Chassis Brace Priority
 

To some of you this may be redundant, to others blasphemy, and to hopefully a few of you some exciting news. But we felt that this section of modifications seems to be the path less traveled. We really hope this strikes a chord with you all because it seems that FRS/BRZ owners are truely in love with suspension theory and tuning. We challenge you to read and think about this. Wed love to have an open minded and positive conversation about the effects of chassis braces and answer any questions you all may have regarding this black art.

WHY CHASSIS BRACES?

Chassis Braces are the most overlooked part of building a performance car. People will buy an intake then exhaust then coilovers when they begin the process of modifying their car. Chassis Braces are viewed as the last piece of the puzzle or a "bonus part." This logic has some flaws in it however. Chassis braces provide the best "bang for your buck" when attempting to extract everything out of your ride! These parts shore up deficits in the stock platform and don't impact the drive-ability of the car. Not only do they make the car a more stable platform to work on, but the price is in competition with an intake. Now you may say, "yeah but I want a little more power and braces don't add any horsepower or torque!" By having a unified chassis you are able to put more power down to the ground! These products help extract every ounce of power by making sure none is lost in chassis slop, wheel hop, or flex. When you think about an intake giving you only a few horsepower but compromising engine reliability, leaning out AFR's, and negatively affecting drive-ability why would this be the FIRST modification to chose? The same can be said for exhaust. It seems counterproductive. By contrast installing a full set of braces will not only improve handling, and drag times, but also make it easier to learn how to drive your car to the best of its ability. If the chassis becomes more predictable you will have an easier time taking your car to its limits because you will have a more tangible limit. We don't modify cars for the sake of adding parts to car, we modify cars to fix problems in the car. In today's world of advanced 4 cylinder designs factory intake and exhaust systems are refined so far that its hard to extract any more power out of them without removing emissions control devices, yet the factory chassis is as weak as ever!

For example we personally have had a bone stock ford fiesta with only braces on it go out on an autocross course(his first time at a track mind you) and beat turbo miatas, Evos, Stis, and a myriad of other "better" platforms that were extensively modified. :confused0068: He actually laid down one of the fastest times for the day. There is a reason why chassis braces have such an impact on what class your car runs in autocross events.

http://www.ft86club.com/forums/showthread.php?t=44360

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[ame="http://www.youtube.com/watch?v=n8400qUXT68&feature=c4-overview&list=UUqrsh8Wh-lJ3bXT4TE3-oOw"]http://www.youtube.com/watch?v=n8400qUXT68&feature=c4-overview&list=UUqrsh8Wh-lJ3bXT4TE3-oOw[/ame]

Perhaps the Fiesta is just _that good_? What about times before and after this magical strut brace?

So you're telling us that a total noob with no track experience beat more powerful cars with more experienced drivers all due to chassis bracing? I'm sorry, there is hyperbole then there is cynicism.

Good call.

I've got a couple questions for you

What engineering goes into the design of the chassis braces? Do you perform an analysis of the structure and target specific weak points? Are there common areas that often need bracing? How do you determine the strength and shape of the required braces?

I'm all on board with the principle that a couple cleverly located braces could really stiffen up a chassis, but I'm skeptical what research, analysis, and testing went into most aftermarket braces. Adding braces costs money, and even for enthusiasts who want perfection at any expense, adding braces costs weight. I think you'd probably agree with me that there's a point of diminishing returns, after which improved handling due to chassis stiffness is more than offset by increased weight. That's why nobody is welding a steel plate between the subframes.

So my question to you is essentially this - what analysis or testing do you conduct to make a brace "buy it's way onto the car" - provide a net benefit by increasing stiffness and adding weight. I'm sure there's plenty of possible braces someone could come up with that don't meet that criteria - the structure they're bracing is stiff enough already that the weight hurts performance more than the stiffness improves performance. What process do you undergo to isolate the weakest areas in the factory chassis, that would have the most to gain from a brace, and ignore the areas in the factory chassis that are stiff enough already?

^ Of course this is the response you get...

