Do you want to build a car for endurance series like the 24 Hours of Lemons, American Endurance Racing, ChumpCar World Series, Lucky Dog Racing League, or World Racing League? Here are my thoughts on that topic.
Cheap, fast, reliable: pick two
This post is about budget racing, so cheap is non-negotiable. Also, in my opinion, the whole point of racing is the driving. That means being on track, not running to the junk yard to find obscure parts. That means reliable is non-negotiable. The good news is there are lots of cheap and reliable cars out there.
BMW or Mazda?
When it comes to budget endurance racing, two brands stand out: BMW and Mazda. Popularity is a good thing. It means that maintenance, tuning, and repair expertise is near at hand and that spare part you need is probably already in the paddock. Mazda Miatas are the most popular track cars now, and have been for some time. They are robust and so light on consumables (fuel, tires, brake pads) that they are very cheap to run. In addition, they have the highest corner speed, which makes them incredibly fun to drive. Before the Miata was the de facto club racer, there was the RX-7, which is also a good choice.
BMW 3-series are rugged and handle extremely well. The BMW 325 in the e30 or e36 platform is a fantastic track car. Each one is almost as popular as the Miata, and e46s are also becoming very popular. Although less common, the 5-series cars also make great endurance racecars. The 2.5 liter inline six is plenty of motor. The 1.8 is very durable and burns very little gas, but few teams are able to make it competitive.
There are lots of other cars that make good endurance racers. Volvos are the most reliable in Lemons. Simple FWD cars like Civics and Escorts do well. If the car is light, which it should be to keep consumable costs down, you don’t need much power.
Build or Buy?
When sold, racecars return about $0.25 on the dollar. An inexpensive $10,000 build is only worth about $2,500. That’s bad news if you ever want to sell a car, but great news if you want to buy one. In order to be competitive in Spec Miata, you need a 1.8 liter engine these days. That means there are lots of 1.6 liter racecars available for cheap. You can also find RX-7s that were former SCCA/NASA racecars. Expect to pay more for an e30 (Spec E30) or e36 (Spec 3) racecar because they are (a) less common (b) more expensive to build (c) BMWs.
As you peruse Craigslist, RacingJunk, racing forums, classified ads, etc., you may come across some can’t miss deals. Some of these will see you spending more money than a Mazda or BMW in the long run, even if you picked it up for free. You know that car that you coveted in your youth? It will break your heart and your bank. Racing is hard on cars. Use your head, not your heart.
If you decide to build a car, there are certain things you absolutely have to upgrade or at least replace.
- Brake pads. Stock brakes are generally fine but OEM pads are not meant for racing. Brake pads work in defined temperature ranges. OEM pads are designed for stopping you when the pads and rotors are cold. Race pads are for when the pads and rotors are hot. At a minimum, get a ceramic pad designed for autocross. But you really want a pad that was designed for full on racing. Replace all the rubber hoses and replace the fluid with something designed for racing.
- Suspension. Replacing tired/worn suspension isn’t necessarily going to make you that much faster, but it will prevent you from getting into some bad situations and help you drive out of those you do get into. It’s okay to have some body roll, but you don’t want the car bottoming out or wandering around on you.
- Oils. Replace fluids as often as you can. Frequently changing engine, transmission, and differential oils prolong the life of those components, which means you’ll have fewer lost days at the track. In endurance races, cars go home early all the time due to failures in these components.
- Tires. The simplest way to improve the performance of your car is to upgrade the tires. There are a large number of 200-ish treadwear tires on the market. Some are stickier than others and those also tend to wear out the soonest. See the end of the post for more thoughts on tires.
- Fueling. Another really simple way to improve your performance is to spend less time in the pits. Remove the ball valve in the fuel filler neck and figure out how to safely empty a 5 gallon tank into your car in under 30 seconds. Fuel spills can take extra time to clean up, so make your fuel filling routine as foolproof as possible.
Every racecar needs at least one camera and some kind of telemetry device. Cameras are important for training and critical to untangle fault in an incident. Don’t go racing without a camera. It should be mounted to the roll bar with the driver in the field of view. Adjust the vertical position of the camera so that it also captures the rearview mirror. There are so many choices when it comes to cameras. You can go with the usual GoPro, but even dashcams are fine. I have a Mobius ActionCamera powered by a USB cable connected to the cigarette lighter. It shoots whenever the kill switch is on. It is set up to record in 1080p and lasts about 10.5 hours with a 64GB card. I also have a Tomtom Bandit for head-mounting and other uses.
To improve your driving, some kind of telemetry device is very helpful. There are two basic flavors: (1) immediate driver feedback (2) data loggers. Some devices do one, others do both. For driver feedback, I like the RumbleStrip DLT1-GPS. It shows your current speed and lap delta (difference between this lap and last lap at this position in the track). For data-logging, I use an Aim SoloDL. While the Aim also does predictive lap timing, I like the big red LEDs on the RumbleStrip. Smartphone apps can also be very useful. They have the ability to do feedback, data logging, and even video overlay. But the quality is usually a little less. An external GPS unit can improve things I hear, but I prefer dedicated devices.
Budget endurance racing series have converged on tires with 200 treadwear ratings (and some allow 180). There are a lot of tire choices. One of my favorites is the Falken Azenis RT615K in 195/60/14. Yes, 14″. These routinely go on sale at Discount Tire Direct, and with free shipping and no tax, you can have them shipped to your door for about $85 per tire. They have good grip and are very durable. You can get about 25 hours of racing per set. If you have a Miata you may already have the 14×6 7-spoke rims that weigh less than 11 pounds. If not, you can pick them up cheap. BMW e30s came with 14×6 bottlecaps that weigh about 14 pounds. The nice thing about these rims and tires is that they are a breeze to mount with a $40 Harbor Freight manual tire changer. Wider tires with shorter sidewalls are a pain in the ass. The problem with 14″ rims is that there isn’t much choice for tires (there are Dunlops in 185/60/14, but they are much more expensive). Also, wider tires are faster.
Once you get to 15″ wheels, there are over a dozen that have 200-ish UTQG ratings. The sticky ones, like Bridgestone RE-71R, tend to wear out quickly. Although the treadwear rating is supposed to be indicative of how long they last (and therefore inversely proportional to grip) this number is controlled by the manufacturer (and their marketing department). Some 200-ish treadwear tires are more like 100 and some are more like 300.
- BF Goodrich Rival – they are on the quiet side
- BF Goodrich Rival S – never tried them, but they are often equated with RE-71R
- Bridgestone RE-71R – fastest 200
- Bridgestone RE-11A – middle of the road
- Champiro SX2 – no idea, but some time trial folks win on them
- Dunlop Star Spec II – most popular?
- Falken RT615K+ – equally most popular?
- Federal 595 RS-RR – cheapest and surprisingly good
- Hankook R-S4 – liked the R-S3, and this is supposed to be better
- Kumho V720 – seen bad stuff happen to these
- Maxxis VR-1 – more PSI-sensitive than others I hear
- Nitto NT-05 – lots of audible feedback, cheaper than most
- Toyo R1R – supposed to be very soft, good for rain
- Yokohama AD08R – also supposed to be a good rain tire
In the UK they race Jaguars as if they were crap cans…