Ok, here is the deal, i am in school getting my race car performance/welding degree. I am about to begin production on an number of suspension bars (f&r strut bars, rear lower tie bars, etc) due to the lack of aftermarket support for good products at fair prices and that there arent any at all for many makes (ie preludes and such). I will of course be making them for the integras, civics, and all the usual makes also. But here is my question...for gsr/itr/si's there are two ways i could mount the bars, using the factory studs for the stock bars (itr/gsr/si) or from the strut tower itself. Now i will be producing bars for the other model integras and civics that do not have these holes...so i will have to make the bars that mount to the strut tower anyways. These two types of bars mount in close proximity to each other, so i am not positive on whether it will make that big of a difference, but if it comes to my attention that the bars that mount to the strut tower work better, i will only produce that model. The bars are still in the planning stages now, but i have gotten quotes on the flanges that will be cnc'd and for materials from different metal supply warehouses, so things should be coming together fairly soon. And if you have any suggestions and or questions concerning these bars, feel free to ask. TIA

I'm asking this forum bc you guys seem to know more in depth about suspension


Modified by MajorPayne at 5:36 AM 8/11/2004

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MajorPayne &raquo;</TD></TR><TR><TD CLASS="quote">Ok, here is the deal, i am in school getting my race car performance/welding degree. I am about to begin production on an number of suspension bars (f&r strut bars, rear lower tie bars, etc) due to the lack of aftermarket support for good products at fair prices and that there arent any at all for many makes (ie preludes and such). I will of course be making them for the integras, civics, and all the usual makes also. But here is my question...for gsr/itr/si's there are two ways i could mount the bars, using the factory studs for the stock bars (itr/gsr/si) or from the strut tower itself. Now i will be producing bars for the other model integras and civics that do not have these holes...so i will have to make the bars that mount to the strut tower anyways. These two types of bars mount in close proximity to each other, so i am not positive on whether it will make that big of a difference, but if it comes to my attention that the bars that mount to the strut tower work better, i will only produce that model. The bars are still in the planning stages now, but i have gotten quotes on the flanges that will be cnc'd and from different metal supply warehouses, so things should be coming together fairly soon. And if you have any suggestions and or questions concerning these bars, feel free to ask. TIA

EDIT: the reason im asking in this forum is that i believe you guys are more suspension oriented than many people in the other forums </TD></TR></TABLE>


Check out this thread, there is plenty of good info here.

https://honda-tech.com/zerothread?id=845799

 

thanks, that is some good info, i had read that thread before, just not in as much detail as i probably needed to. my thoughts on this subject are this...from decent amt of information i know about material strengths and suspension theory, i know it is relatively minute compared to many people, especially those that work for companies and do testing on bracing and other strength charictersitics of different vehicles or whatever the case may be. but the basic theories i have decided to base the bars on is this: 1. the straighter the bar, the less it will flex, perfectly straight being the best way to go imo 2. brackets for strut bars are overlooked many times and they themselves need to be braced (ie an "L" bracket needs lateral support in order for it not to flex or flex as little as possible (no flex being best of course) 3. the straight tube of any such strut bar needs to be attached to a bracket as close to the mounting points as possible, to reduce "possible flex" whether it would happen or not. using these guidelines i believe i can produce bars that will perform well, bc that is priority number one
Another topic that comes up quite frequently is what shape and diameter tubing should be used, as well as what material. My personal opinion (feel free to chime in as i know that there are people who know more about this than i do) is that a round tube will result in the least flex theoretically, when measured against other shapes of the approx same size and thickness, so a round bar is going to be what i will be using. Also mild steel is going to be my first option as far as a material goes, due to the fact that it is easier to weld, and has very good strength characteristics. One problem that will be a concern is the weight of the mild steel in comparison to aluminum. I have taken this into account, and me along with some help from my uncle (a civil engineer) will decide what will be the lightest as well as the strongest diameter/thickness to use and have take up as little space as possible without sacrificing stability. If anyone thinks that they would be very beneficial to my design and production process would like to talk to me personally just let me know, and i will not let your help go unnoticed or unawarded

 

anymore input??

 

You make some excellent points. Especially regarding the mounting brackets. Lets face it, some of (maybe most of) the commercially available strut tower braces are bling, and little else (a good example: the Cusco titanium brace that weighs less than 2 lbs). I think titanium is an awesome material of which I have many parts on my bicycle that are made from it, but most of the stuff on a car can be made from well-engineered aluminum or steel. The tower brace is no exception, and in addition, the parts made from these two materials won't have to break the bank.

Cross-bar Engineering:

Yes, it best to run the cross-bar as straight as possible so that the lateral (from one tower towards the other) load does not induce a bending load into the cross-bar assuming that the cross-bar ends have spherical bearing(s). This applies even if you have to make the end brackets tall so that the straight cross-bar is slightly above the valve cover or intake manifold. Engineer the vertical brackets that extend from the shock/strut tower mounting plates as stiff as possible since they are in bending. However, sometimes clearance issues may make it extremely, if not impossible, to make the cross-bar straight. If the cross-bar is bent, then you need to be very careful about the cross-sectional shape and size of the cross-bar.

