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Drag Racing Christmas Tree Ultimate Guide (2020)

The drag racing Christmas tree, or lights, is the first step in getting serious about drag racing.

Drag racing can be as simple or as complicated as you want. Want to be the top 1% and utilize analytics for your racing operation? Follow Timeslip Charts.

Want to drive your grocery-getter to the track and run for a couple hundred bucks?

Either way, no matter what you’re driving or how much you spent, we all have to look at the same thing before a race.

Understanding the tree is without a doubt the key to winning or losing in drag racing. If you want to understand the lights and gain an advantage as a newbie (or fan) to drag racing, you’re in the right place.

So let’s get started.


Click a chapter title to jump straight to that section, or continue reading to start from the beginning.

Chapter 1: History of the Christmas Tree

Chapter 2: Pro Tree & Sportsman Tree

Chapter 3: Staging for a Drag Race

Chapter 4: How Drag Racing Reaction Time Works

Chapter 5: AutoStart, TruSTART, and CrossTalk

Chapter 6: Practice Tree Simulators


History of the Christmas Tree

Can’t know where you’re going unless you know where you’ve been. Or something like that. 

The history of the tree is fascinating. Knowing a bit about the history of a sport is what separates people like you and me from the filthy casuals. 

When drag racing was first created, they had a flag man stand out just in front of the cars to start the race. They would line up the drivers manually, then he’d wave a flag to signal the start of the race. 


As you can imagine, this was unsafe.

It got even worse when they started to implement head starts into the races. They just moved the slower car up a couple car lengths. The flag man would have to stand waaaaay out in front of both cars so he could be seen. The faster car would then come flying by him using 1950s tires on 1950s pavement.

Who created the drag racing Christmas tree?

1868 saw the first red/green signal on the streets of London. 1912 had a red/green signal in Salt Lake City. In 1920 Officer William Pots introduced the first three color street light signal.

Who invented the drag racing signal though is a slightly different argument. The best I could come up with is that a couple people started working on different versions all at the same time.

We’ve all debated with friends over whether it was Newton or Leibniz who invented calculus. Sometimes people just think of stuff at the same time.

But who could blame them back then? Drag racing was getting bigger and the flag man just wasn’t cutting it anymore. People were fighting over who left first, who redlighted or not.

The human red light.

Older drag race legends will tell stories about certain “tells” from the flag men: an arm twitch or a squint just before he threw the flag. This was their cue to go, they said, and not the flag.

Just like how you don’t wait until green these days, it was the 1950s version of leaving on the third amber.

The craziest part is that drivers used to have a three-strikes rule for foul starts. I suppose when there was still so much human element to the racing, there had to be a bit of wiggle room. (If anyone has more information about this rule, comment below!)

Things got a little better when they instead had the flag man hold a button with his flag. When the drivers were lined up just behind a sensor beam, a green light came on above the lane, which only meant they were ready.

When he threw the flag, the stick released the button. If the beam across the track was tripped before the button was released, the driver had foul started. 

Ollie Riley, W.H David, and Lew Bond

One story goes that NHRA Safety Safari shot-caller Bud Coons met with Riley in the mid 50s to begin working on a system to replace the flag starter.

Another goes that W.H. David from Lafayette, Louisiana, president of Pel State Timing System created two separate light poles with four lights as the first system.

photo courtesy of the NHRA

Why’s it called a Christmas Tree?

One source says W.H. David created a small mockup of his first design and used small glass Christmas lights. The name “Christmas tree” wasn’t adopted until much later; it was originally called the Countdown Starter.

They say David sold the rights to Riley at Chrondek so they could mass produce it. (Oh hey, look, Riley is in this story too.)

A third story goes that the NHRA National Field Director Ed Eaton approached Riley (this guy!) in 1962 with idea of a “step-light countdown.” They brought in Division 1 director and owner of Dragtronics Lew Bond to work with Riley on the project.

This is the official version of history from the NHRA, with photos of Eaton (left, below) and Bond (right) to prove it.

Photo courtesy of NHRA

The first official race with this tree was the 1963 US Nationals at Indianapolis. Some liked it, but most of the older drivers disliked it. They’d spend many years learning the “tells” from the flag men and now their work was wiped away.

To begin, the pro categories of the time had only the final amber light come on before the green. But they still needed handicap starts for some categories. They created a way to delay the sequence between the two sides of the new Countdown Starter.

