BADFNZ

iTrader: (19)

In my last thread I stated that I was having wear problems on the outside of my left front tire, so I decided to get an alignment to try to remedy this. My car was not pulling bad or anything, the left front tire was just wearing heavily on the outside.

So when they first put it on the rack, these were the numbers:

Camber: -0.5/-1.0
Caster: 3.6/4.2
Toe: -0.06/-0.06

After he worked with it for 30 minutes or so, he got them to this:

Camber: -0.1/-0.3
Caster: 3.0/3.7
Toe: 0.00/0.01

Now I know what caster, camber, and toe are but it didn't really hit me until I got home that now the camber is closer to zero, which would cause even more wear on the outside of the tire, correct?

So I have a few questions:

1. Should I go back and see if he can get it to maybe -0.7 on both sides or maybe more?

2. Is -1.0 too much for a street car that doesn't do any tight turning?

3. I see people saying that a little bit of toe-in is good for tracking on bad roads, so should I get that number up to -1/32 (-0.03)?

4. I read that the more caster, the more stable at high speeds. Is this true? Should I try to raise this number too?


Help an alignment n00b!

Cal

iTrader: (1)

1. Yes
2. Yes, but why would you want to drive a fbody without any tight turns?
3. No it will track fine with zero toe and you will get better tire wear
4. Yes, but the stock setting is fine and there is a limit to how much you can get

I have driven my car 161 mph with the stock caster and zero toe and it was extremely stable.

BADFNZ

iTrader: (19)

Thanks for the response!

So how much negative camber should I shoot for?

And I like taking tight turns, they're just not too fun (or too much fun) with no front sway bar

Cal

iTrader: (1)

With no front sway bar, you need even more neg camber because you lose neg camber as the car leans in a turn. The -0.7 to -1.0 range you sugested would probably be good you. Myself, I would want as much neg camber as possible combined with the biggest front swaybar I can get, because I like to have fun on the turns.

dennis68

Not sure I follow you Cal, during bump the camber should gain negative regardless of whether or not a sta-bar is implemented. During roll the outside tends to go positive but not as a result of having or not having a sta-bar. The sat-bar's only purpose is to tune body roll. How does having a sta-bar or not factor in to where alignment should be set?

BTW toe-in is + not -. Running a little bit of toe-in is nice for tire wear and street driving, toe-out helps with turn in during autox and road course events.

After thinking about this a bit, I should clarify that I am ASSuming since you have no sta-bar that this is set up for some particular purpose and it responds better without a sta-bar (I've never seen a car that handled better with no bar at all in the front). If you have simply removed it and done nothing with the springs than you should probably be running way more than -1.0 camber, you should also put the bar back on.

As the car enters roll the springs should be limiting roll to a minimum and the sta-bar is used to tune roll otherwise you would wind up with springs to stiff to be able drive on. In an autox or slow road course most cars respond well to around -2.5 camber, high speed road course can pull some back, maybe -1.5 or so.

trackbird

iTrader: (4)

With no front sta-bar, the body will roll even more, this causes even more "loss of camber" due to the extra roll. So, with no bar, you will see more roll which will cause the front to lose more camber and wear the tires even worse. That's how you'd need more negative with no bar.

dennis68

I'll ask again, where is the front bar? If it were intentionally removed because the rest of the suspension were tuned to not need it, then there would be no extra roll. If it it were removed for any other reason than it should get put back on.

Adding neg camber for better contact patch during roll has very little to do with tire wear, it is to ensure a full contact patch as the tire stands up during roll resulting in better corner grip. Cambering in enough for full contact during roll will tear up front tires in a matter of weeks on the street.

trackbird

iTrader: (4)

Dennis, I appreciate your arguement, but (from what I can gather, and what seems to be standard drag racing practice on these cars), they just rip the bar off and drive the car (and this case is no different). There is no tuning for cornering done to go with it. Also, in all of the setups I've seen for these cars for track/autocross use, you need a front bar. You just can't add enough spring rate to do both jobs well. And, if you do, it will be too stiff to act as just springs.

And, no, cambering in enough for "full" contact patch will not necessarily tear up tires in weeks. Many guys are running -2 degrees or more and getting decent (not great) tire wear. Though these cars probably see less street time than most (which probably helps the tire situation). I'm running -1.3 degrees on my daily driver and I get 30k out of a set of front tires.

Of course you must remember. The more grip the tires generate ("R" compound tires), the more cornering force the car will generate (all things being equal). The more force the car generates, the more negative camber you'll need to compensate for camber loss due to having more body roll due to increased grip with the stickier tires. So, street tires will cause the body to run at reduced roll angles and need less static negative camber to handle the roll angles they do generate. Therefore, an alignment that keeps "full contact" on the street will not be as aggressive as "full contact" on the track (with track tires and setup) and will not be terribly bad for tire wear.

I agree that the bar should be put back on, but I don't drag race.

dennis68

I know back in the 70's it was common practice to pull the front bar or at least the links to improve weight transfer allowing the front end to lift more quickly...that was with mediocre suspension at best. I really don't think pulling the sta-bar is helping ET's much. Does anybody have any actual tech to support ET gain by removin gthe sta-ba, something back to back runs with and without it?

Cal

iTrader: (1)

What happened to BADFNZ? Ha ha. Trackbird, thanks for jumping in here. I agree, he should just put the bar back on to get better tire wear, and who knows how much it helps on the track. But it is common place for drag racers (which I am not) to remove them not only for weight transfer but for less weight period. I was just trying to help him get a little better tire wear without putting the bar back on.

As for as handling on corners, it does not seem that the textbook rule of using sway bars to fine tune the suspension completely applies to 4th gen fbodys. For the rear bar, yes, you can use that one to fine tune the suspension. But our cars seem to like as much front bar as possible. I'm guessing you would have to have a front bar custom made to get too much; even the biggest, stiffest off-the-shelf front bars seem to work well. Someone said it's because they tend to stabilize the whole car, not just the front end. Again, it's an effect peculiar to the 4th gen fbody.

Yes, -2.5 camber does work well on an autoX course; that's what I run. And my tire wear has even been pretty even with this setting on the street. But then, I also drive a windy road to work and back every day, so that may not be best for others.

BADFNZ

iTrader: (19)

I'm still here. Just trying to sort through this stuff! All I know is I'm going back and asking for -0.7* of camber

mitchntx

iTrader: (14)

With stock lowers and LGMotorsports Super Springs, I could only muster -0.8 camber on my car. It appears the amount of camber each car can gleen is very car specific ...