Oval beetle, adjustable spring plates and torsion bars?

[Ol'fogasaurus]

"To use the later longer torsion bar/single arm IRS spring plates I think they would have to be shortened some and re-drilled to match the connection to the swing axle tubes. "

You can't use an IRS spring plate in a swing axle car, the spring plates are too short. Going the other way can be done. I know someone who cut down 60s swing axle spring plates when he converted his 67 to IRS for that stealth look, in case someone looked inside the wheel arch at the torsion cover."

Thanks Bruce: for some reason I remembered it being the other way. I think there are two lengths of torsion bars for IRS but I suspect that it may not be that way for areas outside of the US where "Swing is King".

[Bruce2]

Ok, but what I want to know is if 60' on bars will fit into 56' housings. Thoughts?

The torsion housings are all the same. This means you can put any torsion bar in any chassis.

[Bruce2]

I think there are two lengths of torsion bars for IRS but I suspect that it may not be that way for areas outside of the US where "Swing is King".

All IRS torsion bars are 676mm long. Sway-A-Way is responsible for this myth. If you go to their site now, they have dropped all references to years of VWs (because they don't know!)

There are two types of spring plates, double up to 70, then single after then. But they both use the same bars.

[Bruce.m]

I've got a set of 24 11/16" or 628mm torsion bars in 23.5mm size. Genuine VW.

Allegedly for an IRS thing or perhaps a swing axle square back.

Certainly no good for my type 1 IRS pan so they got replaced!

[Ol'fogasaurus]

I think there are two lengths of torsion bars for IRS but I suspect that it may not be that way for areas outside of the US where "Swing is King".

All IRS torsion bars are 676mm long. Sway-A-Way is responsible for this myth. If you go to their site now, they have dropped all references to years of VWs (because they don't know!)

There are two types of spring plates, double up to 70, then single after then. But they both use the same bars.

You are correct in that SAW now lists only two lengths. No sure about the double spring plate years though.

[Marc]

I've got a set of 24 11/16" or 628mm torsion bars in 23.5mm size. Genuine VW.
Allegedly for an IRS thing or perhaps a swing axle square back.

According to the "Without Guesswork" workshop booklet swingaxle Type IIIs used a 626mm bar, 23mm dia for most but there was a 24mm Squareback. Oddly, it was used in the lighter-capacity (375kg) cars and set to 18½° while the 23mm was set to 20-20½° in Notchbacks and Fastbacks, and at 21½° for the 460/465kg Squarebacks.

IRS Squarebacks use a 23½mm bar but in 676mm length.
The booklet doesn't cover Things so perhaps yours is for them - but the the 24-11/16" length implies swingaxle....maybe it's for swingaxle Thing?

A 24mm bar would be 18½% stiffer than a 23mm of the same length, and as you would expect a 23½mm would be right in the middle of that.