Misconceptions about Strut Tower Braces (Addressed!)

[Dr. Design]

Hello All,
We have noticed that there are a few different thoughts as how the rear strut tower brace works on the EP3.

For starters some feel that the brace that goes underneath the carpet works pretty good. Well if you look at where it is mounted you will notice that there is a rather large bulkhead already there. So you are theoretically adding something that is already there. Since the point that you are trying to stop flexing is higher up on the strut towers you are not doing what was meant to do.....Stop the flexing.

Picture two sticks connected at the bottom. Squeeze the top of the sticks that are not mounted together (should look like a U). What happens?? The two ends move toward each other very easily. Now take those same sticks that are connected at the bottom and put another stick in the middle of them about half way up (should look like an H). Now, try to squeeze those together and what happens? You have a really hard time trying to get those two ends to meet this time? YES. You have placed the brace in the correct location. The pivot point has now been moved to a shorter piece.

That simple test should show you that when attempting to brace something you have to keep in mind what you are trying to accomplish. Your mounting points are very important and could be the difference from 1st and 2nd place on that racetrack. Some people feel that a Strut bar is a strut bar, there is no difference. They all do the same things. However in theory they all do the same thing. However in the world that we live in (Reality) they tend to do different things. There are a lot of key factors that will allow flex in the design:

If a strut bar (or any bar) has tie rod ends = IT ALLOWS FLEX
If a brace uses adjustments = IT ALLOWS FLEX
If a brace uses bolts for mounting = IT ALLOWS FLEX
If a brace is mounted via welding = SIGNIFICANTLY LESS FLEX
If a brace uses triangulation = SIGNIFICANTLY LESS FLEX
Brace is used in the correct location = SIGNIFICANTLY LESS FLEX
If a brace uses inferior material = IT ALLOWS FLEX

Thank you,

[Jpax]

Amen...... :)

[SiR Medic]

Explain to me, please, just how much do we neen a strut tower bar in the first place?

Is our chassis such a limp noodle that, without a 30lb adamantium strut bar, our wheels are free to flex willy-nilly all over the place?

I have always thought that the advantages of a strut-tower bar are dubious at best. Has anyone ever done comparison skidpad tests with and without strut bars? Slalom tests?

The main reason behind strut-bars, as far as I can see, is looks. We may convince ourselves that they make a difference, but to they even come into play during highway driving?


Please explain how a strut bar actually works.

Why do I need chassis reinforcement?

Why do I need so much?

Does a cheap strut-tower brace offer NO benifit?




Please help this (admittedly) un-mechanically inclined individual to understand.

P.S. I did take one year of Engineering in university, so I do understand the concept of moment of force, vector mechanics, etc. So don't go easy on me!:)

[Dr. Design]

Hello,
The best way to explain this would be to use an analogy. Picture a cardboard box without the lid. You can see how much it moves around if you try twisting it. The amount of flexing is easily seen. Now if you put the lid on the box and try to flex it, you will still notice adequate amounts of flexing. So if you apply a large brace that goes to one side to the other, then there is less flex. Obviously there is much more to that then what was just stated. The original post explains the rear strut tower brace. Now we will focus on the front.

The shock towers are NOT designed to stay stationary. If that was the case Honda would of built it with a factory front strut tower brace. But as a result it would raise the price of the vehicle. So with that being said.... Most strut tower braces neglect to attach to the firewall (strike one!). Why is it important to attach to the firewall?? If a straight brace attaches to each strut tower what is to keep them from moving together now? NOTHING. The firewall is stationary. Its funtion is does not include moving. It acts as the perfect anchor keeping the strut towers from moving as a group. So if you attach it to the firewall you have created three attachment points(triangulation). This is why it must attach to the firewall if you are looking for function. If it does not attach to the firewall it is simply a shinny bar for show.

It is not that the EP3 is a limp noodle. It is a hatchback (strike one!). It has long doors (strike two). These are built in reasons of why the car is not a factory racecar. Bottom line. It is real expensive to build a car that is designed to handle well from the factory. So they have to cut corners and that usually starts with the chassis. Remember it is a passenger car, not a racecar. So it will have certain drawbacks from the factory.

As far a singled-out test of how the strut bars perform on the skid pad. A good strut tower brace is not designed to be a cure all for a poor performing suspension. It should be used in conjunction with other suspension mods to achieve the best results. Chassis bracing will strengthen the chassis allowing the suspension to do what it is supposed to do.

At high speeds it is also very important to have the chassis neutral as can be. We cannot express how important it is to keep all four wheels firmly planted at 130 mph! We have quite a few guys that exclusively use chassis bracing in thier racecars. They will tell you how important it is to have a flex free chassis at high speeds.

