by twebb » Mon Feb 05, 2007 4:08 pm
Yes and no. Isn't that always the case.
Race Car example:
With my race car, I set up the suspension as if I am in the car and ready to head out on track. To do so, I substitute sand bags for my fat butt and add enough fuel to get the fuel level to half. To approximate my weight, I place three bags of sand into the driver's seat (I make sure that the 3 bags weigh the same as I do with all of my gear on...driver's suit, helmet, HANS, shoes, gloves....). I go so far as to try and approximate how the weight is distributed within the seat. I put one bag up high in the seat, one in the "seat" part of the seat and then the final off the front of the seat towards the pedals. I'm attempting to create my body out of sand.Â
Once the sand "body" is in place, I start the process of setting up the suspension, ride height, corner weight, camber, and toe in that order. Once I have gone through the whole process finishing with toe, I go back and check corner weights, camber and toe. I might go through the process a number of times to get the corners where I want them.
At the track, if a suspension change is made the car should go back up on the scales and the process done again. It is tedious and frankly a pain in the arse but absolutely necessary if you want to get the absolute last 10th out of the car. Â
Street Car/Track Day:
With the Atom, you need to look at how you intend to use the car. Are you going to be doing track days? Are you going to be taking people with you? What is your experience in racing? How much time do you have to work on setup. Do you have a setup platform? Are you looking to set the absolute fastest time possible, or are you just going out to see what the car will do.  Your answers to these questions and a few more will determine how you do the setup.
This past weekend, Cobra and I worked on his setup. He knows that for the most part his Atom will be on track with both a driver and a passenger. Experience shows that most passengers are males and weigh (give or take 30 lbs) the same as the driver. We also know that we are not looking for the absolutely quickest setup possible (by definition you can't be as quick with an additional 190 lbs in the right front seat). Therefore we opted to set the car up with no weight in the seats. Â
Now come this summer, as we get closer to Atom Fest, our mind set may change. We may decide to look for the absolute best setup for Hallett. This will see us install the sand bags in the front seat and go through the set up process as if there is only a driver in the car. We will get a setup that is maximized for one person. Â
I would assume that most Atom owners will be driving their cars more often on the street than on the track. This would lead me to set the car up with reasonable ground clearance. Also, I would assume that once at the track there will be a driver and a passenger (that's half the fun....scaring the crap out of your buddy). With that in mind, I would try to get the corner weights as close as possible but would not get bent out of shape if they were off by 20 lbs.  If you don't have access to scales, I would try and get the ride height as close to even as possible. By this I mean get the right front ride height equal to the left front  and the right rear equal to the left rear.  More importantly, I would make sure that my settings for camber and toe are within a reasonable range.
We have done a number of lapping days in Cobra's Atom, but I wouldn't call them true test sessions.  The true test sessions hopefully will begin this Saturday.  To date we have found that Cobra's car likes 1/8" to 1/16" toe-out in the front and from 1/16" to neutral toe-in in the rear (road going ride height). With 048s, we see good consistant tire temperatures with camber settings of 1.2 degrees negative on the front and about .5 degree negative on the rear. From my perspective these are "safe" settings that can be used on the road  and the track. For more serious track work, I would  look to increase both the front and rear camber numbers.  Your milage may vary.
These cars handle well and are very sensitive to the toe settings. We have found that the toe settings listed above give a nice turn-in on corner entry and with a bit of toe-in on the rear provide for stability under braking. As one gets more comfortable with the car, I could see going to neutral toe in the rear to reduce scrub.  If you look back at some of the video by Cobra, there is a session where I'm driving the car and have to go to opposite lock (not quite but it seemed like it at the time) through the fastest corner on the track, turn #1.  This is a 80mph corner.  When we went back to the shop and checked the car, there was a massive amount of toe-out in the rear.  Exciting to watch, scary to drive but slow around the track.
Hope this is helpful. Â Â
Â
Setting up a car can take a long time. For you first try, it will take most of a day to get it where you want it. With this in mind,
Yes and no. Isn't that always the case.
