OK, so I just finished doing my alignment with the help of ChrisGTS. We'll do his car next. Before we do, some notes and questions:
I was trying to reach -2.5 camber on the front wheels. I moved the rear eccentric bolt to it's maximum position outwards (thus decreasing camber), and was ONLY able to reach -2.0 degrees without dropping caster below 5 degrees. If I move the front eccentric outwards (also decreasing camber past -2.0), I reduce caster. Is there any other way to get more camber? I thought the Viper suspension could go more negative.
It can. You must lower the ride height of the car to gain more negative camber.
In other words:
1) Moving the rear eccentric bolt towards outside of car gives more negative camber (good) and increases caster (good). I'm maxed out here though.
2) Moving front bolt outwards gives more negative camber (good) BUT decreases caster (bad).
What would you guys do? If I bring camber down to -2.5, I'd have to move the front bolt which will bring my caster down to about 3.5 to 5 range. Which is more important, camber or caster? I'd like to hear from you guys who have actually experienced the difference.
Caster should stay above 5, again lower the car.
It's also worth noting that the Viper X said moving the front bolt does NOT affect caster as much. Several other cars are the same way. However, given what I experienced, I think that only applies when you are within a certain camber range (maybe -1.0 to -1.5). Once you are trying to get to -2.5, it's impossible to get to that camber without moving the rear all the way towards the outside. Or, I should say that if you move the front bolt outwards to reduce camber (without moving rear bolt), you'll decrease caster too much.
Am I missing something here? Is there another combination that I'm not seeing with the bolts?
I am at -3.0 camber front, caster 5.7 at smooth track ride height or about 4.0 inches from the ground to the frame between the lower A arms.
Toe is very easy to set if you have a lift. We tied a string from the front post to the rear post (on both sides), and squared it up (on my lift, 8 feet between the two). After driving the car up, we measured the distance from the hub to the string, and adjusted the string accordingly. You MUST move the strings in opposite directions to keep the 8 foot distance consistent. IE, if you have 13" on one side and 15" on the other, you have to move them both to 14" You can't move the 13" to 15" That would destroy the parallel lines, and give you more of a trapezoid shape with the strings. Then, you measure the front of the wheel with the rear of the same wheel to get toe measurements. We found that 1 turn of the toe rod is equal to 1/8" of movement. The easy way to do this is to turn the rod until all the slack is taken up by the ball joint. THEN count the turn of the rod. Lock the nut, and twist the rod until the ball joint attachment is level again.
All in all, I'd say that doing an alignment job is worth the time invested to learn. Chris and I spent a good 10 hours doing this (which included figuring out how to setup the strings, which tools we needed, etc.). Most of the time was wasted as we tried to adjust both front wheels at the same time, and adjusting both bolts at the same time. This created a lot of confusion and unneeded measuring. It was easier to work on one bolt at a time, reducing the amount of variables AND measurements. I'm sure we'll do future alignments in an hour or less. We marked the starting positions of the bolts with whiteout, so it'll be easy to return to our previous street/track setting of -1.5 degrees, although we'll probably just drop it down to -1.0 for street driving and go to -2.0 for the track.
-1.5 front and 1.0 rear is fine for the street.
The rear wheels were easy. No caster setting. Just move one or both bolts to give you more negative camber. We went from -0.5 to -1.3.
We picked up some good tricks along the way. The most time saving probabably being how to measure caster:
1) You can measure caster with a smartcamber gauge by holding it up to the shock tower. That will give you a good estimate. Also, while moving the front or rear bolts you can literally see the shock tower move, telling you if the caster has decreased or increased.
2) Most people measure caster by moving the wheels left 20 degrees and right 20 degrees, and measuring camber in both situations. Then, using math you calculate caster. This is time consuming if you use the 20 degree paper template provided with most camber gauges, which involves using a straight edge and making sure the template is paralle with the car. We found it much easier to MEMORIZE the steering wheel position at 20 degrees. On the viper, I found it was easy. Just turn the wheel almost a full turn, but stop when the spoke of the steering wheel points towards 5:00 or 7:00 (depending on whether you are turning left or right). You'll know what I mean if you use the template the first few times.
Lastly, in terms of weighting the car we found that it doesn't make too much difference. If I'm in the car, camber changes by decreasing about -0.1 degrees. I'm 165 lbs. I guess I was expecting a greater difference.
