Strut bars: Any evidence they add anything but weight?

BoKu · Post by **BoKu** » Tue Sep 30, 2008 2:22 pm

I've just bought a Neon, and I'm doing the usual upgrades that make the difference between an econobox (or econobubble) and something worth driving: tires, wheels, springs, swaybar.

One of the accessories I've encountered is the strut bar, which spans the strut towers and allegedly "stiffens" and "strengthens" them for better handling.

Here's the thing: Is there anything in the way of actual evidence that strut bars actually do anything besides look cool? Has anybody done FEA analysis of the strut towers? Or maybe made actual deflection measurements of the chassis under load to show how much it flexes?

Given the compliance of the control arm bushings and upper strut mounts, it seems like the top of the strut tower would have to move at least 1mm (.039") before you'd even start to feel things getting squishy.

Thanks, Bob K.

Post by **racer12306** » Tue Sep 30, 2008 2:44 pm

You must be an engineer.

First off, welcome to the forum.

To my knowledge I have not seen anything in regards to an FEA on the strut towers. I think it's mainly driver feeling.

60trim · Post by **60trim** » Tue Sep 30, 2008 4:16 pm

Think of them as strengthing the chassis when it comes to flex. You connect the two strut towers and complete a "box" sort of configure. I only have one in the front and looking to get one in the rear. Ill post up results on my end. I do agree with racer though and it is driver feel.

LilSparkPlug · Post by **LilSparkPlug** » Tue Sep 30, 2008 4:39 pm

I noticed a difference in how rigid the car felt while cornering after adding mine (both front and rear, steel Mopar bars). Not that it felt sloppy before, but it definitely made a noticeable difference afterwards. Though honestly, no one has ever tested it by the standards you are speaking of.

Another thing that made an enormous difference was the Energy Suspension full bushing kit. Wow....what a difference I noticed after I installed that. Much more solid.

Danteneon · Post by **Danteneon** » Tue Sep 30, 2008 5:15 pm

I did my suspension build-up one component at a time to feel the difference. With the addition of the STBs the car had a much crisper turn-in and just enough communication from the rear so I could better feel where the rear wanted to go.

BoKu · Post by **BoKu** » Tue Sep 30, 2008 6:03 pm

racer12306 wrote:You must be an engineer.

First off, welcome to the forum...

Thanks!

But, it's worse than that: I'm a technical writer. I do some engineering under close supervision, but for the most part I test stuff into compliance. And sometimes I just test stuff for fun.

Thanks again, Bob K.

Post by **racer12306** » Tue Sep 30, 2008 6:08 pm

We work in similar professions, different in regards to specifics, but the goal is the same. I evaluate electrical equipment to appropriate UL standards. The company I work for is an NRTL, a direct comptetitor to UL.

hansken_yo · Post by **hansken_yo** » Wed Oct 01, 2008 11:25 am

From what I've heard from people that actually track race SRTs. The front tower bar really does nothing other than look cool. This is because how close the struts themselves are located to the firewall (this is how it has been explained to me). The rear on the other hand increases handling immensely and the "best" one (they claim... who really knows) is the P-Werks tri-point strut bar which also connects to your center seat belt.

Hope that adds some insight.

Hudson_Neon · Post by **Hudson_Neon** » Wed Oct 01, 2008 11:42 am

think of the strut towers forming a big letter "U". now if we connect that "U" we have boxed it in. thus it's stronger. no tests have been done to the best of my knowledge. but then again, most people don't go with the right kind of STB. they'll go with the kind that can still flex. a solid STB is really the only way that can truely stiffen the strut towers

LilSparkPlug · Post by **LilSparkPlug** » Wed Oct 01, 2008 12:45 pm

Hudson which ones in your eyes are considered solid? Just out of curiosity.

2k1MotorSport · Post by **2k1MotorSport** » Wed Oct 01, 2008 12:49 pm

Well metal will usually always bend... even if it is the slightest bit.

What you should say, is which one will bend the least.

I have the Mopar front and rear steel bars

fixitmattman · Post by **fixitmattman** » Wed Oct 01, 2008 12:53 pm

LilSparkPlug wrote:Hudson which ones in your eyes are considered solid? Just out of curiosity.

Non-pin jointed/bolt type.

Hudson_Neon · Post by **Hudson_Neon** » Wed Oct 01, 2008 1:38 pm

fixitmattman wrote:
LilSparkPlug wrote:Hudson which ones in your eyes are considered solid? Just out of curiosity.
Non-pin jointed/bolt type.

exactly... DC's, Mopars, P-Werks, the ones i made.

LilSparkPlug · Post by **LilSparkPlug** » Wed Oct 01, 2008 8:54 pm

I have the Mopars....sexy little pieces

mopar4life · Post by **mopar4life** » Wed Oct 01, 2008 9:43 pm

I may have to pick some of these guys up. I guess the rear is the only one thatll make a difference? Only 130 bucks so oh well.