A purpose built tube chassis car is essential just a web of what we consider chassis braces on an oem car. All cars flex and bend in the same ways and you can fix that a little by connecting certain existing bolt holes together.

Same concept as roll cages. All cages have the same basic design with a few edits to fit the specific car. Would you think a car body is "tested for weakness" by a cage builder?

Maybe the fiesta analogy was a bit more than what most people want to hear, but the concept and facts about chassis reinforcement is legit. :)

These cars respond great to braces. Its not rocket science to look at the car and decide where thrust forces are applied and where improvements can be made. Computer modeling and stress analysis is great but not possible for every shop. There are other more practical ways to determine the effectiveness of a component.

The chassis can be called the fifth spring and can be "tuned" just like the traditional springs at each corner.

If anyone else have driven a car with a proper 8 point roll cage in it thats a great example of a stiff chassis. With a full cage the added stiffness is really a perk since the main design is focused on safety.

Nalc, my post wasn't aimed towards you personally. Just the overall negative response immediately.

Also track times aren't always the end all measure if a part works. I know I try to time my laps at track days but its hard because Im always interacting with other cars on track so that gets reflected in the times thus skewing the data.

Rule books are a good indication of what has been proven to make a car faster. Look at autoX rule book, additional braces will bump you up a class, simple.

I wonder why nobody has ever shown test / results of chassis brake working, I mean on a mechanical level. You could simple design a brace that meets in the middle (not attached to one another) put up a camera and record how much torsion the chassis gets by looking at how far the braces flexes apart from each other during a track / auto-x run.

That would make a good demonstration for your case. I personally hate speculation and love test data.
I made a photoshop to show what I mean.

I have seen a Cusco video like that. I think they left it unbolted where the brace met the nount on one side. It was in Japanese.

I understand, I'm just wondering if there's any proof or evidence of improvement, because practically every mod has a "zomg the mod made the car a bazillion times better" review on a forum. I work in aviation, and "Let's throw weight at it without doing any testing or analysis, based on what looks like it's weak" is some amateur crap. I'm not saying that I expect a little shop to be able to do a finite element analysis, or put strain gauges all over the car, but I would expect them to develop a brace based on looking at parts of the chassis that look weak and previous experience with other cars, then do at least some sort of before-and-after road or track test to confirm that the car actually benefits from the brace. There's probably a number of weak points in the chassis that are designed to be weak because they don't see a lot of load or stress on them, and that wouldn't benefit from bracing. I'm sure there's a number of weak points in the chassis that were either a design oversight, a cost-cutting measure, or a ride comfort compromise that will see big performance gains from braces. How you tell the two apart is the key. Otherwise you're just paying $$$ for a pretty piece of metal that may not be doing anything worthwhile.

You wouldn't want to do it that way, unless the bars are carefully balanced and very rigid, there will be vibration, and you won't get a worthwhile measurement. Better to just fab up a bar and slap a strain gauge on it, then watch what it does. If you get some strain on the bar, it's working, and reacting loads. No strain on the bar, it's just sitting there, looking pretty, costing you weight and money. It's proven technique, and strain gauges are cheap.

Yeah I have seen a few companies do this, I think its a great real world demonstration.

I see where you are coming from with doing complete R&D. However all of those R&D hours will be reflected in the final price so there has to be a balance of data and whats realistic.

Look at how F1 cars are developed, massive budget and mega software. Then once its physically built they still coat it with paint and take it for a spin to see if it actually does what the computer says it will.

Full disclosure: I quit reading after this sentence (read below why), so I'm not sure what other "chassis bracing" you're talking about specifically.

A strut tower brace is just about the absolute worst bang for your buck. Everything else is better. Stickier tires, lighter wheels, intake, catback, drop in air filter, sway bars, end links (even JUST end links!), brake pads, etc, etc, etc. You aren't talking to idiots here.