Most cars are designed to have a certain tolerance of flex through out the car. This is what will make it comfy. This is also the same reason the cars do not handle as well as they could be. Not everyone will race thier cars through twisty canyon roads. So if you would like to make your car handle better, then your answer is simple.
Does the EP3 need strut braces?
Yes!

Please let us know if you have any other questions.
Thank you,




Originally posted by SiR Medic
Explain to me, please, just how much do we neen a strut tower bar in the first place?

Is our chassis such a limp noodle that, without a 30lb adamantium strut bar, our wheels are free to flex willy-nilly all over the place?

I have always thought that the advantages of a strut-tower bar are dubious at best. Has anyone ever done comparison skidpad tests with and without strut bars? Slalom tests?

The main reason behind strut-bars, as far as I can see, is looks. We may convince ourselves that they make a difference, but to they even come into play during highway driving?


Please explain how a strut bar actually works.

Why do I need chassis reinforcement?

Why do I need so much?

Does a cheap strut-tower brace offer NO benifit?




Please help this (admittedly) un-mechanically inclined individual to understand.

P.S. I did take one year of Engineering in university, so I do understand the concept of moment of force, vector mechanics, etc. So don't go easy on me!:)

[chunky]

Originally posted by Dr. Design
Hello,
The best way to explain this would be to use an analogy. Picture a cardboard box without the lid. You can see how much it moves around if you try twisting it. The amount of flexing is easily seen. Now if you put the lid on the box and try to flex it, you will still notice adequate amounts of flexing. So if you apply a large brace that goes to one side to the other, then there is less flex. Obviously there is much more to that then what was just stated. The original post explains the rear strut tower brace. Now we will focus on the front.

The shock towers are NOT designed to stay stationary. If that was the case Honda would of built it with a factory front strut tower brace. But as a result it would raise the price of the vehicle. So with that being said.... Most strut tower braces neglect to attach to the firewall (strike one!). Why is it important to attach to the firewall?? If a straight brace attaches to each strut tower what is to keep them from moving together now? NOTHING. The firewall is stationary. Its funtion is does not include moving. It acts as the perfect anchor keeping the strut towers from moving as a group. So if you attach it to the firewall you have created three attachment points(triangulation). This is why it must attach to the firewall if you are looking for function. If it does not attach to the firewall it is simply a shinny bar for show.

It is not that the EP3 is a limp noodle. It is a hatchback (strike one!). It has long doors (strike two). These are built in reasons of why the car is not a factory racecar. Bottom line. It is real expensive to build a car that is designed to handle well from the factory. So they have to cut corners and that usually starts with the chassis. Remember it is a passenger car, not a racecar. So it will have certain drawbacks from the factory.

As far a singled-out test of how the strut bars perform on the skid pad. A good strut tower brace is not designed to be a cure all for a poor performing suspension. It should be used in conjunction with other suspension mods to achieve the best results. Chassis bracing will strengthen the chassis allowing the suspension to do what it is supposed to do.

At high speeds it is also very important to have the chassis neutral as can be. We cannot express how important it is to keep all four wheels firmly planted at 130 mph! We have quite a few guys that exclusively use chassis bracing in thier racecars. They will tell you how important it is to have a flex free chassis at high speeds.

Most cars are designed to have a certain tolerance of flex through out the car. This is what will make it comfy. This is also the same reason the cars do not handle as well as they could be. Not everyone will race thier cars through twisty canyon roads. So if you would like to make your car handle better, then your answer is simple.
Does the EP3 need strut braces?
Yes!

Please let us know if you have any other questions.
Thank you,





About the comment that implies strut tower bars that do not triangulate are useless. . .

The primary purpose of a strut tower bar is to keep the tops of the strut towers from moving IN. that is from going from | | to | \ around a turn. It keeps them in proper alignment with respect to one another to maintain consistent camber, toe, etc while cornering. A bar that simply joins the two towers CAN have a positive effect on handling. HOWEVER, triangulation is the best way, as it keeps the towers not only from moving in a lateral direction, it also prevents twisting. Any good strut bar must have at least three distinct mount points.

and as for the percieved effects of a strut bar - you will get sharper turn in, mor consistent suspension motion through turns resulting in better predictability through a turn.

IMO the front strut bar has the greatest impact. the rest are not as important for the weekend racer - they mostly come into play during high speed driving. The front strut bar's impact is felt every time you take a corner, wether it be at 30mph or 60mph

[Jpax]

So when can we buy the Dr Design strut bar?

[SiR Medic]

Originally posted by chunky


About the comment that implies strut tower bars that do not triangulate are useless. . .

