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Old 05-17-2006, 04:45 PM   #16
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Quote:
Originally Posted by protc3
anti squat plants the rear on power.it loosens the car a little going ito the corner and plants the rear on exit.i use antisquat on my cyclone with the front spool for this reason and it works well.

i second that !! Jason gave me the same set up on my Cyclone and it works great!
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Old 05-17-2006, 04:50 PM   #17
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Now we're talking.
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Old 05-17-2006, 04:59 PM   #18
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The reason Pro-Squat gives more rear traction on power, and from my experience it really does, is because it pushes down on the rear tires more. Pro-Squat will let the rear of the car squat down more and while it is going down with less force it isn't pushing on the tires.

I am with protc3 on this one, I strongly believe it gives forward-on power-rear bite, just like real cars. Watch a drag car (Pro Stock) carefully and you will see the body rise not go down.
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Old 05-17-2006, 05:11 PM   #19
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To elaborate on Ted Flack's post...

It's simple, anti-squat means the pins are mounted in a location such that they resist the chassis from squatting and puts the force on the arms/wheels instead of the chassis causing it to squat down which will result into more forward bite (on-power traction)...

This is the same in the middle of the corner, when the arms are flat (no anti squat) they are in a position that they requires less force to move them which corresponds to more side bite. The more you angle the front of the rear arms up, the more force it requires to move the arms (albeit a small force) makes a difference and frees the car up off power.
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Old 05-17-2006, 05:34 PM   #20
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without getting into the theory of what it should/should not do, i tried pro squat on the front of my fk05 (large asphalt track). it really smoothed out the off-power 'twitchiness' of the one way.
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Old 05-17-2006, 05:45 PM   #21
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Quote:
Originally Posted by rmargiotta
To elaborate on Ted Flack's post...

It's simple, anti-squat means the pins are mounted in a location such that they resist the chassis from squatting and puts the force on the arms/wheels instead of the chassis causing it to squat down which will result into more forward bite (on-power traction)...
The rear of the chassis will resist squatting down on-power only (corner exit), which will result in less weight transfer rearward and more steering on-power. However, when the chassis pitches forward going off-power (corner entry) the angle of the arms will actually make the rear end lift up less than normal, which will result in less weight transfer forward and less steering off-power.

In effect, rear anti-squat causes less weight transfer front to rear and vice versa. In higher grip situations, and an ideal world of chassis setup, less transfer equals a more responsive car that changes direction quicker and smoother since the cars chassis pitch range is lessened. You also have to take into account that this type of rear end setup requires a more soft spring setting, since the rear arms angle will shift some of the forces away from the spring and the shocks range of motion will be lessened.
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Old 05-17-2006, 05:48 PM   #22
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Quote:
Originally Posted by gee-dub
without getting into the theory of what it should/should not do, i tried pro squat on the front of my fk05 (large asphalt track). it really smoothed out the off-power 'twitchiness' of the one way.
Please keep in mind that the proper use of the term "squat", anti or pro, is only used to refer to the rear arm setup.

For the front arms, the proper term should be "dive".
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Old 05-17-2006, 06:04 PM   #23
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Quote:
Originally Posted by rmargiotta
This is the same in the middle of the corner, when the arms are flat (no anti squat) they are in a position that they requires less force to move them which corresponds to more side bite. The more you angle the front of the rear arms up, the more force it requires to move the arms (albeit a small force) makes a difference and frees the car up off power.
The angle of the arms have the greatest effect on front/rear weight transfer at corner entry and exit either totally off or on power. For mid corner traction the roll centers, springs & anti-roll bars play more of a major roll (pun intended ) as they in effect set the *limit* of left/right weight transfer that is allowed by the chassis at maximum roll.

The more the track surface is uneven (particularly bumpy parking lot asphalt and worn carpet tracks), the more dampening plays a bigger part as well in the middle of the corner. Softer dampening (less oil weight and/or more # of shock piston holes open) will *usually* allow the wheels to track over successive dumps better as long as there is enough rebound action applied from the spring forces and/or shock foam inserts.

NOTE: For those who read this immediately after I first posted it, there are a few edits to take care of typo's...
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Old 05-17-2006, 06:17 PM   #24
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Anti-squat happens when the rear tires are pushed downward by the twisting forces of the drivetrain. When the tires are pushed downward it creates a larger amount of traction for a moment. This is what you see when a drag car accelerates. The pinion gear tries to climb up the ring gear. The rear suspension is configured in a manner that translates this energy into a downward pressure on the tires. This is anti-squat. The exact opposite happens when the car decelerates. The suspension lifts the tires from the surface of the road , which causes the rear of the vehicle to "squat". Pro-squat does the opposite of what anti-squat does. On a RC vehicle, anti-squat places downward pressure on the tires because when you apply the throttle the car wants to remain still so the rear tires try to walk forward under the car due to the angle of the hinge pin. Since the hinge pin has a positive angle to it(front is higher than rear) the force is translated into a momentary downward pressure from the rear arms. If the hinge pin angle was negative (lower at the front than the rear) the tires walking forward would cause the rear arm to rise momentarily which would result in a loss of traction(pro-squat). This is almost exactly how a modern 4-link suspension produces down force from throttle input(anti-squat). I was a suspension and telemetry man for a many time national champion SCCA Trans-Am and IMSA GTS driver, and if this was not the way things worked we never would have won anything. It is all physics.
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Old 05-17-2006, 06:22 PM   #25
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Anti-squat will tighten a car up under power, and loosen it up off-power.

