Category Archives: Tech

things you should know about track days

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A track day is the best place to go out to learn how to drive quickly and explore the limits of handling. Instead of the trees, cliffs, cyclists, police, and oncoming traffic found on your local canyon run, race tracks have wide open runoff space, no speed limits, and friendly driving instructors. If you are interested in driving fast and haven’t been to a track event, get your dumbass off public roads and sign up. Occasionally, accidents happen, but the race track is about as safe of an environment as you can find to drive fast. That said, it doesn’t mean you should show up completely unprepared.

Like I said, track days are safe, and they require little extra equipment. About all that is required is to wear a helmet, closed toed shoes, and long pants. So get a helmet, or borrow one. Actually, many events even have loaners, but having your own that fits well and doesn’t smell like feet is pretty nice.

The other things you’ll want to do are make sure your car is in good shape, take out all the extra junk, and bring a few things.

On the car standpoint, you obviously don’t want to show up with a big oil leak, low coolant, and worn out brakes. The brakes and tires are going to take some abuse, so make sure they are in good shape. Do a fresh brake bleed and pick up some good performance pads. you probably don’t need a full race pad the first time out but it won’t hurt. Bring spare or old pads along too in case you wear yours out. A secure battery tie-down and a cover over the positive terminal are required and they will check that in the safety inspection. It’s also sometimes required to have a tow hook installed. Many cars come with one that threads into the bumper after a cover has been removed, and then usually the tie downs under the bumper can be used.

Then clean everything out of the interior- foor mats, cd cases, shoes, all that crap in the center console, door pockets, glove box, etc. You don’t want the floor mats slipping under the pedals and you don’t want any of the other stuff flying around the interior when you’re out there. Plus it reduces weight. Bring your spare tire and stuff, but take it out when you get to the track and leave it in your pit area.

For your pit area you’ll want a few supplies. A cooler with lots of water, snacks, and maybe a sports drink. Sunscreen and a hat. I usually wear a dorky full brim hat for maximum sun protection and so do other people who are out there on a regular basis

A piece of carpet or a towel, a change of clothes, work gloves, and some rags would also be good things to bring, especially if you wind up working on something under the car. Some tracks even have showers. A chair or two will definitely be nice to have, and maybe an ez-up, as long as it’s not windy. They tend to become projectiles when the wind picks up and you don’t want yours landing on some guy’s Porsche cup car.

In addition to those basic items a few tools and the ability to use them are also a good idea. Being able to change a tire, bleed the brakes, or tighten a loose clamp or bolt comes in handy more often than not.

Now that you and your car are prepared to get on track, the only thing left to do is sign up. Get there early, don’t miss the driver’s meeting, and listen to your instructor. And start out slow- it’s not a race and you don’t want to wind up in the tire wall or upside-down the first time out.

For our next post we’ll be talking about safety equipment, but starting out a helmet is all you need.

 

Things you should know about alignments

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When it’s not a post about time attack, you’ll notice most of this site is dedicated to suspension related things. That should make sense given that this site was started to counter the “hellaflush” trend of ruining suspension. In previous post about bushings and coilovers and ride heights, I mentioned alignment quite a bit, but realize I’ve never actually talked much about it in detail, so here goes.

Simply put, the alignment is what direction the wheels and tires are pointed. Straight, right?

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things you should know about ride height v2

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It’s a pretty common train of thought that lowering a car improves the handling, because of the lower center of gravity. From a physical standpoint, that is true. Lower, wider, and lighter are all keys to improving how a car handles and reducing lap times. But that is not the whole story. Mostly this is because the suspension is designed to operate at a specific ride height/travel range- the one the manufacturer set. So when we go outside of that, some problems can arise. Continue reading →

things you should know about coilovers

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Lately we have read quite a few incorrect comments online about suspension and coilovers, so we decided to write something about it.

Firstly, let’s go over a few suspension basics. There are a few popular suspension arraignments, mainly the Macphearson strut, double wishbone, multi link, and solid axle. Basically every modern car is going to be one of these designs, but that’s not what this post is about. Regardless of the layout, there will be a spring to support the weight of the car and resist roll and pitching movements, and then a damper, or shock absorber, to control the motion of the body and suspension. Without shocks, the body could oscillate freely on the springs and that would not be good. Continue reading →

Things you should know about coolant

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This will be the first winter my car will spend in a cold climate in a few years, and I realized that my cooling system is in danger of freezing if I don’t add some anti-freeze. This brought me to look up the ideal water to coolant for cold weather usage, and then lead to much more research on cooling systems and how coolant works. I thought it might be a good idea to share results on how the boiling point, freezing point, and heat transfer ability of coolant change depending on the mixture. Also, this would have been easier if my thermodynamics textbook wasn’t in a storage unit 1000 miles away.

