IRS conversion - spring plate question

Hi all,

Wasn't really sure where to post this - so it ended up here...

I wish to fit IRS spring plates to my Baja pan, which on its own doesn't sound difficult...but...

...I wish to use the swing axel torsion bars that were fitted to the earlier Beetles....

What is the best way to achieve this? Do I have someone cut down a set of Swing Axel spring plates (safe?)? Does someone supply new spring plates with the correct spline to do this conversion?

Any suggestions welcome!

R 🙂

That's a bit difficult... could get SA spring plates machined down, I guess... but why not use factory stuff?

Because on a a baja the IRS splingplate/torsion set-up limits wheel size to about 31" I think.
Cutting down SA plates would be OK, Jeff Hibbard says to do it in his book, dont know if there was any IRS cars with short torsion bars?

yeah fair enough reason...!

Hi

It would be easier to have your swinger spring plates modified where they bolt onto the arm changed to fit the IRS arms.

Steve

Talk to your brother he has done it it works and he lives no more 5 minus away im sure he will tell you how to do it

MUD BASHING ANYONE ?? wrote:Talk to your brother he has done it it works and he lives no more 5 minus away im sure he will tell you how to do it

...hmmmm, OK Smart A$$ :P - I have already spoken to my Brother, who had a friend who works at an engineering workshop do it for him...I will have to pay to do it, so I want to look at all the options before I hand over the $$$$. As it is, knowing what my Brother had done - his suggestion was to take a hack saw to the SA spring plates as "it will be easy - their not going to be that hard to cut"....and this from someone who had it done for him! :duh

...That said, I am going to see just how hard it is to cut a spring plate, just so I know - I will post the results up here as soon as I know....

R 🙂

Hi all - just thought I would post this for others to reference in the future...

I decided to have a go at converting my swing axel spring plates at home - I figured that if it didn't work I could then go and find someone who could do it for me.

I'm not sure what sort of steel the spring plates are made of, but it can be cut and drilled just like normal steel of the same thickness - this means that a hacksaw, drill and a file are all the tools required to make your S/A spring plates into IRS spring plates.

I made a template using an IRS spring plate, then carefully traced the shape of the end of the IRS plate onto the S/A one. I then measured everything again to make sure it was right - measure twice (or three or four times if necessary) then cut once.

Once I was happy with the markings I dragged out the trusty hacksaw and began cutting. I used a drillpress to drill starter holes where the IRS arms bolt to the spring plate, then spent a couple of fun filled hours with a file, enlarging the holes until they matched the dimentions of holes in the IRS spring plates.

That was all it took! Easy!

Hope this helps someone in the future!

R 🙂

http://geocities.com/peterwood73/buggyproject/buggyproject3.html

look at the 28th of Feb entry. It's got a scanned pick of my template. BTW, DO NOT notch it like I did.

Another thing, shorter torsion bars are not as stiff or progressive as a late type 3 wagon torsion bar. Added to that, the double spring plates are stiffer and work better. So I hope you're using coilovers or you are not getting an improvement springwise.

could you cut the splines part of the spring plates off and swap em?

Dero wrote:could you cut the splines part of the spring plates off and swap em?

No! Extreme no! This would be incredibly dodgy and unroadworthy.

They way to do it is as ratty has stated, cut down a Swing Axle plate to be the same length (shorter) as an IRS one.

Ideally, you shoudln't use a grinder or gas axe either. The spring plates are spring steel, so any heat can weaken them or cause localised brittleness. Lot's of Bad!

So just use a hacksaw and a file, and a sharp drill for the holes of course.