Last summer my camber in the front was -1.7L/-1.6R, and -1.5/-1.4 deg. in the rear. The car is a '99 GSR and is lowered about 1.6-1.7".
A couple of mos ago I get a wheel alignment again. Now camber is -1.6/-1.5 in the front and -1.3/-1.2 rear! I don't touch the height or anything.. On a 6/29 auto-x event I wiped out and skidded sideways for about 30 feet from about 40mph. I thought I heard some stretching/bending noises - hard to explain.. Anyway the car didn't feel right after that and driving back home that day, the car was pulling to one side and the steering felt very loose. I go to another auto-x the following weekend and I 'm rolling over the V700s at 39 cold, 41-42 psi hot, which had never happened before!

I decide to go for another wheel alignment because I had felt the 1st wheel alignment of this year had a little too much toe-in for my tastes anyway (the mechanic apparently didn't understand what 0.0 toe in the back meant..) This is last Thursday's camber: 1.5L/1.4R front, and 1.2L/1.0R rear! Now this is on a different rack (<2yrs old) different shop where the owner does custom wheel alignments for most of the guys in the club, including Evolution school instructors. He has also built his own D Mod race car and is the president of our local SCCA chapter so he 's not just a mechanic, he 's an auto-xer. I ask him to bump up the Total Toe in the front to -0.18" (from -0.12" that I had) in hopes to get some camber back. Nothing. We set the rear toe to 0.0" (from +0.09 left and +0.05 right. Nothing, camber stayed the same. He said the rear left adjusting bolt was loose before he even did anything..

Now my question is, what suspension component(s) can make you lose camber, ie: give you less negative camber? Bent tie rods in the front? Bad rear trailing arms? I 've lost 15% negative camber in the front, and 20-30% in the rear. Something is going on here. I 'm also rolling over the tires now. I thought as your suspension settled more and more you get more negative camber. I 'm seeing the opposite. Could skidding sideways seriously damage something? It seems the wheels got pushed in at the bottom resulting in less negative camber. How can I fix this? Loosen everything up and put it back together? Could worn out shocks cause this? I 'd appreciate any suggestions and advice you may have! BTW, the car just feels plain weird and it wonders a lot since I wiped out June 29th. I 'm hoping it's the OTS Konis that I 've had for 4yrs as I believe they 're on their last leg since I can barely adjust them any more. The GC spring rates are 475F/400R.
New ADs will be in tomorrow along with 650/750 springs but I don't want to inherit something bad and have the new setup partially cover it up. Any thoughts?

 

bump please. Any suggestions would be really appreciated.

 

The upper control arm, lower control arm, and spindle assembly control camber. To a certain extent, other alignment factors will effect camber as well.

So, if you changed toe settings, this may have caused the camber change.

Or, you may have bent one or more of the listed suspension components.

 

Or the alignment machine isnt accurate or wasnt setup the same.

 

one question:

do you always have the same amount of gas in the car each time you get an alignment?

I'd think that the weight of a full tank of gas vs. an empty tank would be enough to change you rear camber a few tenths either up or down depending on the gas level

I think that it's fairly unlikely that a slide at an autoX would have bent suspension components... unless of course you hit a curb or something of that nature.

 

The car never has more than 1/2 tank of gas in it. It's a habit I have picked up after 4yrs of auto-x. I like to race with <1/4 tank. The tank is always 1/8th to 1/4 full and once in a while between 1/4 & 1/2 tank.
Ok, lets assume the biggest skid I ever had auto-xing never happened. The negative camber started decreasing slowly before that ever happened.

 

.RJ is right. And I think the proof lies with the fact each side, front and rear, differed the same amount.

 

Remember that alignment numbers are outrageusly fickle. The machines used are treated fairly roughly and are displaying at their limit of precision to begin with.

I would wager that you could take 3 different readings on the same car, the same day and be off 15-20%. How the car settles on its springs, the temperature that day, slight variances in tire roundness, imperfectly round dims, bushing compliance variations etc. etc. etc. can all effect alignment numbers significantly.

You are dealing with tiny changes in a big, complex, heavy, rubber filled mechanical system. 15-20% error is not surprising.

 

I say get a camber gauge just so you can be the envy of all the other guys in the paddock...

Seriously though, different racks - hard to compare results.

 

well, i have spoken with vteconly numerous times about this... he must find a competent alignment shop. also, ride height affect camber and toe tremendously, so he stop raising and lowering the car on a whim (preferably cornerweight it, then align it) then drive the **** out of it....

 

Chris/Rodney: I went to Mark's shop last Thur. where Bruce Bellom goes and many other National caliber drivers & instructors from our area and we have quite a few. I think his machine is pretty accurate plus it's almost brand new and he spent a good 15-20min. making sure the wheel runout was good and double & triple checked everything. Besides, his machine will tell you if the runout is no good. The older ones don't. Another reason I know his machine is accurate is because it reported the same toe #s the previous shop set it at: -0.06 each front (-0.12 or 1/8" total which is what I had asked for). It hadn't changed. The only thing was the 2 machines disagreed with the rear toe and the camber a little bit. The older alignment had toe set to 0.0 in the rear. Mark's machine last week found both rear wheels with positive toe but Mark also said the rear driver's side adjusting bolt was found loose too..

Anyway, my main concern right now is why my rolling over all 4 tires. I 'm hoping it's just the Konis that are pretty beat up. I haven't touched the ride height in the last 3 wheel alignments.

