Steering, Suspension, & Brakes

Interesting...

[grassrootsmotorsports.com]

Good to know--makes me feel better about using my Ford 8". Thanks for posting, Carl.

Depends on what you are after. generally the solid axle will be better for straight line acceleration and the IRS will be better on uneven or rough road surfaces.

Jim

I agree with the author. I do not believe that the IRS is superior on a road course.

I guess it depends...

Jim

So , are most of us, using our cars primarily for road courses ? Sounds like roads in many states are becoming 1,5 caca ? How do you get a good camber curve on a solid axle ?
Art.

Street cars will have compromises & with IRS squat & dive things are constantly changing. I am certain that designing a good IRS is a giant PITA.

On the other hand my B has little body roll & not that much suspension travel. So, the camber gain is not much of an issue. I prefer the simplicity of the live axle.

Certainly a live axle is much less expensive and much simpler to implement than a well designed IRS, and one that squats on launch is not that well designed. Squatting means that the axle is lifted, a thing that does not contribute to maintaining tire contact. Drag racers lift the rear on launch to put more initial pressure on the tire patch, but much more commonly body height is unchanged. The TR4/6 is a notable exception.

IF the IRS is restricted in travel as the stock axle sometimes is with lowered ride height, stiff springs and shocks there may not be much of a noticeable improvement. However if the install is done in such a way to take advantage of what the IRS has to offer the results can be significant. It may take some time to tune the suspension and achieve these results.

I feel I have accomplished this now with the MG-Roadmaster and my roadster using the narrowed Jag IRS and the widened bodywork.

Carl will be driving the RM this coming weekend to attend the GCBCC show and will have the opportunity to evaluate all aspects of the car including the handling and I look forward to his feedback. The car is not fitted with sticky tires like his so it won't be any sort of direct comparison but it should be interesting nonetheless. I do have a couple of twisty local roads I can show him.

Jim