95jersey

How much camber do you think is lost under a 1.3g+ turn using stock rubber bushings?

davidfarmer

between bushing deflection, tire deflection, and body roll, ALL of the camber is lost....that is the point of running neg camber

Relative to a solid or poly bushing, I'd GUESS 1/4 degree max. Not enough for me to ever run poly bushings on a street car.

ghoffman

On the front it is about 7-8mm per degree of camber, and from looking at Chris Ingle's video it looks like at least that much. In addition, from what I see from setup data it confirms that in must be about a degree under load in the front, perhaps a little less in the rear due to smaller bushings. A solution besides poly or spherical bearings is needed.

95jersey

This is what I was thinking. I figured around 1/2 degree, so I was close. I just replaced my left control arm bushing and decided against poly again, but wanted to see some feedback as to how much camber is lost with rubber. I am sure I will destroy the new bushing, but hopefully it gets me through the season. What was interesting, was that the only bushing I had go bad was my left front (I think this is due to the fact on most road courses, you are mostly making right turns).

Do you think even more camber would allow the bushing to last longer or is that only helping the tire?

davidfarmer

I agree, 1"=3deg=14mm. 1/3" of deflection seems like a lot considering how small the bushings are, however I've never examined them. I've studied race photos over the years to try and gauge how good my contact patches seemed to be mid-corner, but you are balancing suspension deflection, tire deflection as well as body roll with varies greatly depending on geography as well as load.

I don't see how more camber would effect the life of the bushing at all. Obviously more camber gives more grip, which ultimately would put more stress on all components, but there is nothing mechanical in the alignment itself that would cause a wear issue.

I imagine you just got a bad one, had bad luck, etc.

Rob Burgoon

I think Pfadt had a video showing the actual deflection. It was pretty substantial IIRC.

gkmccready

Why? I put poly bushings on and really don't notice it as harsh, it doesn't squeak, etc, etc. I'm liking the idea of delrin as trackboss has done, honestly...

gonzalezfj

Pushing bushings out of the control arm is common in C5 and C6 cars subjected to high cornering forces with very sticky tires (Hoosier A6 or Kumho 710). AutoX use is a typical example. You can switch to a T-1 control arm which has higher durometer rubber bushings, but in the end they will push out with time.

If you don't want poly bushings or spherical joints, you have two choices: get new control arms or change just the bushings. You won't be able to cure this problem completely.

YMMV.
Frank Gonzalez

Rob Burgoon

I didn't notice the change on my miata, but I sold my Energy Suspension bushings to a friend and he could tell.

John Shiels

fatbillybob

Does anyone make a delrin bush kit? Everyone has poly even prothane and they are cheap cheap cheap.

throwit

I thought thats what the camber plates were for?

NemesisC5

gkmccready

A full delrin kit just doesn't work. In the rear lower there's only one camber adjustment. In the front if you want to adjust caster by setting the camber assymetrically -- be it spacers on the uppers, or the cams on the lowers... that sets the bolt running through the bushings at a bit of an angle.

Basic delrin bushings will really only work in some of the locations, and those locations can differ whether you're running camber plates or stock adjusters.

---

http://mmr-direct.com/catalog1/RX7FC/index.htm

This is an example (from a 2nd gen RX7) of using delrin for some locations, and sphericals for others. It keeps the overall cost down but gets you roughly the same performance as all sphericals.

gkmccready

Camber plates just remove the stock adjustment cams; they have nothing to do with bushing deflection... this thread really discusses how much a bushing compresses to allow the control arms to have uncontrolled motion.

This is one reason why you can run less static camber and toe with poly bushings, and even less with sphericals...

fatbillybob

I'm not sure I buy this. I have cut my own delrin bushings but it is a lot of work. Delrin and go anywhere poly can and deflects less and is self lubricating. The wear on delrin is way longer than I thought and the stichon on my a-arms were non-exisitent. I bought the stick of delrin for like 50 bucks! It would be nice if one of the poly guys made delrin. I bet they would have less squeaking relative to poly and the performance is close to spherical. I wish someone did this for the C5.

trackboss

The C5 for example should not use delrin in the rear lower arm. Reason is all adjustment is done with the front eccentric and the arm pivots off the rear bolt. The bushings must either have compliance or allow misalignment (like a monoball) simply because the arms may not be mounted square to their mounting points with the desired alignment. The primary reason to use delrin is for minimal deflection and for that very reason they simply will not allow any needed misalignment to occur.
On my polys I can actually see what looks like poly dust from the wear in that particular location as a result of suspension cycling. Factory rubber bushings don't show any frictional wear like that because they twist rather than rotate on a shaft.

fatbillybob

Oh yeah...I did not think of that. You are right. I guess you could do cheap delrin everywhere and monoball the rear. I think LG kit for monoballs was like $1800?? I forget but it was costly. I would think there would be a way to get close to monoballs with a lot less cost. Of course monoballs would be the best but if they are 1800 bucks you are on your way to a decent set of coilovers. It is just too easy to spend 10 grand in suspensions. Know what I mean?