Material: A good resource for material properties is http://www.matweb.com.


I believe that the cross-bar can be made from aluminum, 4130 steel, as possibly 1010 through 1020 Mild steel. If you weld the aluminum (assuming 6061 alloy) or the 4130 Chromoly, you need to heat treat after the weld is complete to regain the ductile crystal structure that was transformed by welding. Mild steel does not need to be heat treated after welding, but it's strength properties are far smaller than those of both the 6061-T6 or the 4130 Chromoly. Therefore, the mild steel part may need to be slightly heavier than the 6061 or 4130 piece.

Cross-sectional shape of the tubular cross-bar:

Round sections are best if the bending can be along any random axis in the tube. At the same time, the buckling strength is optimized with a round section. If you make the cross-bar straight, then this becomes a buckling problem if the ends of the cross-bar are attached to the brackets using spherical bearings (rod-ends).

Anyhow, hopes this helps.

 

JM, your posts have been very informative and seem to reinforce some of my concerns as well as ideas. Could you elaborate a little more on the last section of your post under "cross sectional shape...", i think i understand what youre saying, i just want to get it as clear as possible

 

I was referring to the slice or section of the tube - assuming that you want to use a tube section as opposed to a solid section. The tube sections can be commonly found in round, square, or rectangular shapes.

 

i know what cross sectional shape itself refers to (if i didnt i dont think any design or engineering should be in my daily life lol), what i meant was what do you mean in this paragraph you wrote, specifically dealing with how the round sections would be best if bending along any random axis, and also how it becomes a buckling problem if attached to the brackets using spherical bearings. Thanks, I appreciate your help btw

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Johnny Mac &raquo;</TD></TR><TR><TD CLASS="quote">
Cross-sectional shape of the tubular cross-bar:
Round sections are best if the bending can be along any random axis in the tube. At the same time, the buckling strength is optimized with a round section. If you make the cross-bar straight, then this becomes a buckling problem if the ends of the cross-bar are attached to the brackets using spherical bearings (rod-ends).

</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MajorPayne &raquo;</TD></TR><TR><TD CLASS="quote">i know what cross sectional shape itself refers to (if i didnt i dont think any design or engineering should be in my daily life lol), what i meant was what do you mean in this paragraph you wrote, specifically dealing with how the round sections would be best if bending along any random axis, and also how it becomes a buckling problem if attached to the brackets using spherical bearings. Thanks, I appreciate your help btw

</TD></TR></TABLE>

Round sections have the same second moment of area (moment of inertia) about any diameter. Buckling, which is derived as a bending problem, will occur about the section of lowest bending stiffness. Since round sections have the same moment of inertia about any diametral axis, then there is no preferred axis about which the buckling will occur. Not so with rectangular sections, the buckling will occurs about an axis aligned with the large dimension since this is the axis of lower moment of inertia.

Spherical ends do not induce a bending moment into a straight cross-bar, therefore, the load is directed from the center of one spherical end to the other spherical on the other end. Therefore, the load in a straight bar is axial only. If there is any bending in this section in addition to the axial load, the buckling problem needs to be altered to account for this. So, even if you do not use a straight bar, or sphericals, you can still calculate the strength of your cross-bar. It is just that it's easier to calculate the strength for a straight bar.

 

anymore input, especially good stuff like Johnny Mac has posted, would be greatly appreciated

 

just a thought, i had clearance issues with my front ucas when using a benen 3pt front strut bar that mounts in factory locations. the bolt heads protruded into the wheelwell enough to contact the skunk a-arms and damage/colapse the slider.



also, removing the strut bars that mount there is more difficult b/c the car must be jacked up to reach the bolts... i would suggest a strut tower mount location that uses the existing shock bolts such as the carbing 3pt, if you manufactered a tubular aluminum bar that mounting like the carbing but also allowed for clearance of the brake MC (for cheaper) i think you would have something.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by euclid &raquo;</TD></TR><TR><TD CLASS="quote">i would suggest a strut tower mount location that uses the existing shock bolts </TD></TR></TABLE>

