Positive or Negative Roll Radius?

[SprintStar]

Can someone l list the offset of wheels that came with the early vs. late Supers?

I'm doing some thinking about the roll radius and I'm baffled...

Does the late Bug come with negative roll radius? I recall reading it. Does the 924/944 come with it too? Yes, I do recall that too. But how come my early Bug with complete 944 brakes and suspension has positive roll radius?! And I'm using Boxster rims which should enhance the roll radius even more...

How did I find out? I experience some bumpsteer and uneven braking, hence leading me to check for simplier things like tie-rod angles and stuff, which checks out ok. Now, only roll radius is left and from all the stuff I've been reading online, it seems it's the culprit.

But WHY?!?! Unless the early bulkhead is not giving me enough whatever as the mounting points are higher than the late ones.

Someone shoot me....

Sprint.

This has been discussed on the SBO! Forums, do a search in the suspension forum.

[SprintStar]

Originally posted by Superman
This has been discussed on the SBO! Forums, do a search in the suspension forum.

Yes, I read that thread, but it still doesn't answer my question... How come when I moved on from a 3-bolt to a 2-bolt conversion, I still don't get negative roll radius?

In fact, the postive seems even more!

Sprint.

We are altering our suspension/brakes and seriously affecting the geometry. Lowering the car, 944 hubs, wide wheels, high offsets, etc. These things are making drastic changes in the original design concept and thus will have a positive/negative result on the overall geomtry of the altered suspension.

Take note that we all modify our cars differently, some with VW brakes & some with Porsche brakes, some use ET23 wheels & some with ET52, some with spacers & some without. My point is when you alter the design you should expect the geomtry to be altered as well.

[SprintStar]

Originally posted by Superman
We are altering our suspension/brakes and seriously affecting the geometry. Lowering the car, 944 hubs, wide wheels, high offsets, etc. These things are making drastic changes in the original design concept and thus will have a positive/negative result on the overall geomtry of the altered suspension.

Take note that we all modify our cars differently, some with VW brakes & some with Porsche brakes, some use ET23 wheels & some with ET52, some with spacers & some without. My point is when you alter the design you should expect the geomtry to be altered as well.

I know. I except changes, but I wish to know what causes the change so as to remedy it...

Ok, let's do it slowly.... When I convert a 3-bolt Super to a 2-bolt Super without changes wheels and all, what changes? I believe the lower control mounting points hold the key to the riddle as it's higher for 3 bolt and lower for 2 bolt....

Can anyone confirm this?

Sprint.

Sprint.

Although the 74-79 does have that extra set of bottom mounts I've never seen them used. Every late car I ever worked on had the control arms in the top mounts, which is the same location as the early mounts. I have attached a picture that should aid in your questions and understanding of the changes.

Also, read this:

http://www.clubvw.org.au/what_is.htm

[SprintStar]

Hmm.... So the late model ones have control arms that mount in the exact same position? Ok, thanks fo that tip. Here in Singapore we only got about 3 or 4 original late model ones... So, it's note as if I can compare anytime I like...

Then I've got a question. How come when I mounted my late arms on my early car, I had to grind a bit off the control arms? It won't travel upwards till I took of a little corner of it.... Weird... Anyone had that problem?

And thanks for the link. I do know what it is. Just unsure how come I don't have it on my car...

Sprint.