Ok so i have been wondering. what happens when the atom needs a 4 wheel alignment? How do you perform an alignment on it. and is everything adjustable? toe/camber/caster. on hondas you can only adjust toe from the factory everything else is set in stone.
and what are the specs for the toe caster and camber? or is it all non adjustable?
Alignment ?
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dp
Re: Alignment ?
camber and toe are adustable front and rear, caster is fixed. specs should be in the manual (haven't looked myself yet but was told it's in there).
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1965Cobra427
Re: Alignment ?
We got track settings from Tom at Brammo and did our setup in november before our last track day. The car was much more stable, especially under hard braking with the track settings. Tim Webb will do a suspension clinic at AtomFest complete with toe, camber, ride height and cornerweighting for street and track. We have all of the equipment and will also help Atom owners set their cars up during the event. When you guys come over this summer, we'll be sure to bring the equipment if you like and can set your car up. (Maybe at my shop the night before?)
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sloppyjoe
Re: Alignment ?
What exactly does 'cornerweight' mean? I understand toe, caster and camber, but not that.
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twebb
Re: Alignment ?
Reader's Digest version:
Put your car up on four scales (we use electronic scales built specifically for race cars). The four scales will each have a reading. That reading is the weight of each corner. Add the four weights and you have the total weight of the car. Depending upon the location of the motor and other variables, more weight will be on the front or the rear. If you are weighing a formula car and the car is straight, theoretically it will have equal weight distribution side to side. Front engine cars generally will have more weight in the front of the car while mid engine and rear engine cars have more reward bias.
Cars such as the Atom with adjustable spring perches (coil overs) can alter the handling characteristics of the car by moving the weight from front to back and from side to side. Roundy Round racers (NASCAR and the ilk) set their cars up to maximize handling while always turning to the left. Road racers want their cars to perform in both directions.
The process of setting the corner weights needs to be incorporated into the overall suspension set up. The steps include setting the ride heights, corner weights, caster, camber and finally toe. So, once the race car's ride height is set, the car is put up on the scales and weighed. Numbers are recorded. Generally we want to equalize the weights on the front tires and equalize the weights on the rear tires. Total side to side weight cannot be adjusted unless you are physically moving some of the weight, ie reposition the battery or fuel cell.
To adjust the corner weights you move the spring perches up or down. Raising the spring perch increase that particular corner's weight. There is some art/skill to setting corner weights. Changing the left front will impact the right rear. You need to work slowly and methodically to get the car to the spot you want it.
A personal example of the effect proper corner weights can have on performance a number of years ago, I had a race car that was not corner weighed correctly. Where it was I don't know. One weekend I spent a great deal of time up on the scales getting the corner weights as close to equal as possible. The next time on track I went 1.5 seconds quicker than I ever had in the past. No other changes were made.
Can you tell the difference after the car has been corner weighted? Some people can, but more likely the driver just feels more comfortable and confident resulting in a driver that can then push the car harder. It all about feel.
Put your car up on four scales (we use electronic scales built specifically for race cars). The four scales will each have a reading. That reading is the weight of each corner. Add the four weights and you have the total weight of the car. Depending upon the location of the motor and other variables, more weight will be on the front or the rear. If you are weighing a formula car and the car is straight, theoretically it will have equal weight distribution side to side. Front engine cars generally will have more weight in the front of the car while mid engine and rear engine cars have more reward bias.
Cars such as the Atom with adjustable spring perches (coil overs) can alter the handling characteristics of the car by moving the weight from front to back and from side to side. Roundy Round racers (NASCAR and the ilk) set their cars up to maximize handling while always turning to the left. Road racers want their cars to perform in both directions.
The process of setting the corner weights needs to be incorporated into the overall suspension set up. The steps include setting the ride heights, corner weights, caster, camber and finally toe. So, once the race car's ride height is set, the car is put up on the scales and weighed. Numbers are recorded. Generally we want to equalize the weights on the front tires and equalize the weights on the rear tires. Total side to side weight cannot be adjusted unless you are physically moving some of the weight, ie reposition the battery or fuel cell.
To adjust the corner weights you move the spring perches up or down. Raising the spring perch increase that particular corner's weight. There is some art/skill to setting corner weights. Changing the left front will impact the right rear. You need to work slowly and methodically to get the car to the spot you want it.
A personal example of the effect proper corner weights can have on performance a number of years ago, I had a race car that was not corner weighed correctly. Where it was I don't know. One weekend I spent a great deal of time up on the scales getting the corner weights as close to equal as possible. The next time on track I went 1.5 seconds quicker than I ever had in the past. No other changes were made.
Can you tell the difference after the car has been corner weighted? Some people can, but more likely the driver just feels more comfortable and confident resulting in a driver that can then push the car harder. It all about feel.