Pro-squat will loosen a car under power, and tighten it up off-power.

The key words are on-power and off-power. That's it.
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Old 05-18-2006, 08:54 AM   #26
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You have a point, as it applies to the world of drag racing where the *initial* power hit is critical to getting out of the hole quicker. Back in the day I used to race (drag & on-road) 1:1 cars and bikes on an *unofficial*, but I like to think professional, level if you know what I mean. However, the effects of dive/squat are not quite the same with an on-road racing vehicle on a road racing track. And from what I've heard, the effects are a lot more complex and different in off-road as well, where traction forces from tires and surface material/irregularities are much different.

Keep in mind that the comments I have provided apply to on-road racing specifically, given this forums audience.

With that said, I believe that we could still be talking about two different areas of traction for an on-road vehicle. The first is during the initial force applied either going instantly on or off power (related to the explanation concerning drag cars). The second refers to the subsequent traction that comes after the tires have fully engaged in grip and the chassis weight starts to shift.

It gets even more complicated when you factor in the amount of droop that is used in conjunction with pro or anti squat/dive. In a corner, the arm angles will affect the inside wheels in an opposite fashion with respect to the affect on the outside wheels. In the case of anti-squat, the outer loaded wheel will rise up less which would normally equat to less traction. However, the same arm angel will allow the inside unloaded wheel to rise up more causing more chassis roll.

From what I have tested on the track using anti-squat, if you have limited the rear droop to less than 2mm, then the rear end has more overall traction off-power and less overall traction on-power. Basically, I used minimal droop (1.5mm) in order to suppress the initial amount of rear end lift when going off power and also to suppress the initial amount of weight transfer to the outside rear wheel when rolling on the throttle early in the corners while the chassis was at its maximum roll point.

As soon as you open up the downstops to allow more upward chassis travel, the more the rear end will initially move with abrupt throttle/braking changes. This causes more initial weight shift forward off-power and also a more constant weight shift to the outside rear wheel on-power coming out of the corners.

Per CarbonWerks explanation, I regularly saw a one to two car length advantage out of the hole (similar to drag racing) at the start of an RC race on carpet with foams when I used anti-squat. As stated, this was due to the fact that the rear end didn't squat down and the power was applied to the tire much quicker. However, after the start in road racing a driver is best served by rolling on the throttle through and out of the corners. At this point, there really shouldn't be an abrupt surge of power, and the forward to rear and inside to outside weight transfer forces of the car are what should be taken into account.

With rubber tires on low to medium grip asphalt the abrupt power hit that anti-squat gives to the tires at the start of a race will actually cause them to break traction and spin coming off the line for a poor start. And subsequently, the effects of dive & squat will change with each differing grip situation. Hence the most commonly used term in F1 today by drivers, mechanics & owners...the { pahk-idge } is key.

Unfortunately, there really are too many variations between each persons overall setup ('package' ) to clearly and comprehensively predict how anti/pro squat/dive would affect their car. Track time anyone?
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Old 05-18-2006, 09:26 AM   #27
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The only real point I was trying to make was concerning the mechanical aspect of anti-squat, or pro squat. The more traction a racing surface has, the more pronounced the effects of anti(pro)-squat will be. If you were racing on ice, you wouldn't notice any difference in this setting at all. It takes traction to produce more or less traction in terms of these adjustments. The mechanical aspects of anti(pro)-squat are always present and I think the purpose of this thread was to examine them irrespective of the "package". Every adjustment is somehow related to another. If someone is able to grasp the physical action that is produced from anti(pro)-squat, they are less likely to view the adjustment as black magic and begin to understand how it affects other setup areas. It does the same physical thing on every vehicle in the world. It is an adjustment that can be used in a controlled way to manipulate other areas of setup. It makes the rear end go up or down under power or off power. How it affect other areas of the chassis is topic for another thread.
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Old 05-18-2006, 09:58 AM   #28
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Quote:
Originally Posted by CarbonWorks
Anti-squat will tighten a car up under power, and loosen it up off-power.

Pro-squat will loosen a car under power, and tighten it up off-power.

The key words are on-power and off-power. That's it.

As stated in your other post, anti squat will affect every car out there alike. It affects my T2 the same as my XB8TQ, it doesn't matter, anti-squat is called anti-squat on EVERY car for a reason.

Anti-squat: you (teamgp) can think of whatever physical weight distribution diagram you wish and you are correct in doing so, but adding anti-squat will give you more forward bite and less side and the opposite as you take it away... Look in the back of the XB8 manual.
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Old 05-18-2006, 10:42 AM   #29
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Quote:
Originally Posted by CarbonWorks
Anti-squat will tighten a car up under power, and loosen it up off-power.

Pro-squat will loosen a car under power, and tighten it up off-power.

The key words are on-power and off-power. That's it.
This is the simple facts and are 100% correct.

Teamgp; anything further and you are just trying to convince yourself at the expense of someone that may not know any better.
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Old 05-18-2006, 11:07 AM   #30
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what does tighten the car up mean? or loosen the car up? sorry.. newbo
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