Race Car example:
With my race car, I set up the suspension as if I am in the car and ready to head out on track. To do so, I substitute sand bags for my fat butt and add enough fuel to get the fuel level to half. To approximate my weight, I place three bags of sand into the driver's seat (I make sure that the 3 bags weigh the same as I do with all of my gear on...driver's suit, helmet, HANS, shoes, gloves....). I go so far as to try and approximate how the weight is distributed within the seat. I put one bag up high in the seat, one in the "seat" part of the seat and then the final off the front of the seat towards the pedals. I'm attempting to create my body out of sand.Â
Once the sand "body" is in place, I start the process of setting up the suspension, ride height, corner weight, camber, and toe in that order. Once I have gone through the whole process finishing with toe, I go back and check corner weights, camber and toe. I might go through the process a number of times to get the corners where I want them.
At the track, if a suspension change is made the car should go back up on the scales and the process done again. It is tedious and frankly a pain in the arse but absolutely necessary if you want to get the absolute last 10th out of the car. Â
Street Car/Track Day:
With the Atom, you need to look at how you intend to use the car. Are you going to be doing track days? Are you going to be taking people with you? What is your experience in racing? How much time do you have to work on setup. Do you have a setup platform? Are you looking to set the absolute fastest time possible, or are you just going out to see what the car will do.  Your answers to these questions and a few more will determine how you do the setup.
This past weekend, Cobra and I worked on his setup. He knows that for the most part his Atom will be on track with both a driver and a passenger. Experience shows that most passengers are males and weigh (give or take 30 lbs) the same as the driver. We also know that we are not looking for the absolutely quickest setup possible (by definition you can't be as quick with an additional 190 lbs in the right front seat). Therefore we opted to set the car up with no weight in the seats. Â
Now come this summer, as we get closer to Atom Fest, our mind set may change. We may decide to look for the absolute best setup for Hallett. This will see us install the sand bags in the front seat and go through the set up process as if there is only a driver in the car. We will get a setup that is maximized for one person. Â
I would assume that most Atom owners will be driving their cars more often on the street than on the track. This would lead me to set the car up with reasonable ground clearance. Also, I would assume that once at the track there will be a driver and a passenger (that's half the fun....scaring the crap out of your buddy). With that in mind, I would try to get the corner weights as close as possible but would not get bent out of shape if they were off by 20 lbs.  If you don't have access to scales, I would try and get the ride height as close to even as possible. By this I mean get the right front ride height equal to the left front  and the right rear equal to the left rear.  More importantly, I would make sure that my settings for camber and toe are within a reasonable range.
We have done a number of lapping days in Cobra's Atom, but I wouldn't call them true test sessions.  The true test sessions hopefully will begin this Saturday.  To date we have found that Cobra's car likes 1/8" to 1/16" toe-out in the front and from 1/16" to neutral toe-in in the rear (road going ride height). With 048s, we see good consistant tire temperatures with camber settings of 1.2 degrees negative on the front and about .5 degree negative on the rear. From my perspective these are "safe" settings that can be used on the road  and the track. For more serious track work, I would  look to increase both the front and rear camber numbers.  Your milage may vary.
These cars handle well and are very sensitive to the toe settings. We have found that the toe settings listed above give a nice turn-in on corner entry and with a bit of toe-in on the rear provide for stability under braking. As one gets more comfortable with the car, I could see going to neutral toe in the rear to reduce scrub.  If you look back at some of the video by Cobra, there is a session where I'm driving the car and have to go to opposite lock (not quite but it seemed like it at the time) through the fastest corner on the track, turn #1.  This is a 80mph corner.  When we went back to the shop and checked the car, there was a massive amount of toe-out in the rear.  Exciting to watch, scary to drive but slow around the track.
Hope this is helpful. Â Â
Â
Setting up a car can take a long time. For you first try, it will take most of a day to get it where you want it. With this in mind,