I agree - as I said, I wouldn't expect a finite element analysis or computational fluid dynamics or anything like that from the aftermarket (nearly impossible anyway unless Subaru sold you their models, which they wouldn't do), I'm just wondering if there's any testing that goes into it. Do you fab up a brace, take it for a spin on a test track or an autocross event, and see if it made a measurable improvement, or built one with a $40 strain gauge to tell if the bar is actually seeing any tension or compression during cornering, or is it just "We know enthusiasts buy braces that are visible in the engine bay or that look complicated and impressive and that are easy to bolt on, so we'll just build something and make sure it fits, then sell it". I like the idea of improving my car with braces, I'm just wary of braces that were designed mostly for looks and that were never really tested with the same car, driver, and track with and without the brace to see if it actually made an improvement. I don't think it's "massive R&D" to say that in back to back test, it shaved off a half seconds of time around a course, or that with a strain gauge, it showed that the bar was under a fair amount of compression during hard cornering.

Mind linking your times from ACS?

What kind of engineering goes into your chassis bracing? Any type of stress analysis? How much torsional rigidity does your brace add? What is a hyme joint?

Do you have any before/after results that are backed by a baseline time that is in line?

tl;dr: I'd love to see substantiated results.

You know you're always smart to take a vendor's advice with a grain of salt. I've gotten some great advice from vendors here on the forum. And, I've seen some vendors offer advice that I thought was questionable. I'll let everyone pass judgement about this one on their own.

HAY GUISE ADD WEIGHT TO YOUR CAR IT GO FASTER

http://i1350.photobucket.com/albums/...ps4af45ecc.jpghttp://i1350.photobucket.com/albums/...psa406545a.jpg

Um, no.

WOW! I really appreciate all the feedback from you guys! Its good to see so much interest in braces! First off Id like to address some facts on our business because after all we are the new kids on the block here. We've been doing this full time for two years now and have had our hands on tons of cars and experience is our biggest weapon. As per our size, We have a small staff of 4 guys, and we have now shipped thousands of braces internationally. Hell, the Parts Manager of Scion of San Diego has been talking with us about carrying our products in their dealership and Turbokits.com has been licensing our Kia Forte Braces for 8 months now. As far as engineering goes we designed everything based off of our real world testing and sat down with an aerospace engineer who currently is out helping the Saudis design planes. The guy has been an engineer for over 30 years and was absolutely brilliant...if a little rough around the edges. Now I could sit here and post track times from our turboed TC2, 400whp speed3, or 450whp track evo and the comparison of before and after but those times can easily be refuted based on sandbagging one lap and going hard on another...Braces truly are a hard product because the difference is in feel as well as times. As for the benefits outweighing the weight argument...we totally agree, there were several braces we tested for the frs/brz that didnt make enough of a difference, and as such we dont produce them. We have always striven for complete honesty and transparency with the community. We all drive and race modified cars and want the community to have REAL products with TANGIBLE difference. In the past two years we have never had a weld failure or ANY person say that they didnt notice a massive difference, however i know you will all take this with a grain of salt as this is our business lol.

As for the weight of our braces, the WHOLE package weighs in at around 15lbs...Which having owned a 2450lbs track MR2...makes the added weight worth it. Our Speed3 owner originally posted a 48 second Adams pass but after brace work ONLY shaved off right under 3 seconds. Again, i know a few of you will probably argue this with Temperature, humidity, tires, race gas, or any other myriad of reasons...however you asked for it and will give it to you. Simply put...If you dont notice a difference, ship it back and we refund you...no questions asked...Like I said weve never had any complaints of our products not working...

I was the test car used for the r&d of these braces. I can vouche that they had tried many different designs and braces for the vehicle and only released what they truely felt would be benefitial to the vehicle.



[/QUOTE]Full disclosure: I quit reading after this sentence (read below why), so I'm not sure what other "chassis bracing" you're talking about specifically.

A strut tower brace is just about the absolute worst bang for your buck. Everything else is better. Stickier tires, lighter wheels, intake, catback, drop in air filter, sway bars, end links (even JUST end links!), brake pads, etc, etc, etc. You aren't talking to idiots here.[/QUOTE]

They sell many braces other than just the strut brace

And a great example of something you should NEVER run on a street car. Aside from bashing your head in on the cage since you're obviously not wearing a helmet and properly strapped in on the street, caged cars are more prone to flipping from everything I've seen.

