Benefits of Independent Rear Suspension

REDFLASH

New Member
Nov 1, 2004
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Pardon my ignorance on the subject, but what are the advantages of an independent rear suspension? In many reviews, the lack of an independent rear suspension on the 2005 Mustang is noted and it has me curious, particularly as a likely buyer within the next year. Thanks in advance.
 
since I haven't driven the 05 yet, I don't know how well Ford did on the solid axle design for this one, BUT I can tell you that comparing my 01 cobra to my 03 GT, there was a world of difference. The Cobra grips the road better and IMHO better transmits what the car is doing to the driver. Granted I didn't have a panhard bar or torque arm on my GT, and that would improve things vastly for the solid axle. From what I've heard this new design by ford is much better and really turns the new stang into a handling champ. Now I'm pretty sure it won't hang with a C6 or Elise but still, anything is an improvement over the previous solid axle design.
 
IRS is overrated.

A nicely set-up live rear axle can be just as good in terms of handling. From my quick stink behind the wheel of an '05, i can tell you that the live axle out back is far more advanced than the axle in my '03.
 
Mustang5L5 said:
IRS is overrated.

A nicely set-up live rear axle can be just as good in terms of handling. From my quick stink behind the wheel of an '05, i can tell you that the live axle out back is far more advanced than the axle in my '03.

I wouldn't say its overatted. It is a different approach to the same goal. It allows the car to always keep the back tires on the road. If you think of it in this situation when riding up an onramp to a highway there is usually a lip where it meets the highway. In my 01 GT when i hit the gas hard and hit the lip the back end would skid a little to the left because one back tire reached the lip before the other causing the opposite side to lose traction. With a IRS both tires would be able to maintain their traction. In the end an IRS will give better handling out of the box if you ever decided to do autocross. It can also give a more comfortable ride. Now thats not to say that you can't get a great ride out of a solid rear axle. It just seems you need more things to get that out of it. Oh did i mention IRS can get a lot of wheel hop, but with the right add on's that can be limited and almost eliminated.
All i can really say is that every top car made has an IRS. The Cobra has an IRS. For drag racing you can't beat solid-rear axle. For autocrossing you can't beat IRS. For everyday driving both are fine.
 
For handling on a perfect road surface there will not be much difference in how fast you can go through curves between and design IRS and a live axle suspension that is equally well designed.

Where the difference comes about is in the real world of imperfect road surfaces, bumps potholes, cracks in the pavement, transistion strips, etc. On a live axle, both rear wheels are tied together so whatever one wheel does effects the other wheel. When you're in a corner and one wheel goes over a bump, it causes the other wheel to move to which can make the car hop sideways. On the street it's usually just a discomfort. On a road race track it costs you speed.

In EVERY road racing series where IRS is allowed in the rules, IRS equipped cars dominate the races, no ifs ands or buts.

Drag racing is another story.

Back to your original question, the advantage of a good IRS on a street car is that the ride can be more comfortable and in hard cornering on imperfect roads the rear end will have less tendancy to side-step.

For road racing cars, the advantage of IRS is that you go faster.
 
351CJ said:
Back to your original question, the advantage of a good IRS on a street car is that the ride can be more comfortable and in hard cornering on imperfect roads the rear end will have less tendancy to side-step.

For road racing cars, the advantage of IRS is that you go faster.

Excellent points. For simplicity, if you're not drag racing, IRS gives a better ride and handling - lots better. Most people who don't know what IRS is vs. live axle will just say "It rides and handles better." Proof of the pudding - go find a curved road that has railroad tracks in the middle (I did this when I bought my first IRS equipped car). Go around it fast in each type car and the difference will jump up and bite you!!!