Time to math.
Yellow yellow yellow yellow yellow yellow yellow yellow yellow yellow yellow yellow yellow GREEN!

Switching to three amber bulbs

As I mentioned above, the pro categories only had the very bottom bulb flash. But sometimes the bulbs would burn out and when their bulb didn’t light up, this affected the race.

The bulbs began flashing all at once (like we see today) when they moved to a three-amber tree in 1986. Going from five to three ambers on the sportsman tree was also able to cut one second from every sequence. This added up when talking about an entire weekend of racing.

Incandescent to LED bulbs

The final major switch for trees was the change from incandescent bulbs (that is, bulbs with little filament wires) to LED bulbs in 2003. The NHRA went through about 20 lights every weekend because Top Fuel and Funny Cars would roar past and break the little filament wires inside.

Because LEDs were instantly on/off instead of fading on and then off, reaction times from the pros improved by a few hundredths of a second. After a couple of years, some classes ended up adding a “filter” to change the true delay of the lights. (More on this in a second.)

I remember this switch, and I got to run my final year in Jr Dragsters with the new bulbs. I was awful the new lights. With the gentle fade on and off of an incandescent bulb, I was able to split the third amber into fifths in my head. Leaving at 2/5, or not quite fully illuminated at its peak, I was able to solidly get .02x reaction times all day long. In Jr Dragsters, this was plenty good enough for a track championship the year before. 

With the new bulbs, I found myself having to try building in a slight delay. I would need to wait roughly two tenths after I saw the bulb before leaving. This was not an efficient way to react. It took me longer than I care to admit to adapt to these new lights in Jr Dragsters.


Pro Tree & Sportsman Tree

These days, there are two basic styles of tree:

PRO TREE is where all three ambers illuminate at once, then the green.

SPORTSMAN TREE (or more often called “full tree”) is where each amber turns on then off in a sequence, starting at the top and ending on the green.

You could also put “instant green” style heads-up racing in there too as the third type. This style is popular at outlaw and no-prep events. This is where the ambers don’t light at all (or very, very quickly flash) before the green. I’m not entirely sure how this differs from a 4-tenths pro tree in practical terms, but I suppose if nothing else it’s a way to distinguish the racing from an organizational event (ie NHRA).

.400 Pro Tree

Pro tree, if you read through the history above, is the representation of a flag drop. It’s a signal that typically means go right now. Because of rollout, most are able to simply stare at the tree and go the instant they see anything light up. By the time the car leaves the beams, the green light will be on anyway.

However there are a few exceptions. To start with, know that trees are also separated by how long each yellow light is on. Pro tree (like for Top Fuel) is usually a “4-tenths” pro tree. This means all yellow lights will be on for 0.400 seconds, then turn off, then the green.

In the NHRA, this tree is used by the professional categories (Top Fuel, Funny Car, Pro Stock, Pro Stock Motorcycle), Pro Mod, Top Alcohol Dragster & Funny Car, and the Super categories (Super Comp, Super Gas, Super Street). IHRA would be similar: the Professional categories and Super categories use it. Other organizations that feature similar heads-up classes (like 10.5 tire classes or Pro Extreme etc) frequently use this too.

.500 Pro Tree

Some events and classes feature a 5-tenths pro tree. This means the yellow lights are on for exactly half a second before the green comes on.

A popular example would be in the NHRA’s Super Street category. This is an index class where everyone has a door-car (as opposed to a dragster or roadster) and is dialed 10.90 in the 1/4 mile.

Switching to 5-tenths pro tree is common any time the cars involved aren’t fast enough for a 4-tenths tree. All this means is that on a 4-tenths tree the same cars would get for example .130 reaction times instead of .030. The hope I think is to eliminate jumping the tree (that is, randomly guessing to improve your reaction time. The ego boost to seeing a better reaction time on the ticket is an added bonus. 

.370 / .470 NHRA Pro Tree and the “Filter”

After a few years running the LED bulb, some teams in the NHRA weren’t happy with quicker reaction times. Being more of an instant on, they were red lighting a lot. Rather than engineer a solution or adjust to the new lights, some instead lobbied for the NHRA to bring the rules to them.

A “filter” (officially referred to as an LED Compensation) is now applied to the tree to reduce the time between the flash and the green. The result was making the green come on .030 of a second quicker. Anyone consistently going -.015 red could now enjoy .015 lights. Huzzah!