@nalc's questions may seem smart-ass if they all go over your head but they're really not smart-ass at all. They are objective, intelligent questions that pursue truth, not negativity. But I'll argue that his aerospace engineering way of thinking (where tolerances are of utmost importance) may be a tad out of place. That world is literally rocket science, whereas automotive engineering isn't. Applying the same levels of R&D/dev testing may be overkill.

I'll wager a guess that there are some universal points at which this unibody chassis can benefit from bracing. Examples: Front/rear stabilizer bars or the stock V-brace in the engine bay. The V-brace shall go from the strut to the center of the firewall, there's not really much wiggle room to design it any other way. But how would they know to apply it in the first place? Perhaps the proof of concept has been proven over and over again/immortalized within structural/automotive engineering circles. No need to reinvent the wheel. To be thorough, the OEM may have used a strain gauge to validate the decision. Or not, because that might be like doing integral calculus then taking the derivative of your answer to prove it (an academic exercise).

I'm no structural engineer, but I imagine they adhere to some common truths in rollcage fabrication to get it maybe 80% to 95% accurate towards being optimally functional. That last 5% may require extensive computer modeling and hundreds of thousands in resources/fab/adjust/verify/re-fab/readjust/verify/refab, etc. just so they know the perfect mounting point down to the millimeter and perfect bend angles to the tenth of a degree. But 95% accuracy may just require a tape measurer+protractor across critical points of the unibody and basic application of geometry/structural principles. I imagine it to be a plug-and-chug deal. Otherwise, thousands more dollars to squeeze out that last 5%? Ain't nobody got time for that. :bonk:

Skip to 3:50 for quick clips of a Chassis Design Engineer fabricating a one-off rollcage for Toshiki Yoshioka's Formula Drift BRZ. The work he does appears to be a routine, unsophisticated deal for him:
[ame="https://www.youtube.com/watch?v=KSS9l4yjjbg"]The HANDICAM DIARIES: GTNET TOMEI BRZ- Episode 4 Picking up the Pace (re-upload) - YouTube[/ame]

Switch, I think you have hit it on the head. There are many points in unibody bracing that all brace companies tend to stick to. There are variations but in general we adhere to similar points because after designing new braces OVER AND OVER (tbperformanceproducts.com has over 120 different braces alone) we figure out how it works. Its our day to day job. We go over chassis ALL DAY LONG every day. It becomes second nature on where and how to brace a car. We promise it works, and if someone doesnt feel a change well refund them...BUUUT two years and running and no one has ever taken us up on that...we aren't here to try and market everyone to death with "our designs are better" or "if you don't buy this then you don't know about cars." We feel the products sell themselves and if someone doesn't want to buy them, we understand. If someone does, well be there to help them. Honesty and transparency is what I personally value in a company and that is how I run TB Performance. Simple as that.

Hell, if he offers a 100% guarantee on his products that you will be satisfied or your money back, why not try the products?

On a side note, I will say that just about every other brace offered for this car is made out of aluminum. TBPerformance seems to make every brace out of carbon steel. This is a hell of a lot stiffer, and when it comes to bracing, stiffer is better, no?

Did you seriously claim a 3 second improvement in lap times from a strut brace??

why does everyone keep assuming that all they sell are strut bars, look at their site and their different offerings for vehicles before you bash people...

Some chassis braces help, especially ones which tie suspension points together which are prone to flex. So I'm not going to poo poo on chassis braces.

However, please don't come on here and treat people like they are stupid. Don't make claims about chassis bracing improving the lap time of a car 3 seconds. Don't brag about a Fiesta ST beating EVOs, STIs, etc. in autocross "due to the addition of chassis bracing." If it beat those cars it beat them because it was driven better, period. It really takes away your credibility from the getgo.

Look at other vendors on here like Hancha, Raceseng, RacerX, etc. Those guys back up their designs with engineering, including FEA analysis, etc. which they are willing to share.

He said after "brace work" which could mean many.

the problem is that dropping 3 seconds off a course as short as adams is that it is a serious jump. you have to forgive people for being skeptical considering that nobody here has ever seen a 3 second from braces only in the entire collective of our experiences. especially on such a modern car.

