front end questions for my joyner project

[jerseydevil]

hi, been here as a study guide but this is my first post.
in november i started a build that i am trying to complete by april. i have an 08 joyner 250sv that i am doing a motor transplant in. ive been doing my best w/ the front end which i scrapped all the stock stuff and have been building from scratch. my buddy chuckorlando has been helping me through this process via phone and chat. i have done alot of reading here and trying to apply what i can. i am at the point where i have my arms and spindles mounted, so i started cycling through and taking some numbers down. what i have discovered is that i literally have no camber change through the cycle. for example i set the camber at neg 2* and whether i bump it up 9" or let it droop 4 1/2", it stays at neg 2*.
i dont know how good or bad this is. i know some neg camber change is desired as it cycles up. i'll post some pics to give a visual. if anyone has some suggestions please feel free. hopefully i wont have to go backwards too far...... thanks, JD

[jerseydevil]

here's the last pic

[evan]

What you have should be plenty sufficient. You have a rounded profile tire so even is roll you still have tread contacting the ground. Increased caster will also help with contact in turn. If you would like to induce camber in bump, shorten the upper link and move the pivots outboard the same amount. You can also lower it but you will get pos camber in droop. Remember you are building a buggy and not a ferrari.

[chuckorlando]

He's building a machine intended to race in the utvrr. That means jumps, off camber landings and turns, and very hot turns. He also intends to use itp hole shot style tires which are not very round. 205/80r/12 round abouts. Unless his ind has changed on that.

I told him I dont think what he has would hurt. I know more change tends to be more desirable. So the big question is, does he need camber change or, like mentioned above, will this be sufficient in a short coarse/rally race

[evan]

I recommend not painting anything before test driving. If it exhibits undesireable traits, all that needs to be done is to remake 2 arms and change a couple brackets. If it handles in a balanced manner, go with it.

[rgvkid]

Try to take pics head on at a lower level so you can see a better change in the degrees. From the pic angle your at, your looking down at the wheel and makes it hard to see if there is any degree change.

Look through pics of ProtoDies Buggy front end. He has a few pics of a Bare Buggy at Full droop and Full Compression. They have a great geometry in their Front cycling setup.
At full Droop its almost or is at 0*, at full Bump they are at a few degrees Negative and pulling about 20 inches of travel. The Negative Degree, at full Bump, helps the wheel grab in turns. For instance, if your turning Hard Right, the body will have a tendency to want to Roll to the Left, compressing the Left side suspension. If you have 0 degree or Positive camber at full bump while the body rolls to that side, you are more likely to have less traction and or blow the tire bead.
If you have Negative Degree on the side of the Body roll, the tire wheel grab into the ground better and be less likely to blow a bead.

The KPI angle on the spindle comes into factor to achieve this type of setup, but I found that it works best for me to have a bit of Negative Camber at full bump and close to zero at Full droop.

Also your upper arm has to be a bit shorter then your lower to achieve a change in camber.

[nutz4sand]

I recommend not painting anything before test driving. If it exhibits undesireable traits, all that needs to be done is to remake 2 arms and change a couple brackets. If it handles in a balanced manner, go with it.

Just something to think about.

I know powder coat is tougher than paint but removing it to fix areas or add stuff is a pain. If you gotta powder coat paint first till you know its done then the paint can be removed easy enough for PC.

Anyways heres why I posted.

I agree that painting before test driving still means you gotta remove the paint to do say crack repair and add tubes/bracing.

Yet paint can often flake off showing areas that are stressed and bending but not broke. Especially if you use paint that does not flex well.

So paint could be a little benefit to help ID potential problem areas.

But better yet is there something out there (some kind of product) that could easily be put on and taken off yet would crack off to indicate metal fatiguing underneath it??