Well, Chris Shenefield is corner weighting my car this wknd, right after we install new AD shocks and ERS springs. Then we 'll see how the car feels and if I 'm still rolling over the tires. Of course I 'll need another wheel alignment too and I 'm curious to see any of those rear bolts came loose again..

 

wait, you _know_ an alignment rack is accurate because it had the same numbers as another alignment rack, of which accuracy is unknow??? talk about blind leading the blind. i think you're barking up the wrong tree concerning your tire wear issue. my guess is that 90% of your problems stem from the driver and not the car. stop messin with the thing and just drive it! you can worry about the car once you are in the top 10 in pax in your region consistantly.

and don't base your performance off of other equally inconsistant drivers. and here's a quick hint. _everyone_ is inconsistant in autocross. has something to do with how some course designs favor some cars over others, and some drivers prefer certain course elements that others don't like. i've had events where i've won by a very small margin, then the next week won by over 2.5 seconds.

nate

 

geez, I wish you were telling me something I didn't know. Last year and this year, I 'm constantly PAXing in the top 10-15% and the same with RAW times in 2 SCCA regions and several other clubs. Been doing this for 4yrs (not a long time but I 'm no novice or beginner either) and have a few regional championships as well. It's not my driving. I 've never rolled over the tires in 4+yrs.
It started after I believe I got a messed up alignment, and the next day I skidded auto-xing really bad and the car felt differently immediately after..

Having 2 wheel alignment racks/machines give the same exact front Toe #s, certifies that the machines are accurate (and very close camber #s), rather than both being off. What are the odds that 2 machines that I happened to use, are off by the exact same percentage? And the reason I went to use a different rack, was to verify the previous alignment settings. I 'd hate to use the same shop all the time if it's not calibrated and is always giving out wrong readings.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTEConly &raquo;</TD></TR><TR><TD CLASS="quote">Having 2 wheel alignment racks/machines give the same exact front Toe #s, certifies that the machines are accurate (and very close camber #s), rather than both being off. </TD></TR></TABLE>

accuracy: The ability of a measurement to match the actual value of the quantity being measured.

precision: The ability of a measurement to be consistently reproduced.

Just because they agree doesn't mean they're right.

 

well, for one, if you are suspicious that your camber is mysteriously changing without any outside interference, you can't use your car as a control. take the same car and put it on both racks back to back, and then you'll have a good comparison.

fwiw, top 10-15% is very different then top 10. the top ten in my region can be seperated by as little as .5 seconds. go back to the top 15% and you'll find the 28th place pax finisher 5 seconds back.

nate

ps. i've had spins where i've lost it at close to 60mph, gone agricultural and had the car partially airborne. didn't screw up the alignment in the least. not trying to be elitist or puff myself up, but i still think it's the loose nut behind the wheel.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTEConly &raquo;</TD></TR><TR><TD CLASS="quote">I 've never rolled over the tires in 4+yrs.
It started after I believe I got a messed up alignment, and the next day I skidded auto-xing really bad and the car felt differently immediately after.. </TD></TR></TABLE>

Hey Harry, Are you talking about the "Rollover" you showed me on saturday last weekend? If that's the case you are NOT experiencing rollover. They're Hoosiers... at 40 psi.... nope... no rollover. sorry.

 

no, the 2-3 events before that. I was rolling my V700s very badly I showed people at NYR and they were like "holy sh*t".. Sat. was my first time on Hoosiers. I think the Hoosiers can hide a problem because the sidewall is so stiff. Still, I walked around and looked at other people's Hoosiers during the 3d & 4th heat, and their wear line was much further back (on top) than mine, yours too. I was right there on that last line before the sidewall begins.

 

I thought hoosiers liked higher pressures than 40psi?

 

Pat Salerno sometimes runs with them in the low 30's!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTEConly &raquo;</TD></TR><TR><TD CLASS="quote">Pat Salerno sometimes runs with them in the low 30's! </TD></TR></TABLE>



hmmph... i dont need no stinkin hoosiers anyways.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTEConly &raquo;</TD></TR><TR><TD CLASS="quote">Pat Salerno sometimes runs with them in the low 30's! </TD></TR></TABLE>

i have run as low as 26psi in the back

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rodney &raquo;</TD></TR><TR><TD CLASS="quote">

i have run as low as 26psi in the back </TD></TR></TABLE>

Maybe that's why you're so slow!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTEConly &raquo;</TD></TR><TR><TD CLASS="quote">
no, the 2-3 events before that. I was rolling my V700s very badly I showed people at NYR and they were like "holy sh*t".. Sat. was my first time on Hoosiers. I think the Hoosiers can hide a problem because the sidewall is so stiff. Still, I walked around and looked at other people's Hoosiers during the 3d & 4th heat, and their wear line was much further back (on top) than mine, yours too. I was right there on that last line before the sidewall begins.
</TD></TR></TABLE>

Was that a 225 hooiser? or a 205? Either way... compared to most tires hoosier are true to their listed width. I'm guessing that its also on a narrow wheel so the tire will get a bulge or crown to it which may be causing it. Still I would n't worry about it cause it won't rollover

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">

I thought hoosiers liked higher pressures than 40psi?</TD></TR></TABLE>

So I had heard as well... I havn't done alot of experimenting real high. In my experience they tend to feel faster at lower pressures but are not.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTEConly &raquo;</TD></TR><TR><TD CLASS="quote">
Pat Salerno sometimes runs with them in the low 30's!
</TD></TR></TABLE>
Probably not on all four corners... but who cars anyways... When you can drive as well as Salerno then you can run out of the ordinary tire pressures. Beside a stock 350Z is a slightly different animal then a DSP GS-R.