this may be a stupid question,i am looking at a 1973 beetle doner car to build a speedster. i see most people use swing axle cars. is the irs suspension to wide for the rear fenders, i dont want a flared body speedster.
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this may be a stupid question,i am looking at a 1973 beetle doner car to build a speedster. i see most people use swing axle cars. is the irs suspension to wide for the rear fenders, i dont want a flared body speedster.
It's a simple matter of numbers produced. There were far fewer IRS cars made than swing-axle cars.
It is harder to fit wheels/tires under the rear of a standard speedster when using IRS with standard axle length.
If you go with discs on the rear you'll be running no bigger than a 185/15 tire on a 4-1/2" mangel wheel.
I have a 5-1/2 Mahle wheel that fits because the backspacing is 4-3/4" and the right rotor has been shaved to accommodate the width.
But, if you're looking for better performance through the twisties you can't beat the added advantage of an IRS setup.
If you go with discs on the rear you'll be running no bigger than a 185/15 tire on a 4-1/2" mangel wheel.
I have a 5-1/2 Mahle wheel that fits because the backspacing is 4-3/4" and the right rotor has been shaved to accommodate the width.
But, if you're looking for better performance through the twisties you can't beat the added advantage of an IRS setup.
Dwight..... A "donor" car tells me you are building it yourself ??? If so, pay special attention to the centering of the body on the pan / frame..... As someone on this forum suggested, measure from the grease caps (front) and the axle stubs (rear) to the outer edge of the fenders.... Use a framing square on the floor and touching the fender edge to get your measurements.... I'm redoing a car that is offset about 3/8 inch to the passenger side in the rear....( makes it VERY difficult to fit tires on 5 inch Fuchs rims.) Just something to think about...
Handling wise, IRS is superior to swing axle.
Yup, over all an IRS is gonna give you better handling and more opportunities to upgrade as well. It's a tight fit, but as mentioned, you can make it work with correct wheel width and offset, plus paying attention to the measurements and details when mounting the body.
Along with the IRS rear, you usually get the ball joint front ends as well. A more tunable set-up with a wider availability of upgrades at better prices than the link/king pin assembly.
The '68 was the mixed year in that it had a ball joint front and swing axle rear. The draw back is that 1968 Beetles also had long axles. You would need a short axle conversion to use the '68 successfully.
I would imagine that Canada and Mexico have different year breaks and such. I don't think that the IRS was ever introduced at all in the Mexican Beetle, and the swing axle may have been held onto longer in Canada, but honestly . . . around here, we pretty much avoid both of those countries like they had cooties.
Luck,
TC
Along with the IRS rear, you usually get the ball joint front ends as well. A more tunable set-up with a wider availability of upgrades at better prices than the link/king pin assembly.
The '68 was the mixed year in that it had a ball joint front and swing axle rear. The draw back is that 1968 Beetles also had long axles. You would need a short axle conversion to use the '68 successfully.
I would imagine that Canada and Mexico have different year breaks and such. I don't think that the IRS was ever introduced at all in the Mexican Beetle, and the swing axle may have been held onto longer in Canada, but honestly . . . around here, we pretty much avoid both of those countries like they had cooties.
Luck,
TC
I've looked on google pics for a side by side comparison of what each even looks like !
I'm with TC.
While there were fewer IRS bugs built (IRS arrived towards the end of the bug lifetime) the increase in handling performance is amazing (especially with flared fenders and 7-8" wide wheels, which you don't want, but it still is far better than a swing axle classic sided car). Wheels can be sourced with the proper off-set to work well, although you may be limited to about 6" width before you start rubbing fenders and spring plates, depending on off-set.
I, too, can't remember what overall track widths happened in what years, but I seem to remember that after 1971 they tended to be slightly narrower, although I've never personally dealt with anything later than 1971. 1969 was the first year with ball joint front and IRS rear - don't remember if they were wide or narrow.
gn
While there were fewer IRS bugs built (IRS arrived towards the end of the bug lifetime) the increase in handling performance is amazing (especially with flared fenders and 7-8" wide wheels, which you don't want, but it still is far better than a swing axle classic sided car). Wheels can be sourced with the proper off-set to work well, although you may be limited to about 6" width before you start rubbing fenders and spring plates, depending on off-set.
I, too, can't remember what overall track widths happened in what years, but I seem to remember that after 1971 they tended to be slightly narrower, although I've never personally dealt with anything later than 1971. 1969 was the first year with ball joint front and IRS rear - don't remember if they were wide or narrow.
gn
My CMC has IRS with 4.5" wide wheels and 3/8" equally spaced gaps at the top of tires..