The number one reliability issue to deal with for track day driving is heat. The buildup of heat affects all automotive systems and track driving results in heat the way street driving cannot touch.
Introduction to Track Day Vehicle Modifications
by Michael Allen
March 17, 2014
I’ll admit it. I am an instructor and so I need to start with a lecture. Car modifications are not for beginners. First of all, it is highly unlikely that you will be going fast enough to need car modifications. And there is no modification more important than you. If you are hell bent on spending money, spend it on driver improvement. Sign up for a school, book some time with a coach, buy a great video-enabled computer and subscribe to iRacing. Read Going Faster: Mastering the Art of Race Driving by Carl Lopez. Once you begin to test the limits of your car, and that is highly unlikely given the capabilities of even average modern cars, then it may be time to look at track-oriented modifications. Realize that the more modified a car is, the less comfortable the car becomes for everyday use. There are many stories of people who start out using a daily driver and end up with a track dedicated vehicle that is no longer street legal. There are also many stories of people who make modifications and then make additional ones as their goals and needs change. Plan out your modifications and start by realistically setting goals for yourself and your car. You do not have to break the bank either.
Safety and Reliability
The first two issues to consider are safety and vehicle reliability. Safety is top priority. Invest in a harness bar and two sets of harnesses. Make sure your seat has slots to accept the harness straps. If not, a racing seat is another modification. Purists will tell you that harnesses are not safe if not used with a roll bar and racing seats. Get a mount on the base of your passenger seat and have a fire extinguisher placed where you can reach it. Invest in a head and neck restraint system.
The number one reliability issue to deal with for track day driving is heat. The buildup of heat affects all automotive systems and track driving results in heat the way street driving cannot touch. Since brakes are the most important, let’s start there. Brake fluid can boil with repeated application lap after lap. Changing to a Dot 4 brake fluid is a cheap and easy modification. This will give you a much higher operating range. Examples are ATE Super Blue or Type 200 (amber colored) or Motul RBF 600. Track oriented brake pads are another must. These also give you a higher operating temperature range. They may squeal like hell, but they will stand up to repeated heavy braking applications. Consider what happens on a track like Sebring. In 3.7 miles you are braking hard before 17 turns in a two to three minute period one lap after another. This is much more frequent braking and harder braking than you ever will experience on the street and with no time for the brakes to cool before being called upon again. Get yourself some steel braided brake lines. These will reduce that squishy brake pedal feeling as temperatures rise and they will hold up better than your stock rubber lines. Finally, another low cost modification is brake ducts. A high temperature hose run from the grill back to the rotors will decrease heat by about 30%. The more air you can get on your brakes the better. This will increase performance and also increase the life of the brake components. Your pads and rotors will last longer and this will save you money. In this regard also consider removing the backing plates behind your rotors to increase airflow. You do not have to go out and buy that big brake kit for your car for thousands of dollars. These four relatively inexpensive brake system modifications will give you the performance you need for track day driving.
Other things you may need to do, depending on your particular car, relate to heat buildup as well. Aftermarket oil, transmission and differential coolers are available for most makes. These will allow you to stay on the track longer and avoid damage to major components. Larger intercoolers are often needed for turbocharged cars to avoid heat sink during track driving. Free flowing air into and out of the engine also helps reduce heat issues.
Oil starvation may be an issue for cars that do not have dry sump oiling systems. The fixes can include deeper and baffled oil pans and oil accumulators from Accusump and Canton. We have a Lancer Evolution X MR with a dual clutch transmission and my wife got a transmission heat warning at a recent track day. Before going the route of spending money on an expensive aftermarket big transmission cooler, I bought a $60 fan from Spal and mounted it to the back of the rather small stock transmission cooler. I wired it into the fuse box. At our next event, we will see if that eliminates the transmission overheating issue.
Street cars are softly sprung for ride comfort. This makes for a lot of instability at track events. You basically want a stiff platform with not a lot of dive and lean. Stiffer track-oriented springs are the first line of defense. Larger anti-sway bars will also keep your car stable in turns and will not affect street driving at all. These, again, are a relatively inexpensive modification and will improve your car’s track handling and stability. You do not have to go for that racing oriented coil over kit costing thousands. Stiffer springs and larger anti-sway bars are all that you should need for track day driving. Make sure your springs are not just meant for lowering. They should be stiffer and meant to improve ride stiffness.
