Additional camber...
 

Hi guys, I was wondering what the EP guys use to add extra camber. I have cusco camber plates up front, as well as a rear subframe spacer to adjust camber, but am unable to go above 3 degrees negative. Im still getting my tires wearing more on the inside than outside, so I would like to try to add a bit more. Should I cut the front strut mounts and fab larger adjustable camber plates or is there another way?

Wearing more on the inside? You have too much camber. If you mis-typed and you are wearing more on the outside I would work on limiting body roll. In the rear we try to get as close to zero camber as we can depending ride height.

Yeah what jgrewe said. you got to much camber if the inside of your tires are wearing most. Unless you typed it wrong.

Ive seen people cut the strut mounts but i wouldnt suggest doing so.

yeah sorry guys, thats what I meant. Im wearing the tires significantly more on the outside that inside still, and all of my camber settings are at max. Im running about 3 degrees negative in the front and about 2 in the rear. Car handles well, but Im wondering if im leaving time on the table by not using all of the tire available in the corners if its still scrubbing so much on the outside.

Try to get some pictures of the car in the middle of a corner from straight ahead of it. You can get a pretty good idea of how far it is leaning with a protracter. More than 3 degrees is tough to deal with on a strut car.

I'm with jgrewe on this. Start focusing on roll control (swaybars) rather than trying for more camber.

On my 1st gen (not sure what you've got) I can run over 3 degrees negative, but only race at about 1.5 I've found that any more than 1.5 wears the inside of the tire, because my car has almost no roll even in the hardest of corners. Between the low ride height and the massive swaybars (Respeed hollow bar on front), the car just doesn't roll. And if it doesn't roll, then you don't get the huge camber changes that require you to overcompensate by running massive amounts of negative camber. :)








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what gen rx-7 are you running?

you can always try crash bolts up front. I'm running dual crash bolts on my corolla with the stock top mount and I'm at -3.4* negative camber.

http://i242.photobucket.com/albums/f...xseal/PBIR.jpg

here is a pic of the car at PBIR. Im running a speedway swaybar, on the middle of the three adjusting points . The car is handling very neutraly, with a touch of easy to induce oversteer when needed, so Im a bit hesitant to throw it off. I have been thinking of purchasing some higher spring rates all around to test out, but I could also tighten up the front sway bar, and maybe add the stock rear bar as well (not running a bar in the back). What do you guys think?

hmm..what are crash bolts? never heard of them. is this an offset bolt for the suspension?

Put the rear sway bar back on. I see no real reason to take it off.

Yes, it replaces the bolts that hold the strut to the spindle.

Man, that rear hatch looks good!

haha...yeah man..I just repainted the car and did a general overhaul so now its blue! The hatch is still looking great!

What tires and rims are you running? It could be your wheels are a little narrow and are letting the tires roll over too much.

-Trent

Im running a few sets of 15x7 rotas with ra1s, hoosiers, and now BFGs. Both the ra1s and the hoosiers are showing the same wear.

yeah, crash bolts = cam bolts.

I'm considering installing some on my rx-7 so I can change the camber plate to a caster plate. you should be able to get a lot more camber out of it.

are you having the same issue on the back? I find that hard to beleive... I had -3* of camber on the rear when it wasn't adjustable... just from lowering.

What tire pressures are you running?

Double check your bushings too, if you don't have poly bushings you might want to consider switching as it will tighten everything up and may make more of the camber you have a little more effective.

For racing i would only run 1 cam bolt per side. I have only ever run them on the top, but i wanted to try the bottom to get wider track width (marginal i know).

Also coat them generously in red locktite and set them to max position. Use the strut plates for final and future adjustment. If you mess with them after the locktite dries or dont use locktite expect them to move around on you.

Holey shmoley, your car is set up just like mine!!!!! I could wear the outer 3 ribs off a Toyo RA1 in a 1 Hour race and leave the inside 3 ribs almost pristine.

Just some thinking on my part as I have exactly the same issues and have tried for years to come up with a solution. I tried massive bars on the front with no change. I, like you, run without a rear bar as it makes the car a lot more neutral in the high speed corners, so I tried 3 different bars with an improvement. I tried all different spring rates up to 900 lb fronts and 800 rears and found little improvement. I tried messing around with alignments (up to 5 degrees) with little to no improvement, but I think I know what is happening.

About 5 years ago I added a data logging system to my car. I started to measure peak and sustained cornering G's at the high speed track. What I found was that with the added aero on my car, I was able to maintain 1.2 g's on the long sweepers with momentary loadings of almost 2 g's. I also started to measure (by eyeball and compass) front wheel camber in those high g corners and found that the camber was changing fairly dramatically under load. I then went back and looked at what could be moving under load and finally traced it down to the Poly bushings I am using in my front control arms. The poly bushings were allowing the front control arms to move almost a 1/2" inwards under load. I then looked at what the AWR EProd guys were using and realized that they had eliminated that compliance.

Aero + Grip + Load + Turning causes the wear. I think that we both need to step up to the AWR front control arm bushings.

As well Toyo RA1's are notorious for second rib wear under high grip and load conditions, just an FYI.

Eric

I assume you're toe neutral since it wasn't mentioned? If not, the wear may be amplified by bad toe. Just a thought. Good luck!

Hi guys, thanks for all the answers and suggestions!

The car is fitted with mazdaspeed delrin bushings all around, so all of the control arm bushings should be pretty solid. The Ra1s were running with 30psi cold that would bring them up to about 38psi hot. I have 400 and 250 springs front and rear and think I will try to bring them both up together. Like I said I like the way that the car is handeling so Im hesitant to go stiffer on the sway bar without adding something in the rear to balance it out. Maybe I will try going to full stiff on the front sway bar and adding the stock rear bar.

I may just be the tires, and it may also just be s1mpsons suggestion that the toe be slightly off. The car has been due for an alignment for some time, and I have been blowing it off. Im aligning the car, zeroing everything out, and going out with brand new rubber next time. Will report the findings from a clean sheet.