A few years ago the fender braces where a hot topic and all the rage for the stiffing the front end. But the 'Search' did not bring any results up for them. Has anyone track proven these braces as a worthwhile investment?
At first glance, they seem silly and worthless. But claims keep popping up about how some people have felt a 'noticeable difference". (isn't that an oxymoron?)

Just wondering if anyone has actual track experience with them.

Once thread I found:
https://honda-tech.com/forums/suspension-brakes-54/firewall-brace-anyone-seen-heard-used-them-1267514/
[edit] For some reason the search worked this time and I found some other major threads:
https://honda-tech.com/forums/honda-acura-28/fender-braces-wtf-anyone-tried-these-lol-1855494/
https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/fender-braces-932551/

Plenty of mixed feelings. There was supposedly an article in Honda-Tuner or some magazine where their race car test driver claimed he felt a noticeable difference.

Another thread that is has some classic quotes from bad-monkey
https://honda-tech.com/forums/suspension-brakes-54/basics-better-handling-street-strut-bars-front-upper-lower-etc-brands-use-127448/

 

IIRC, the company that was pushing them went out of business. Have you found anyone still selling them?

 

Yes, from one of the links above someone posted this site:

http://www.more-japan.com/home.php?cat=281

J's Racing also sells a version of it.

Also Ebay has some no-name brands too:
http://shop.ebay.com/items/_W0QQ_nkw...Q_fromZQQ_mdoZ

 

Don~

I added these after a season of racing and wanted to see if there was a difference and i felt absolutely nothing. If they were easy to un-install from my chassis that's for sale i would take them off and send them to you for free if you paid shipping....

 

And the cars that would most benefit from this part (if it actually worked) would be a stiffly sprung race car.

Don't bother reading anything about them from a street car driver, they have more bushing play than chassis flex and would never be able to tell if they worked or not.

 

EleanoR's car was a stiffly sprung track car...

 

I have a chassis almost ready to go on my jig. I want to spend some time twisting the chassis to see what flexes and what doesn't. It would be interesting to see if adding these things really make a change or not. I plan on twisting a bare EF chassis with no glass, doors, fenders, seam sealer, etc. Then I intend to seam weld it and twist it again, then I am going to put the cage in and twist it again.

At least I will then have some measurable data about the changes.

 

What type of seam welding are you doing? (mig/tig) Are you adding filler and if so, can you do a weight addition estimate?
Also, how are you measuring the frame twist?

 

I am probably going to MIG the chassis. Its much more forgiving of crap in the seams. Plus it is faster. I am planning on putting the tub on the scales before it goes on the jig. I would imagine you won't ad more than 5-7 lbs. I doubt I will use a whole spool of wire.

Now, as for the test rig. I have two options. I can copy the fancy test rig mentioned in this paper:
http://74.125.95.132/search?q=cache:...ient=firefox-a

but those linear actuators are expensive. I think I can do something similar with a long lever or by anchoring three points and using a jack on a scale to push up on the other side. I have to keep the bending moment down and use a true twisting motion. So I may have to get a little creative to keep the cost of the test rig down.

 

Sounds like a awesome project. Please do a full post on the project! I don't recall any in depth post on seam welding. Especially with actual data. It would also be worthwhile to start a side bar on how seam welding would effect a car's classification in different race/time trial series.

 

Most classes don't allow it. But the new Super Touring Class in SCCA does allow it. Back in the day seam welding a chassis was considered the first step in building a good race car. For some reason people whined about it and had rules made to outlaw it. But since this class allows professionally built race cars to compete against amateur built cars, the rules had to be made to reflect those modifications.

I have to get a couple of other customer and personal projects out of the way and the car will be on the jig shortly.

 

Found a full pdf of the document. Click on the "view or download" at the bottom of the page.
http://citeseerx.ist.psu.edu/viewdoc...10.1.1.25.8734

 

Which is why I was stating that EleanoR's observation that they did nothing is significantly more valid than most of the "I installed it on my daily driven Civic and I love it" type of posts you see on here about them.

Apologies for poor communication.

 

Ah, and I equally misunderstood you. Apologies all around!

 

Some more fuel to the fire:
http://www.korbachperformance.com/purchase.htm

http://www.uscomposites.com/foam.html
I personally think this would be more effective. A lot of new cars apparently use this method to fill the voids in the frame rails/rocker panels and certain JDM companies (JUN off the top of m head) sell these kits, albeit at a much lower density (3-4lb IIRC)
http://www.junauto.co.jp/products/re.../index.html?en
JDM enGRish for ya!!

http://foamseal.org/auto_aftermarket.htm
Some other variations.

 

my buddies CTR was foam injected into the frame rails and in the side beams underneath the side skirts

 

Your making my head hurt now.......

 

Did ya'll do any testing or make any conclusions as to whether or not it helped?

 

I can't find any hard data to support the amount of stiffening (that anyone is willing to share).
One source I have not fully checkout says:
"SAE paper 1999-01-1785...increase of 29.1% in modal frequency."

