Region: Detroit
Car #: 06
Year : 1990 Posts: 357
Status: Offline
posted
I was doing my post test alignment today with the new shock hats and found that I was only at -2.2 deg of camber on the LF and -2.7 on the RF with about 1/2" between the shock and bump stop on the RF and and 3/4" on the LF. So I lowered the LF, and RR, keeping the corner weights @ 50%. I ended up at 4.25" to the pinch weld on the LF and 4.5" on the LR, 4.625" RF and RR. I still could only get -2.2 deg of camber on the LF. Camber and caster bolts are maxed out on the LF. The control arms and spindles are only 1 season old with no heavy offs or contact. The subframe is older and has had a decent hit or two, but has always aligned straight and has no apparent damage. The chassis is straight (fresh tub last year). Any hint as to what is going on?
Region: MidDiv
Car #: 13
Year : 92 Posts: 2873
Status: Offline
posted
Something doesn't add up. Take the car back up to 5" and see what the camber is. If it doesn't change your measurements must be off somehow. You have to get more as you go down.
-------------------- ---------------- Z Brothers Racing / East Street Auto
Region: Detroit
Car #: 06
Year : 1990 Posts: 357
Status: Offline
posted
I took the car back up to 4.75" LF and 5" LR and camber stayed the same. I'm baffeled. I'm measuring on leveled scales w/ slip plates, fresh tires (no uneven tire wear) at 39 psi, new wheels (no bends). I'm using a Smart Camber gauge. I'm trying to eliminate any variables.
I compared subframe measurements at the lower control arm mounts and a couple of the holes in the bottom to a spare I have. They are exactly the same.
One more note: the eccentric bolts on the left front are maxed out for neg. camber and pos. caster. The RF camber bolt (front) is maxed out and the caster bolt is about 3/4 turned. If everything was theoretically perfect, would they be equal left to right?
I don't want to buy brand new parts yet, so what can I measure on control arms to check for dimensional correctness?
Region: OVR
Car #: 88
Year : 1991 Posts: 2401
Status: Offline
posted
Sorry in advance for a stupid question, but are you sitting in the car or have an equivalent weight in the seat?
Usually, a visual inspection will tell you if you have a bent control arm. Look for cracked paint and compare L side vs. R side. Although if you didn't have any offs I can't imagine they're bent.
Region: MidDiv
Car #: 13
Year : 92 Posts: 2873
Status: Offline
posted
Phil,
Before you take it apart, make a really large change in RH. Go all the way up to 5 1/2" or something like that. Just use that to rule out any possibility of the camber change being too small for you to detect with your measurement process. Even if the arms are bent you should still see the camber change as the suspension geometry changes.
I am scratching my head on this one.
-------------------- ---------------- Z Brothers Racing / East Street Auto
Region: SF
Car #: RIP #56
Year : -- Posts: 663
Status: Offline
posted
Two things. First, I pound a crowbar between the lower control arm and the subframe near the front (camber) adjusting bolt before tightening that bolt. The leverage from the crowbar will guarantee that you get the most possible adjustment at that point.
Next, MEASURE! I've measured 6 lower control arms and 4 uppers and they were all exactly the same to within my measuring noise - 1/32". I found the same thing for spindles/uprights measuring between the top and bottom ball joints on my car and several others. There are small drilled holes near the welds for the cylindrical steel that holds the bushings where the cam bolts go. You can measure from those points to another reference (the ball joint mounts, for example) and those distances will all be the same for left and right (and 90-97 and 99-up arms, if I recall correctly). I've replaced arms with waves and cracks even though they measured like new and sure enough, they were never the problem. Without buying anything you can make these measurements on left and right sides and pinpoint if you have a bent lower arm or upright.
Region: SF
Car #: RIP #56
Year : -- Posts: 663
Status: Offline
posted
Oh, I forgot to mention that the crowbar trick is with the car weighted (easy with scale platens or at least jack up the LCA while the car is on stands).
You are going to have to clarify the crowbar trick for the slower ones in the class. What does this accomplish, and what are the mechanics behind it? How does it get you "the most possible adjustment at that point"?
Region: Great Lakes/Detroit
Car #: 51
Year : 1994 Miata Posts: 401
Status: Offline
posted
I think he's saying that there will be some slop in the castor adjustment bolt. With weight on the car, it will force the bolt inward (less camber). Using the krobar to force it out as far as possible as you torque the camber bolt may give you a bit more camber.
Region: Oregon Region
Car #: 7
Year : 1992 Posts: 57
Status: Offline
posted
I've been going through the same issue on my new to me 1.6 SM. While I get 2.5 deg neg camber on my RF ... I can't get more than 1.75 deg on my LF. My lower LF control arm looks "experienced" being somewhat flatter on the bottom than the one on the RF. Using the shop manual for more neg camber, I turned the lower front camber bolt past 3 o'clock ... still didn't have much of any change. I must have tried every combination of front & rear camber/caster positions I could ... but could not get 2 deg neg camber. I didn't try the crowbar trick ... but, I'm guessing I've got a bent control arm? Is there something basic I'm not doing? I have NOT updated to '99 hats yet. thanks,
Region: Detroit
Car #: 06
Year : 1990 Posts: 357
Status: Offline
posted
I got the chance to measure the control arms yesterday to the best of my ability. From what I can see, they are the same. I took off the LF and compared it to a spare that I had (old style however), and didn't see any obvious differences. So I've ordered new lower control arms for both sides and new lower ball joints to eliminate the possibility that something is wrong with them. I need spares anyway. I ordered all new eccentric bolts and washers too. The washers were definitely worn on the keys and that may be part of the problem. I'll let you know what I find.
Region: Detroit
Car #: 06
Year : 1990 Posts: 357
Status: Offline
posted
So here are my findings.
I found a slightly bent ball joint base (held a new one next to it and the inner bolt hole area was 1/8" higher on the old one). That tells me the control arm was also slightly bent.
I've set the ride height at 4.75 at the LF and i got to -2.5 camber. I still think I should get more, but I'm not to my lowest ride height yet. I'll be testing on Friday to see how low I can go and how much more camber gain is there. Thanks for all of the input!
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