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Is-a-strut-brace-worth-it-header

Is a Strut Brace Worth It?

When it comes to car modifications, strut tower braces have been the topic of many a great debate on the Internet. Whether for street use, track use, or additional chassis reinforcement on an already stiff and caged race car, the question always comes up: Is a strut brace worth it?

Yes, you need a strut brace!
“Yes! You need a strut brace. Trust me! You’ll feel it working!”

There are those who will argue to the e-death that they can feel a noticeable improvement in chassis stiffness and suspension control with a strut tower brace installed, and there are those who refuse to even look at strut bars because they believe they’re nothing more than engine bay bling and eye candy. There’s plenty of conjecture, but it’s extremely hard to find any actual facts to back up claims from either side. Since we love to have actual data to make an informed decision or recommendation, we turned off the proverbial butt dyno and decided to measure the actual amount of strut tower deflection on a BMW. What can we say? We like to go the extra mile – and we like learning just as much as we like sharing knowledge.

No, strut braces don't do anything!
“No! A strut brace is a worthless piece of eye candy. I couldn’t feel anything!”

 

When in doubt, test!

Spec E46 testing
Our Spec E46 330i was the test subject

While plenty of people like to run strut tower braces on street cars, we wanted to get measurements on something that would see much more severe duty, so our test car was our BimmerWorld Spec E46 BMW 330i, and we used both Lime Rock Park and the full course at Virginia International Raceway (VIR). VIR gave us the most usable data since it has elevation change and some significant high-loading features that really put a chassis through a workout. Plus, it’s our home track, and we’re intimately familiar with the layout.

Strut-tower-deflection-data-setup

Testing was conducted without a strut bar in place to determine “the problem” that a strut bar would otherwise solve. Nick Large, BimmerWorld’s Product Development Engineer, configured the onboard AiM MXL2 data system to include linear potentiometers in several locations/configurations to measure distance changes between points. After recording on-track data, we filtered out some level of noise with an exponentially weighted moving average, or for those of us who aren’t engineers, that means data smoothing, which gives us a cleaner look at the data. You can see the results in the graph below.

BimmerWorld SE46 Strut Tower Deflection Data from VIR
(Click image to view the full-size graph)

The Delta Distance on the graph measures the change in distance between the tops of the strut towers, so a positive number means the towers are spreading apart while a negative number means the towers are getting closer together. Note that the measurements are in millimeters, or more specifically tenths of millimeters. As a rule of thumb, the distance increases during cornering because the load on the tire is twisting the top of the inside tower away from the vehicle center line, and the distance decreases under braking and over bumps because the towers twist simultaneously and in opposite directions. If you know the layout of VIR well enough, the annotations allow you to understand the trends and see how they correlate to certain sections on the track.

The data was gathered over many laps, with every lap showing incredibly consistent deflection numbers, and as you can see, the movement in this measurement location is minimal on this particular car. A strut bar, or any other structural member, provides strength almost exclusively in this tension/compression range, and most E30/E36/E46 BMWs exhibit movement purely laterally across the strut towers, as our measurements reflect. Further testing of additional locations showed similar minimal movement, although those locations wouldn’t typically be affected by an aftermarket strut bar regardless.

 

So, is a strut brace worth it?

That brings us back to the main question: Is a strut brace worth it? The scientific answer is, “It depends!” Based on the data from our specific Spec E46, this car didn’t need one on this particular test day.

But that isn’t the comprehensive answer, and from experience, we know there is a need in some cars. Why is that? BMW is iterative in their chassis design, and part of the added weight of each new chassis is the added stiffness. The older, lighter, and more flexible E30 definitely needs a strut brace, which we know from the high number of racers with collapsing strut towers that are actually pushing together with age; a strut tower brace solves this! And one hard concept to accept is that everything wears out over time, including the metal chassis of a car, so even newer models will likely head down this path eventually with enough mileage, age, and pounding on the street or track.

We’ve also seen other E46 cars bend strut tower braces, which was the catalyst for this experiment, so there is clearly something moving. But remember, standard strut braces help in tension and compression, not bending, so while there is movement, a strut brace really didn’t help much in the cars where we saw damage. And why was there movement? The example cars we saw had been hit previously in the front, weakening the spot welds or sheet metal. If our test car were older, in worse shape, or if it had any broken spot welds in the strut tower, then a strut brace would help.

