negative camber.....i dont get it

[nismofly]

no way to check patch shape, no, but there are ways to find out if youre running the right camber...youll notice a difference in the feel, you can use a pyrometer when you pull the tires off, etc

[one ton garage]

Here's a thought: the fact that people tend to delve too deeply into proving how camber affects race cars (and they always do), should be a sign already that THAT has nothing to do with street cars! Not saying that everyone should accept the crazy neg camber ways, but at least realize that unless you ARE tracking your car consistently, you honestly prob won't notice a dramatic performance/driving difference between having -1deg camber and -3deg camber in 99% of your every day driving. I mean, I'd be willing to pay someone money if they COULD honestly say they feel a difference in their EVERY DAY driving. And from there, I'd even be willing to pay someone if they could tell me they feel the difference when they pushed their car a little hard on the street. There isn't really a marked difference when going to something a bit more extreme either (i.e. over -5deg camber), as long as you make sure the rest of your alignment is adjusted accordingly to accomodate that additional camber. And as I've mentioned before, people here would be amazed at how often those crazy cars we see from Japan are driven... a lot of these guys are travelling to shows and get-togethers every weekend, and in a country the size of Japan, they're driving those cars-like you see them in pics-sometimes hours between events. It's funny to see people dissing those guys from Japan for having "trailer queens" when in reality, those guys could quite possibly be logging more miles on their bad ***, crazy cars than we do on our sedate rides over here. Something to think about....

EDIT: To add to what I said above about making sure that the rest of a cambered car's alignment is taken care of... I'd also be willing to bet that the majority of cars that have extreme camber also have had the rest of their car aligned, and the rest of their suspension in order... vs. how many folks who decry the neg camber cars actually have their suspension within OEM specs (read: when did you last get an alignment done?) and components/bushings in good operating condition?

[Q45tech]

Little things drive me crazy, so I spend way too much on keeping the suspension tight. Every little looseness in steering gets fixed, to that end every compoment has been replaced often multiple times [tension and upper links 6-8 times].

The only part of my front suspension that is as built are the ABS sensors and the upper link shock tower brackets.

[maxnix]

And although I think OTG's post is well considered (but how large is Japan?), one area where this becomes critical on the street in emergency maneuvers where drivers approach or exceed actual limits of adhesion. At that point, most will wish or be glad they are as persnickety as Q45tech when it comes to suspension and brake maintenance.

And don't forget your tires. Cheap it out there, and nothing else matters very much.

Dennis, thanks for the great links. Much appreciated.

[Q45tech]

Consider that most street shocks have a 7" stroke, so the designers design for a +- 3.0+ body roll................street tires are designed to accommidate this roll [remember street tires run 1100-1500 side wall stiffness per inch [obviously 18-20" are siffer than 15"].................so a car that comes oem with 15" may have a lot of camber gain because they model the oem tires with 5.5" sidewalls to roll under significantly........change from 15 to 17=ok [in the range] but change to 20-22"...............the body rolls but the tires don't so you end up with way too much camber gain for the amount need for the giant tires.

When you go with larger tires you need to limit body roll [via springs] to match the tires. If the body roll is cut in half via springs you need special short stroke [plus twice as stiff] shocks.

The old Q with angled twisted upper link has a significant camber gain to match 15" ULTRA performance tires.........which might be too little for run of the mill tires.

When going over bumps in a straight line, though, you don't want the camber changing that much. The [30 degree] angled upper arm [90-96Q]solves this problem. With the wheel pointed straight ahead, the upper arm pulls in at an angle as the suspension compresses. This still introduces some negative camber, but some of the movement is translated in to a rearward tilt instead. As the wheel is turned, it comes closer and closer to being at a right angle to the upper link, at which point all of that tilt is camber change.

In other words, the camber curve increases the more the steering wheel is turned. Very clever but stressful on upper link bushings [why you must change them every 30k]

[Q45tech]

One would need to consider the sine cosine of the steering angle to calculate the camber gain increase. The camber gain will vary depending on the steering wheel angle in the curve.During an alignment you could pay the technican to move wheel on alignment machine in increments to get say 45,90, 135,180 degrees of steering wheel and develop your own individual camber gain curves. Then measure the static camber changes as you pull the front end down with a chain hoist to simulate the body roll.

Measure the static camber straight ahead and measure as the tires are turned 30 degrees you will see the negative camber increase 10 degrees negative ideal for 15" tires but wrong for 17" tires and really wrong for 20".

You can obviously have too much negative camber which is just as bad a positive camber.

One of the reasons Nissan dropped this unique suspension as they increased base size tires 15>16 >17 >18>19........as you decrease the spread angle to match larger tires you loose the advantage and easier to go to more conventional unequal A arms.

As you go up from 15" tires you need to decrease negative static camber..........really a serious problem with lowered springs and bigger wheels.

Hopefully you can visualize WHY lowered with bigger wheels eats tires so badly................only G20 and Q45 [90-96] has this unique camber system the Z and J had more Macpearson like systems.

[CrimsonQ]

So I see that the tires on the VIP cars have rounded edges on the tires. Are those motorcycle tires like the ones they use on American Chopper? I never seen regular tires like that.

I beleive thats called "stretched tires"? (dont quote me on that)

ie: running tires that width-wise are smaller than what you would normally put on that specific wheel.