Originally Posted by Caustic

The whole live axle vs IRS is a ridiculous debate. Billy Johnson is right from a technical standpoint. But he is also speaking from a professional standpoint, which most of are not.

The main difference between a live (stick, solid, or whatever you want to call it) vs IRS is grip and consistency. When a wheel connected to a live axle hits a bump, both wheels are affected in terrible ways. It completely throws off the handling to all but the best of drivers.

IRS is a benefit when a wheel hits a bump, the opposing wheel is still settled, the handling characteristics on the opposing wheel haven't changed. This creates consistency and predictability for handling in the majority of conditions.

The point being is that when you see Mustangs closing in on M3 lap times, everyone points it out as the Mustang being as fast and as good as the M3. But the reality is these those lap times are close because professional drivers have the ability to correct for the Mustangs weaknesses.

You put weekend warrior track day drivers in those two cars, the driver in the M3 will consistently outperform the Mustang driver by a large amount. The Mustang driver will have their hands full every time they clip an apex and roll over rumble strips.

Live axle technology is good for just one thing, price. If there were little difference between live and IRS, why does every high end race car have IRS?