New composite bodies take pole position in NASCAR

Fuels |  2 min. read

After Tyler Reddick won this year’s NASCAR Xfinity Series’ MoneyLion 300 at Talladega Superspeedway – he figured that a year ago, if he’d driven the same track, the same way, he would have lost.

That’s because last year he was driving a steel body car, and this year?  NASCAR’s new carbon fiber composite car.  So early in the race, when Reddick had a close encounter with the wall, as he told Autoweek:  “It hurt the car pretty bad.  I’m not sure if the steel body would have handled that as well as the composite.”

His crew chief was sure though.  Here’s how Randy Burnett broke it down for Autoweek:  “If it were the ol’ steel body, it would have done more damage and hurt us more. … I think the composite bodies are very durable.  Same thing when he won the championship last year.  He kept hitting the wall at Homestead and you can’t do that with a steel body.

“With the old car, that contact would have destroyed the car and gave a lot more work to do.”

The new car, which is now THE car for all of NASCAR’s XFINITY series races, looks like the old car – but instead of that old steel body riveted and welded together – this car body is assembled from 13 panels that basically snap together, and bolt onto the chassis.  As Reddick and Burnett can testify, the composite body is stronger.  It’s also lighter, and because it’s assembled in snap on/snap off panels – it’s a lot easier and faster to fix, in case you overdo your Darlington Stripe.

Ok, so now you’re wondering – what IS this composite car body all about?  For starters, we’re talking polymers (or to be old school about it, plastics).  But composite means we’ve got a mix of materials, so we bring in carbon fiber to reinforce that plastic.  And it’s not just any old plastic either.  This high-tech polymer is from a chemical family called epoxides (aka epoxy resin).  Epoxy keeps those fibers in place and produces a material that is lightweight and as strong as steel.  Then layer those sheets of carbon fiber, with the fibers of each sheet going in crisscross directions (for added strength).  Finally, you can laminate or “sandwich” those sheets between a material like fiberglass on the outside.  (And in the case of these cars, apparently there’s some Kevlar® in there too – which you know is tough, because it’s the stuff they make body armor from.)

The chemistry of all that (because that’s where the magic is) looks like this:  the carbon fiber itself is often made from polyacrylonitrile (PAN), which starts with the building block propylene.  The epoxy?  Also from the petrochemical propylene.  Fiberglass?  Glass fiber in epoxy.  And Kevlar®?  An aramid fiber, made from benzene and xylene.

And maybe that’s just right, that the new NASCAR cars are built out of materials made from petrochemicals, which come from petroleum (and natural gas).  After all, what makes NASCAR run is another petroleum product – gasoline.