There is no greater change that you can make to improve lap times than tires. I did a lot of track day events when I first started and I wore out my street tires in no time. It was more cost effective to get a set of wheels and track dedicated tires than to keep buying new street tires every six months. I had a Porsche Boxster at the time and it was easy to find a deal on take-offs. Take-offs are the stock wheels that people replace with those big 19 and 20 inch wheels they buy for looks. You do not want big wheels for track driving. Eighteens are about spot on for track days. Back at the time I had my Boxster, we did not have as many choices as we do now in terms of track tires. We used Hoosier slicks and Michelin Pilot Sport Cups back then. The Hoosier slicks presented problems in that you could not drive to the track on them. You either had to trailer the car or find a way to trailer the tires. Some shops that do track support will bring your wheels and tires to the track for you and put them on and take them off for you for a price. They will change your brake pads at the track as well. The Michelins were expensive and were also not the best for driving in the rain. Today there are many tires available that will give you high track performance and allow you to drive to and from the track. These include the Kumho Ecsta Xs, Nitto NT01, BF Goodrich g-force Rivals, Yokohama ADVAN A048, Dunlop Direzza Star Specs, Toyo Proxes 888 and others. There is nothing like driving to the track on your track tires for convenience and hassle-reduction.
You may have noticed that I have not yet talked about power. This to me is the last area to think about as far as modifications. You will go faster on a track by focusing on driver improvement, brakes, suspension and tires than by going for bigger horsepower numbers. If you must, getting more air flow is a way to go. Consider a cold air intake first. The next step would be a free flow exhaust system and then a free flow or stainless steel intake manifold. These modifications will not only increase horsepower and torque numbers, but will also reduce heat and possibly yield reliability gains for the major drivetrain components as well. A tune-up can offer assistance in the power and reliability areas also.
The Scientific Method
If you do modifications, use the experimental or scientific method. If you make many changes at one time, you will not know which contributed to any improvements. Try to stick to one change and then do several track events. Get used to that change and adjust your driving to it, before you do the next modification. Evaluate the mods one at a time. Spread out your research, obsessing time and budget and just concentrate on enjoying the hobby for the long haul.
A Cautionary Tale
Beware that modifications may void the warranty on new cars and can also interfere with your development as a track driver. I had a track buddy who got himself a Porsche 911 Turbo and brought it to a shop for modifications right away. It wasn’t enough that the car came with about 450 horsepower. He had new bigger turbos put on and increased his horsepower to 550. I was behind him coming into turn 17 at Sebring and I was catching him all the way through the turn. I was on his bumper at track out and thought I had momentum on him. As soon as he was pointed straight he hit the afterburners and took off like a rocket ship. My friend eventually blew the engine. He went to Porsche and they rejected his warranty claim. They sat down with him for a meeting and had printed copies of his forum posts wherein he talked about having modifications done to increase horsepower. Dealerships will monitor forum posts if they need to. That was the end of the conversation. He ate the cost of a new Porsche engine and retired the 911 Turbo from track days. His next step was to buy a race prepared Porsche 944 to use as a dedicated track day car. Mind you, he was still in the intermediate group getting instruction at this point and was considerably slower than when he was using the 911 Turbo. He said that before the 944 he felt like a world beater on the track and was “eating a lot of humble pie.” With a lot more experience, instruction and some private coaching, my friend went on to become an excellent driver and the chief instructor of a major club region. His progression had much more to do with his personal development as a driver than that 550 horsepower rolling explosive.
List of Modifications
Harness and harness bar with proper seats
HANS or other head and neck restraint device
Steel braided brake lines
Remove brake backing plates
Dot 4 brake fluid
Track brake pads with proper bedding-in procedures
Slotted or cross drilled rotors
Titanium brake shims
Thicker anti-sway bars
Deep, baffled oil pan
Cold air intake
Free flow stainless steel exhaust
Stainless steel intake manifold
Larger, front mounted intercooler
Bigger fuel and oil pumps
Track wheels and tires