23 Oct DT.:M:. – Cold As Ice
We return to the coverage of M’s DTM-for-the-streets build today with a chilling tale. No, seriously, it’s literally bone-chilling.
Reducing the overall weight of a car is necessary when you’re trying to build a car that can perform on both the street and the track. Both aftermarket fabrication specialists (like us) and OEMs (like BMW) recognize this. However, many track ready daily drivers still contain a large amount of creature comforts from the factory to keep consumers happy on both the street and track. One of the ways that OEMs utilize for this comfort is sound deadening. Also known as Dynamat, it’s a material that adds a little weight, but helps to cut down on unwanted vibrations and noises that may otherwise ruin a nice drive. Some owners like it, while others will choose to get rid of it for the sake of that weight reduction. Our customer, known only as the single-lettered M, is in the latter camp.
Now, Dynamat is not necessarily easy to remove. As the material is meant to remain in place for the life of the vehicle, it’s connected to the body’s sheet metal using a high-strength adhesive. That adhesive can spell all sorts of trouble when you’re trying to remove it, especially if you don’t want to screw up the sheet metal underneath. However, utilizing a solution taken from the age-old gum-in-the-hair problem, we’re able to make it a bit easier.
That white block you see on the Dynamat above is solid carbon dioxide, otherwise known as dry ice. Dry ice sublimates (moves from a solid directly to a gas) at approximately -109 degrees Fahrenheit, and it does not harm sheet metal via direct application, making it perfect for removing Dynamat. After applying the dry ice directly to the Dynamat’s surface, we let it sit for a minute or two before moving the block to another part of the car. We then take the newly-frozen chunk of Dynamat and chip it away.
Even though it’s frozen, it’s still a little bit of a pain in the ass to remove it. You have to act while the Dynamat is still cold, but it won’t lift up in giant sections, instead choosing to chip off a little bit at a time. If you can get a chisel underneath a large portion, it speeds things up a bit, but there are many small contours and curves that require a bit more finesse, making the job a bit tedious and rather messy.
Some spots are trickier than others, as well. BMW did a very good job of deadening the body to unwanted sounds, meaning that Dynamat found itself in some rather hard-to-remove places, such as the side of the trans tunnel all the way up by the firewall; for that one, Zak laid down a blanket so he was at least halfway comfortable. Furthermore, there was another section of Dynamat near the trunk that refused to give up its adhesive properties after being frozen. This also took a bit more effort, requiring help from both the chisel and a small grinder.
With a little extra help from the grinder to remove the final bits of Dynamat, we then applied some thinner to get the last little bits off, wiping and cleaning as we went from section to section. As you can tell, there was a good bit of vacuum usage, as well. After all, the Dynamat itself won’t sublimate into thin air.
And with that, we have ourselves one lighter and louder vehicle, ready for our next nefarious step.
Now, obviously this isn’t the final step in making this car. As a matter of fact, we’re only at the beginning of our coverage, so stay tuned in the coming weeks as we dig deeper into this one-of-a-kind custom E46 M3!