The Suspension Fire Story

AKA "that time we almost burned down Entropy Racing"

Posted by Roger on October 06, 2020
Oh my f***ing God... Go put that out! Go!

January 2013 - Entropy Racing HQ

Martin is a clever guy. Yes, he is prone to some oafish behavior and he occasionally does things that would make you question his maturity. But some of those antics later proved to be flashes of his inner genius, peeking out from behind the curtain while a chaotic comedy act took center stage.

One such incident would happen in January of 2013. Bodywork guru Travis had just finished putting a gorgeous yellow livery on ProjectCRX, and the car was back at Entropy Racing HQ. When the team arrived that morning, there was a pile of brake and suspension parts waiting for them. At the top of this small mountain of shiny new components sat one big black and red box - The Energy Suspension master suspension bushing kit.

Although these types of polyurethane bushing kits are no longer a necessity on newer cars, they remain a popular resto-mod upgrade to replace the disintegrating rubber in older sports sedans. Not only do they last longer than rubber, they also offer a stiffer construction that can better withstand the high-G cornering that you would typically experience at a racetrack.

The most difficult part of this upgrade is in removing the old rubber bushings. OEM rubber bushings are usually molded into a metal sleeve, which is then pressed into the suspension at the factory. The factory recommended method for removing these suspension bushings is to use a giant hydraulic press and precisely machined pressing dies. However, this is incredibly dangerous, unreliable, and most shops don't have this equipment laying around where a group of amateur racecar builders could get their poorly trained hands on it.

So, we went with the DIY method. Use a combination of a ball joint press, hole saws, and a Sawzall to press, bore, and slice out the stock bushings. The five of us went to work with Martin and Sean disassembling and removing bushings from the front suspension while Cessna, Andy, and Roger took turns tackling the rear.

Some of the control arms cooperated while others resisted. While the rubber inserts in the upper control arm anchors came out with little to no effort, the inner sleeves in the lower control arms refused to budge no matter what we did. The layout of the rear trailing arms further complicated our efforts. In order to get the new trailing arm bushings in, we had to cut out the 4" diameter rubber bushings while leaving the factory sleeves intact. This proved to be much easier said than done.

Automotive bushings are extremely resistant to cutting of any sort. Razor blades were too weak, the Sawzall would just jam up, and the rotary cutter produced so much smoke that we may as well be building a car in a coal mine. Eventually we settled on a hot knife technique. Andy would heat up a cheap Walmart steak knife with the propane torch and pass it to Cessna and Roger, who would use it to slowly carve the rubber bushing out of its housing. Emphasis on slowly. After fifteen minutes of work, we were halfway through removing one bushing.

Suddenly, a triumphant bellowing from Martin interrupted our work.

Hey! Check this out!

It seemed Martin and Sean had figured out a technique for freeing the stubborn front suspension bushings from the rusty lower control arms. The three of us spun around, hoping to see a set of fresh, bushing-less suspension members that the duo had produced while we were struggling with the rear end.

Instead, we were greeted to the sight of Martin brandishing one of the front lower control arms like an Olympic torch. And yes, "torch" is the most accurate word I can use to describe what we saw, as there were huge flames and a plume of black smoke emanating from the stock rubber bushings.

It turns out that Sean had seen us using the hot knife technique and decided that the fastest way to get the bushings out would be to melt the adhesive with heat. This is a perfectly valid and common technique that involves heating the control arm to melt the adhesive holding the rubber to the metal sleeve. There must have been a misunderstanding of the procedure, because what the pair had actually done was to point the blue flame from a propane torch directly at the exposed rubber instead.

Well, for those of you who don't know, rubber burns. In fact it burns so well that model rocket enthusiasts use it as a propellant for their larger rockets. And once it gets to the point of where it's hot enough to produce flames, it's actually quite difficult to extinguish.

Curiosity turned to panic as we realized that not only was the shop filling with putrid black smoke, Martin was standing just a few feet from a pair of bright red gas cans. Andy stood in wide-eyed disbelief at this fiery display while Sean laughed at the sheer ridiculousness of the scene. The safety-conscious Cessna sputtered as he tried to comprehend the explosive disaster that was unfolding in front of his eyes. After what seemed like an eternity, someone finally regained enough composure to yell at Martin.

Oh my f***ing god... Go put that out! Go!

The team quickly cleared a path so Martin could run the burning suspension member to the sink where he could douse the flames under tap water. But to everyone's surprise, he did an about-face and ran towards the open garage bay door instead. Panic turned to confusion as we all wondered what he was doing. It was the middle of winter in Pennsylvania, and the outdoor spigots were all turned off. There was no water outside.

But Martin wasn't looking for water. He was looking for snow. Somehow, he instinctively knew that pouring water on burning, half-melted rubber would come with its own dangers. Instead, he ran towards the nearest snow drift and stabbed it with the exaggerated pose of a matador plunging a sword into a bull. After a brief pause, he turned around with a beaming smile. In his gloved hand was the control arm, magically cleaned and devoid of any of the old rubber bushing that we had so much trouble removing.

It turns out that the prolonged exposure to high temperatures had fully separated the rubber bushing from the control arm. Normally this would stick to the metal sleeve again as it cooled. But by immersing the bushing in snow, Martin had flash-cooled the outside surfaces of the rubber, hardening it sufficiently so it wouldn't have a chance to get stuck to the metal. The same theory applied to the congealed grease that was caked onto the outside of the control arm. By ramming it into a pile of half-frozen water, he had successfully hardened and abraded all that nasty black tar away, leaving us with the nice clean control arm that we needed.

To this day, I can't tell if this was a wild coincidence or if this was some sort of brilliant plan that Martin and Sean had hatched up while we were too busy futzing with the textbook method. At the time though, none of us cared. As Cessna quietly shuffled the gas cans away, I sheepishly brought a humble request to the now-exuberant pair of pyromechanics:

Hey uh... can you do that again for the other side?