IRS - Is there a way to adjust camber and toe without effecting ride height?

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eskamobob1
Posts: 27
Joined: Mon Jul 23, 2018 2:46 pm

IRS - Is there a way to adjust camber and toe without effecting ride height?

Post by eskamobob1 » Fri Aug 03, 2018 2:48 pm

Hey guys,

So I am trying to figure out about lowering the rear of my beetle and am having some trouble with how to do it/if I even should do it. I had initially just planned to just use drop plates to maintain proper preload and move on with my life. However, I recently got an entire early 944NA suspension and found out that the camber adjuster on the 944 spring plates also effects ride height slightly due to the nature of semi-trailing arm. That got me thinking, is there any way to maintain camber/toe adjustability on the rear while maintaining a specific height? (buying more/aftermarket parts is totally fine)

I was planning on lowering specifically for the ride benefits of the lower CG, but it seems like this may actually be removed by the decent negative camber induced on the read wheels (plan was 2.5" to match the drop spindles I was planning for the front). Does anyone know what kind of camber a 2.5" lower will induce?

Thanks for your time,
-esk

Bruce2
Posts: 6852
Joined: Sat Oct 13, 2001 3:01 am

Re: IRS - Is there a way to adjust camber and toe without effecting ride height?

Post by Bruce2 » Sun Aug 05, 2018 4:05 am

eskamobob1 wrote:
Fri Aug 03, 2018 2:48 pm
I had initially just planned to just use drop plates to maintain proper preload.....
IRS drop plates are a FRAUD. They do not "maintain proper preload" any different than stock. Someone has been feeding you a load of BS. Good thing you went away from drop plates.
eskamobob1 wrote:
Fri Aug 03, 2018 2:48 pm
is there any way to maintain camber/toe adjustability on the rear while maintaining a specific height?
When you change your ride height, you get a wheel alignment. When the shop does that, they will set your toe to the correct value.
Camber can also be changed once you pick a ride height. By loosening the bolts that attach the spring plate to the TA, you can tilt the rear up to add positive camber. You may have to slot the holes in the TA.

vwo60
Posts: 69
Joined: Fri Oct 14, 2011 4:29 pm

Re: IRS - Is there a way to adjust camber and toe without effecting ride height?

Post by vwo60 » Sun Aug 05, 2018 4:50 pm

You can remove the shock mount on the steel trailing arms and weld them on the other side, if you lower the car this will restore the camber back to an acceptable angle, toe will be though the normal adjustment. This is covered in a book by Keith Seume (VW Performance Handbook)

eskamobob1
Posts: 27
Joined: Mon Jul 23, 2018 2:46 pm

Re: IRS - Is there a way to adjust camber and toe without effecting ride height?

Post by eskamobob1 » Mon Aug 06, 2018 3:19 pm

Bruce2 wrote:
Sun Aug 05, 2018 4:05 am
eskamobob1 wrote:
Fri Aug 03, 2018 2:48 pm
I had initially just planned to just use drop plates to maintain proper preload.....
IRS drop plates are a FRAUD. They do not "maintain proper preload" any different than stock. Someone has been feeding you a load of BS. Good thing you went away from drop plates.
I guess calling it propper preload was a bad way to put it as unless you are wresting on the lower stops you always have the same preload (the weight of the car). It was my understanding that the actual usefulness of drop/adjustable plates was to maintain a more limited downward travel. With the bump stops obviously stopping you with upward travel (even cut down, i think a 2" drop only leaves you 1" of movement or so over the 2.5" stock upward travel), dont you want to limit the downward travel for road use? When you lower by reindexing the plates you gain as much downward travel as you lowered obviously, and I was under the impression that this wasnt particularly desirable from a handling standpoint (but maybe im wrong, still learning a lot)
Bruce2 wrote:
Sun Aug 05, 2018 4:05 am
eskamobob1 wrote:
Fri Aug 03, 2018 2:48 pm
is there any way to maintain camber/toe adjustability on the rear while maintaining a specific height?
When you change your ride height, you get a wheel alignment. When the shop does that, they will set your toe to the correct value.
Camber can also be changed once you pick a ride height. By loosening the bolts that attach the spring plate to the TA, you can tilt the rear up to add positive camber. You may have to slot the holes in the TA.
Maybe im misunderstanding exactly how the camber is changed on bugs then. I was under the impression that camber was changed by changing the angle of attachment between the trailing arm and the spring plate (and as such changing the ride height from what i understood). Is the wheel bearing slightly off of the vertical axes or something to change actual camber without effecting the ride height?
vwo60 wrote:
Sun Aug 05, 2018 4:50 pm
You can remove the shock mount on the steel trailing arms and weld them on the other side, if you lower the car this will restore the camber back to an acceptable angle, toe will be though the normal adjustment. This is covered in a book by Keith Seume (VW Performance Handbook)
Ty for the book recommendation. Ill go out and get one. as for slipping the trailing arms, I was under the impression that wasnt needed until far more extreme lowering than 2"

Bruce2
Posts: 6852
Joined: Sat Oct 13, 2001 3:01 am

Re: IRS - Is there a way to adjust camber and toe without effecting ride height?

Post by Bruce2 » Fri Aug 17, 2018 7:55 pm

eskamobob1 wrote:
Mon Aug 06, 2018 3:19 pm
Maybe im misunderstanding exactly how the camber is changed on bugs then. I was under the impression that camber was changed by changing the angle of attachment between the trailing arm and the spring plate (and as such changing the ride height from what i understood). Is the wheel bearing slightly off of the vertical axes or something to change actual camber without effecting the ride height?
Yes, camber changes when you alter the angle between the TA and spring plate.
See FJC's pic:
Image
Notice how the TA is tilted up at the rear relative to the long plate? Likely to get the camber to where he wants it after he lowered the car.
I've never looked at why this happens. It just does.

Bruce2
Posts: 6852
Joined: Sat Oct 13, 2001 3:01 am

Re: IRS - Is there a way to adjust camber and toe without effecting ride height?

Post by Bruce2 » Fri Aug 17, 2018 8:07 pm

eskamobob1 wrote:
Mon Aug 06, 2018 3:19 pm
I guess calling it propper preload was a bad way to put it as unless you are resting on the lower stops you always have the same preload (the weight of the car). It was my understanding that the actual usefulness of drop/adjustable plates was to maintain a more limited downward travel. With the bump stops obviously stopping you with upward travel (even cut down, i think a 2" drop only leaves you 1" of movement or so over the 2.5" stock upward travel), dont you want to limit the downward travel for road use? When you lower by reindexing the plates you gain as much downward travel as you lowered obviously, and I was under the impression that this wasnt particularly desirable from a handling standpoint (but maybe im wrong, still learning a lot)
What is preload? Is it the twist on the torsion bar while the spring plate is resting on the edge of the shock tower and the tire off the ground? I fail to understand why anyone would think that was important. It's a condition that doesn't exist when you're driving the car. You might as well measure the camber while the car's on a hoist, just as useless.

Don't be fooled by the gap between your shortened rubber bumper and the stop on the shock tower. Since they are ahead of the axle, the true suspension travel is greater than that gap.

If your car is lowered, and you corner so hard that your stock spring plate hits the down stop, you've got way too much body roll. Better to use anti-roll bar to limit the down travel. An anti-roll bar progressively resists downward travel on the inside wheel.


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