Cryogenics - fact or fiction
Roger Penske made ‘The Unfair Advantage’ famous but I suspect that from day one racers have been looking for that little extra that gave them a perceived advantage, either real or imagined. I am going to start a series of articles that look at products and processes that are used by racers that might or might not offer an appreciable advantage. Some of it is black magic that needs to be appreciated for what it is and may make sense for some applications. The first we are going to investigate is cryogenics.
A cryogenic treatment utilizes liquid nitrogen to bring the temperature of the parts down to -300°F. The parts are then kept at this temperature for 24 hours. This relieves the residual stresses and produces a more consistent and uniform material. The benefits of this process are increased part life, less wear, and potentially improved performance. One area where it has provided a significant increase in life is in cutting tools and bits. The increase in life for these parts is documented and impressive. Another area it is used in with great success is on brake rotors in police cars, buses, fire trucks and yes race cars and karts. It has also been used in the past for a variety of parts including non-ferrous engine parts and complete ignition systems.
Frankly, I question how it can offer an advantage when used on non-ferrous parts as there can be no resulting realignment at the molecular level. However, there are proponents within the karting industry that claim it offers some advantages. It is currently being used on cylinders, heads, cranks and other parts. However, I am not convinced this doesn’t fall into the imaginary benefit category.
The use of cryogenic treatment of ignition systems and spark plugs is an area on which I will reserve judgment. There are kart and motorcycle racing teams treating entire ignition systems and are claiming a noticeable increase in hp but I am having trouble understanding why/how. It is possible that the treatment reduces the resistance in the cables and connections within the ignition module but I am not sure how that would equate to an increase in power output. A major motorcycle drag racing team is looking at doing some actual comparative dyno testing and if this happens in the summer, I will try and share that information.
Where there is extensive and documented proof of cryogenic treatments offering some help is in brake rotors. As I mentioned, it is used by police forces and fire departments where they see a significant and cost-effective increase in the life of the brake rotors. Does that translate into any kind of advantage for us? Notice that no where did I say that a cryogenic treatment of a brake rotor for a race car would offer a performance advantage as defined as a lower lap time. What it may offer is longer rotor life and durability in endurance races. We have experienced cracked rotors in the Robo Pong 200 for example. While I don’t expect the treatment to make us faster, I hope to show that the treatment, which isn’t very expensive, will be cost effective by providing a longer life plus provide a more reliable part for longer races. The cost is in the $35 range for a rotor. Given that a rotor runs in the $150 range and we normally use 2 per year, if we can extend the life so we can go the entire season on one disk, it will prove to be very cost effective.
We normally replace a disk when we see significant cracking which occurs around the drilled ventilation holes. These will extend out to the edges of the disk and will eventually result in a failure. This is particularly an issue at an endurance event where we have seen catastrophic disk failures. We are having two disks; both used but neither showing cracks, treated. Our goal is to run one disk all year and save the other for the Robo Pong race. We will monitor the disk closely and see if any cracks begin. Do we expect any miracles from the treatment? No but it will be interesting to see if we detect any difference from past seasons.
I haven’t talked to anyone who believes this treatment offers a lap time advantage or impacts the short-term durability of rotors including the person I am about to reference. That person was a team manger for a major CART team whose team owner mandated that they treat the rotors for each car prior to every race. The thing was that they replaced the rotors every race so they never saw the real advantage offered by the treatment but ‘it wasn’t very expensive so why not..’. There are a lot of ways to spend money in racing that don’t translate into wins but sometimes spending a little more upfront saves a bunch later on. The trick is to figure out where it makes sense to spend that little extra and where it doesn’t.
Coming shortly will be a look at REM Microfinishing, something that is used by virtually every major race team in the country along with some major kart shops plus a look at a new, exciting rear axle bearing.