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Mazda Projects \ My Build (updated 9/16/07 )My Build (updated 9/16/07 )
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v8mazda4ever
+1y
I can only see a problem with lift as you are pulling in to different derections you can't get as much lift as with a forward system.
speedster93b
+1y
like they said they only get 2 degrees of change with that setup. if it had a bag over link setup it would be more extreme, because they'd get more lift. the shortness of the upper link bars will pull the top of the axle backward as it lifts and cause an exponential amount of pinion angle change. thank goodness they're only doin a over axle setup.
twisted minis has a pretty good point about being able to setup roll center and anti squat being a bit harder... heck i don't even remember how to figure anti squat... lol.
twisted minis has a pretty good point about being able to setup roll center and anti squat being a bit harder... heck i don't even remember how to figure anti squat... lol.
lost_b2200
+1y
What number for anti squat would be best for a b2200? And roll center should be at the front bumper correct?
speedster93b
+1y
the roll center should be above ground in the center of the vehicle when looking at it from the front. if you had it at front bumper height on a stock rig it'd be really unstable, and be more 'top heavy' than if it were near the ground... depending on what your doing (road racing or whatever) you'd want it to be higher or lower maybe below ground.
i think actually twisted minis was talking about instant center... like setting up the link bars to shift weight. i know that's what i meant. if you angle the upper links downward to the front it'll launch harder, but will give you more pinion angle change with your bags.
i think actually twisted minis was talking about instant center... like setting up the link bars to shift weight. i know that's what i meant. if you angle the upper links downward to the front it'll launch harder, but will give you more pinion angle change with your bags.
twisted minis
+1y
Okay both of you are a little lost on what roll center is I believe. I think you are thinking of the vehicles COG (Center of Gravity) which is generally around here you rest your feet, midway through the door, but hard to find exactly where.
Roll center has nothing to do with the front or back of the vehicle, but more side to side. Its basically the point at which the back of the truck will pivot. So say you have a 3-link, and the upper bar is dead center on the pumpkin. That is the point where all of your suspension will pivot, or roll, around. So say you move that point off to the left side by about 6 inches. Now one side of the suspension will roll different than the other. Do you understand what Roll Center is now? Same with a 4-link, but just averaged between the two points of articulation.
Instant Center is what you want to set up to point at about the front grill or bumper of the truck, at a level height, and at your general ride height. At this point you also want the bars close to level with the ground because the air bags will absorb bumps more efficiently in this position, and provide a somewhat better ride (assuming bags on bars). So in order to achieve this, you generally want the spread of the bars to be smaller at the frame mounting point of your 4-link. So say your bars are 11" apart on the rear axle, from the center of the lower bar, to the center of the upper bar. [Now is the time to find ride height, and set the lower bar up roughly level, pointing up a little is good.] Now, you've measured 11" spread at the axle. So where you 4-link mounts, you will want around a 9.5-10" spread (assuming standard cab truck, an extended cab is longer, so a little less spread will be okay). This is just an average measurement that I have found myself to be close for a standard cab short bed truck. This generally puts the intersection point of these two bars around the grill area. You will have to fine tune that measurement yourself if you want to be dead accurate, but just getting close will suffice really. Its not a race car.
Now if you do this correctly, you should get very little, if any, squat or rise during aceleration. The setup I just build was done like this, and I get 0 degrees of pinion change through 18 inches of travel. It should not have any squat or rise in a respectable amount of that travel. But as the lift increases the geometry will not be as great and some may be experience. But seriously who drives a foot and a half in the air?
Sorry for the essay, hope this helps to clarify some things.
Okay both of you are a little lost on what roll center is I believe. I think you are thinking of the vehicles COG (Center of Gravity) which is generally around here you rest your feet, midway through the door, but hard to find exactly where.
Roll center has nothing to do with the front or back of the vehicle, but more side to side. Its basically the point at which the back of the truck will pivot. So say you have a 3-link, and the upper bar is dead center on the pumpkin. That is the point where all of your suspension will pivot, or roll, around. So say you move that point off to the left side by about 6 inches. Now one side of the suspension will roll different than the other. Do you understand what Roll Center is now? Same with a 4-link, but just averaged between the two points of articulation.
Instant Center is what you want to set up to point at about the front grill or bumper of the truck, at a level height, and at your general ride height. At this point you also want the bars close to level with the ground because the air bags will absorb bumps more efficiently in this position, and provide a somewhat better ride (assuming bags on bars). So in order to achieve this, you generally want the spread of the bars to be smaller at the frame mounting point of your 4-link. So say your bars are 11" apart on the rear axle, from the center of the lower bar, to the center of the upper bar. [Now is the time to find ride height, and set the lower bar up roughly level, pointing up a little is good.] Now, you've measured 11" spread at the axle. So where you 4-link mounts, you will want around a 9.5-10" spread (assuming standard cab truck, an extended cab is longer, so a little less spread will be okay). This is just an average measurement that I have found myself to be close for a standard cab short bed truck. This generally puts the intersection point of these two bars around the grill area. You will have to fine tune that measurement yourself if you want to be dead accurate, but just getting close will suffice really. Its not a race car.
Now if you do this correctly, you should get very little, if any, squat or rise during aceleration. The setup I just build was done like this, and I get 0 degrees of pinion change through 18 inches of travel. It should not have any squat or rise in a respectable amount of that travel. But as the lift increases the geometry will not be as great and some may be experience. But seriously who drives a foot and a half in the air?
Sorry for the essay, hope this helps to clarify some things.
speedster93b
+1y
that's quite the write up. i see you have a boat load of experience.
i wasn't referring to CG tho. i have been taught that roll center is the line that the car will pivot on when cornering. i can see how it was worded and kind does sound like CG. you can set up the roll center by playing with angles of the control arms. i haven't ever played around with it or set up any race cars to test or prove anything though. just learned 'theory' i guess it'd be called.
i wasn't referring to CG tho. i have been taught that roll center is the line that the car will pivot on when cornering. i can see how it was worded and kind does sound like CG. you can set up the roll center by playing with angles of the control arms. i haven't ever played around with it or set up any race cars to test or prove anything though. just learned 'theory' i guess it'd be called.
twisted minis
+1y
I re rear what you wrote and see how I got confused. Lol. Sounds like you've got it.