Per Compulink, Top Alcohol Dragster & Funny car, Sportsman & ET motorcycle, Super categories (Super Comp/Gas/Street), and Jr Comp are all given the LED Compensation. I believe Pro Stock Motorcycle is too, but I’m waiting on a reply as to whether the other pro categories use it. 

.500 Sportsman Tree aka Full Tree

If you want to start drag racing, chances are you will be using the five-tenths full tree. If you go to any street night event at your local track, they default to the full tree. The largest group of organized drag racers run a format called “bracket racing.” This is the handicapped-style racing that is more budget-friendly. It involves a much heavier dose of driver skill (mental skill, mostly) than just plain outspending your opponent. These groups all primarily use the full tree.

When the tree was five ambers, drivers were waiting for them all to flash in a sequence that lasted 2.5 seconds. Now, it’s a shorter 1.5 second sequence. 

But what happens when drivers get antsy? What happens when they have trouble trying to leave consistently and just before the green?

They invent “delay boxes.”

The 1980s saw computers called delay boxes introduced to the drag racing world. We’ll learn more about understanding reaction times – and why delay boxes are a thing – a little later.


Staging for a Drag Race

We’ve already gone over a bit about how they use to “stage” (or line up) for a race. It was a pretty crude system to be sure. When the entire race was “exact” only to the point of someone eyeballing the winner though, it was plenty good enough.

But these days everything is all computer-y. Because of that, not understanding exactly how the stage beam works can have detrimental effects on everything about your entire run.

Modern systems use photocells to shoot an invisible beam across the track. When it detects anything between the two photocells, the corresponding lights on the tree, well, light up.

Trip the pre-stage beam? The pre-stage lights light up.
Trip the stage beam? The stage lights light up.

What is Shallow Staging?

Sloooooowly finding the beams to pre-stage, then shallow stage.
Distances shown are just concept references.

On a drag strip, there is really only one starting line though, so what is the “pre-stage” beam for? A pre-stage beam is simply a “warning” that you’re close (usually about 7″) from the “stage” beam. The pre-stage beam has zero influence on any part of the timing system or on your ticket. It is 100% meant as a reference.

It’s all about the stage beam. But how?

In the video just above, “shallow staging” is simply the opposite of “deep staging”, which most people probably have heard of.

To shallow stage, your only goal is to creep forward just enough so that the stage beam is tripped by the least amount possible. I’ll explain why this is valuable in the reaction time section below.

What is Deep Staging?

Deep staging.

In the first video, the idea was to go forward just until the exact point of breaking the stage beam. In deep staging, the idea is to continue rolling forward just until the top light goes out (another way to say the pre-stage beam is no longer broken). Again, the reason why will be explained later in the section on reaction time and rollout.

What is Courtesy Staging?

Courtesy staging is a “rule” – sometimes enforced, sometimes not – that says both drivers should pre-stage before attempting to stage. For some classes/tracks, you can be disqualified for turning on the stage light before the opponent has turned on the pre-stage.

Pro tip: Want to look like you know what you’re doing? Simply follow this rule whether it’s mandatory or not. Pre-stage, then wait for your opponent to pre-stage before rolling to stage. This is a quick way to set you apart from those beginners that “double bulb” everyone.


How Drag Racing Reaction Time Works

If you’re just getting started, reaction time is a great way to prove you sorta-kinda know what you’re doing. And if you’re stuck with a slow car while at a street night with some friends, getting great reaction times will allow you to gain at least some bragging rights for the night.

Let’s learn how reaction time is calculated and what you can do to manipulate it.

What do the reaction time numbers mean?

As you probably already know, when you see “R/T” or “Reaction” or “Reaction Time” on your time slip, it is the time (in seconds), between the exact moment the green switched on and when the stage beam is unbroken (ie your tires stopped blocking the beam).

In the past, the reaction times were shown as the time after the final yellow had turned on. So with a .500 full tree, a reaction time of .500 was perfect because you left exactly when the final bulb was done. That is, the green was now on. A red light looked like .480 on the time slip (or .020 before the green).

About 15 years ago, the reaction times were changed to where .000 is now perfect – the exact moment the green light turns on. This makes more sense, because the reaction times are shown as a countdown to perfect then switch to counting up after perfect. -.019 means you left 19 thousandths of a second before the green light came on.

What is rollout?

