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      03-23-2021, 12:02 PM   #1
fleetfoot
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Drives: 2017 M2, 2013 E92 328i
Join Date: Apr 2013
Location: Atlanta,GA

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Track Day Attire: A better summer option than cotton? How about Merino wool.

This past weekend at Atlanta Motorsports Park, I finally got my E92 328i out on the track for the first time. I learned a lot, but I thought I’d share one specific thing since there doesn’t seem to be any previous posts on this topic. The following ideas are based on my experiences as an outdoorsman and doing some deep research on various clothing fibers online. If you have additional insights from your experiences please share!

TL;DR: If you don’t want to invest in a Nomex race suit yet, skip the 100% cotton clothing and wear Merino wool for a material that’s just as comfortable with much higher ignition temps, no melting, and WAY better cooling performance when you’re sweating.

As an avid outdoorsman, I was appalled by the HPDE requirement to wear 100% cotton on the track (for fire safety reasons) since cotton is TERRIBLE for temperature and moisture regulation, particularly in the summer when many driving events are held. Cotton tends to capture moisture, which disrupts your body’s natural sweat cooling system. No wonder everyone always looks so sweaty out there! You can read more about why cotton is a terrible performance layer here: https://www.outsideonline.com/178508...end-base-layer

Wearing nylon or polyester sports garments near flames is a bad idea, since those materials will melt at relatively low temperatures, which can lead to dangerous skin injuries. Cotton helps you avoid the melting problem but totally compromises cooling performance and the resulting sweat can boil and cause steam burns. Nomex solves the melting problem, but it’s fairly expensive for casual drivers and I’m not sure how well it wicks…I’m guessing not great since many manufacturers don’t list “wicking” as a feature.

As I purchased a $99 Nomex balaclava that looked very similar to my $26 Merino wool balaclava that I use for snow-skiing, the thought crossed my mind: “I wonder how Merino wool would do in a fire?”. Turns out it’s WAY better than cotton! Check out these ignition temps:
  • Cotton: 255 Celsius (no melting)
  • Nomex: 370 Celsius (no melting)
  • Rayon: 420 Celsius (no melting)
  • Polyester: 485-560 Celsius (but melts at 252-292)
  • Nylon: 485-575 Celsius (but melts at 160-260)
  • Merino: 570-600 Celsius (no melting)

Wow, Merino looks pretty awesome with no risk of melting and a much higher ignition temperature than cotton or even Nomex! Additionally, Merino is self-extinguishing, has a low rate of heat release, and forms an insulating char when it does burn. Per Sola (a company that makes fire-resistant technical clothing): “Wool’s natural flame resistance properties make it an ideal fiber for protecting firemen, military and anyone else exposed to fire or explosives. Wool’s attribute of only smoldering and not melting or dripping into the skin, can be a lifesaver.” If merino is good enough for firefighters, I think it’s good enough for me to drive in!

Now for those of you thinking, “no way I’m wearing itchy long-sleeve wool shirts and pants in the middle of the summer” go ahead and throw out your preconceived notions of what a wool garment feels like. Merino wool is super comfortable, and per my favorite gear site Switchback Travel, it’s “just as good of a summertime material as it is winter. We consistently wear merino wool for running, hiking, and mountain biking for its comfort across a range of temperatures. In the morning, it’ll keep you reasonably insulated, but you’ll be cool, dry, and ventilated once you start working up a sweat.” You can read more about Merino’s performance characteristics here: https://www.switchbacktravel.com/mer...is-it-worth-it

So, if you’re just getting started on the track, I’d suggest checking out some Merino clothing to stay safe AND comfortable. You’ll also be able to wear these things in daily life or under a Nomex suit if you buy one in the future. Here’s the 100% Merino apparel I bought after quite a bit of research:Total: $223

Comparable Nomex motorsports stuff:Total: $486

Here are a few of the sources that support my hypothesis that Merino is probably the best material for you to be wearing in a fire (beyond a Nomex suit):
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2017 F87 M2: MGM, 6MT, AA Tune, Eibach Pro-Kit, Fabspeed Catted Downpipe, Evolution Racewerks FMIC+Chargepipe, Autosolutions SSK, CDV Delete, Vorshlag Plates, PFC-08 pads, Apex EC-7 18x9.5"
2013 E92 328i M-Sport: BSM, 6MT, 3IM+AA Tune, BMW PE, M3 control arms, Eibach Pro-Kit, Bilstein B8, BMW SSK, CDV Delete, Apex EC-7 18x9"

Last edited by fleetfoot; 03-23-2021 at 03:14 PM..
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