Most clearance for 6" zero ET wheels- IRS or SA?

[deansplit]

Hi

In a nutshell here, I need to know what set up gives the narrowest track for the rear without serious modifications to torsion tube etc...

I'm building a 356 couple on a 71 swing axle T1 chassis. I don't have any other parts yet other than the shell, sub frame and chassis so I have a clean slate for suspension set up. But that said, the wheels are limiting me to my options for the rear (and I'd really love to make the wheels fit!) – the front I can get over with 6" narrowed beam. They are a 5x 205PDC. The car will be lowered, Outlaw style.

The rear inner wing to wing width is 1600mm at the front of the arch, tapering to 1550mm at the rear. I understand an early Beetle is 1550mm front and rear so if anyone's done something similar on a Bug it'll work for me.

The distance from the back of wheel's mounting surface to the outside edge of the rim is 81mm. I'm told '67 axles are shorter than '68> but also read somewhere that the track widths of the two years is the same...? I'm assuming swing axle will be narrower than IRS? I'd also prefer discs to match the front, but again, does that add width?

Any help gratefully appreciated, cheers!

[ach60]

'67 axles being shorter than 68 has nothing to do with track, it's for the spline engagement.
For what you are trying to do you want the early short axles, and short axle tube casting.
Remember I gave you the track width data for a bunch of years vw's bugs.
That's why I put that data in that post.
Look at this:
https://swayaway.com/product-category/axles/axle-vw/axle-vw-swingaxle/

Short Axle tube casting Long axle tube casting

You can narrow the rear too.
https://swayaway.com/product-category/spring-plates/sp-vw/

This guy did the same thing on a Bus

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_________________
Good Luck
Al

[ALB]

I am a replica Speedster owner and am working on fitting the widest wheel/tire I can on the back of my car, so I know what you're going through. My car is an older Intermeccanica and I've got it on an irs pan (1970), with Karmann Ghia discs on the front, 4x130mm (redrilled) Beetle back drums with oe 911 Porsche Fuchs alloys for wheels. 6" wheels with 185/60's will fit on the front. I've tried 195/55's (you can still find them in a summer tread/compound) and other than adjusting the turn stops slightly so the tire doesn't rub on the inner body at full lock, they'll work as well. The back, as I've said, is irs with swing axle torsion bars and cut down swingaxle spring plates bolted to the inside of the trailing arm flange with 7" wheels (6" Fuchs cut and widened 1" to the inside, a la 1967 911R wheels). With 205/60's, there's maybe 1/8" sidewall/springplate clearance (had to shorten the bolt that threads into the flange) and the outer part of the tire contacts the fender at the back. Although the ultimate goal is to run 205's or maybe even 215's (with type 3 rear drums, which will necessitate narrowing the trailing arms) I'll be putting some 195's on it for the moment, just so they clear the fenders and is actually rolling. It helps to get to know the local used tire dealer. Anyway...

1966 rear track is listed (1966 VW sales brochure, looked up here in the Archives) as 51.2". The axles and tubes can be categorized as short axle/short spline- I believe they are 1 1/8" shorter than 1967 only axles and tubes, which are long axle/short spline. In 1968 VW went to long axle/long spline (5/8" longer again, in the spline area this time) axle and drum assemblies with 53.1" rear track and irs is listed at 53.1" rear track as well. One anomaly- the rear track for 1967 is listed at either 53.4" (VW 1300) or 53.1" (VW 1500)- I'm guessing in 1967 VW used wheels with different offsets?- but it's just an uneducated guess. And to top it all off, most rear disc brake assemblies use a type 3 style hub, which adds 5/8" each side as well. I have heard that there are "zero offset" wide 5 rear disc brake kits, but I haven't researched it.

If you're looking for the best handling and most fun car you can build, I'd suggest going irs (you can mount 5x205 brakes by cutting 5/8" off the snout under where the 36mm axle nut). The trailing arms can be narrowed or the wheel centers can be cut loose and repositioned. The backs of the rear fenders can even be cut loose, the backs pulled out to eliminate the rear taper and re-glassed (if interested I can send pics).

Otoh, if you're intent on going swingaxle- use '61-'66 axles and tubes. There will be room left over for disc brakes. And put a camber compensator on it- they're a life saver! Stay away from the Empi piece of sh*t.

As usual, just my 2 1/2 cents (I'm Canadian, eh).
_________________
On a lifelong mission to prove (much to my wife's dismay) that Immaturity is Forever!!

[chickengeorge]

My Beetle is IRS and I modified my trail arms and sourced Type III short side automatic axles. You can buy narrowed trail arms though and new short axles. Blind Chicken Racing used to build the arms. I can't find them on their website, but they might still have the jig...