Building in front camber

[JWP]

I apologize if this has been posted before. I've read numerous pages within this forum with topics discussed by FJCamper and others.
I am planning to do adjusters in my beam. I'm wondering if it would be prudent at all to weld the beam back together such that the top was just a touch narrower to build in some camber. I realize this would also require re-reaming spring pack for the grub screws to pull the upper trailing arm in to achieve this increased camber.

My thought was if I build in 1-1.5 degree's negative camber then the ball joint adjusters can fine tune camber and not be at their limits.
I don't have the extreme adjusters yet so I'm not sure what they can even achieve. If my math is right i would need to trim 1/4" out of the upper tube (1/8) on each side of the adjuster to build in just over a degree of camber into the beam.

[Bruce2]

The two tubes have to be parallel to fit the frame head. If you narrowed the top tube more, it wouldn't be straight when you weld it together.

Take the top control arm and bend it in with a press.

[Ian Godfrey]

or do the formula vee thing and use spacers between the beam and the arm on the lower arms. (redrill the dimples). I think you can buy the spacers ready machined.

[JWP]

Ian, that is a much simpler way to achieve what I wanted to do.
I'll search and see if I can find these parts unless you already know of a reputable source. I would expect I'm just looking for a ring that slides over the lower arm. Should be easy enough to make if they can't be found already made.

[JWP]

Here is a link to a page that sells these if anyone is interested.
There is the regular spacer at 12 bucks and then the one machined for the thrust bearing at 102.

http://www.sracing.com/Store/FST_Stuff/FST_Stuff.htm

[Dale M.]

If you add adjusters and do it correctly you will not change the relationship of the stock camber built into front beam. You should be able use stock camber adjuster to achieve "proper" alignment.... IF not go extreme adjusters.... If you build in to much camber, you can not get enough compensation in adjusters to correct initial build mistake...

I do not know how much camber you want but I my IRS beam has so much adjustment with extreme camber adjusters (eccentrics) you can pull wheel almost 3/4 inch (+/-) off vertical line and is more then the car needs ...Although I run extreme negative camber for autocross it will also go positive camber way beyond factory specs.......

Dale

[JWP]

I'm still working with parts on the bench. I was more exploring ideas than anything. It sounds as though the extreme adjusters will get it where I need it and beyond. I guesstimate they should yield as much as 5* camber which is too much.

[Ian Godfrey]

one more thing.....
yes with camber eccentrics you can get a fair bit on neg camber, but depending on your wheel offset, your wheels/tyres will start to contact the top of the shock towers restricting your turning circle. The towers can be clearanced and welded and you can slot the shock mount hole to move the shock inboard at the top, or you can adjust some of the camber at the bottom beam AND have a good turning circle. My car has a bit of everything, adjusted bottom arms, eccentrics and clearanced shock towers.

[PhillipM]

They'll start to hit the top arm near the beam on full droop too, mine just skim them with this:



Bit more hassle on a link pin setup though!

[tmatre]

The two tubes have to be parallel to fit the frame head. If you narrowed the top tube more, it wouldn't be straight when you weld it together.

Take the top control arm and bend it in with a press.

I do not see why you cannot shorten the top tube
If you grind the weld between the bttom tube and damper tower, then shorten the top tube and move the damper tower and against the center of the lower tube, and then weld the bits in the new position this will work.

I know Carsten has done this to a BJ front end. This is a picture from his buid thread on vwnorge.no

[Bruce2]

I do not see why you cannot shorten the top tube
If you grind the weld between the bttom tube and damper tower, then shorten the top tube and move the damper tower and against the center of the lower tube, and then weld the bits in the new position this will work.

That will work. But it is a hell of a lot more work than simply bending the top control arm a bit. Or just put in the extra camber eccentric suggested above.

One benefit of bending the arm is that you gain a bit more caster at the same time. Win-win.

[buildabiggerboxer]

Don't forget, extreme caster also adds camber in turns, i run extra camber nuts, bent top arms and 9 degs caster, 11 in the rain if i get time to set up, after 3.5*, the braking efficiency starts to go away,
in many ways the t/b beam scores over mac strut supers, its easy to go real low with drop spindles and adjusters without geo' problems, caster is the biggest winner if your car is proper quick, stock caster is about 3*, not enough.
my beam also adjusts for corner weighting.
here's my ride qualifying with 3.5* fromt neg' camber and 9* caster, its about straight up in the tight turn with track surface camber and the roll angle.

[PhillipM]

^Yep, definately don't forget some extra castor if you're at it, we run 9 to 20 degrees.

[Bruce2]

..... after 3.5*, the braking efficiency starts to go away,....

Can you elaborate on this?

[Ian Godfrey]

depending on the width and shape of your tyre, as you crank in more neg camber there comes a point where the contact patch on the front tyres is on such an angle that braking is affected. So its a balance between cornering and braking. Each car will have an optimum angle for the course you are on. You might set it up on a slower twisty course with a bit more neg camber, and on a fast course with long straights keep the tyres more upright for better braking.