Contemplating a car. Do I want IRS or not and why. In the old days we put a camber compensator on VW's and we were happy. Thanks. Also what is a "freeway flyer" trans and do I want one?
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I only know what a swing axle car drives like so I have no comparative information. I have a camber compensator on my car and drive the snot out of it on twisty roads and everywhere else I go and have never had a problem. Well, one time I did and that why I put the camber compensator on the car.
A “freeway flyer” is a name given to a VW transmission that has a 3.88 RP if my memory serves me. If I’m wrong Al Blanchette (ALB) will correct me. Or Stan will because he hates the name Freeway Flyer.
IRS will handle better. Swing is more authentic to original. IRS forces a wider rear stance making off set of wheels and tire size limited for a classic body. Trailing arms can be cut/welded to reduce width. Adding rear wheel adapters or disc brakes that add to width an also be an issue. IRS would take a rear anti sway bar.
The IRS will handle better and leave you more room for error. Typically the trailing arms are narrowed 1 to 1.5 inches. Airkewld and a few others make rear disc brake conversions that add no track width, so you can get a 185 section tire under the rear fenders with discs, and depending on the tire maybe even a 195, but that's going to vary a bit from car to car given our plastic fantastic bodies.
You can opt for a sway bar or not, I have opted to run one. The difference in feel is noticeable, a more planted sensation at higher speeds and on bumpier surfaces. If you're running a wide body, it's a no brainer, go IRS.
All that said, these are old tech cars and they require skill, patience, and concentration to drive fast. For most of us, that right there is a big part of the charm.
IRS handles better; swingaxle is truer to the original car concept and parts are cheaper and more available just because there were so many more swingaxle cars made as compared to IRS which started in 1969. And that discounting the subsequent Mexican and Brazilian production cars which never used IRS. Depending on what you want a camber compensator can be all that you need, such as in my case. I got an inexpensive EMPI unit and it's still there working fine 15 years after I installed it. Then again; I am not a race car driver. Swingaxles present another set of challenges and complications such as not being able to have the pan be freestanding while you replace the transaxle, more probabiity of transaxle/axle fluid leaks into your rear brakes, etc, etc.
For me, swingaxle is fine and dandy.