Hi.
Going to get my alignment done tommorow. My S is a DD, but i don't care much about tire wear since my round trip to work is around 10 miles a day But what i need most is rear end stability in high speed corners and little to none understeer in slow ones.
Right now i'm on german specs which are:
Caster - 5.5 deg
Fr camber - -0.3deg
Fr toe - 0/0 for total of 0mm
Rear camber - -1.3deg
Rear toe in - 1.6/1.6 for total of 3.2mm

While on the track i'm running on Toyo R888 235*40 r17 non-staggered. In ~100mph corners back end is very nervous, which made me visit a ditch once already
So after scouring this forum i'm settled on:
Caster - 6deg
Fr camber - -1.5deg
Fr toe - 0/0mm (or maybe 1/1mm toe out)
Rear toe - 3/3mm for total of 6mm toe in
Rear camber - -2deg

Will this cure high speed rear end stability problems? And most of all are those settings good for a non-staggered setup?

thanks in advance

 

I'm concerned about the 235 in the rear which is most likely contributing to your oversteer. Most guys who go non staggered use 255s or even 245s. You might have to back off the front camber in order to decrease front traction a bit. You could also install a stiffer front sway bar or disconnect the rear sway bar, or some combination of both. Those are just some of the quick options you have. There are more things you could do depending on other suspension mods.

 

So around -0.5 deg of front camber and maybe -2.5 at the rear to make it a bit more planted in the corners?

 

Add a bit more rear camber, the rest looks ok. I would do -1.5 front and -2.25 rear. Also I'm not sure what 6mm of total toe in translates to but you want more like 3/8" rear toe in to really settle the oversteer.

 

6mm is ~1/4"

 

what are the specs of your rear wheel? you should not be running anything less than a 245 in the rear even if that means you have to go stagger.

your alingment will help with your current setup, but you should really "fix" your tire in the rear.

 

i'm running 235*40 right now. When i wear them out then i'll change to 255*35. While 235 R888 is way better than 245 Potenza on the slower tracks it's really too narrow for the faster ones. rookie mistake, but i learned from it without any dire consequences, except one trip sideways to the runoff field at 90 mph Right now i'm looking for a "quick fix" for couple of events on slower tracks, and i'll deal with everything else in the spring.

thanks guys

 

I think less front camber might work. Don't forget you could also play with pressures, raise the front, lower the rear, relatively speaking.

 

You don't need to run 245 or 255 on a non staggered setup. I run 215 r compounds all around (it was a mistake purchasing those tires) with zero toe all around and it works well enough but it is pretty loose. I think the key is maximizing negative camber and ideally a little positive toe in the back will help as well. When i do my alignments i ballast the drivers seat with my weight and shoot for the most negative camber that i can get. For my car it ends up being -1.7 in the front and -2.5 in the rear. These settings work for me but they may not work for everyone.

 

I am running 245 R-compund all around, with 0 toe front -3 camber, 5.5 caster, and 1/16 toe in rear, -2.5 camber. Runs great with stock sway bars, but push udersteer with bigger front bar. Just got my new coilover installed, will redone my alighment too probably end of this week, thinking about 0 toe all around, same camber and caster.
I would recommend more front camber than rear for R compund, just my experience.