Software makes lots of pretty colors, but all parts still get tested in physical form. So if a company doesn't have access to software and goes with testing multiple physical parts thats just another method of reaching an effective product. There is more then one way to skin a cat.

Anyone remember the Virgin F1 team, a car designed solely with CFD.

Im do not mean to deny the usefulness of software but its just not the end all means of design.

There's no sandbagging when the baseline time is clearly competitive. That's why I specifically asked for before and after times.

What kind of tangible difference does your product provide, when you're not giving us tangible evidence in the form of results?

I don't mean to call you out, but if you're going to make claims, then I want to see them substantiated.

Now, if you had just said "he's a chassis brace, it's well crafted and high quality", then you'd be just fine in my book. With the claims of engineering in the product, I'd like to see substantiated results.


I'll offer up our car for testing, and invite forum members to come observe to see that there is no sandbagging. Competitive times will be run for both the before and after runs. If a 3 second gain was realized on a 48 second course, imagine the gains on a 2 minute course. We'll break records and then some.

I think it's safe to say at this point, people want to see evidence and data supporting the claims.

There was mention that people buy intakes and exhausts all the time, but you know what? Those companies support those products with measurable data like dynos. Whether or not it shaves 3 seconds off their lap time isn't the point.

Oh, they absolutely do. It's called the pedigree of the analysis tools, and it's a big thing. You've got a nice pretty computer simulation, but that's all it is - a simulation. Who knows if it's correct or not? Only way is to run the simulation, make the design, test it with strain gauges, see if it matches the model, then refine the model. It's an iterative process. Your computer model isn't worth a fart in the wind if it doesn't have a pedigree. I'm sure Subaru has a nice model that is refined from years of development and testing, and it's worth a lot of money to them. You can bet the computer code for that model is as closely guarded of a secret as Coke's secret formula.

And frankly, that's why I'd be worried about a chassis brace developed by an aftermarket company solely using computer analysis tools. They don't have Subaru's chassis models, they don't know what all the loads are or what the chassis is doing. It'd be a huge task just to develop a functioning computer model of the BRZ chassis, and that's without even seeing if it's accurate. (Note: I'm referring to determining the locations where braces are needed, not for the analysis of how the braces themselves are constructed, that should be easy). Simple tests like before-and-after laps, or using a strain gauge or another test method to look for chassis flex (like leaving one end unbolted and seeing if it stays lined up) is probably the best you're going to get, and a refund if you don't like it seems pretty reasonable to me.

I guess at the end of the day, I'm mostly just skeptical that Subaru, who went out with the intent of making a great handling car, and had the analysis tools, test equipment, and manufacturing capabilities to do whatever they wanted to, would miss any "easy" spots to add a brace and get a big handling improvement for a small weight impact, but who knows how rushed they were, or how worried they were about weight, or whether they were trying to reduce costs.

As stated before 100 percent money back guarantee speaks for itself. If you are skeptical you have nothing to lose. The difference wasnt between a strut bar...we dont even make strut bars for speed3s because no difference was measured with the factory having an integrated front strut bar in the firewall. The 3 seconds came from EVERY brace we have working together on the vehicle. As said by Brett...Its not all about our strut bars, its about everything else. You asked for times and I gave them to you. If you dont believe it then thats fine, however it was and is truth. I encourage everyone who is skeptical of my work to go sift through scionlife.com and see how many people there have bought braces and been shocked by the difference.

What time do you think can be gained by a full set of your bracing on a FR-S/BRZ? This is the record holding lap, on video, at Buttonwillow.

You're interested in fabricationg, I'm interested in dropping time in our shop car. If there's results to be had, I can recommend to my bosses to try the parts, but we don't blindly pick parts simply because the manufacturer claims they work.

[ame="http://www.youtube.com/watch?v=nGBZWkoQO-s"]CSG BRZ Buttonwillow 2:00 lap - YouTube[/ame]

I cannot give you an estimate. However we would love to put our products on yet another track car. I will be sending you a PM in a second.