Interesting Cusco Article on Tower Bars
08-15-2007 | 08:20 PM
#21
Registered User
Joined: May 2003
Posts: 1,874
Likes: 0
From: Los Angeles/Orange County
yep, good evidence right there why the bars work. I'm a firm believer in the bars. i have the cusco ti front bar, and alex rear bar on my car, and they work great. theres another thread about strut bars, but there are many doubters.
08-15-2007 | 08:40 PM
#22
Registered User
Joined: Oct 2003
Posts: 990
Likes: 0
From: KCAI/Osaka
it's not that they are doubting what it does or if it does it, they are just saying that with the way the front suspension is designed the effect is negligible, but I can't say I agree with that.
there reasoning makes sense but it is not really focusing on the main point of using a STB in the first place I don't think, which is simply to reduce very slight chassis flex, which it can do, and can lead to slightly more travel in the shock.
like basically everything in this industry and in the motorsports world, just because it is very slight doesn't mean it is negligible.
with all the information that they laid out in that thread, I am still kind of confused why they think they would have no effect at all.
there reasoning makes sense but it is not really focusing on the main point of using a STB in the first place I don't think, which is simply to reduce very slight chassis flex, which it can do, and can lead to slightly more travel in the shock.
like basically everything in this industry and in the motorsports world, just because it is very slight doesn't mean it is negligible.
with all the information that they laid out in that thread, I am still kind of confused why they think they would have no effect at all.
08-15-2007 | 09:21 PM
#24
Registered User
Joined: Oct 2003
Posts: 990
Likes: 0
From: KCAI/Osaka
Originally Posted by trivium,Aug 15 2007, 10:58 PM
You are trying to sell the products you stock. DUH!
i highly doubt he is trying to "not" sell the products he stocks.
but it doesn't mean he doesn't believe in the effectiveness of these products, and he is actually providing info on their effectiveness instead of posting completely unbacked statements based on what he has read in a forum.
08-15-2007 | 09:29 PM
#25
Joined: Aug 2002
Posts: 28,136
Likes: 8
From: Seattle, Washington
borrowed from the other thread-
6-7% maximum. So yes, there is a difference BUT it is tiny at best and negligible at worst IMO...
That's not to say the bars see no horizontal force. There is still a horizontal force that is imposed where the coilovers mount to the body. The problem is, since the a-arms oppose the forces and moments created by the force between the wheel and the road (side note: this is the important difference between struts and double wishbone, the lower control arm of the strut could oppose the horizontal force by itself, but must instead rely on the strut mount to also provide a horizontal force to balance the moments), the only force the body sees at the coilover attachment is the force of the compressed spring.
The spring force on a car pulling 1g with 100% lateral weight transfer is going to be about the same as the cornerning force (with two wheels providing useful traction at 1g, each is seeing about half the cars weight in cornering force, and with 100% weight transfer, both outside spring will be compressed by, and therefore pushing back with, half of the cars weight). However, while the cornering force is horizontal, this force is mostly vertical. Therefore the horizontal force is only a component of the total force, equal to the sine of the angle of the mount (around 20%). In addition, this force is acting to flex the chassis over a moment arm that only extends from the top of the large engine bay cross brace to the top of the shock towers instead of from the bottom of the chassis to the top of the strut towers. In the end this means that the top of the towers are only seeing about 6-7% of the horizontal force they would have in a strut configuration.
The nail in the coffin is that now that this bending moment has had is fulcrum moved to the engine bay brace, any deformation doesn't even effect the suspension geometry. You'd not only be resisting a smaller bending moment, you'd be doing it for no useful purpose.
The spring force on a car pulling 1g with 100% lateral weight transfer is going to be about the same as the cornerning force (with two wheels providing useful traction at 1g, each is seeing about half the cars weight in cornering force, and with 100% weight transfer, both outside spring will be compressed by, and therefore pushing back with, half of the cars weight). However, while the cornering force is horizontal, this force is mostly vertical. Therefore the horizontal force is only a component of the total force, equal to the sine of the angle of the mount (around 20%). In addition, this force is acting to flex the chassis over a moment arm that only extends from the top of the large engine bay cross brace to the top of the shock towers instead of from the bottom of the chassis to the top of the strut towers. In the end this means that the top of the towers are only seeing about 6-7% of the horizontal force they would have in a strut configuration.
The nail in the coffin is that now that this bending moment has had is fulcrum moved to the engine bay brace, any deformation doesn't even effect the suspension geometry. You'd not only be resisting a smaller bending moment, you'd be doing it for no useful purpose.
08-17-2007 | 09:45 AM
#26
Thread Starter
Former Sponsor
Joined: May 2006
Posts: 16,133
Likes: 2
From: Chicago Burbs
Well i know our cars dont have "struts". Thats quite obvious. There is still some flex that comes in to play, all be it little because the S2k was designed so well from the get go. It still does have any effect on handling of the car.
so say that double wishdone cars dont need them as a blanket statement would be a bit out of line. Hell, even Honda engineers desided to put them on Si model EKs, and Type R's (both are double wish bone configurations)
so say that double wishdone cars dont need them as a blanket statement would be a bit out of line. Hell, even Honda engineers desided to put them on Si model EKs, and Type R's (both are double wish bone configurations)
08-17-2007 | 10:22 AM
#27
Registered User
Joined: Oct 2003
Posts: 990
Likes: 0
From: KCAI/Osaka
the point they were arguing in the other thread that due to the giant crossbeam that runs right through the engine bay, or whatever it is called, the suspension geometry won't be affected due to chassis flex in that area . becase the beam is basically directly supporting the main mounting points of the A-Arms of the suspension. which is completely correct.
so the suspension geometry will basically always stay very true, but my point was the shock towers ARE still going to flex a small amount unless they are reinforced in some way, because although that beam does provide quite a bit of support to the shock towers, i think they could still flex a small amount. it is a very small amount, but a little flex goes a long way in terms of whay it does to driving feeling and a slight increase or decrease in suspension travel.
again, it is small, welcome to the world of cars.
so the suspension geometry will basically always stay very true, but my point was the shock towers ARE still going to flex a small amount unless they are reinforced in some way, because although that beam does provide quite a bit of support to the shock towers, i think they could still flex a small amount. it is a very small amount, but a little flex goes a long way in terms of whay it does to driving feeling and a slight increase or decrease in suspension travel.
again, it is small, welcome to the world of cars.