Dont you mean UCA bolts?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">

Dont you mean UCA bolts?</TD></TR></TABLE>

no the front shock bolts





this benen bar mounts in stock location with seperate bolts

 

don't forget the thrid option. UCA bolts like neuspeed uses

1-stock
2-Shock
3-UCA

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by euclid &raquo;</TD></TR><TR><TD CLASS="quote">
also, removing the strut bars that mount there is more difficult b/c the car must be jacked up to reach the bolts... i would suggest a strut tower mount location that uses the existing shock bolts such as the carbing 3pt, if you manufactered a tubular aluminum bar that mounting like the carbing but also allowed for clearance of the brake MC (for cheaper) i think you would have something.
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yes, using the existing shock bolts as the carbing bar does seems to be the best idea, i like it better than the existing stock strut bar bolts for 2 reasons (1) the bolts are bigger and less prone to any kind of bending or breakage (2) they are bolted to both shocks and help them stay a relative distance apart (in theory anyhow) One problem now is that the bar would not be aluminum, as i do not have the necessary welder for that at this time, i have access to one, so i could possibly go ahead and start working on one, but it would be a while before it was actually offered. I dont see any problem with the bars being mild steel. I will be able to make them smaller diam and thickness than the alum bars and still retain thier strength qualities. And i will be powdercoating them to the buyers preference from a list of colors that is not determined yet, as well as leaving them raw for the buyer to do whatever they want to them

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by euclid &raquo;</TD></TR><TR><TD CLASS="quote">

</TD></TR></TABLE>

this will be my basic layout of the bars, with some differences of course. First of all I will offer two bars, one that is a two point and one that is a three point, just as carbing offers two different styles. Also, mine will be using round tubing rather than oval, due to the fact that round may not be as pretty, but for use in an application where it is not bent, as the carbing bar is above from each shock to the other in a straight line, round is best (the theory being that round tube in a straight line will transfer the load directly from one end to the other, and not tend to bend or buckle, Johnny Mac touched on this earlier)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drkarrow &raquo;</TD></TR><TR><TD CLASS="quote">don't forget the thrid option. UCA bolts like neuspeed uses

1-stock
2-Shock
3-UCA

</TD></TR></TABLE>

The thing that bugs me about this design is not where it attaches to the body, i think they had a good idea with that, however, being such a thin diameter tube and being bent at such an angle in two places, the structural integrity is compromised. If you put two integras in big car compactors that squeezed from the side, one integra having the carbing, one having the neuspeed, and you watched the bar as the car compactor squeezed (which in theory is just the extreme case of what happens when a car is experiencing gravitational pull, thus the compression or tension btw those two points) I have no doubt you would see the neuspeed bar bend first and finally buckle, where the carbing bar will likely not bend, but eventually will buckle, but it will take much longer, this is my opinion however, but i am talking to some material engineers in addition to my uncle, and they seem to agree, that i would rather have no bends, and only 90 degree welds if possible, that can be braced themselves. Thanks for the input guys

 

from my use, neuspeed bar does the job quite adequately. carbing unit looks way overkill. im not doubting its a "better" concept, but theres also cost of mfg and design issues.

and i dunno why on later bars neuspeed uses the UCA points. EF/DA models use the shock bolts. the bend is a little less.

 

the thing is, if you want to design something to work as well as possible, for it to be as good a product as possible you want to consider every aspect of it and possible thing that needs to be engineered correctly. if that makes any sense. idk, my theory is just that you shouldnt only do enough to get by, do everything possible to ensure you reach your goal...i will say this though, the bar i make will be better engineered than the neuspeed bar, and likely cheaper in price too

 

anymore input?

 

i had mugen front bar at first, it was a 2point, i was sceptical about switching to the benen 3pt but it was cheaper finacially and i read good things... anyway it did make a difference over the 2point, placebo or reality im not sure.

weight is also a factor, the benen bar i have is like 12lbs, im pretty sure the aluminum carbing is less than half that, you should consider that aspect as well, 5+ lbs in such a high location its enough for me to eventually buy an aluminum bar and sell the benen which is painted chromoly.

 

yeah the weight is going to be something that im going to have to work around a little, i will be making these out of aluminum, thats just going to take some time, i havent decided yet as to whether or not ill make a 3 point to start out with in the mild steel, i am kind of leaning towards making just to 2 point to start out and see what the response is, then go from there, but i should be getting things moving along this week, just have to do some material selection

 

good luck

if you have access to materials or machinery or whatever you should consider forged or machined aluminum front lcas that accept factory swaybar.

competition engineering make chromoly lcas for drag racing use that save a combined 24lbs and use spherical bearings instead of bushings. but they are not strong enough for lateral force and have no swaybar mount holes. many OEM perfomance cars have aluminum suspension components, honda should have thrown us a bone and did special application for the type-r or somehting.

one design/size will work on all 94-00 integra and 92-00 civics, thats a big market.

 

yeah that is a very good point and something i will consider, as i do have access to a fair amount of machinery, actually though time is the thing that will be the problem, but since you brought it up, if anyone has a spare front lca lying around and would want to send it my way, i could talk to the machine shop and get some more materials quotes

 

up for suggestions...also, i am def considering making the machined alum front lca's, just need to do a little more research on it and try some things out

 

How much good does strut braces do on a double A arm setup? I was under the impression its more for a McPherson strut setup, as the shock on a double A arm only mounts to the top, it doesn't act as a strut.