Kla strut brace
11-13-2003, 09:27 PM
#16
Instructor
Just as a general review the KLA brace from a quality standpoint is great, from a price standpoint is outstanding, and hell, it even tighened the front of the car up, nice! I have his rear coilovers, (awesome) and rear sway bar drop links as well, bang for the buck does not do his stuff justice, great work KLA guys!
Curt
Curt
11-13-2003, 10:46 PM
#17
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Damn... I KNEW there was a reason I'm paying 25 grand a year to go to school!! I actually understood all that!. Thank God for my Statics and Materials classes 
In reference to a comment made earlier... are strut tower braces meant to counteract outward spreading of the towers or to simply connect the two for a static equilibrium (creating a fully closed box structure), where the brace would then have a compressive force on it?? ..or is it a little but of both??
Also... in hard cornering, wouldn't sideward weight transfer bow the towers close together due to an excessive upward/inward force (normal force) on the outside tire?
Thanks for the info,
Kevin
In reference to a comment made earlier... are strut tower braces meant to counteract outward spreading of the towers or to simply connect the two for a static equilibrium (creating a fully closed box structure), where the brace would then have a compressive force on it?? ..or is it a little but of both??
Also... in hard cornering, wouldn't sideward weight transfer bow the towers close together due to an excessive upward/inward force (normal force) on the outside tire?Thanks for the info,
Kevin
11-14-2003, 01:07 AM
#18
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I've been looking for a strut brace for a while, I once had the Weltmeister bar, it barely fit and weighed a ton. For the price, weight, and strength I will go with KLA bar. Reno
11-14-2003, 03:00 AM
#19
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Unfortunately we must all endure the fact that all Porsche owners aren't mechanical engineers - what a mess that would make on this site!
KLA make one of the best products on the market, bar none (no pun intended)!
Ever thought why "Porsche" on this site is always "checked" as misspelled!
KLA make one of the best products on the market, bar none (no pun intended)!
Ever thought why "Porsche" on this site is always "checked" as misspelled!
11-14-2003, 03:17 AM
#20
Rennlist Junkie Forever
Honestly...
I wish someone would make a real strut brace... ie> a triangulated brace: strut tower-to-stut tower-to fire wall.
The first issue is that the upper stut mounts are rubber and will flex a TON more than the stut towers ever will. By far, the best strut tower brace is a set of camber plates.
The second thing is that to really stop strut tower movement, you have to secure them (the stut towers) to something else (the firewall usually) that isn't part of the chassis flex as both stut towers are moving in the same direction when cornering. Bolting the stut towers together, without the benefit of a triangulated brace or X brace, doesn't do much but ensure the strut towers move the same amount together.
TonyG
I wish someone would make a real strut brace... ie> a triangulated brace: strut tower-to-stut tower-to fire wall.
The first issue is that the upper stut mounts are rubber and will flex a TON more than the stut towers ever will. By far, the best strut tower brace is a set of camber plates.
The second thing is that to really stop strut tower movement, you have to secure them (the stut towers) to something else (the firewall usually) that isn't part of the chassis flex as both stut towers are moving in the same direction when cornering. Bolting the stut towers together, without the benefit of a triangulated brace or X brace, doesn't do much but ensure the strut towers move the same amount together.
TonyG
11-14-2003, 03:33 AM
#22
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David Ray
Not so. Many production cars have triangulated strut braces stock.
And... there's no reason not to have a triangulated strut brace.. street car or race car.
TonyG
Not so. Many production cars have triangulated strut braces stock.
And... there's no reason not to have a triangulated strut brace.. street car or race car.
TonyG
11-14-2003, 11:17 AM
#23
Burning Brakes
Originally posted by TonyG
And... there's no reason not to have a triangulated strut brace.. street car or race car.
And... there's no reason not to have a triangulated strut brace.. street car or race car.
I agree in a unlimited money, no rules world a triangulated strut brace is better.
11-14-2003, 11:33 AM
#24
Three Wheelin'
11-14-2003, 11:51 AM
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Tony,
The biggest misunderstanding about strut towers is that in a hard turn that both towers move in the same direction the same amount. This is not the case.
Actually when you look at the forces that are applied to the car during cornering, the towers are not loaded evenly and do not flex the same. When a car is turned many forces are applied to the tire in the outside of the turn that are not applied to the tire on the inside of the turn. The forces that are applied are deceleration and change in momentum. This causes the cars weight to shift forward and toward the outside of the turn. This is what racers refer to as car rotation. During the turn the car rotation exerts max loading onto the tire on the outside of the turn. Add to this the forces that are applied by a sway bar and they are very different. I have autocrossed my 930 and in some of the corners I have actually pulled the inside tire completely off the ground. So what happens is the towers are loaded very differently and the flex is concentrated in the tower on the outside of the turn. In most streetcars the strength of the two towers combined (if tied together) can maintain position without need for a cross brace. In a racecar it needs the triangulation.
Ken
The biggest misunderstanding about strut towers is that in a hard turn that both towers move in the same direction the same amount. This is not the case.
