Topic: Front brace types comparison, cross-bay, ladder, DDM, Werks, LatinVenom

[kennysabarese]

There are a few different front suspension braces available. I will try to collect as much reference information in the first post as possible for historical reasons. If you think there is something that should be added here, send it to me and I'll put it up.

DDM Cross-Bay brace: http://ddmworks.com/sky/suspension/cross_bay_brace.html
Werks: http://www.performanceautowerks.com/catalog/product_info.php?cPath=334_165_216&products_id=1697
LatinVenom: http://www.kappaperformance.com/forum/index.php?topic=5206.0

In the diagram below (thanks TomatoSoup!), the red indicates the DDM brace, the blue for LV's brace, the Werks brace is further towards the front of the car than LV's according to this post http://www.solsticeforum.com/forum/f102/front-frame-braces-63378/#post961854

[attachment=1]

Discuss away!

[kennysabarese]

I wanted to keep my opinions in a separate post. So here we go:

Traditionally a tower brace is used with a MacPherson strut type suspension since the top of the strut is used for locating the wheel instead of a second wishbone. Our car which is double-wishbone, has the wishbones for locating the wheel and determining where it moves and the shock is solely for damping, there is little, to no, lateral force on it, just up and down. Also notice, that the top of our shock is mounted pretty much directly to the frame! So I don't think shock movement is that big of a concern. That's a really solid spot!

So after this you may think that the DDM part is completely pointless, it's not doing what a traditional tower brace does, because our car doesn't NEED a tower brace!

That being said, the DDM brace creates an O shape where there is a U shape on the chassis. I think that this probably helps the chassis frame rails from moving up and down, or twisting. It just happens that they used the shock tower points for mounting since there is no other place to do this. I think this may be why they don't call the product a tower brace, it's performing a different function than other products called that.

On Werks and LV's brace, or "ladder" style braces. To me these seem less likely to prevent twisting of the chassis given they just go straight across. They would be more effective at keeping the frame rails from moving towards or away from each other on a horizontal plane. But between the under engine brace and the front bumper, I think it could be redundant.

That being said, I trust Werks and LV when they say that there is a positive effect in handling.

Both of those things being said, if you are competitive, these parts may make you have faster lap times, but the weight of them may cancel that out. But if you are not competitive, and they make your driving feel better, get all of them and enjoy!

[snaponbob]

The DDM unit is very light. I would assume that the other two braces are light as well. If one is a solid tube versus a hollow tube, the hollow will be stiffer, but I can't imagine that they are solid. An extra 5-7 pounds will not degrade times as much as the chassis stiffness will help improve times. In my case, the DDM is the only class legal solution, and that should be a concern for anyone that is racing in a class structure - SCCA or NASA.

[TomatoSoup]

OK, So I'll move my enquiry here as to whether having both DDM's and LV's would pass the point of diminishing returns...

Kenny, you said that the Werks brace is in the same location as LV's, but my understanding was that it was further forward than that (based on this: http://www.solsticeforum.com/forum/f102/front-frame-braces-63378/#post961854 ).  I think that LV's is fulfilling much the same role as DDM's and that's why I'm wondering if both are worth it.

Don't get me wrong, I think LV's design is simple, elegant, easier to install (no d*mn PS can relo) and above all, cheaper!  But I already have the DDM one and have been through the install pain

I think either one would be good.  But both? I'm guessing not really required, unless LV's brace would help with lateral expansion flex between the rails over and above DDM's.  But even then, how much would that be noticeable?

All (intelligent) responses welcome.

[Kelu]

Kenny: some explanations about struts and double-wishbone? Maybe pictures?

[kennysabarese]

Kenny: some explanations about struts and double-wishbone? Maybe pictures?

This is not the thread to teach people about the different types of suspensions. Sorry.

[kennysabarese]

Kenny, you said that the Werks brace is in the same location as LV's, but my understanding was that it was further forward than that (based on this: http://www.solsticeforum.com/forum/f102/front-frame-braces-63378/#post961854 ).

Updated the main post with this info. Thanks.

[LatinVenom]

Let me start by saying the Werks brace is not really forward it appears that way but it is not.
The problem with their brace is the design, it tries to accomplish the U but it makes it harder to install. It needs to be install by a professional because of the design.
Our cars DO NOT HAVE A SHOCK TOWER. If you look at Kenny's drawing you will see, as he points out the shock is mounted directly to the frame.
My Kappa Front Chassis Brace uses a hallow tube design 1" in size. It also uses the chassis rail with a side ways T to capture or close the U.
My Kappa Front Chassis Brace is a SOLID PIECE with no moving parts, that lucks the front chassis rails.
The thing that I find troublesome to the DDM design, is their use of BOLTS to secure the upper part of their brace. You will need to check them periodically to see if they have loosen any.
I understand in the case of the SCCA you MUST use theirs.
The best way to check and see if there are differences or advantages is to have Tomatosoup test the differences.
All he needs to do is remove the upper part of the DDM brace and install mine.

[TomatoSoup]

The best way to check and see if there are differences or advantages is to have Tomatosoup test the differences.
All he needs to do is remove the upper part of the DDM brace and install mine.

Gee thanks, LV!

I was hoping to not have to do that  

[LatinVenom]

By the way if you find it that both braces are redundant, then have one of the folks in the new waiting list get it from you.

[Sly Bob]

Gee thanks, LV!

I was hoping to not have to do that  

Oh come on TomatoSoup, take one for the team!  

