Duk
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Re: Upper control arm angle mods

Post by Duk »

From what I can tell, Vince Sharp modifies a different balljoint. 1 that has a long shaft and a left hand thread on it to begin with :wink:
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PietereQ
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Re: Upper control arm angle mods

Post by PietereQ »

Hmm it took a while but that's what I came up with. Too bad they wont fit 15" so they're worthless to me atm :x Anyone interested?
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Bruce
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Re: Upper control arm angle mods

Post by Bruce »

How effective is this in reducing understeer and/or roll when compared to lengthening the suspension upright or modifying the lower A-arm?
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Mats
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Re: Upper control arm angle mods

Post by Mats »

Why not attack the real problem, super soft wheel rates?
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Zamani
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Re: Upper control arm angle mods

Post by Zamani »

Super soft wheel rates can't be the only problem.

But that "knuckle riser" raises the upper A-arm a lot. I think drop spindles doesn't go that far.
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Re: Upper control arm angle mods

Post by Mats »

It's the root cause. The front is extremely soft and rolls plenty -> outside wheels gets lots of positive camber and lose grip.
That's why the "huge roll bar mod" works.
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Bruce
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Re: Upper control arm angle mods

Post by Bruce »

I want to reduce body roll on my road car without too much detriment to ride comfort, so do I reduce roll by installing a thicker anti-roll bar, thicker torsion bars, RS (or similar) kit, A-arm/upright or upper link modifcation?
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Re: Upper control arm angle mods

Post by Zamani »

The problem definitely has to do with the wheel rate. But once you lower the car, the geometry is no longer optimal due to the a-arms angle relative to each other. The extended/drop spindle will fix this issue. The "correct" way of handling this is to fix the geometry as well as to correct the super soft wheel rate. But for most drivers, fixing the wheel rate will have a more apparent effect.

For the occasional track and fast street car with lowered suspension, I would do the following:

GTV6:
25.4mm torsion bars
bigger sway bar
drop spindles

75 V6:
Install TS bumpers
Move battery to the back
25.4mm torsion bars
bigger sway bar
drop spindles

But even for normal road use, the 25.4mm torsion bar and a big sway bar will work well with slight lowering.
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Re: Upper control arm angle mods

Post by Duk »

Mats wrote:Why not attack the real problem, super soft wheel rates?
Mats, doesn't your race car use upside down lower balljoints?

The geometry is deffinately a problem. The suspension actually gains positive camber during bump.

A narrow car, with a relatively high center of gravity, suspension geometry that starts out with a low roll center and that roll center goes down at a higher rate than lowering the car. Chuck in the movement to positive camber on compression and soft factory spring rates (torsion bars), it's no wonder when you see pictures/footage of these things cornering, they are leaning heavely on the outside front tyre that's been pushed into 3+ degrees of positive camber.

My opinion: Correct the front suspension geometry with either drop spindles or knuckle risers and then play with springs (TB) and if you still need to, antiroll bars.
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Micke
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Re: Upper control arm angle mods

Post by Micke »

The suspension actually gains positive camber during bump.
Is that your guess?
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Re: Upper control arm angle mods

Post by grant »

No matter the geometry, the car seems to be more fun when the wheel rates are higher. Therefore, increase spring rates first, then fix the geometry :shock:

I've been driving a car with struts for a while now...bolted on some $80 roll center adjusters and was done with it. I'll see you guys on this forum when I have some money :roll:
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I'm kidding -- please don't ban me.
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Re: Upper control arm angle mods

Post by MR2 Zig »

Grant,

Most of us here own and drive Alfas.




Therefore we are all short on money :|
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Mats
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Re: Upper control arm angle mods

Post by Mats »

Haha, that's funny.

Well, not that I'm broke, that's not funny. :|

Someone wants a 164 3.0 24v Super? :roll:
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155 V6 Sport -96 - Sold!
Duk
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Re: Upper control arm angle mods

Post by Duk »

Micke wrote:
The suspension actually gains positive camber during bump.
Is that your guess?
I base that on looking where the vertual swing arm pivot point is in relation to the wheel.
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