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Classic Beetle question

Posted: Mon Mar 13, 2023 8:50 pm
by Winston Teague
I know there's a considerable Beetle knowledge base here (to say the least) .....
A question, is there a 1300cc Classic Beetle model with irs rear suspension and torsion bar front?
W

Re: Classic Beetle question

Posted: Mon Mar 13, 2023 8:53 pm
by Sam
Yep. 1968 onwards cars had IRS.

Re: Classic Beetle question

Posted: Mon Mar 13, 2023 9:44 pm
by simon james
By IRS I assume you mean the one with CV joints rather than the regular Swing Axle (still technically IRS…)
In which case I thought it was only the semi-autos
and most of those were 1500cc???

Classic Beetle question

Posted: Mon Mar 13, 2023 10:13 pm
by hot66
Sam wrote:Yep. 1968 onwards cars had IRS.
Wrong. Most were still swing axle. Your thinking of the ‘sporto ’ gearbox model cars ( see Simon’s response )

IRS was the. 1302 and 1303.

When we did my last build we took a 1303 chassis and installed a beam front frame head.

Rare event to out geek Sam :lol:

Re: Classic Beetle question

Posted: Mon Mar 13, 2023 10:19 pm
by KS
The only IRS Beetles in 1968 were 1500 semi-autos. However, semi-autos were also available with a 1300 engine from August 1968.
In August 1968, US-spec models were fitted with IRS rear suspension, matched to torsion-bar front ends.
From 1971 model year, 1300 Beetles with McPherson strut front suspension (flat-screen 1302 or the later curved-screen 1303) had the IRS rear.
So a basic 1300 Beetle with IRS rear would have to be an import, or a converted semi-auto.

However, you could buy a swing-axle Beetle right up to the very end of production in Mexico...

Re: Classic Beetle question

Posted: Mon Mar 13, 2023 11:22 pm
by Winston Teague
Brill, thanks chaps, that is good info. That leads on to: Would the torsion bar front end a bolt off/on swap for the macpherson strut setup, or is it a splice-2-chassis-together job? And if the latter, is converting a swing axle car to IRS easier than converting a Macpherson Strut car to Torsion bar beam? W

Re: Classic Beetle question

Posted: Tue Mar 14, 2023 12:36 am
by Nige
Totally different chassis up front on mac strut so you would need to do some major surgery to make that work, not sure what the benefits are either.

Red9 do their own conversion kits for front and rear. https://www.red9design.co.uk/type1.htm

I'd imagine you can get an off the shelf IRS kit for a swing axle setup. I think it's different trailing arms, some bracketry and different axles.

Re: Classic Beetle question

Posted: Tue Mar 14, 2023 7:11 am
by hot66
Winston Teague wrote:Brill, thanks chaps, that is good info. That leads on to: Would the torsion bar front end a bolt off/on swap for the macpherson strut setup, or is it a splice-2-chassis-together job? And if the latter, is converting a swing axle car to IRS easier than converting a Macpherson Strut car to Torsion bar beam? W
My 66 cabrio we did this 1303 chassis with torsion bar frame head welded on .. splice on the tunnel. You need to make sure everything is in the right position as you could really mess up …

Re: Classic Beetle question

Posted: Tue Mar 14, 2023 7:15 am
by hot66
What are you trying to achieve though ? If it’s performance then 1303 beetle with its front suspension design is the best way unless you want the style of the older cars

Re: Classic Beetle question

Posted: Tue Mar 14, 2023 7:24 am
by KS
Winston, what are you actually after? A nice Beetle to drive around in? One to do trials? Hillclimbing? Circuit racing? Rallies?

Converting a MacPherson strut floorpan to torsion bar front is pretty easy as everything from the pedals/front bulkhead back is essentially the same (apart from the IRS bit obviously). Chopping off the front part of the floorpan and replacing it with the torsion bar set-up is a matter of alignment and good welding...

Yes, you can buy bolt-on IRS mounts to accept factory IRS trailing arms to convert a swing-axle floorpan if you go that route. Once the alignment is all set up, weld the mounts in place.

Re: Classic Beetle question

Posted: Tue Mar 14, 2023 7:24 am
by KS
Snap! :lol:

Re: Classic Beetle question

Posted: Tue Mar 14, 2023 7:30 am
by Winston Teague
The idle musings are based on the best combo for a lifted, tail heavy trials car, that can still be a reasonably stable and sensible road car. When lifted, we assume the swing axle setup will become pretty twitchy on a smooth road, and the tyre footprint is poor for both mud and tarmac. The front end would want light weight components, and strength and travel.....the bulk of the rear balast would be demountable between events.
We are also airbag curious, as this could give us the lift we need just for the observed sections, returning to normal for road use......but not if fragile, expensive or heavy....
The IRS conversion, whilst very doable, is quite a big shopping list with driveshafts, gearbox etc....
The obvious and sensible solution is to snap up a pre prepped car, but where's the fun in that! W

Re: Classic Beetle question

Posted: Tue Mar 14, 2023 7:32 am
by Winston Teague
And with my sensible responsible Dad hat on the rot status of any potential candidate trumps the suspension spec.....

Re: Classic Beetle question

Posted: Tue Mar 14, 2023 10:46 am
by jwhillracer
My brother's 1955 rally beetle - with IRS :wink:

Image

JW

Re: Classic Beetle question

Posted: Tue Mar 14, 2023 10:59 am
by hot66
if lifted .. how about trying to put together a swing axle rear end with reduction boxes from a split screen camper ... Ive no knowledge of wether you could do this or even if its sensible ... might be a stupid idea. ( I've only ever wanted my beetles / campers to go quicker and go round corners )

otherwise .. have a look at the Baja bugs ( the ones actually competing in the US not just the 'style' )