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  #1  
Old October 12th 2003, 15:50
vennard vennard is offline
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irs coversions???

Want to change the rear of my 72 to IRS. read a few articles on it via this and some other forums. but I am sure Ive seen some ready made brackets that I assume you weld to the frame horns. Is this correct? cos this would save a lot of cutting of structural parts that Im not to happy about.
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  #2  
Old October 13th 2003, 15:16
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MattKab MattKab is offline
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Fitting any IRS mounts to a Bug requires some majorish surgery.

The Bugpack/Chenowth brackets are awesome, stronger than standard but do have to be set deep in the original steel.

I've seen some made out of box section that looked poor.

The tops of 1302/3 frameforks are notched for the CV joints but clearance here shouldn't be an issue If T1 CV's used.

Matt
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Old October 13th 2003, 16:34
jrinlv jrinlv is offline
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Wouldn't your 72 be IRS already, I thought that all beatles after 69 where IRS, or is this a country thing?? JR
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  #4  
Old October 13th 2003, 17:29
vennard vennard is offline
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Yeah. Its a country thing over here in England only semi-autos and the 03s had IRS rears. Can you tell me some more about those brackets.Do you cut them into the framehorns?
Cheers
Karl
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  #5  
Old October 14th 2003, 14:51
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MattKab MattKab is offline
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Karl,

The brackets have to be welded to the torsion housing, at a location that requires clearancing the top and bottom sections of the frameforks, where they meet at the tube. This clearancing has to be very neat so the brackets can be fully welded to give the necessary strength.

The importance of correct alignment goes without saying.

If your skills are up to an IRS conversion, fabricating a pair of fixtures will be easy. These fixtures should pick-up the position of the trailing arm bolts/mounts on a genuine IRS 'pan. Rigidly connect these to the swing-axle springplate covers bolted to the IRS torsion housing. The fixtures will then unbolt and bolt up to your SA 'pan and you'll have a bracket mounting point to work from.

I appreciate the inconveniance this may cause, as you'd need a donor 'pan. If so, consider a BJ framehead/(Chassis number?) swap for a better result (IMO)

Matt
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Old October 14th 2003, 16:41
vennard vennard is offline
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Matt , OK so now im not quite so confident.starting to get to grips with the work involved for making the 901 box fit(which is the reason for the IRS) but IRS mountings sounds a bit too critical for my skills.Do you have an idea how much this would cost to get done and someone in the East Anglia area who could do it.

Cheers Karl
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Old October 14th 2003, 17:14
vennard vennard is offline
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Any pics or tech articles on the subject. easier to understand with pics. Already seen the blind chicken article

Cheers. Karl
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Old October 14th 2003, 18:11
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Karl,

Don't be put off so easy! sorting out gear selection will be far more challenging...

I cannot recommend anyone to modify your VW.

I'm almost sure late P901 CV's will foul the top of late swing-axle T1 frameforks, if stock engine position is retained. Clearancing may comprimise the structure somewhat. Never forget your VW is old.

A BJ framehead on a duty-free '02 'pan, or better still a stickshift with dead box, go for it. Pay no more than £300, with/without bodyshell

You will have read that this swap is a body-off operation and the cost of that can all too often hit ~£4000 just to get it to bolt back up if less than A2 condition, sadly. Consider the health of your heater channels before 5gears. If you tackle it yourself, you still have to pay through the nose for that modern car, I tell myself

Matt
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Old October 14th 2003, 18:33
vennard vennard is offline
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matt
the bodywork inc. heater channels are solid as far as I know at the moment. all welded up 5 years back. body off at the same time to replace floors. Maybe sounded a bit more scared than I am because without pics I cant get a clear picture of whats involved in my head. Been reading up on the porsche versus berg thing for about 2 months so getting a good mental pic of that. Cant find a lot of info on IRS swap though.
Cheers
Karl
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Old October 15th 2003, 14:16
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I don't recall seeing anything on the net either r.e. IRS swap, I'll pm you a link if I find such.

It maybe worth contacting VWTrends in the US, they covered it in detail with pics 'about' 10 years ago.

Matt.
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Old October 15th 2003, 19:32
vennard vennard is offline
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Cheers Ill give them a go. If its any good Ill let you know. If I go ahead is it worth making a tech article of it as theres not much info about

Karl
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Old October 23rd 2003, 09:54
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nbturbo nbturbo is offline
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I have done the conversion on my early ('66) pan and it turned out very well,but was a fair bit of work.As stated, can only be done with the body off and don't even start if you cannot weld of have someone who can to help you. I purchased the whole rear suspension from a '73 Type 3 including the trans. This whole unit just unbolts from the body. I purchased some custom made pivot brackets and hired an alignment jig from a VW supplier here in Australia.The pivot brackets were rubbish, so after getting two lots to try gave up and cut the brackets from the Type 3-it took about 10 mins with a small disc in a 5'' angle grinder and these brackets are perfect and are genuine. A couple of things to do before you start-bolt the metal bracket to the frame horns that normally supports the trans bellhousing and I made up a jig to check if the frame horns pull during welding( which they did)I used a piece of 19mm square tube, about a metre long and welded a piece of flat bar to it, and used the pan along side of the gear shift coupling opening as a reference point, and placed it rear wards above each frame horn and measured the gap down to the end of the horn(right at the point where the large bolts are holding that metal trans bracket)and record your reading.If you can't find any one with a jig you will have to make your own using someones pan as a donor.I have a drawing with sizes and materials needed to make some jigs if you need them.From here on its just straight forward with cutting into the frame for the pivot bracket to fit in the correct spot before welding. Take special care around the hand brake tubes because a little extra time here will save heaps when welding.You do not have to touch these tubes but you will get real close when cutting.I think the reason my horns pulled was because I was too fast with the welding-should have kept the whole thing a bit cooler. I also welded along each frame horn where they are spot welded at the factory.I have built up a 2.7litre Type 4 motor for mine so thought welded seams would stiffen up the horns with all the extra torque of the bigger motor. The last job is to heat up the frame horns where the CV joints go and flatten it down with a large hammer.You can check on another car to see how much you need or just slip in the trans and give it about 10mm clearance.I have used all the suspension from the Type 3 inc.the double spring plates and torsion bars and the single side plate trans.Back to the drama of my horns pulling-the tool I made showed they had pulled up 6mm which meant the back of the motor was about 15mm too high, which meant my engine bay sealing was no good.Had to get a long RSJ and chain it to the frame horn at one end and to the front beam at the other and heat and jack the frame until I got it right.So take your time when welding and keep it cool.Only have pics of before and after-none during the job.Good luck.
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  #13  
Old October 24th 2003, 03:24
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There's a good 'how to' on www.blindchickenracing.com I also have one in the speedster section of my site www.ricola.co.uk

Rich
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  #14  
Old December 18th 2003, 11:08
Karmann Karmann is offline
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IRS conversion

I've done this a couple of times and I put some pics up last time I did it.
The page is in Norwegian but the pics are international

http://home.c2i.net/emarthin/vwpower...tering/irs.htm
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  #15  
Old January 3rd 2004, 16:11
GUTTERS GUTTERS is offline
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KARL YOU HAVE A P/M
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