Post by **racer12306** » Wed Oct 01, 2008 9:46 pm

Anyone have access to Catia or other modeling software? I'd be curious to see an FEA

King Crab · Post by **King Crab** » Thu Oct 02, 2008 11:34 am

LilSparkPlug wrote:I have the Mopars....sexy little pieces

I too, will have those sexy little pieces (at least the rear one) as soon as modern performance receives their backorders. I've already paid for in full and have been waiting since the beginning of July.

kstevens91 · Post by **kstevens91** » Thu Oct 02, 2008 12:45 pm

previous owner put billet aluminum Vibrant brand ones on the front and rear of my acr...whats ur guys thoughts on those?

2k1MotorSport · Post by **2k1MotorSport** » Thu Oct 02, 2008 12:51 pm

i think they are sketchy... i had the front and rear. then went to the mopar. but if they are on now.. then i would just leave them on.

c987long · Post by **c987long** » Thu Oct 02, 2008 1:09 pm

i got a great deal on my dc"s 130 fro front and rear.. thanks opi

Mr Josh Zombie · Post by **Mr Josh Zombie** » Thu Oct 02, 2008 1:19 pm

forgot i even had those

personally, i did notice some change in steering... but i could be completely crazy and the bars just be a placebo effect.

JRM · Post by **JRM** » Thu Oct 02, 2008 3:20 pm

Yes they help.

bone-yard-racing · Post by **bone-yard-racing** » Thu Oct 02, 2008 3:46 pm

kstevens91 wrote:previous owner put billet aluminum Vibrant brand ones on the front and rear of my acr...whats ur guys thoughts on those?

Useless comes to mind, next time you are under the hood put your hand in the middle and hold your self up with it you can feel the bar deflect.

hansken_yo · Post by **hansken_yo** » Thu Oct 02, 2008 4:27 pm

The deflection is not meant to be a vertical deflection of energy but rather a horizontal deflection. So yeah, you can bend the vibrant up and down a little, however it functions better than useless on the horizontal deflection. For $50 they work well... not the best on the market, but not the worst.

I'm using the vibrant strut bars... there was and remains a noticeable performance increase from not having any strut bars at all... Pretty much... i got what I paid for - mediocre to decent improvement.

King Crab · Post by **King Crab** » Thu Oct 02, 2008 4:39 pm

Yo, are you sporting front, rear or both?

hansken_yo · Post by **hansken_yo** » Thu Oct 02, 2008 4:42 pm

Both.

bone-yard-racing · Post by **bone-yard-racing** » Thu Oct 02, 2008 5:33 pm

I guess my issue is that for the price of 1 vibrant you can have the full set of e-bay bars.
http://cgi.ebay.com/ebaymotors/00-05-DO ... 0261816890

Wenuden · Post by **Wenuden** » Thu Oct 02, 2008 9:36 pm

if a strut bar will flex considerably with a force applied to the center of it vertically, it will also flex considerably (probably more, considering the bobo ass bolted joints) with a force applied to it horizontally from its ends. force is force when it comes to long thin pieces of aluminum.. especially when you factor in the bolts holding the mounting brackets on to those bars. sure they may help a little, and they look nice. but if you're buying a strut bar for its intended purpose, i'll take performance over price any day of the week.

when i installed my CF hood and trunk on the srt, i supported my entire body weight on my mopar STB's, front and rear, just to see what would happen. guess what? nada. at least nothing perceptible to the naked eye. had my pops watching, he's been an operating engineer for about 50 years. the man is 72 years old and still shaves with a straight razor w/o his glasses on. he's got good eyes and saw nothing. of course, that really doesn't mean shit and has nothing to do with the OP's question...

no, i don't think anyone has done any kind of testing like you're curious about on a neon. but if you do, please youtube it, and like it here, cause that carabiner vid was awesome and i want to see results.

fixitmattman · Post by **fixitmattman** » Thu Oct 02, 2008 10:16 pm

racer12306 wrote:Anyone have access to Catia or other modeling software? I'd be curious to see an FEA

Oh man, you don't need 3D modeling or FEA for this shit

Almost a waste of time to go through the effort of building the model other than for dimensional verification and to make it look pretty on the installation manual. You can run through the stress calcs faster by hand on a piece of paper. I did them once for a bar I was gonna build similar looking to a mopar. Never built it though. IIRC it was good for around 8000lbs in compression before buckling, and that was with EMT that has a yield somewhere around the same level as cold butter.

ZeroChad · Post by **ZeroChad** » Thu Oct 02, 2008 10:43 pm

Doesn't solid works or NX3 have stress testing built in? A lot of MEs use it at my school. Its not that hard to take dimensions and draw one up.