rear alignment question, how many degrees change in camber/caster per mm for shims Options

[DRPHIL914]

also I want to clarify does adding shims increase negative camber?
- looking for a fast easy answer of if I want to just a slight amount of negative camber since it seems I am at 0 now, to go to 2 degrees negative how many mm generally will it take- trying to just buy a few shims not a bunch! currently does appear that the right and left a same, my initial check was 0 and 0.

Phil.

[Retroracer]

So adding shims will DECREASE neg camber - make it more positive. Camber on the rear is very dependent on ride height - if you have aftermarket springs (or tired springs for that matter), that may need addressing first: a "higher than stock" ride height will tend towards positive camber, a low ride height, more negative. Hence with the more aggressive, lower rear height settings on 914's you have to start bulking up on the shims, or taking more drastic measures to offset the neg camber you got as a result.

Rake also has a minor contribution. Adjustable height shocks, or coil-overs, allow you to adjust ride height to varying degrees of granularity.

As ever, the excellent article here:

http://www.914world.com/bbs2/index.php?act...t&id=363723

...is a great starting point to understand whats going on. Wealth of suspension expertise to tap on the forum as well.

- Tony

[jmitro]

6mm of rear shims = 1 degree of camber

[SirAndy]

Adding shims will add camber. For the maximum negative camber, remove all shims.

The max negative camber i've ever gotten from a straight stock tub was just under -2 degrees.
(IMG:style_emoticons/default/shades.gif)

[DRPHIL914]

Adding shims will add camber. For the maximum negative camber, remove all shims.

The max negative camber i've ever gotten from a straight stock tub was just under -2 degrees.
(IMG:style_emoticons/default/shades.gif)

after pulling up the diagrams and looking at that makes sense I had it backward lol!

- so 6mm adds 1degree- good to know, will definitely double check with proper actual alignment as I get the front end figured out on that bump steer issue as well.
need to find someone with expertise in doing the older P-cars....

[DRPHIL914]

So adding shims will DECREASE neg camber - make it more positive. Camber on the rear is very dependent on ride height - if you have aftermarket springs (or tired springs for that matter), that may need addressing first: a "higher than stock" ride height will tend towards positive camber, a low ride height, more negative. Hence with the more aggressive, lower rear height settings on 914's you have to start bulking up on the shims, or taking more drastic measures to offset the neg camber you got as a result.

Rake also has a minor contribution. Adjustable height shocks, or coil-overs, allow you to adjust ride height to varying degrees of granularity.

As ever, the excellent article here:

http://www.914world.com/bbs2/index.php?act...t&id=363723

...is a great starting point to understand whats going on. Wealth of suspension expertise to tap on the forum as well.

- Tony

thanks for the info Tony. I have pretty stiff sport Bilistein shocks and newer stock springs, and right now my spring retainer clip is on the 4th slot up from the bottom, so kinkd of middle of the road. Car is very close to level at this point but I have that front bump steer issue making me think the front has to be adjusted but from angle of the tie rod and a-arms I think the front needs to drop some. so if front has to lower and we bring the rear down one clip that would add a slight amount of rear negative ? may not need to take any of those shims out, but if I go up one then probably ill have to pull out atleast 3mm if not more to get to negative camber.
I am going to get some exact measurements of where it sits now before I get messing around and then go from there. I do know that when I first installed the new shocks and springs a few years back it was too high and very springy/bouncy, so I know I don't want to go up much if at all.
I really wish Bob Woodman had not closed his shop!!!

Anyone in the Palmetto State know of someone that can do this? How about Charlotte area? maybe Billy Whitesides or John@Black Forest Racing up in Denver?

[rgalla9146]

Be prepared
Any chance a frend can lend you a selection of shims when doing the alignment ?
Afterward replace those you've used.

[DRPHIL914]

Be prepared
Any chance a frend can lend you a selection of shims when doing the alignment ?
Afterward replace those you've used.

good idea, Bob closed his shop and a former employee took it over but does a lot less Porsche stff and more performance stuff on European models, but he may have some there still in storage since he still owns the facility, if not maybe someone here will offer up a set..... Hey Bill you have any sitting around?
@Billh1963

[mepstein]

Couple places.
Bdstone914 makes them in stainless and also has a 1mm
Maddog
Garold probable has them too.

[914werke]

Couple places.
Bdstone914 makes them in stainless and also has a 1mm
Maddog
Garold probable has them too.

And OE shims HERE (IMG:style_emoticons/default/smile.gif)

[billh1963]

Be prepared
Any chance a frend can lend you a selection of shims when doing the alignment ?
Afterward replace those you've used.

good idea, Bob closed his shop and a former employee took it over but does a lot less Porsche stff and more performance stuff on European models, but he may have some there still in storage since he still owns the facility, if not maybe someone here will offer up a set..... Hey Bill you have any sitting around?
@Billh1963

I've got those two parts cars you are free to pick over. Only thing I want off them is the original radio.

Both cars have complete suspensions and such. I tried to give the cars away. But, most 914 owners are such BDMF's I couldn't even do that. (IMG:style_emoticons/default/lol-2.gif)

[jmitro]

but I have that front bump steer issue making me think the front has to be adjusted but from angle of the tie rod and a-arms I think the front needs to drop some. so if front has to lower and we bring the rear down one clip that would add a slight amount of rear negative ? may not need to take any of those shims out, but if I go up one then probably ill have to pull out atleast 3mm if not more to get to negative camber.
I am going to get some exact measurements of where it sits now before I get messing around and then go from there. I do know that when I first installed the new shocks and springs a few years back it was too high and very springy/bouncy, so I know I don't want to go up much if at all.
I really wish Bob Woodman had not closed his shop!!!

just to elaborate on the front end issue again....lowering the front end is not going to fix the bump steer issue (if in fact you have a bump steer issue). if you have the stock non-adjustable tie rod ends, your bump steer will remain.
what you really need is tie rod ends that are adjustable for bump steer like these:
https://www.rsrproducts.com/product-page/re...-bump-steer-kit
However, these are really only needed for cars lowered excessively, such as track only cars. I have this product on my car because the spindles are raised.

you need to check your ride height, rake, and alignment as the car sits now before you make any drastic decisions about what to do. It sounds to me like you are guessing without knowing the current settings

[jmitro]

Couple places.
Bdstone914 makes them in stainless and also has a 1mm
Maddog
Garold probable has them too.

And OE shims HERE (IMG:style_emoticons/default/smile.gif)

or here: (no affiliation)
http://www.914world.com/bbs2/index.php?showtopic=341769