Hi,

i have GT3 LCAs all around on my car, front camber is -3, rear is -2.5 and I think, almost sure, each LCA has at least one 7mm shim. front axle definitely has.

Could anybody who deals with this stuff often enough and knows by heart how alignment works - if I remove one 7mm shim from each arm for street driving - by how much does it change toe settings? will it be toe in or toe out? current setting is 0 toe front 0.10 rear toe in.

 

shim affects camber not toe

 

each mm shim is a change of 0.1 degrees of camber, so if you remove a 7mm shim you'll decrease camber by ~0.7 degrees. The shortened control arms will toe out your front wheels if you don't readjust the toe, toe in on the rear if you have shimmable control arms back there. Pull strings around your car to measure and readjust your toe.

 

thanks a lot, it is exactly what i wanted to know. thanks!

 

utk,

is your car unsettled when hard on the brakes (does the back wiggle?)

If you are running street tires that is way to much camber imo.

I used to run -3.3 & 2.8

car turned in amazing but was a beast under hard breaking and high speed sweepers

I now have -2.5 front & -2.8 rear and car works great and is much more user friendly.

(these specs are with toyo R compound tires)

i know its of topic but just trying to share my 997 data

 

Mo, is there a specific reason why you're running more negative camber in the back? Isn't more negative camber up front help our cars turn in better?

 

That's a lot of mods for not knowing what the shims do, did you buy the car with the mods?

You run a lot of neg camber, maybe just go to around -1.5 to -2 camber? That should be fine for the track and you might not need to change it for street driving.

Is it the "wondering" on the street handeling that you are concerned about or the wear of the tires?

For me it is tire wear, so I over inflate a bit. I am not sure, but it seems to lessen the inside wear.

 

totally correct. much better put than i did.
while toe changes by pulling shims, that's not how you adj toe.
and if you do pull the shims out, the toe change isn't always the same. you need to re-adj the toe.

 

no. if you want sharp turn in, toe out front. not just add camber. camber has other issues/prob.

how much camber you have R vs F also depends on toe values.
that i see is many ppl with big front amber vs rear, but they also have major rear toe in.

 

i just put back my street narrow PA2 tires - car is noticably unsettled on them. on 265/335 kumhos i did not feel that at all. car was very stable, may be rubber was just wide enough to begin with to compensate issues subsequent to camber increase. plus of course riding on r-comps for whole summer since february does not help much when you change back to street tires.

i will revert camber back to -2.5f -2r area some time next season, i realy want to try this -3f -2.5r setup for a6 hoosiers at auto-x, and compare if i will have any actual progress compared to how i run with other club where i will keep using either v700 or RA1 toyos.
perhaps it has little sense, but i am curious about this so i want to try it.

i regret i did camber increase at same time with shocks install. car goes via slalom blazingly fast now but i cannot say how much of that is due to stiffer sways/springs and how much due to more aggressive camber. from what my logger shows - car previously was going spinning in a sweeper about at 1.4g, now it holds until almost 1.6g. very significant change actually. at my Sunday run before DE i was running car at the course exactly as I did 2 weeks before where i did spin, this time it went over very similar corners like it was glued to the ground. very different feel.
all that is pretty much irrelevant for track i guess, i would never get even close to this any time soon there. still, it is quite interesting to explore.

i appreciate your advice, and actually to have more camber in rear than in front is somewhat new to me, not sure if i saw any 996/997 car with such setup. i know your suspension, but what tires do you run? still i do not probably want more camber in rear and i do need quite some amount of oversteer to force rear end off at auto-x but it is definitely interesting to see comments and personal experience from somebody doing that.

 

you do intentionally put here your statements in the way so they would cause an immediate reaction associated with an 'F' word, do you?

As of rest of skipped stuff - mostly - 'yes', on street tires this camber is not what should be kept.
Winter is coming, so r-comps will come off and i simply wanted to know if i can neglect any toe correction after removing extra 7mm of shims or not as beleive you or not, i know that toe does change ALSO after you take shims out. But, no, i did not know by how much.

After several responses it is obvious that it cannot be neglected as toe will change quite a lot (and i even was told by how much exactly in a PM) so it will simply be another $150 due to my mechanic for an alignment in October or so to get camber/toe adjusted for winter.

 

Huh? I must have misunderstood you.

 

i put more camber in the rear as recommened to me from 2 race teams.

Also it settles the rear under hard breaking and settles the rear end under VERY fast long corners (80-120 mph) (think willow springs and auto club speedway, where you are going into turns at 120-155 mph)

for tighter tracks i use more toe out and more camber up front.

i use toyo ra1 tires in 245/305 config

hope i can help

 

yep it does help.

not quite same problem as going late into a corner at 35-40mph slipping sideways at auto-x but i see (i hope i do) what you say here.

i just wonder what it will do with relative neutrality i am trying to achieve on my car, car obviously will start to understeer quite a bit with such camber, is it right?
as i understand to the lack of my knowledge you do deal with understeer then essentially by compensating that with a heck of trailbraking so front is kept constantly loaded in turns and then you have your rear end stability improved while still having enough traction in the front as car is under braking, right?

again, only point of reference i have is a memory of how my car behaved with -1f -1.5r camber while it was stock. it was a very disctinctive understeer and going to -2.3f -1.9r camber with gt3 LCAs was like a day and night difference.