RF Lack Of Camber Gain

[7uptruckracer]

I have all my geometry plotted out my RC height is around 3.5" High and 7.8" Left. I finally got my LF camber correct by correcting some of the Motion Ratio Numbers I was a little off on. The final problem I'm having and tire wear shows it is lack of RF camber gain, the program shows me losing some camber from roll and at full travel pretty much staying the same as my static, and this is with an 8" upper. I only have about 10* in the arm I can go with more angle so it will gain more but it raises my RC closer to four and shifts my lateral location a bit. I can compensate by putting more angle in my Left Upper but its already around 21-24*, How much is too much before I run into issues? and whats the handling characteristics of my Height. The Right side also has the Lower at 0* and 5" ride height on a stock pinto spindle and K727 and K772 Ball joints. I know someone may have suggestions I'm open to any. I'd like around 1.5-1.75 of gain its a flat flat track

[twisterf5]

you will have to move the mounting point of the upper arm / my new chassis ( late model ) uses a slide mount on upper so that can be adjusted.ours is set at 4 camber and will go to 5.5 under full travel.

[HEAVY DUTY]

I have all my geometry plotted out my RC height is around 3.5" High and 7.8" Left. I finally got my LF camber correct by correcting some of the Motion Ratio Numbers I was a little off on. The final problem I'm having and tire wear shows it is lack of RF camber gain, the program shows me losing some camber from roll and at full travel pretty much staying the same as my static, and this is with an 8" upper. I only have about 10* in the arm I can go with more angle so it will gain more but it raises my RC closer to four and shifts my lateral location a bit. I can compensate by putting more angle in my Left Upper but its already around 21-24*, How much is too much before I run into issues? and whats the handling characteristics of my Height. The Right side also has the Lower at 0* and 5" ride height on a stock pinto spindle and K727 and K772 Ball joints. I know someone may have suggestions I'm open to any. I'd like around 1.5-1.75 of gain its a flat flat trackAnything that adds camber gain to the RF causes thr roll center to move right and up. Having enough camber gain is waaaaay more important than having the roll center to th left. If you only have 1/2 the tire on the ground, how is it gonna turn better even if the roll center is where you want it? I would rather have the whole tire patch on the ground ( thru the whole travel, not just at maximum roll) than have the roll center where some guy writing a book that works on asphalt cars that dont hike up and roll says it needs to be.

[racer69]

^^^^^ We all know who your talkin bout!

[7uptruckracer]

Yeah most all that I get. I can move my uppers in any direction, and I know more upper angle will let me gain more camber as well as a shorter arm the 8" arm I mapped it out for seems to not changed it laterally much and I am going from a 15 5/8 lower to a 17 5/8 I guess my real question is to get my RC back left i'm going to try to add more LF Angle how much angle is so much before you have a ball joint issue? I also plotted a 7 1/4 RF upper it will only shift the RC about 2 inches farther left after dive and roll so I'm not to concerned and with all the changes I end up right at 4" high and it does move downward much either. I also see it would be better to move my arm on the mount side then run a taller ball joint because that would make me gain even less camber by acting as a taller spindle isn't that correct? Hope this is followable lol

[7uptruckracer]

Your only gaining 1.5 on camber through full travel? That seems old unless its because the RF's run a more tied down rf now which I can understand your just traveling to optimal camber in the corners and never recovering any? Just seems like some are running alot more but It could be because they roll more and its an optical thing with the body....

[twisterf5]

Your only gaining 1.5 on camber through full travel? That seems old unless its because the RF's run a more tied down rf now which I can understand your just traveling to optimal camber in the corners and never recovering any? Just seems like some are running alot more but It could be because they roll more and its an optical thing with the body....it is a body thing. the track we run at is why i have it set at that but can move arm up a gain less or move down and gain more. you can over think it.you can not get one side perfect with out changing the other side. i run 4to 4.5 and 5.5 caster right with 2.25 and 2.5 left that works good for me.

[7uptruckracer]

Yeah thats what I thought I know the inside edge isn't wearing right it had an 9.25 arm on it and I'm going through the suspension and correcting stuff, obviously this isn't a DLM which is what I primairly work with but its a full adjustable tube car and we run against DLM chassis but its a Mod4. I know with tire deflection along with my static camber and the arm I had on it I had a bad deal. Do you think as long as I keep the LF control arm angle under 30* I should be ok? I can run the 10* angled sleeve That might take some bind outs the Ball Joint. I guess I wont worry about it traveling toward the right roll center wise as it's not traveling far. Just want some opinions I'm going to add more static camber too. What will I notice with a raised RC besides less roll. Is it like the rear where a higher roll center is a looser car because of less side bite?

[twisterf5]

a car is a car . why would it change the RC. we set the front and ride heights together.set the upper arm to what you need reset ride height /and wedge.

[7uptruckracer]

Is there anything I can do with my lowers my mounts are vertically slotted. I know it doesn't have as much of an effect but my software doesn't have the means to adjust the lower angle.

[twisterf5]

ya if you needed to change roll center. but all chassis and drivers are different you really just need to get your numbers set on the front and take it out. then check tire temps. i may run as much as 8 caster on the right front to make me happy and some one else may not like that. depending on the car foot print you may need to raise roll center to make it work. best laid plans go to waist when you hit the track.

[jedclampit]

'best laid plans go to waist when you hit the track'


yes indeed!

[grt74]

roll center is greatly over rated,the front of the car has independant suspension,do what works for the car,even if it seems like it shouldnt work,we have found a ton of speed in the front end,its really not as hard as everyone says,now that being said if you find something that works great,now you need to find the roll center and the rest of the front end settings,jmo

[grt74]

one other thing if im at a new track,i always put on new front tires so i can get a good read on them and do what ever it takes to get the tire to wear even across it,even if it seems like a crazy number

[7uptruckracer]

Any Idea of Maximum Control Arm angle before you run into risk of breaking a joint I'm at 26* now I can buy the 10* Upper sleeve for it if it will help

[Matt49]

Any Idea of Maximum Control Arm angle before you run into risk of breaking a joint I'm at 26* now I can buy the 10* Upper sleeve for it if it will help

That's going to depend on that ball joint and the KPI of your spindle relative to your camber.
I would make d@mn sure my shock bottomed out before any of the ball joints were in a bind.

[7uptruckracer]

Yeah I think I'm going to get a 10* Angled sleeve It cant hurt its on the LF anyways which rolls. I'm running the K772 joint probably the afco low friction, QA1 or Howe Joint. It will be around 27 degrees of control arm angle the books ive read say up to 25 but its by our good friend mentioned above :) and i take everything with a grain of salt, just an arm or joint breaking is the last thing I want :) Thanks for the input guys I'm headed to the RACEWISE school this week so maybe I won't have to rely on yall so much to help me think things through