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Old 11-12-2013, 12:19 PM   #16
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It makes the suspension "bind" under compression because of the direction of the hinge in relation to the force being applied to it. This creates a stiffening effect.

You also have the your analogy of the push up thing backwards.

If you were to do the analogy of the push up, you would have to think about leverage. The leverage point comes from the tire to the bottom of the shock, not from the stance of the car relative to the hinge pin. When a car has a further inside shock position the length of the lever (the distance between the tire and the shock pivot) is longer than when you have the shock pivot further out. Arm sweep has a minimal effect on the length of the lever given that you adjust your toe setting equally.
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Old 11-12-2013, 01:24 PM   #17
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Quote:
Originally Posted by CristianTabush View Post
The more angled a hinge pin is, the more suspension bind you will create as forces work against each other when compressing.

Arm sweep essentially makes the front end stiffer because the hinge pin is essentially angled towards the opposite direction that the outside arm is trying to hinge in compression in a corner.
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Originally Posted by jlfx car audio View Post
I think I have to disagree on one of Ur points (at this time )
Don't see how adding arm sweep (back) makes suspention stiffer .
I think I see where Cristian is going. We may be speaking the same language in a sense.

I do think using the terminologies of stiffer/softer may be a less than ideal (or possibly just misunderstood?) means of describing what's going on. However, to Cristian's point (and I may be contradicting myself, what I tend to think is that it has an affect on redirecting and/or limiting the weight transfer due to it's "opposing" angle. This is not much different than the use of pro/anti dive and squat to increase or decrease weight transfer for and aft. As an example, anti-dive creates a pin angle that opposes weight transfer from high and rearward to low and forward.
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Old 11-12-2013, 01:31 PM   #18
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I have read Ur post 20 times trying to rap my head around Ur thinking , still no luck. Lol
What " bind" effect r u referring to ? The arms pivot on the pin not pin pivot in mounts. Don't see how they bind any more or less.
If anything I see the affect of adding .5mm per side in the FF mount making shock work just like u moved TOP of shock in .5mm ( angle wise) which is a more progressive /softer feel
And my sweeping each arm back .5mm this moves front axils back 2+-mm? Thus putting more weight over front tires ? Again making front spring act like a softer spring ?
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Old 11-12-2013, 01:32 PM   #19
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BTW I have nothing better to do today lol
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Old 11-12-2013, 01:34 PM   #20
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Lessen, I completely agree. It creates angles that limit or rather prevent "free" suspension movement fractionally. It is totally like anti squat and anti dive, etc. Statically it should create marginal differences in suspension feel, however, under load they essentially provide less than "optimal" hinge points, which give the car a different feel and driving characteristics on the track.
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Old 11-12-2013, 01:34 PM   #21
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Justin, I am supposed to be shipping orders myself!

Almost done for the day though.
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Old 11-12-2013, 02:23 PM   #22
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Think of it this way: what would happen if your door hinges were installed at an 80 degree angle at the top and 100 degree at the bottom instead of 90? It would still open, but it would be nowhere near as free.
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Old 11-12-2013, 02:49 PM   #23
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I also always run arm sweep.. I always run 0.4mm per side..I use a brass motor shim on each side. I feel it had a nice effect to keep car calm at corner entry and still allowing the same overall steering.
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Old 11-12-2013, 03:30 PM   #24
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Quote:
Originally Posted by CristianTabush View Post
Think of it this way: what would happen if your door hinges were installed at an 80 degree angle at the top and 100 degree at the bottom instead of 90? It would still open, but it would be nowhere near as free.
Where r u thinking the movement is happening ?
On a xray the arm moves pin does not move or shouldn't . I can pull a arm from a old T1 and u only see marks where arm has pivoted on pin , theirs no reason the hinge pin mounts should allow the pin to twist .
Think this is where I'm "cogging" on Ur theory .
But L.F. I see the way Ur explaining his thought I believe .
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Old 11-12-2013, 03:41 PM   #25
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Thinking out loud from a physics point of view , arm sweep does create suspension bind but not necessarily due to the angle of the arm and how it relates to other suspension components. The bind created is at the out drive and bone , by angling the arms back you are also creating a angle between the out drive and driveshaft. The driveshaft is no longer parallel with the outdrive at any point in the suspensions cycle thus creating bind, and adversely a stiffer front end predominantly under power.
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Old 11-12-2013, 03:46 PM   #26
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That I can understand
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Old 11-12-2013, 04:14 PM   #27
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Funny.. I don't. Ha!

But seriously... I do understand there are varying degrees of friction depending on the position of the outdrive/dogbone at any given moment, but I don't believe that's the specific "bind" that Cristian is attempting to explain.

What he's talking about is a deflection of motion. Anytime you deflect the movement of something (well, with the exception of light), you inherently slow it down. That's why you hear folks talk about losing initial steering. More sweep means more deflection and more time. Now that's not to say that zero sweep means zero deflection, it's still there. The lateral load on the front suspension is never 90* to the pin if you run them parallel or with sweep (unless you go the opposite direction which I've never heard of anybody doing). Loading pushes this way "/" and the suspension moves it this way "-".
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Old 11-12-2013, 08:12 PM   #28
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Lessen, thank you.
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Old 11-12-2013, 08:56 PM   #29
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So Christian, using your xray chassis with the pivot balls in the toe blocks, wouldn't that reduce some of the friction you are talking about? I could see in the old style xray roll centers it would create a lot of friction as they weren't really designed to be set for pin sweep. BTW, I bought 2 of those chassis and think they are great. Keep up the good work.
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Old 11-12-2013, 10:33 PM   #30
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It can and it should. But it still does not change the direction of the force being applied in relation to the hinge or deflection as Lessen kindly explained. I think the gains might be more marginal with a "freer" suspension movement, but I don't know if there is a practical way to measure or quantify this.

What I have noticed is cars that use pillow balls are "freer" in the corners, vs cars that go straight into the suspension mount. The cars with no pivot balls seem to dig into the track harder while pivot ball cars glide more if it makes sense (especially if they are going into aluminum vs plastic). That's a whole new conversation for another day though.

And, thank you for the compliments and your support of our little brand. I am glad you are enjoying your stuff.
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