The distance in inches (or in milliseconds) from where a wheel begins blocking a beam until it unblocks the beam.

Let’s see how that looks.

Approaching the starting line kind of looks like this. Note the location of your car (blue line) and the location of the beams.

The car is now pre-staged, as we can see on the tree. Yellow line #1 has been added to remember where the car when then your tire broke the pre-stage beam.

The car is now staged. The pre-stage beam is also blocked, so both lights are on. Staging the car – turning on the stage light – means you are now ready to race. At this point, you should be prepared for the lights to begin.

It is a given that if you are staged, you fully accept all conditions as they are on track, and you are ready to race. Do NOT stage if you do not accept all risks and conditions of a drag race.

Continue rolling forward and eventually you will unblock (“break”) the pre-stage beam. This turns off the pre-stage lights as you can see. This is called deep staging.

Note the distance you need to travel between turning on the pre-stage beam (first yellow line) and this third yellow line.

Finally, as the car continues forward (or it’s time to go), both beams have been unblocked (“broken”) and both sets of lights at the top of the tree go out.

If the tree had been activated, this is also the exact moment that a) the reaction time is stopped and recorded based on the time between this and the green light; b) the timer begins for all intervals (60′, 330′, etc) including elapsed time (“ET”).

I’ll say it again: Reaction time on your ticket is an independent and completely separate timer.

Note the distance you need to travel between turning on the stage beam (second yellow line) and this final (fourth) yellow line. This distance is called your “rollout” – the distance, in inches, it takes for your car to roll out  the beam.

When using a “practice tree,” or simulated tree, “rollout” usually refers to this distance but uses time in milliseconds instead.

Changing your rollout

1: Pre-stage on; 2: Stage on; 3: Deep/pre-stage off; 4: Both lights off

Imagine you went to a different track and the beams were lower (pink). You see how much shorter the rollout becomes (pink arrow length vs yellow arrow length). On a practice tree, this corresponds to a lower rollout time.

For bonus points: how would this change your reaction time and ET? More bonus points: how do the pre-stage location lines (set #1) affect rollout?

If you imagine all the different variables associated with rollout, like tire diameter, beam height, and how far your tire sits in the groove of a racetrack (some tracks have a crown for water drainage), you can begin to see how these things can vary your reaction time and ET. The “arrow” between the lines gets longer or shorter.

If you’re to the point of really looking at your numbers and trying to find hundredths here or there, or chasing consistent lights (your “spread”), your rollout (and all the variables you can control) absolutely matters.

Do I leave on the green light in drag racing?


Here’s why: let’s look at the graphic below of a full tree sequence counting down. The numbers represent the reaction time in seconds at that exact moment. This is you leaving when you see the green.

Enjoy your .640 reaction time, grandpa.

Average Human Reaction Time

Shown here (blue bar) it is .230 seconds. Human Benchmark says they’ve calculated it to be .273 seconds, but that the average display has a .030 ms lag, and mobile devices are slower by default. So .230 is probably fair-ish. It takes you .230 seconds for your brain to even realize it’s seeing something and react to it.

Vehicle Reaction Time

Then there’s the physical rollout, as we described earlier. Here, coupled with many other factors about your car, we’ll call it “Vehicle Reaction Time.”

This is the time it takes for your car – once your brain reacts – to get fuel and air, transfer the power through the engine, through the transmission, axles, and wheels, then roll out from the stage beam (which we described just above). I’ve set it to .420 seconds for the green bar, which is about the value of my own car’s rollout when shallow staged.

Finally, there’s the “spread” which is only because we are human and not robots. React to a light 100 times and it will not be the same every time. There will be some variance, and the .050 here (pink bar) represents that natural variance.

Reducing your spread is a valuable advanced drag racing skill. However unless you can stage perfectly every time, and you know your car is reacting the same way every time, plus a hundred other things, it should be far down your list of skills to hone. For now, just try to be a robot.

Anyway, you’ll notice the reaction time here would be about .625-.675 if I tried leaving when I saw the green.

But let’s back that up because that is pathetic.

When to “go” in a drag race

Let’s instead try leaving when we see the third yellow flash (or flash of the pro tree). Bonus points: Can you predict what the reaction time would be without looking at the chart?

Better than some but not great.

Aha! This is looking much, much better. If we try reacting to the flash of the third amber instead, it cuts – you guessed it – half a second off our reaction time. We’ve got a light that would probably be in the .125-.175 range.

