The first thing to do when contemplating an IRS conversion is to locate the bits you will need. These are: an IRS gearbox, and early gearbox nose-cone, IRS spring plates, IRS semi-training arms (with brakes attached), IRS driveshafts, and a set of IRS semi-trailing arm mounts.

Next we fit up the gearbox.

(August 99)

To do this you have to bolt an early gearbox nose-cone onto the later IRS box. This is relatively simple and is a straight forward swap.

An alternative would be to hack the original front gearnox mount off the chassis and weld on a later one.

(August 99)

If you want to put the later nose cone on the earlier box you have to grind away the section that I have circled in red

(August 99)

Although its hard to see in this picture, I cut strengthening gusset just below the outlet for the handbrake cable, and ground it back to the torsion tube, in order to make way for the IRS brackets.

(August 99)

Then I inserted the rear spring plate, roughtly in the position where I thought it would sit whe the car was sitting stationary on the ground. I then bolted on the IRS arm lightly to it and clamped it with weding clamps. The clamps made it easier for me to adjust the positioning of the arm on the spring plate.

(August 99)

Then I used a spirit level to check the camber. Highly accurate..........NOT !!!

(August 99)

These are the aftermarket brackets that you can buy. When you buy them thats all you get, no instructions or anything that might help fitting them. I had to grind a hell of a lot off the to make the fit, about 10mm in some areas (which perhaps was a mistake in hindsight, see later).

Following the instruction in a well know VW magazine I worked out the angle it would sit at and scribed this onto the frame horn.

(August 99)

Then I hacked a mighty big hole out of the frame horn, following the line I had scribed.

(August 99)

Then I bolted everything back together, including the new bracket (with one of the large washers at either side of the IRS arm) and tack welded it in place to hold its position.

(The bolt is only half screwed in as I had started to unbolt everything when I realised I hadn't taken the photo yet).

(August 99)

Then I did the same with the other side. Notice the high tech device used to enable microscopic adjustment of the brackets position prior to welding it.

(August 99)

And the high tech support mechanism for holding the IRS arm against the torsion tube.

(August 99)

After a lot of measurements, I tacked the bracket into position.

(August 99)

In spite of the fact I used a bunge cord and a bit of wood to hold things in position - not easy when you are working alone - I measured everything I could possibly think of to ensure that the brackets were welded in the correct positions. I measured the camber, the toe-out, the distance diagonally from the front shock tower on the front axle to the opposite stub axle on the rear.

I literally spent about an hour with my dad and a measuring tape checking this all so it would be perfect. When I was convinced I welded her up.

(August 99)

After a short break of almost a year (I moved house), I bolted my newly aquired Porsche 944 suspension and brakes to the car along with a set of 928 turbo alloy wheels. Looking from behind it was clearly obvious that I had screwed up somewhere. The wheels sat at hughly different angles. I have no photos of this (I dont know why because I have photos of everything else) to show you but trust me it was bad. You can perhaps see from the photo above the the angle of the brakets wasn't right. I noticed this at the time but thought it was due to the fact that I had to grind so much off the brackets.

(Summer 00)

Here a 1303 chassis is sitting directly on top of the '64 chassis. You can see the difference in the angles of the IRS brackets.

(Summer 00)

So I decided to use the brackets off the 1303 pan to fix my 'alignment' problems.

(Summer 00)

So I chopped off the framehead. I did think about just putting the later framhead on this chassis but decided against it for the same reasons that I never used the '73 chassis.

(Summer 00)

I then cut out the pans which were pretty rotten anyway.

(Summer 00)

Here you can see the difference in the framehorns as well as in the IRS brackets. The framehorns on the IRS chassis are thicker where they meet the torsion tube, the also have a steeper angle and then strainghten out. You can see the IRS chassis has an indentation on the ops of both framehorns where the CV joints would be, assuming the box was fitted

(Summer 00)

So I hacked out the brackets I had welded in just a year earlier.

(Summer 00)

Then I cut the two IRS mounts from the IRS chassis. This was a really hard job as you have to cut the torsion tube off from the inside so that you dont remove any material from the brackets themselves. I'll let you work out how I did this, suffice to say it took about 3 hours a side using a grinder, a hacksaw and a cold chisel. It looks easier than it actually is.

The black part in the foreground is acually from inside the framehorn.

(Summer 00)

Here is the view of the bracket from the outside.

(Summer 00)

After cutting out the holes for the brackets (using the brackets as a template) the chassis was then cleaned up in the areas where it wold be welded.

(August 00)

I used the seam that runs the length of the chassis as a datum point for welding in the brackets. Both chassis's have them, however, since the framehorns themselves are slightly different shapes I'm not exactly sure they are in the 'correct' positions. I am about 95% sure though.

Even if they are slightly out, each side should be out by the same amount.

(Summer 00)

After fitting up etc the bracket was tacked in place.

(Summer 00)

The fit of using these is far superior to the aftermarket items, as far as mating to the framehorns themselves is concerned. All the lines flow together as opposed to looking like you just welded a bit on as an after-thought.

(Summer 00)

Then I did the same with the other side before seam welding it up.

(Summer 00)

I ground down the weld very slightly, just t make it a little more tidy.

(Summer 00)

After another year I got my enthusiasm back and seam welded the first bracket which was still only tacked in place.

(November 01)

Another view of it.

(November 01)

And a third view (I just got a digital camera and I wanted to get my moneys worth !! :-] ).

I will give the weld a slight buff with a 40 grit flap disc like the otherside, just to tidy it up.

(November 01)

Another thing which needs doing is to modify the tops of the framehorns so that the CV joints dont foul on them.

(February 02)

I did this by cutting 3 slots and bending the flap down before welding the two ends. I then trimmed the side and welded it up also. I choose not to weld the side which has the outlets for the heat exchanger cables. I dont intend to use these.... but you never know.

(Februaryr 02)

Another problem I ran into is that the heat from the welding has caused the frame horns to move about 5mm further apart so the gearbox carrier no longer fits. I have still to fix this one - hence no pictures yet. his photo is from the Bentley workshop manual which describes how to repair it. Note that this area is very strong (it needs to be as its supporting the engine and the gearbox) so banging it repeatedly with a very large pounding hammer doesn't work - I tried it !

(February 02)