You are a racer, which means you are a bit nutty. What I mean is you lie in bed at night and obsess over minute details of your car. The front toe setting is 1/32 of an inch off. Your differential fluid viscosity is too thick. The car is one pound too heavy. These are the things that only racers concern themselves with. This month’s Toolshed Engineer is going to help you lose that one extra pound that your racecar has, and we are going to do it with … science!
Unless you drive a formula car or a sports racer, most of us race a machine originally designed and manufactured for passenger transportation. That means it has a bunch of stuff that isn’t needed for racing around a track, namely sound-deadening material glued to a floor pan. Racecar drivers want their cars loud and light and this gooey, hard-to-remove stuff serves neither of those purposes. So, we want to get rid of this unneeded evil. If you have ever tried to use a putty knife and simply scrape the sound-deadening material off, you have realized that this material is seemingly welded to the floor pan. I’ve tried everything, elbow grease, chisels, hammers, and it is useless. The stuff simply won’t go away.
Most race shops have a torch handy, and you can heat the material up to the point where it becomes a black gummy mess that you can scrape off. You will burn most of your clothes off in the process, make an awfully smelly, smoky mess as you try to get all of this material off of the floor pan. Instead of using fire, you can use ice to solve your problem.
Not just any ice will fix your predicament. It has to be dry ice. Pick up a block of dry ice — a seven pound block costs around $20 — set it on the floor pan and wait a minute. It will cool the sound deadening material to the point where the adhesive is no longer affective. Then grab a big mallet and start pounding on the floor pan. Voila! The vibration of the mallet impact knocks the pesky sound deadening material right off the floor pan in little easy-to-clean-up chunks. Yes, science is awesome!
Be careful though, dry ice is dangerous stuff to work with. If it touches your skin it will burn you, badly because it registers at -109 degrees Fahrenheit. Use large leather welding gloves to handle the material. Once you have the right gloves and a nice big hammer, the process is easy. With one block of dry ice and 10 minutes, I was able to clear out the entire hatchback area out of an Acura Integra. The process is simple — and kind of fun.
Here is some “I-learned-the-hard-way” advice. 1) Use a large-faced mallet as opposed to a smaller metal or woodworking hammer. The dry ice makes the sound deadening material extremely brittle, but it also makes the floor pan brittle too when the temperatures are so low. I actually put a hammer through a floor pan with some overzealous whacking. 2) Before you go crazy making your racecar as light as possible, find out what your minimum class weight is. There is no point in taking away evenly distributed, low-center-of-gravity, safely mounted, weight from a car, just to have to add 10 pounds of weight in another manner to get the car to legal weight. We all want the lightest car possible, but sometimes looking at the bigger picture can save you a bunch of unnecessary work and expense.
When all is said and done and every square inch of sound deadening material is removed from the floor pan, you will be glad to know you have removed about the same weight as a bottle of water. I know, I know, you’re a racer and every ounce of weight counts. Plus, you won’t be able to sleep at night until every sliver of this stuff is removed from your floor pan. I get it. Sweet dreams and happy pounding. I’ll see you at the track.