Actually when you look at the forces that are applied to the car during cornering, the towers are not loaded evenly and do not flex the same. When a car is turned many forces are applied to the tire in the outside of the turn that are not applied to the tire on the inside of the turn. The forces that are applied are deceleration and change in momentum. This causes the cars weight to shift forward and toward the outside of the turn. This is what racers refer to as car rotation. During the turn the car rotation exerts max loading onto the tire on the outside of the turn. Add to this the forces that are applied by a sway bar and they are very different. I have autocrossed my 930 and in some of the corners I have actually pulled the inside tire completely off the ground. So what happens is the towers are loaded very differently and the flex is concentrated in the tower on the outside of the turn. In most streetcars the strength of the two towers combined (if tied together) can maintain position without need for a cross brace. In a racecar it needs the triangulation.
Ken
11-14-2003, 11:57 AM
#27
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Kevin,
Where compression happens is when you are driving on an uneven road where one tire goes over a bump that the other tire does not. This causes my cars to dart around. One side bebefit I have found is that the car will dart back and forth less with the bar.
Where compression happens is when you are driving on an uneven road where one tire goes over a bump that the other tire does not. This causes my cars to dart around. One side bebefit I have found is that the car will dart back and forth less with the bar.
11-14-2003, 05:16 PM
#28
Rennlist Junkie Forever
Ken From KLA Industries
The 930 strut tower loading cannot be compared to the 951 strut tower loading, nor can the body twist be compared. You're talking apples and oranges here. Not only are the two cars night and day different structurally in every respect, the weight distribution is not even remotely the same. These two thing alone are enough to make the comparision a bad one.
And as I've said before... there is far far more strut displacement with the rubber upper mount than there ever will be, by huge margin, with the strut tower flex.
By tringulating the strut tower brace, neither strut tower will move in any direction. Problem solved.
The 930 strut tower loading cannot be compared to the 951 strut tower loading, nor can the body twist be compared. You're talking apples and oranges here. Not only are the two cars night and day different structurally in every respect, the weight distribution is not even remotely the same. These two thing alone are enough to make the comparision a bad one.
And as I've said before... there is far far more strut displacement with the rubber upper mount than there ever will be, by huge margin, with the strut tower flex.
By tringulating the strut tower brace, neither strut tower will move in any direction. Problem solved.
11-14-2003, 05:37 PM
#29
Three Wheelin'
Tony,
The triangulation that you are advocating addresses the axis that is of the least concern during cornering. Ken's bar addresses the axis that has the least amount of support, and the greatest force applied.
I agree that the stock strut mounts are a source of a significant amount of geometry change in the front of the 944 during cornering. Once these are replaced, the majority of the force is transferred directly to the top of the shock mounts. By far the largest component of this force acts in the direction that the bar spans. Any fore or aft movement of the shock towers is handled by the sheet metal that extends forward of and behind the shock tower into the firewall. The bar effectively distributes the load over the two shock towers, rather than requiring that the load be born by the single outer tower.
Once you start triangulating in the engine bay, you might as well start thinking about where to run the rest of the cage. Not very practical in a dual purpose car. And before you get to that point, you're going to want to start accounting for the movement that occurs due to the method of fastening the bar/bars to the sheet metal.
-J
The triangulation that you are advocating addresses the axis that is of the least concern during cornering. Ken's bar addresses the axis that has the least amount of support, and the greatest force applied.
I agree that the stock strut mounts are a source of a significant amount of geometry change in the front of the 944 during cornering. Once these are replaced, the majority of the force is transferred directly to the top of the shock mounts. By far the largest component of this force acts in the direction that the bar spans. Any fore or aft movement of the shock towers is handled by the sheet metal that extends forward of and behind the shock tower into the firewall. The bar effectively distributes the load over the two shock towers, rather than requiring that the load be born by the single outer tower.
Once you start triangulating in the engine bay, you might as well start thinking about where to run the rest of the cage. Not very practical in a dual purpose car. And before you get to that point, you're going to want to start accounting for the movement that occurs due to the method of fastening the bar/bars to the sheet metal.
-J
11-14-2003, 08:07 PM
#30
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Jon, great link... and Ken, thanks for the addition!
I have another question in regards to Tony's post: Extra members extending back to the firewall mostly resist fore and aft movement of the strut towers, and therefore resisting chassis flex on the axis of the wheel axles... correct? How does this translate into a far greater advantage in cornering than inward/outward flex of the towers? Fore and aft changes disrupt the castor of the wheel(s) but inward/outward flex screws up camber, toe (bump-steer) and a few other things.
Kevin
I have another question in regards to Tony's post: Extra members extending back to the firewall mostly resist fore and aft movement of the strut towers, and therefore resisting chassis flex on the axis of the wheel axles... correct? How does this translate into a far greater advantage in cornering than inward/outward flex of the towers? Fore and aft changes disrupt the castor of the wheel(s) but inward/outward flex screws up camber, toe (bump-steer) and a few other things.
Kevin