The primary purpose of a strut tower bar is to keep the tops of the strut towers from moving IN. that is from going from | | to | \ around a turn. It keeps them in proper alignment with respect to one another to maintain consistent camber, toe, etc while cornering. A bar that simply joins the two towers CAN have a positive effect on handling. HOWEVER, triangulation is the best way, as it keeps the towers not only from moving in a lateral direction, it also prevents twisting. Any good strut bar must have at least three distinct mount points.

and as for the percieved effects of a strut bar - you will get sharper turn in, mor consistent suspension motion through turns resulting in better predictability through a turn.

IMO the front strut bar has the greatest impact. the rest are not as important for the weekend racer - they mostly come into play during high speed driving. The front strut bar's impact is felt every time you take a corner, wether it be at 30mph or 60mph


Thanks for clearing this up Chunky! It seems to me that, yes, if you do intend to seriously race your car, beefy chassis stiffening is needed.

But for regular day-to-day use, more modest applications are all all that is needed.


Dr. Design, I also appreciate your explanation. It would seem as though I don't quite require one of your mondo products... Yet;)

[william]

For starters some feel that the brace that goes underneath the carpet works pretty good. Well if you look at where it is mounted you will notice that there is a rather large bulkhead already there. So you are theoretically adding something that is already there. Since the point that you are trying to stop flexing is higher up on the strut towers you are not doing what was meant to do.....Stop the flexing.


If you look at the bar mentioned above you'll see that it and every other bar out there must mount to the same strut bolts, you cant mount them higher because the strut bolts are the highest point. Also the above bar is mounted to two additonal mounting points, which would improve its rigidity. In my opinion, the bar that goes under the carpet "mr. alex" is the best one currently out there.

[Dr. Design]

Hello,
The bar that you are talking about is a good example. The mounting points are one the strut tower. However there really are no strut towers there. There is the body structure that needs to be supported that the bar you are talking about does not address. The shock towers are really short and is supported by the floor. There is also a large bulkhead that is in front of where the bar would be located. This is also a good example of over engineering something. Overkill is not always a good thing.

"Picture two sticks connected at the bottom. Squeeze the top of the sticks that are not mounted together (should look like a U). What happens?? The two ends move toward each other very easily. Now take those same sticks that are connected at the bottom and put another stick in the middle of them about half way up (should look like an H). Now, try to squeeze those together and what happens? You have a really hard time trying to get those two ends to meet this time? YES. You have placed the brace in the correct location. The pivot point has now been moved to a shorter piece. "
That is the best way we can describe it.
Notice where the D3 brace is located. Notice the difference?
Thank you,



Originally posted by william



If you look at the bar mentioned above you'll see that it and every other bar out there must mount to the same strut bolts, you cant mount them higher because the strut bolts are the highest point. Also the above bar is mounted to two additonal mounting points, which would improve its rigidity. In my opinion, the bar that goes under the carpet "mr. alex" is the best one currently out there.

[SiR Medic]

Unfortunately, they brace you have pictured is simply NOT an option for many of us.

Part of the reason for buying the EP is its utility... That brace pretty much puts the brakes on using the rear seat pass-through, which is one of the big reasons for me buying a hatchback in the first place.

[william]

do you have any pics of where that bar mounts to the chassie?

[Quicksilver]

I've gotta agree with Sir Medic on this. The rear upper brace just isn't practical for everyday use. By the looks of some of the welds, it looks like you have to weld it into place or is it a bolt-in?

As for the front strut tower brace, did you change you design on it where it connects to the firewall? On your website it looks like you've got two different designs, one that has a small connector to the firewall and another that runs about 1/2 of the firewall. Do both of these require drilling holes in the firewall or do they use existing holes? Do they require any welding for installation?

Thanks,
Kurtis

[Dr. Design]

Hello,
The picture of the RSTB-C is bolted in using factory bolts and holes. We felt that you may sacrifice cargo space, but we did not want to compromise the performance, since that doesn't coincide with our performance guarantee.

AS far as the front strut tower brace. Attached is a picture of the production FSBT-C. During R&D we found that this design is much better then the first one. This brace also is a complete bolt on. No drilling with any of our kits!
Please let us know if you have any other questions.
Thank you,



Originally posted by Quicksilver
I've gotta agree with Sir Medic on this. The rear upper brace just isn't practical for everyday use. By the looks of some of the welds, it looks like you have to weld it into place or is it a bolt-in?

As for the front strut tower brace, did you change you design on it where it connects to the firewall? On your website it looks like you've got two different designs, one that has a small connector to the firewall and another that runs about 1/2 of the firewall. Do both of these require drilling holes in the firewall or do they use existing holes? Do they require any welding for installation?

Thanks,
Kurtis