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Chassis Stiffening importance...?

Jaymar

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On the s550 the strut to cowl brace is more effective than the strut tower brace. Since both come in the kit I installed both. The front lower K brace was surprisingly effective.

I installed each piece one at a time to see what it did.
By front lower K brace you mean a BMR CB006 or equivalent? Or do you mean the Ford factory bracing from the PP1/20" wheel package?
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bnightstar

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Most of the look how great adding braces accounts I see are from when they added a whole bunch of suspension upgrades, and there is no way to tell what made what difference. Because they were not tested one by one, but only before and after.
I only added tower brace, Camber Plates and Front Sway and there is noticeable reduction in front body roll and car is turning better. So the Tower brace does make a difference how big hard to tell but it's noticeable. Though I bought it because it looks cool and the Euro spec cars have the Cowl extension and k-member bracket but still the Tower brace made a difference.
 

Norm Peterson

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I only added tower brace, Camber Plates and Front Sway and there is noticeable reduction in front body roll and car is turning better. So the Tower brace does make a difference how big hard to tell but it's noticeable. Though I bought it because it looks cool and the Euro spec cars have the Cowl extension and k-member bracket but still the Tower brace made a difference.
Of the modifications you listed, any reduction in roll comes from replacing the OE front sta-bar with a stiffer bar. Not from either of the other mods. Body roll is body roll, and you're not going to be able to separate "front body roll" from body roll (generally) or in relation to some notional amount of "rear body roll". The OE chassis isn't flexible enough for you to observe those things without a fairly fussy instrumented test setup.

Turning better is the bar (and the camber plates if you used them to dial in camber that's more negative than it was before with the OE strut mounts).

With the tower bar what you notice is that the car feels a little better, a little more 'solid'. Which helps you drive the car harder even though it's not particularly better mechanically or structurally.


Norm
 

bnightstar

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Of the modifications you listed, any reduction in roll comes from replacing the OE front sta-bar with a stiffer bar. Not from either of the other mods. Body roll is body roll, and you're not going to be able to separate "front body roll" from body roll (generally) or in relation to some notional amount of "rear body roll". The OE chassis isn't flexible enough for you to observe those things without a fairly fussy instrumented test setup.
Try explaining that to my rear bushings please :)

Otherwise yeah just the front feel more planted and in contact with the road especially when turning and response is better/faster from when you turn the wheel to when it corner but this is also because of more toe out in my alignment.
 

Jaymar

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Of the modifications you listed, any reduction in roll comes from replacing the OE front sta-bar with a stiffer bar. Not from either of the other mods. Body roll is body roll, and you're not going to be able to separate "front body roll" from body roll (generally) or in relation to some notional amount of "rear body roll". The OE chassis isn't flexible enough for you to observe those things without a fairly fussy instrumented test setup.

Turning better is the bar (and the camber plates if you used them to dial in camber that's more negative than it was before with the OE strut mounts).

With the tower bar what you notice is that the car feels a little better, a little more 'solid'. Which helps you drive the car harder even though it's not particularly better mechanically or structurally.


Norm
If you can separate front body roll from rear body roll by feel then the subject of chassis bracing just got way more important to you.
 

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K4fxd

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If you can separate front body roll from rear body roll by feel then the subject of chassis bracing just got way more important to you.

Some of us can feel these things.

The S550 strut towers move around quite a bit without bracing.

My cowl brace when unbolted at the strut tower, has all tower studs centered in the brace holes. After my test drive I had witness marks all around the holes. Had I drove much longer I would have ruined the studs.
 

TeeLew

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I doubt if any of the normal chassis bracing will be something that shows up over a single flying lap on the watch. What you gain with stiffening the chassis is feel and consistency. If you're driving a car with a particularly flexible chassis, you'll find it tends to handle differently from corner to corner or from lap to lap. You'll also find that when you make a tuning change, that change's effects will be muted.