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Things you should know about suspension bushings

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Have you noticed how quiet and smooth most modern cars feel to something a few years older? Drivers are being increasingly isolated from the road with soft rubber, liquid filled mounts, and sound deadening. This is done to reduce what’s called noise, vibration, and harshness, or NVH, and the downside is often a reduction in handling performance and response. The enthusiast driver who actually wants to feel the road is stuck with a numb, disconnected feeling, sofa on wheels.

The nice thing is that there is a fairly easy and inexpensive way to regain some control and performance, in the form of replacement suspension bushings. Bushings are all the little rubber parts in our suspension that absorb vibrations and allow motion. Changing out these tiny, often overlooked bits makes a difference in a number of ways.


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Things you should know about anti-Lag

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Anti-lag is a very interesting technology that came about in the 1980s when rally cars started to use turbochargers. To fully explain it, first I have to explain what lag is, and why it occurs.

An engine is an air pump, and the more air that goes into a motor, the more power it will make. The primary factors that determine how much air is flowing through an engine are displacement and RPM (although in reality it is a little more complicated). As engine speed increases, so does the amount of air that goes through the motor. The same goes for displacement: a bigger engine moves more air and makes more power. Most of the time, we don’t have much room to increase displacement or revs. This is where forced induction, and the turbocharger comes in.

A turbocharger is a compressor spun by exhaust gasses. The purpose is to both reclaim some of the lost energy from the exhaust, increasing efficiency, and to increase the pressure of the intake air. Forcing more air (and the corresponding extra fuel) into the engine means that you can make more power with less displacement.

The downside is that it takes some time for the turbo to get going, especially when you are using a large turbo to make a lot of power out of a small displacement engine. Until the engine is moving enough air to spin the turbo, you’re stuck with a low displacement motor with low compression and no boost. This is called turbo-lag. In some cases you can compensate for the lag by increasing the revs to give you a larger in-boost powerband, but you still have that dead spot at low revs and higher engine speeds mean much higher stress on the engine components. Additionally, many racing classes require the use of an intake restriction, which limits the amount of air that can be drawn in, and therefore limits the maximum power and useful rpm range. These inlet restrictors will actually cause lag on all their own due to the fact that the turbo has to draw air through a smaller size hole.

The most simple form of anti-lag, used in the 80s, was to never lift off the throttle. This kept air going through the engine and the turbo spinning, but resulted in significant wear on the brakes and transmission, especially given that some rally cars were making over 600hp. Soon, systems were created to keep the turbo on boost even when the throttle was lifted.

To generate the low end power and response required by a rally car, it’s necessary to have the turbo spinning as soon as possible, creating boost before the driver actually presses the throttle. The simple way to do this is to keep the throttle partially open so plenty of air is going through the motor, dump a bunch of fuel, and then wait until the super-rich air fuel mixture is on the way out the cylinder before igniting it. Instead of having the combustion event force the piston down to make power, it explodes going into the turbo, creating boost.

As you might imagine, having the combustion occur in the exhaust is bad for the exhaust valves, exhaust manifold, turbocharger, and anything else in the vicinity like an EGT or O2 sensor. It sounds a little something like this:

The “add fuel, retard timing” form of anti-lag was used in the late-80s to early 90s, at which point rally teams began to come up with more sophisticated methods. Bypassing the combustion chamber entirely and injection air straight into the exhaust manifold allowed more boost at lower rpm. The Mitsubishi EVO VI, for example, came stock with an air injection anti-lag system that could be enabled simply by modifying the ecu. Then Prodrive came up with an even more complex system:

That little doohickey attached to the up-pipe is known as “the rocket.” A canister connected to the charge pipes stores pressurized air, and when the throttle is closed an air/fuel mixture is ignited in the rocket, spooling the turbo. This allows the 2.0 Subaru WRC motor to create useful boost (and 200hp) at the idle speed of 2000 rpm. By 2500 rpm the manifold pressure is 30psi, and reaches a maximum of 45psi by 3000 rpm. Peak torque is 520 lb-ft, and a little over 300hp is available from 3000 to the 7500 rpm redline. The important part about this system is how precisely it can control turbo speed and boost. By using a turbo speed sensor, this system is much more efficient, and allows more manifold pressure at lower revs with less wear to the exhaust components and turbo.