People ask why we don’t recommend strut braces for all cars. Easy answer – not every car requires one, and we don’t believe in pushing products you don’t actually need. But there are certainly situations where BMWs benefit from having a brace.

E46 strut tower brace

So, what about installing a high-quality, single-piece strut brace like the Rogue Engineering Race Brace to simply add reinforcement to the strut towers – the prevent a problem before it happens approach? That could certainly be a benefit, as it may very well help to disperse the energy from potholes, bumps, and severe cornering loads (especially when running camber plates). Anything you can do to help distribute loads and avoid deformation of the strut towers is a plus, but there are less expensive ways to do that if you don’t need a strut brace – BMW’s factory strut tower reinforcement plates being a prime example. The minimal movement shown in our test graph proves to us that a strut brace would be most beneficial if you have an older car or tired chassis with noticeable flex and/or pre-existing issues. Then you may get the intended benefits of the brace with the added insurance against strut tower deformation.

Ultimately, we’d like to perform this same test after five years of racing with this car. While the movement in our graph is minimal, it may certainly be enough to have a fatigue effect over time. According to James Clay, who once had his finger stuck between the main hoop of a cage and the B-pillar for part of a lap by accident (ouch!), this would likely be no more fatigue than the entire metal chassis of the car would suffer from. So it becomes a question of the added weight from an extra part (weight is normally considered the enemy) versus the potential long-term benefits. That’s not as easy to answer.

tarheel-april-2016-1_26214506342_o-wm

BimmerWorld and Tarheel & Toe – Spring HPDE 2016

While our pro racing season has been in full swing for a couple of months now, the HPDE season has only recently started back up, and we just got back from our first great BMW CCA weekend of the year: The spring HPDE with BimmerWorld and Tarheel (& Toe) at VIR.

 

Helping build better drivers

We had a whole BimmerWorld crew head out to help at the first event of the year for BMW CCA’s Tarheel Chapter.  Along with help from HMS,  we donated a few AiM Solo units for use in Tarheel’s A-Solo program as a means to increase their learning curve. Our own Phil Wurz ensured that the students were able to both use and understand the data from one of the best tools available for increasing driver potential. It was a great success as students were picking up a lot of great info on where they could improve to maximize their time spent on track. Tarheel Chapter’s Phil Antoine was grateful for the assistance, stating, “BimmerWorld’s support of our A-Solo Program was a tremendous success. By providing AiM Solo units and a the necessary training, they were able to help us introduce data acquisition to our advanced group of students. The results were immediately obvious.”

Gary Gray not only worked registration on Friday night and early Saturday morning, he also bolted on his helmet and communicator to hop in the right seat with some students to show them where the track goes and how to use all the asphalt they were paying for over the weekend. Well, he actually had to borrow a helmet for the first time in 25 years and buy a new communicator, but you get the point. With a D student in a fully-prepped (and very loud) 2.5L E30 M3 and a B student who was significantly faster on Sunday, Gary managed to wrap up the weekend knowing he had helped some track addicts make some big improvements. He’s also been raving about his excursion to Aunt Millie’s so much that we’re thinking a company field trip for pizza and banana splits may need to happen soon.

Mike Renner BMW Performance Center M2
Mike Renner from the BMW Performance Center came out to give e-ticket rides and promote the new BMW M2.

In between all the work, we somehow managed to squeeze in a pretty good time while enjoying the Tarheel hospitality…

 

Good times on track… and off!

Phil and Brandon Marshall managed to get some time behind the wheel of our E36 325i enduro car, allowing them to shake off the cobwebs as well as discover a few small issues that developed over the off season. Those issues didn’t stop Brandon from getting bumped up to C group at his second-ever track event, eventually getting signed off to drive solo. We’re sure it was his raw talent and not just the instructor needing a break. Speaking of instructors, word has it that Phil may be adding that role to his ever-increasing driving resume soon.

Phil Wurze and Brandon Marshal Tarheel VIR BimmerWorld
The BimmerWorld endurance car getting a workout and shaking off the winter cobwebs.

Carrie Wurz and Nick Large got into a major karting battle, but the results may go down in history as a mystery. Nick claims they both lost, Carrie says Nick is a karting wizard who can’t be beat, and based on the pain they’ve both been feeling all week, maybe they did both get beaten.