It's very difficult to feel the absolute magnitude of roll on one end of the car, but it's not difficult to feel the relation of the front/rear. If you don't believe me, go disconnect your rear anti-roll bar and take a lap around the neighborhood. You'll feel it straight away. The rear will feel as if it's moving a lot compared to the front. It is. You will also feel the slower response of the rear when transitioning from side to side. That's not necessarily a bad thing. It's just _a_ thing. You may appreciate the added grip if you were previously fighting for rear grip.

Chassis stiffness is analogous to improving the foundation on your house. You might not notice it initially, but it will be obvious over time.
 

K4fxd

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I like consistency. That was my biggest complaint about the stock base S550. It never did the same thing in the same situation.

Hence my add-on's. Rear was moving around, I added IRS braces, now the front was moving..Front braces added, now the dampers were not controlling the springs, added dampers........

In an old thread I was trying to get across a feeling of the car turning on the rear wheel, still can't describe the feeling but it turned out to be the previous owner trimmed the rear bump-stops. This caused a geometry change in corners.
 

TeeLew

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I like consistency. That was my biggest complaint about the stock base S550. It never did the same thing in the same situation.

Hence my add-on's. Rear was moving around, I added IRS braces, now the front was moving..Front braces added, now the dampers were not controlling the springs, added dampers........

In an old thread I was trying to get across a feeling of the car turning on the rear wheel, still can't describe the feeling but it turned out to be the previous owner trimmed the rear bump-stops. This caused a geometry change in corners.
Had you gone the other direction, dampers & springs first, the chassis deflection (front and rear) would be proportionally greater. This is why it's necessary to build from the foundation up.
 

K4fxd

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It ain't my first rodeo.

LOL
 

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SmokinAces

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owner trimmed the rear bump-stops. This caused a geometry change in corners.
wouldn’t trimmed bump stops increase travel, travel within the shocks capability. That would normally be a good thing, right. So for you, in this situation the trimmed stops produced a negative result? Just trying to understand my suspension better is all, not arguing your point.
 

shogun32

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That would normally be a good thing, right.
In my book it is.
So for you, in this situation the trimmed stops produced a negative result?
probably because he had gotten accustomed to the artificially stunted rolling movement that (too long) bump stops cause. I don't buy this 'a car should not pitch and roll'. Uncontrolled wallowing is bad, sure. but movement and weight transfer are GOOD things. If you've got bodywork that will drag and break from contact then sure, a stop makes sense. Once the suspension is on the stops it's rigid. There is no more bump absorption left and it's now up to the tire sidewall to take it, and if that's not enough the entire car gets thrown around. No thanks.

A full glass of water should stay full as I go careening around a track and not be smashed to bits by flying all over the car. (a little facetious here for effect)
 

K4fxd

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Stock ride height. I also thought more shock travel the better. After working with a suspension engineer, not Bmak, we traced it to the trimmed bump stops.

I don't care if you believe me or not.

If you lower by 1 inch and trim by 1 inch you keep the same Ford designed suspension geometry. If you keep stock ride height and trim 1 inch you will feel weird things.
 

GT 550

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Makes sense, IIRC the S550 bump stops - as with some other cars - are part of the overall suspension tune and not just for preventing shock damage.
 
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shogun32

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If you keep stock ride height and trim 1 inch you will feel weird things.
weird because the car is tilting more than you are accustomed to or want? Or the damping goes to shit after passing a certain part of the oil column? Or are we running into wheels coming unglued because the articulation limits have been reached?

Or the mechanical ratios are really bad once out of a narrow range? Like say at +/- 20deg the dynamic camber/toe are bounded but once you get to >25deg the rate of change is so severe the result is evil?

I'm not doubting your observations.
Makes sense, IIRC the S550 bump stops - as with some other cars - are part of the overall suspension tune and not just for preventing shock damage.
they are just travel limiters that have a 'soft'ish landing instead of being abrupt.
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