Found some threads on it:
https://honda-tech.com/forums/road-racing-autocross-time-attack-19/chassis-foam-rules-violation-1219064/
https://honda-tech.com/forums/road-racing-autocross-time-attack-19/do-you-remember-structual-foam-s-c-c-mag-june-2000-did-anyone-ever-try-294835/

https://honda-tech.com/forums/road-racing-autocross-time-attack-19/expanding-foam-1969393/

Since it's illegal in most racing circles, it would seem to provide some advantage.

 

sorry to get WAAAAAY off topic, kind of, i'm actually going to be installing some frame rail braces for my 94 miata today. they are rumored to be the best stiffening item for a miata other than a full roll cage.. i was wondering why no one has made this for a honda? they make them for camaros, mustangs, etc..

 

Miatas chassis suffer as most of the cabrio rwd cars, and stiffening their frame rails is essential. My best friend has installed the flying miata braces and the car feels much more solid. But i strongly beleive they would be worthless in a sedan chassis.. (dont forget how much they weight too)

 

they only weigh about 15lbs.. i understand where you are coming from, but also think of this: they are a number one upgrade for Mustangs and Camaros.. this may have to do with more torsional stability needed because of... what's that word??... um.... tork? or maybe torque? i dunno.. neither would honda! hahahaa. j/k..

but seriously folks, it was just a thought because i spent the time to do it in the miata and you know what, i forgot about them, but i noticed it on my test drive and it really did make a surprising difference..

i'd have to stick my head under my hatch to actually see how the frame is compared to the miata, too. i feel like a hatch could have enough torsional flexibility that it could benefit from frame rail braces.

 

Im doing a set in my EG. Just for **** and giggles look how thin the door hindge A frame area is. Put a bolt in and move it around . You can move it with a simple socket its not to stiff. I did a set on a EG back in the day and we did a quick tes on the hoist with one jackstand to 3 wheel the car call it and the doors had a hard time closing. We put in some A frame braces and did the same test and there was minimal flex in the chassis compaired to not having them. I will probly be making a jig for them this summer for EG and EK.

 

A stiff chassis will work better in every capcity than a chassis that flaps in a moderate breeze. Hondas, while well engineered in nearly every way, has fallen down a bit when it comes to chassis stiffness. The current Civic and Fit have been re-engineered to be much stiffer than any previous Honda.

For those of us in the "classic" Honda community, there is not a lot of aftermarket support for our old cars and we have to fabricate many bits ourselves. Fender braces make a HUGE difference in chassis stiffness in our cars and so some of us have created our own.

If your class rules allow a fender brace I highly recommend adding them, even if you have to make your own.

Scott

 

I see these parts as a waste of time. I won't say that they are completely useless, just the same way that I would not profess a strut tower bar to be completely useless. But I will say that when you are talking about building a race car why dick around with a bandaid fix when you have at your disposal real world solutions.

Don, you have a rollcage. Triangulate that thing to the damper towers and call it a day. Is it technically more difficult to accomplish? yes, but even if these braces do anything at all, their effectiveness will not even be remotely comparable to what a triangulated roll cage can accomplish.

Taking the design shown above, while it certainly would appear to be more rigid than the 2D pieces I have seen on the market and or the non triangulated pieces, it is still dependent upon the mounting points on the unibody. Therein lies the problem. I am concerned that there is not any part on the unibody that is a reliable enough of securing even the most rigid device with hope of holding that rigid device in place.

Imagine a solid, non hinged strut tower bar. Imagine the best possible version that you can think of. It still would not be something you would find on a real race car, and I would be so bold as to assert that the two points the above mentioned piece intends to couple are much more susceptible to external forces than the strut towers would be. Hell, the whole concept behind why you would need a strut tower bar stems from the fact that the unibody section that ties the front bulkhead to the strut tower is insufficient.

Also, with regard to the foam. I have been reading about that for about a month, and I have come to the conclusion that it will have an incredible impact on the rigidity of a hollow member. However, even if that member is entirely rigid, it still has to contribute to a well designed structure to get any type of positive results in the big picture.

For illustrative purposes, imagine that you had two rain gutter drain pipes (the metal square-ish tube that carries water from your rain gutter to the ground). And let's say that you welded the end of one to the middle of the length of another offset at 45 degrees so that the end result was giant Y shape. It doesn't matter if you fill them with high density closed cell foam, concrete, or freaking chicken nuggets. Regardless of how rigid the components of that shape are, it is a shape that has built in flaws that only proper triangulation can fix.

Simply turning the Y shape into a triangle (adding a vertical section to connect the ends of both tubes) would do more for the overall rigidity of the structure than stiffening the members themselves while leaving a crappy design unattended to. Do both and now you are on to something.

What I just stated was fairly obvious as that is an extreme of example of a crappy shape. But, the portion of unibody from the bulkhead to the strut tower on a honda civic is a pretty crappy layout just the same.

look on the bright side. for only 350 bucks you can buy these awesome parts, and kind of sort of not really strengthen a completely insignificant part of the chassis.

http://www.iapdirect.com/manufacture...ufacturerid=34

I'm tired. I'm probably just rambling now.