Are-you-a-wizard
Common question whenever Nick gets out of a kart.

BimmerWorld donated some door prizes to the Saturday night banquet, and we got to put some faces with some names and mingle a bit with new friends and old. It’s always a great weekend when you’re at a racetrack, but even better when you’re with good friends. Thanks to the BMW CCA Tarheel Chapter for hosting another great event.

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Event Gallery by Phil Wurz

BimmerWorld-84-Fire

BimmerWorld #84 Car Fire – Always Have a Plan

When it comes to on-track safety, you should always have a plan. That’s particularly true for fire safety, and you absolutely must get to a point where your reactions are second nature, so there’s less chance for error in your speedy exit from a burning BMW (or any trackday or race car).

The video below is a very scary and teachable moment from the start of our race week at the 2016 Sebring 150 with IMSA/CTSC. It certainly didn’t feel like we were heading to the podium when a high-pressure fuel injector failed, spraying a red-hot turbo with fuel and igniting the engine bay. Our Lifeline 3M Novec-based fire system squashed the fire, even as it was being fed fuel while heading to our pit stall, which was our best chance to ensure we limited our damage. With well-calculated decision making and a fast crew, we turned what could have been a dangerous disaster into a solid race weekend.

 

Always Have a Plan!

From the perspective of James Clay, BimmerWorld president and driver of our #84 BMW F30 328i when things started to get hot: 

“This is the first time I have been in a car fire, and I can tell you it is HOT! Instead of panicking, I made a few decisions in a row that weren’t necessarily standard process, but all led to bringing both myself and our car in safely.

If I hadn’t drilled in the standard process and contingency options in advance, I would have had much bigger problems. Fire is scary (I have had 3rd degree burns all over twice in my life – not fun), and it would be tremendous if how smoothly this can go with the proper equipment, installation, and processes is as widely discussed as the horror of what happens when it doesn’t go right, or the equipment is sub-par, or not installed or used correctly. You always hear about the guy that died on the track – maybe we need to hear more about the guy that came to a controlled stop in his pit box with a fuel fire raging without physical harm to any person, and minimal equipment damage. In a huge number of situations, this COULD be the reality with a little preparation.”

Here’s the in-car video, and make note of the fact that the electric fire button was pressed while entering pit lane, bringing the fire under control. What appears to be smoke in the cockpit is actually the atomized Novec, so James was still able to breathe comfortably while preparing the crew over the radio.

Also note that this was a test day, so stopping in another team’s box with no warning and expecting them to be prepared when there is no refueling on pit lane would be more than optimistic. Our team was ready with multiple bottles because James was on the radio talking through the situation since the entrance to pit lane. Remember, equipped doesn’t always mean ready, and our guys were both. This is also a strong reminder to drivers that don’t wear Nomex driving suits at HPDEs and track days: Fire doesn’t care what day it is!

 

Foam Versus Novec

Aqueous Film Forming Foam (AFFF) and other foam suppressants are good when it comes to suffocating a fire, but they work in 2D – if the foam doesn’t fully smother the fire, the problem isn’t solved. Foam has to “see” and touch the fire to work.

Novec is a 3D extinguishant – it lives in the full space, not just on the surface. This makes the the entire area unable to sustain a fire. Pound for pound, it takes more foam and many more nozzles to fully cover an area because you have to cover all surfaces.  Think of it as though you were trying to paint your engine with pre-positioned paint nozzles… You have one chance to spray a full coat of paint on every surface, including  the nooks and crannies. That’s not an issue with atomized Novec.

Powder is another agent with very good fire knock-down capabilities, but the vibration in a race environment compresses the powder in the cylinder, preventing it from discharging properly when you need it most. Consider that to be a warning to those who strap in a cheap hardware store handheld unit! The car environment is very unique compared to building or other applications.

Novec is also non-toxic and environmentally safe. It’s a 3D extinguishant, but it kills fire with a chemical reaction, so it is atomized in the air and allows you to breathe it with no side effects.

Learn More

Want to know more about Lifeline, Novec, and fire safety? Give us a call at 877-639-9648 or email info@bimmerworld.com – you don’t have to learn the hard way about how to properly protect both YOU and your track day or racing car.

 

 


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