The interesting thing here though is that these are not my reaction times when I do this. They’re slightly faster. Because we can anticipate the third bulb (thanks to the other two in our peripheral), the reaction time might be just a bit faster than this when on the track.

You can test this yourself if you have access to a tree. React to a full tree third bulb a few times, then block the top two ambers and try it again.

Now it’s your turn: think about ways to get your spread – or natural variance of reaction times – even closer to the perfect .000 reaction time.

And remember, for both of these runs, your Elapsed Time on your ticket would be roughly the same. All you’ve done is now potentially “gained” half a second on your competition (if they’re leaving on green) just because you understand how the tree works.

As you get more advanced or begin racing in competitions, avoiding inconsistent reaction times becomes more and more important.


AutoStart, TruSTART, and CrossTalk

Ultimately, drag racing should be a fair competition. But there will always be someone trying to bend the rules. Bending is fine, but sometimes people take it too far. Thus the invention of AutoStart.

Additionally, technology has advanced to the point of leveling the playing field with something called TruSTART.

And finally, we’ll briefly touch on CrossTalk. It only affects drivers that run a Delay Box category (if you don’t know what this is I explain it below) but it wouldn’t be the Drag Racing Christmas Tree Ultimate Guide without mentioning it.

Now let’s talk about why these advanced topics matter.

What is AutoStart and why do we need it?

If you are ready and staged, and your opponent is pre-staged but refuses to roll in to stage (for any number of reasons), how long should he be allowed to sit there and “hang you out”?

A minute? Two hours? A month and a half? Your car is going to be getting hot sitting there, and eventually you’d need to eat.

For nearly everyone (apart from Jr Dragsters and upper-most level categories), the suggested value from NHRA and Compulink is 10 seconds. Some races I’ve been to were 7 seconds to time out, some were 15 seconds. Put another way, if your opponent is staged, and you are pre-staged, you have between 7 and 15 seconds to stage. If you don’t, your red light comes on and your opponent wins the round.

The timer starts, and the right lane now has 10 seconds to stage.

I’m going to tell you right now that if you’ve never been in this position, time does not behave the same way you’re used to. If you know you only have 10 seconds to stage or else you’re disqualified, you might be tempted to rush your routine. It feels like there’s no time at all. Taking five seconds suddenly feels like you’re about to be timed out.

But 10 seconds is a long, long time. Still, this is a good reason why developing your own routine when you stage is very important. Sometimes a dingus will double bulb you, leaving you to pre-stage then stage within the time limit, but all that means to me is that I bring the RPMs up for the entire staging process instead of just before my final bump in.

Depending on your series, AutoStart may not be on. Usually the rule book for your event or track will say if AutoStart is enabled or not, and how long it is in seconds. A test and tune style event typically doesn’t not turn on AutoStart.

Honoring Deep Staging

You will also usually see whether or not deep staging is “honored” at an event or track. You can find this in the track or race rule sheet. If it is, it means they will not flip the switch to turn on AutoStart (ie start the race) until you are fully in to deep stage.

If deep staging is not honored, the tree can begin once both cars have lit the stage lights. Usually this means that within two seconds, the first amber will begin the full tree.

You don’t want to be still rolling in to go deep while the tree is coming down. In most of the tracks I run, I’ve found deep staging is not honored more than it is. This is just one reason why personally I prefer to shallow stage every time.

Plus, if it is not honored and your opponent sees you want to go deep (it’s customary to write “DEEP” on your window in shoe polish if that’s your plan, so the starter honors it) your opponent might rush to get staged, leaving you to get deep like you want within the very narrow time frame. Ask me how I know.

What is TruSTART?

In April 2016, legends of the sport Peter Biondo and Kyle Seipel unveiled TruSTART during their Spring Fling Million Race in Las Vegas.

Originally, drag racers lost using the common adage, “First or worst,” which had meant the loser is the one with the first infraction or the worst infraction. For instance, a driver may red light, but if the opponent crosses the center line, that’s worse.

Same goes for a breakout in bracket racing. It doesn’t matter when it happens, whoever has the worst breakout is the loser.

However at the starting line, the way it had always worked is the first driver to red light lost. It was “First is worst.” This meant that there was a slight disadvantage in being the slower car with the head start. Even if the faster car went red by two tenths, if you went first and were red by one thousandths of a second, you lose.

