Camber Issues

[gottacatchup]

So I'm having alot of issues with my tires rolling over in tight corners during autox. I've done all I can with tire pressures setting them from mid 30's to mid 40's with no noticeable change in wear patterns during my runs. Its become a problem to the point of the tires rolling to wear over halfway down the sidewall. At this point the majority of the tread has plenty of life left but the shoulders are nearly destroyed. So in an attempt to save whats left of my current tires and to not have them lose the bead and come of the rim mid-corner I'm questing for more front negative camber.

I run in STS so anything is up for grabs but I only plan on running this car for the rest of this season so I'm not looking to start a whole suspension build this late in the game. The options as I see them are camber plates which I'm not excited about because of cost and raising the front suspension further, crash bolts which honestly I don't know how they work, getting a custom alignment, or getting new tires with stronger sidewalls.

Also I understand that the front suspension looses alot of camber during compression probably negating any options listed above. If anyone has any other suggestions or advice please help!

 

[aMaff]

what suspension setup do you have? Also what tires? Because they shouldn't be rolling over that far unless they have jello sidewalls, esp. not at mid-40 psi pressures.

 

[gottacatchup]

Completely stock suspension with factory spec alignment.

BF Goodrich Gforce Sport 205/45/17
over Kazera KZ-B 17x7.5 +48

I know thats a narrow tire for those rims and thats another arguement for just getting new tires. However I still feel the BF's shouldn't be rolling that far.

 

[apexlater]

Ummm...I'm going to say that you are over-driving them...alot.

If you enter a corner and the car keeps going forward instead of turning, don't turn more. You actually need to straighten the wheel to regain traction.

I'm guessing that having someone instruct you would be the biggest help, and let someone competent drive your car so you can see what the car can do.

 

[apexlater]

So learn to drive the car "fast" as it is and THEN start throwing parts at it once you can intelligently know what the car is lacking.

 

[gottacatchup]

I understand the concept of learning to drive first then building the car, hence the stock suspension. I also am aware of the hazards of overdriving the car and I promise you I am not overdriving atleast not to that extent. I know you just have to take my word for it over the internet but I've been doing autox for a while and my friends at the track say I drive very smooth lines, I also tend to PAX fairly well all things considered.

 

[aMaff]

With those tires, at those pressures, that's pretty much the only explanation for rolling onto the sidewalls as much as you are saying you are (shrug)

 

[Jeff@Tri-Point]

Have you marked the tires at all to see if they are rolling over with higher pressures? Shoe polish can be your best friend with stock suspension (thumb)

 

[122 Vega]

Easiest solution is camber bolts. 205's on a 7.5" rim is stretching it a bit, I imagine the sidewalls are already deflected so you don't get the natural lean designed into the tire. The sidewalls are already taught on the outside edge when turning, so you are likely increasing the natual slip angle of the tire. I doubt you will gain much by camber, the solution is to put a wider tire on the car. No matter how much pressure you put in that narrow tire, it will always bow the middle of the tread inward as if you were running too low of a pressure. Most of the load bearing is on the shoulders, even in a straight line.

Britt

 

[gottacatchup]

Easiest solution is camber bolts. 205's on a 7.5" rim is stretching it a bit, I imagine the sidewalls are already deflected so you don't get the natural lean designed into the tire. The sidewalls are already taught on the outside edge when turning, so you are likely increasing the natual slip angle of the tire. I doubt you will gain much by camber, the solution is to put a wider tire on the car. No matter how much pressure you put in that narrow tire, it will always bow the middle of the tread inward as if you were running too low of a pressure. Most of the load bearing is on the shoulders, even in a straight line.

Britt

Yeah I think that makes sense and not really what I wanted to hear. When the tire is sitting on level ground it looks like this:

|_____|
\_____/

Not that sever but it is noticable. So if I need to upgrade what width would you recommend, 215 or all the way to a 225?

Oh and I always use old bits of sheetrock to chalk my tires and check the wear patterns.

 

[Gobbracing]

225 would be just right on 7.5" wide wheels.
Also go with a tire that had made its mark in the autocross community like the Falken RT-615, Bridgestone RE-01R and a few new others.

You'll notice a big difference in steering feel and grip.

 

[gottacatchup]

I'm thinkin bout dunlop dizzera sport Z1 star-specs. I know they're are new tire but I've only heard good things bout them. However they only come in 225/45 which I dont think'll fit without some rubbing unless I'm mistaken.

 

[apexlater]

I think they come in a 215-40-17.

 

[Auto-Xer]

yes...and a 215/45 as well. They are excellent.

I have 215/40's on a 7.5" wheel; the tire is about 8.125" wide...fits the wheel very nicely.

 

[aMaff]

I'm running 195/50s on a 7.5 wheel and I haven't had anything remotely like what you're describing...

 

[khaosman]

muff those are re01rs aren't they? Those tend run oh, EXTRA HUGE. My 205s looked damn close to the same size as my 225 v700s.

 

[aMaff]

muff those are re01rs aren't they? Those tend run oh, EXTRA HUGE. My 205s looked damn close to the same size as my 225 v700s.

I agree, however the BFGs don't run quite small either. The 195 RE-01Rs are a smidge narrower than the 205/50/15 Azenis RT615 for comparisson. And the sidewalls on the BFGs shouldn't quite be 'walmart $20 special' soft I'd imagine... Putting the tires on a narrower wheel may not hurt, but I don't think it'll fix the problem.

 

[gottacatchup]

I might still be overdriving I'm not trying to say I'm an expert. Heres some pictures of whats happening. You can see not an extreme radius turn and the car isn't visibly pushing, just following the path of the front wheels.

The last picture shows the tires unloaded so you can see how the sidewalls angle in away from the wheels like I was talkin bout before.

 

[Auto-Xer]

Doesn't seem that bad to me...I've seen photos (on other cars) that show far worse.

As for the BFG Sports--they are 'autocross worthy' for sure. A good 2nd tier tire.

 

[apexlater]

Ok, your cheap fix is to get some camber bolts (like Eibach), but this will move the wheel in closer to the strut, so make sure you have the tire/wheel clearance. Cheap, easy, effective. If you use bolts in both the top and bottom you can get more camber than you will ever need (I ran about -3.5 on my old MP3 on race tracks).

A front swaybar will help to hold the negative camber, but can be a pain to install, with the expense of some exit wheelspin. Maybe you should get both front and rear bars.

Loosen up the rear of the car. More pressure, more total toe out. Maybe the rear is gripping more than it needs to and not allowing the front of the car to take a tighter line.

New tires with stiffer sidewalls may help, but I've seen 615s on the sidewall from overdriving and wrong pressures (not saying that is your problem).

I still think you should have someone else drive your car that is experienced to see what they think. It's hard for your intardweb friends try and help solve a problem that we can't see/experience for you.