscle car is to provide reasonably accessible thrills for those of us who can't quite pay off the national debt from our trust funds, and seek value for a dollar and they succeed admirably in this mission. While they may not impress in the Hamptons or at Laguna, these are interesting if crude rides for the rest of us. We'll sacrifice a little paper performance for some real-world accessibility and reliability.
mmarshall's right, the solid axle got a bad rap from a number of muscle cars being built on rather conventional platforms. That long leaf spring produced mammoth windup and axle hop as the spring would twist up until the tire let go, then would dump that torque as wheelspin before reengaging the planet for another try. The result was usually a furious up-and-down pounding of the axle and that dashed line of abused rubber that marked your contest with inertia.
The solution was an aftermarket set of traction bars, or just an extra half leaf, forward of the axle to direct the thrust load directly to the frame, preventing that windup. A four-bar setup similar to what you see on a purpose-built drag racer would seem to be the ultimate solution - and such are available in the aftermarket. It may not be sophisticated, but it works and it's tough.
A solid rear axle is absolutely preferable for drag racing due to the virtual elimination of wheel hop compared to IRS, and ridiculous durability for a low cost and weight.. it's also not the end of the world for handling... especially on smooth roads. IRS shines more when it comes to ride quality and handling on less even roads.
An independent rear suspension may be good for bragging rights to the assembled multitudes of mouth-breathing spec racers, whose current ride is a skateboard, but if I'm going to apply some serious torque to the abuse the big rubber out back, give me a solid axle every time. I'll laugh and wave at the elitists left in a smoking heap of busted half-shafts and split U-joints.
A solid rear axle is absolutely preferable for drag racing due to the virtual elimination of wheel hop compared to IRS, and ridiculous durability for a low cost and weight.. it's also not the end of the world for handling... especially on smooth roads. IRS shines more when it comes to ride quality and handling on less even roads.
When I worked at Saleen before the first Mustang Cobra IRS was offered this was a subject of constant debate. Ford is in the business of selling cars Saleen is in the business of selling parts to increase the performance of Mustangs. If you want to increase the performance of your car & have a limited budget you should start with the most cost effective parts. IRS is way down at the bottom of that list. Ford finally caved to criticism & adapted the current T-bird IRS to the Cobra Mustang 1999 I think. Why did the T-bird already have IRS? Ride comfort the main advantage of IRS for street driving.
So the Cobra debuted with IRS & warranty costs increased right away.IRS cars lost performance on the dragstrip due to wheelhop. It cost aprox. $2500 retail to put IRS in per Mustang, remember that is about 10% of MSRP on a GT. $2500. would buy a supercharger that adds about 80HP to a base V-8
So the Cobra debuted with IRS & warranty costs increased right away.IRS cars lost performance on the dragstrip due to wheelhop. It cost aprox. $2500 retail to put IRS in per Mustang, remember that is about 10% of MSRP on a GT. $2500. would buy a supercharger that adds about 80HP to a base V-8
solid axles, leaf springs, push rods, Hemispherical combustion chambers, I'm think domesitc automakers put these things in to save $ and appease the heritige/classic club owners.... even Porsche owners complained when they <gasp> started cooling their engines with water. If you want a car with modern technology and not spend an arm and a leg stick with Japaneese, the 370Z is a bargain for what you get.
Last edited by toy4two; Jun 24, 2009 at 03:24 PM.
The kind of "pounding" that many sport-oriented cars get from their drivers is a LONG way from the abuse that a lot of Mustang jocks give their rides. I'm sure, for example, that you don't abuse your Miata that way.
Trust me......though not all are that way (and I wouldn't suggest otherwise), a lot of Mustang V8 drivers are just plain NUTS.

I have seen them do crazier things with their cars, and have seen more kids killed and injured in them, than any other single make/model of car.....even the notoriously unstable Suzuki Samurai that kids were flipping over left and right. This is not just something I came up with in my mind right now just to post it here in this thread; I've seen it for years....even decades.