[Dave@DDMworks]

Let me start by saying the Werks brace is not really forward it appears that way but it is not.
The problem with their brace is the design, it tries to accomplish the U but it makes it harder to install. It needs to be install by a professional because of the design.
Our cars DO NOT HAVE A SHOCK TOWER. If you look at Kenny's drawing you will see, as he points out the shock is mounted directly to the frame.
My Kappa Front Chassis Brace uses a hallow tube design 1" in size. It also uses the chassis rail with a side ways T to capture or close the U.
My Kappa Front Chassis Brace is a SOLID PIECE with no moving parts, that lucks the front chassis rails.
The thing that I find troublesome to the DDM design, is their use of BOLTS to secure the upper part of their brace. You will need to check them periodically to see if they have loosen any.
I understand in the case of the SCCA you MUST use theirs.
The best way to check and see if there are differences or advantages is to have Tomatosoup test the differences.
All he needs to do is remove the upper part of the DDM brace and install mine.

That is why we ship the braces with crimp top lock nuts

LV - I was modeling up what I think you are doing for your brace in CAD and was wondering if you are only using the single bolt on each side for attachment? Also are you attempting to make an interference fit to the frame rails on each side? Thanks, just want to run some simulations on it

Dave

[LiquidPT]

Kenny: some explanations about struts and double-wishbone? Maybe pictures?

This might help: http://auto.howstuffworks.com/car-suspension.htm

[LatinVenom]

That is why we ship the braces with crimp top lock nuts

LV - I was modeling up what I think you are doing for your brace in CAD and was wondering if you are only using the single bolt on each side for attachment? Also are you attempting to make an interference fit to the frame rails on each side? Thanks, just want to run some simulations on it

Dave

Dave,

It also uses the chassis rail with a side ways T to capture or close the U.

Maybe I did not make myself clear.
There are a total of 4 bolts that are part of the Kappa chassis rails.
I posted a picture of the Kappa frame and circled the area where the 2 bolts are located on each side.
I had mine in the car for about 3 months with no issues.
The prototype on my car can not compare to the final production model.
The fabricator making it, uses a CNC plasma cutter to make the parts.
Dave,
I really do not want to compete with you guys, it also goes the same for Werks.
However neither one of your products fit my criteria, yours requires for the OEM engine cover to be replace, a NO in my book.
Werks had the correct idea, but I think he over designed to be able to price it where he did.
I honestly do not know why he did it that way, it looks to much like the front sway bar.
Also if you do some simulation with CAD you would need a little more info than just how it is secure to the rails.
You would need the pipe size which I have already disclose as been 1" or the same size as the front sway bar.
Then you would need the geometry of the sideways T and it thickness. Let's just say it is a lot thicker than the one use by WERKS.
One last thing you would also need to know where the pipe connects to the side ways T.

[old goat]

My grandpa used to say there is more than one way to skin a cat. I like options, I like options a lot.

[GXPinKC]

My grandpa used to say there is more than one way to skin a cat. I like options, I like options a lot.

I as well old goat.  Pick and choose!  That is the American way, and it is good to share input that helps clarify the issues of this thread.  Then those who are undecided can make an appropriate decision.

Thanks Kenny for beginning this thread.  Very informative indeed! 

[Gentleman Jack]

Is there a standard test in the industry to test the results of theses chassis stiffeners?  There are hundreds of them on the market for thousands of different cars / trucks.  Surely someone has come up with a way to test the effectiveness other than the simple "butt" test?  Some of us like quantitative data to evaluate...

[LatinVenom]

In our case you could have one of our best AutoX driver test them on the same circuit.

[Critterman]

Come on TS there is only a few bolts to remove from the top of the brace

[kennysabarese]

Is there a standard test in the industry to test the results of theses chassis stiffeners?  There are hundreds of them on the market for thousands of different cars / trucks.  Surely someone has come up with a way to test the effectiveness other than the simple "butt" test?  Some of us like quantitative data to evaluate...

If you saw the Hot Rod Magazine V8 Solstice project, GM used CAD programs and whatever software they use to design cars to find the weak spots and strengthen them. I am not sure if any old CAD program is able to do things like this, or if the software that can do it are priced out of the range of most parts makers. But that would be the most realistic way to have an industry wide test afaik.

DDM has done a test for the Backbone where they measure flex based on how much the 4 corners move when you jack up the car.  Not sure if that test would apply much here.

[kennysabarese]

Hey does anyone know if GM added any strength to the front of the chassis when doing the Hot Rod Solstice project? That would be a good indicator if it was necessary.

I know they put a plate style support in the passenger footwell, where the fusebox is.

[GXPinKC]

The Hot Rod used a 7 liter Corvette V8 and it was rated at 585 bhp  I believe the install also included a T56 six speed transmission from a Chevy SSR as well as a Cadillac CTS-V rear axle.  Yes, there is quite a write up on pages 106, 107, and 108 in "The Pontiac Solstice Book"  written by Gary Witzenburg.

[Critterman]

Dave uses a CAD program to design his products, I believe he can run some tests on the design

[kennysabarese]

Dave uses a CAD program to design his products, I believe he can run some tests on the design

Yeah, but I'm wondering if he apply forces to different parts of the car in the software to see if how much the braces reduce flex.

[Sol Asylum]

In order for Dave to do an FEA (finite elemental analysis) he is going to have to have a pretty complete CAD model of the car.  Which I doubt anyone outside of GM has taken the time to draw. Your talking hundreds if not thousands of hours of time to draw.