IRS alignment setting for wide rear tires

[boygenius]

Here is a pic of what I was talking about. You would probably have to switch to a 944 pivot bolt instead of the beetle bolt since it is narrower and you will get more adjustment. You could either put cogs along the perimiter of the bushing cap and use a bracket to hold the bushing from tuning. Or you could simply tap the bushing cap in several places and use an "L" bracket to thread into the trailing arm and the bushing cap holding it in place. Just an idea... :idea:

[paul_f]

Originally Posted by Sandeep

Thanks for the pic Panel. It makes sense now. I was looking on the web and found a similar pic.



This is from the Rennwerks website where they are restoring a GT2. Look at the trailing arm mounts and see how they are adjustable for camber.

Sandeep

How do you lock this mounting point into position though?? I have seen the clamps on IRSed buses move before - so surely it must happen hear unless the use a toothed adjuster or something??

This way is better than a rotating clamp as you won't get as severe toe changes with the change in camber.

Hey Panel can I have a copy of that picture too please

[Panelfantastic]

Sure Paul but it's not as clear as the one Sandeep posted. I'll try to post them here so everyone can see.
These were taken from Excellence magazine so all rights are theirs... If I get in trouble, I'm sayin' boygenius told me to

[boygenius]

Originally Posted by paul_f

How do you lock this mounting point into position though?? I have seen the clamps on IRSed buses move before - so surely it must happen hear unless the use a toothed adjuster or something??

This way is better than a rotating clamp as you won't get as severe toe changes with the change in camber.

Hey Panel can I have a copy of that picture too please

You could thread both the inner and the outer pieces of metal in the pivot. Next you could remove some of the threads about a 1/2 inch from the base of the adjuster bolt. You can thread the bolt through both pieces of metal but as soon as the bolt goes through the bottom bracket it will stop threading in since the threads have been removed. If you can place a nut on both the top and bottom of the lower plate you can "LOCK" them together to prvent the camber from changing. Just an idea...

[boygenius]

I found this picture right here in the forums of a camber box.

[paul_f]

Great picture boygenius, mmmm now i need to get something made up for my bus!

Paul

[boygenius]

The bracket itself is pretty easy to make. The hard part would be figuring out a good way to access the nut that replaces the threaded boss in the original mount. The porsche doesn't have frame horns in the way.

[paul_f]

My bus doesn't have them that close either!!

Paul

[Sandeep]

For an IRS bug, I think you may have to cut a slot in the frame horn so the nylok nut could fit through. I would replace the pivot hex head bolt with a grade 8 bolt of equal diameter.

Lots of great ideas in this thread but I'm going to go the camber box route.

I'm going to try and mock the camber box up in the next few weeks. Unfortunately, I'll have to cut some access panels in the rear parcel tray as the body is already on the pan

My plan will be to keep the stock mounting points intact incase this project goes sideways :whoops: as I need to have it on the road at the fist sign of spring !

Sandeep

[Sandeep]

Here's another pic from the web .. this is Bugformance's red tube chassis beetle .. found on 55Superbeetle's site.



There are no frame horns that I can see but the camber box is there and the range of adjustment does not seem to be too large.

Sandeep

[boygenius]

Don't cut a hole in your body just take it off the pan. It will only take an hour or so to remove the body and then you will have easy acces to the suspension parts. If you can get at the suspension easier you will actually spend less time modifying the suspension...

[brent]

Here is an idea I had been thinking about.......
Firstly cut off the end of the IRS arm...right behind the bush.
Fabricate a plate 4-5mm with a beefy threaded tube on one side,weld this on to the IRS arm..this would give you a threaded hole in the end of the arm.
Now you could run a rose joint or rod end here,this would eliminate all movement as does the uniball system.Toe settings would now be very easy.

Second...the rod end wouldn't be as wide as the original bush so a new box section could be fabricated with a series of vertical holes...this could be fabricated inside the original inner mount.

It wouldn't give you fine camber adjustments but some adjustment.

I think toe settings are more a priorety than camber for a good handling car,though both are very important.

Your thoughts would be appreciated here.

regards Brent Marquart.New Zealand.

[Michael Ghia]

Just to cover the IRS camber post...
I ran IRS arms swapped over side to side and found I could only just get 0 camber on the rear wheels with the car being absolutley on the floor! Otherwise you ended up with positive camber (not good ).

You can adjust the camber on the rear suspension by simply loosening the 3 bolts which connect the spring plate to the rear arm and move the arm up and down. Up will give you move negative camber and down will give you more positive camber. Remember just the 3 bolts which hold the spring plate to the arm.

I'm sure you've all covered this.. just saying it in different ways

Re - adjustable inner mounts for IRS arms. It's only worth doing with coil overs and you must move both inner and outer suspension points up as one or you'll end up with the most horrible suspension geomtery imaginable.
You can see this on the spring plates of Porsche works race 911s.

MG

[Bruce2]

Originally Posted by Michael Ghia

You can adjust the camber on the rear suspension by simply loosening the 3 bolts which connect the spring plate to the rear arm and move the arm up and down. Up will give you move negative camber and down will give you more positive camber. Remember just the 3 bolts which hold the spring plate to the arm.
MG

You've got it backwards Mike. Tilting the rear of the trailing arm up gives positive camber. Down gives negative.

[Michael Ghia]

Originally Posted by Bruce2

You've got it backwards Mike. Tilting the rear of the trailing arm up gives positive camber. Down gives negative.

Bruce,
Are you sure? Think about it as simply jacking the car up and down. If you jack the car up (the suspension arm goes down) you get positive camber and if you lower the car down (the suspension arm goes up) you get negative camber....

Mike