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rfmarz@frontiernet
Re: Alignment ?
twebb, shouldn't this corner weight be done with the driver in the seat- when possible? Great explanation!
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bolus
Re: Alignment ?
The manual says corner weights are set at the factory but it does not say what they set them to. Anyone know what the standard setup is? The manual gives the camber, toe and ride height though.
(thanks, twebb, I'm learning about a ton of stuff I did not know about suspensions and alignment)
(thanks, twebb, I'm learning about a ton of stuff I did not know about suspensions and alignment)
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twebb
Re: Alignment ?
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,
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,
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dp
Re: Alignment ?
corner weights are set by adjusting them so that cross-weights are equal. Â yes, this needs to be done with driver (or equivalent weight) in the seat.
think of it as a 4-legged table. Â if you make one leg longer it will 'teeter' on that leg and the diagonally opposing one. Â so if you increase preload on let's say left rear, both left rear and right front corner weights will go up and the right rear and left front will go down, causing a 'teetering' situation.
the above is my initial weight reading on the atom when i got it. Â this is without me in it and some pieces are missing (the overall weight will go up). Â notice that the left rear/right front crossweight is higher than right rear/left front. Â to adjust it, one can either decrease preload on one of the loaded corners or increase it on one of the loaded ones. Â
notice that only CROSS weights can be adjusted with preload. Â right-left balance and front/rear balance can only be adjusted by moving weight around.
think of it as a 4-legged table. Â if you make one leg longer it will 'teeter' on that leg and the diagonally opposing one. Â so if you increase preload on let's say left rear, both left rear and right front corner weights will go up and the right rear and left front will go down, causing a 'teetering' situation.
the above is my initial weight reading on the atom when i got it. Â this is without me in it and some pieces are missing (the overall weight will go up). Â notice that the left rear/right front crossweight is higher than right rear/left front. Â to adjust it, one can either decrease preload on one of the loaded corners or increase it on one of the loaded ones. Â
notice that only CROSS weights can be adjusted with preload. Â right-left balance and front/rear balance can only be adjusted by moving weight around.
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dial911
Re: Alignment ?
I've been reading Speed Secrets by Ross Bentley. In it he says toe out (my car was set at the factory for minimal toe out) causes initial understeer. As there is a tendency in mid-rear engine cars to understeer I was wondering if anyone has tried a slight toe out alignment?
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MadMaxedAtom
Re: Alignment ?
Dragged this from the dead eh? 
I like 1/16" toe IN up front and about the same in the rear (or zero out back). I find the car is more stable and less twitchy.
Camber depends on what tires and wheels I am using.
Bigger/wider and 30mm extra wheel offset gets -1 all around.
Std size tires/ no wheel offsets get -1.5 to -2.5.
I find the toe makes the biggest difference on the Feel of the car
I like 1/16" toe IN up front and about the same in the rear (or zero out back). I find the car is more stable and less twitchy.
Camber depends on what tires and wheels I am using.
Bigger/wider and 30mm extra wheel offset gets -1 all around.
Std size tires/ no wheel offsets get -1.5 to -2.5.
I find the toe makes the biggest difference on the Feel of the car
Re: Alignment ?
[quote="bolus"]
The manual says corner weights are set at the factory but it does not say what they set them to. Anyone know what the standard setup is? The manual gives the camber, toe and ride height though.
[/quote]
Factory gave me a copy of my inspection checklist when I arrived to pick up my car and it has this info. I don't know if they typically supply these though.
The manual says corner weights are set at the factory but it does not say what they set them to. Anyone know what the standard setup is? The manual gives the camber, toe and ride height though.
[/quote]
Factory gave me a copy of my inspection checklist when I arrived to pick up my car and it has this info. I don't know if they typically supply these though.
300hp Ecotec Atom that is driven. Visit my website.-
dial911
Re: Alignment ?
My bad I misquoted: Toe out causes initial oversteer.
I figure I need another season behind the wheel before I start making adjustments to the suspension but trying to get some ideas.
There's a lot of info in the book about anti roll or sway bars and adjustments you can make to them to correct for over/understeer. Guess there's no need for anti roll bars on the atom cuz the whole chassis is an anti roll bar!
What other adjustments have people made (I know I should have dragged my sorry ass to atomfest!)?
I figure I need another season behind the wheel before I start making adjustments to the suspension but trying to get some ideas.
There's a lot of info in the book about anti roll or sway bars and adjustments you can make to them to correct for over/understeer. Guess there's no need for anti roll bars on the atom cuz the whole chassis is an anti roll bar!
What other adjustments have people made (I know I should have dragged my sorry ass to atomfest!)?
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