In fact, it’s still this way where I race. The NHRA is can be extremely slow to implement fundamental changes like this to the sport (though quick on perceived safety changes, like any racing organization).

But at Biondo and Seipel’s Million dollar races (and currently 44 other tracks according to Mr Seipel, with 3 more signed up), the patented TruSTART tree with Compulink waits until both drivers have left the starting line, and only then applies the worst red light, if there is one.

Left lane leaves first, it shows green to wait for other driver’s reaction time. Left lane did red light, it was worse, his red is shown.


“Accutime recently bought a license from Compulink to distribute their own version in 2019 also,” said Seipel. “It is for sure picking up momentum and something Peter and I believe in 100%.”

Modern practice trees like the Eliminator Next Gen even offer this as a settings option.

What is CrossTalk?

Years and years ago, drivers noticed that it wasn’t exactly perfect to try reacting to the third amber (or some variation) in order to get great reaction times.

Drivers invented devices that would allow them to hold a button for a “transbrake” (which activates reverse and first gear simultaneously to hold the car in place) and then release at the first flash of the top light. They could adjust the delay so that the car always left perfectly at the green light for great reaction times. This was more consistent than simply trying to time the green light just right.

After many iterations, scandals, and rule changes, today we’re left with “Delay Boxes” which allow drivers to still release a button when the top light turns on. After a bit over a one second delay (because it’s waiting for three bulbs but accounts for human reaction time and vehicle reaction time), the car takes off.

Because of the advantage these pose, nearly all bracket races these days are broken into categories based on whether or not they have a delay box. These classes can be called “Box class” (how original), Super Pro, Top ET, or similar. Sometimes the “no box” class can be further divided into whether or not they use the button or just their feet. For most people, releasing a button provides a better average of reaction times than using your feet.

Regardless, drivers began finding the difference in the dial-ins as the faster car and adding it to their own delay box timer settings. This allowed them to react to the very first light they saw, instead of waiting for their own first light. With similar dial-ins, this could cause a driver to jump or mis-time their reaction to their own top light turning on.

Some tracks however were using blinders to block one side of the lights from the other driver. For “no box” or “bottom bulb” racers, this can help with focus when there is a difference in dial-ins, causing the full tree to alternate with an odd sequence.

Takes a good deal of practice and focus not to get distracted.

So in order to make them happy, some tracks would put a big sheet of metal between the sides of the tree, so you could only ever see your side. This would keep the same feeling of the sequence in tact.

Lots of drivers also experiment with a tree blocker of their own – hanging something from a roll bar or sun visor, or simply holding a piece of cardboard up and closing one eye.

Anyway, this made the top bulb racers upset because now they couldn’t see the other side’s top bulb. With their box calculated for the delay of both sides, they didn’t know when to let go.

So it was either remove the blinder in the middle of the tree or invent something special for the top bulb guys.

Introducing: CrossTalk. Sometimes called Cross Over.

Both top bulbs will come on at the same time. Both drivers release their buttons. Then, the faster car’s top bulb hangs until the normal sequence given the difference in dial-ins, where it continues.

CrossTalk shown. Slower car in the left lane versus a faster dragster (not shown) in the right lane.

There are ways to let the track officials know that you don’t want CrossTalk activated – and there are various reasons for this – so if you find yourself running an electronics class, you might want to check.


Practice Tree Simulator

We know that really, really good racers win about 75% of their rounds. And in the right hands, a reaction time advantage on the tree is about twice as likely to get you a win than being late.

I am a bracket racer, which means both reaction time consistency and your car’s consistency matter.

There’s a reason why the number one thing I tell people when they ask what they need to go drag racing is a practice tree. It pays for itself over and over and over.

Regardless of whether you’re a bracket racer or not though, reaction times on the track are a symbol of status. Plain and simple.

You get status via bragging rights when you and your friends take some cars to a simple open track night. Or you’re being watched while you head to the tower to collect yet another winner’s check.

The Best Practice Tree

There are two parts within this category. These practice trees are able to be used by themselves, but you can also purchase a separate full-sized tree (just like at the track!) for a more true-to-life experience.

You need to know that a full-sized practice tree you see online will NOT work without a corresponding tabletop box to control it.

Really there’s no other options even close. If you’re in the market, this is the one to get.

Portatree Eliminator Next Gen Practice Tree

The Portatree Next Gen is recommended by many top-flight racers like professional drag racer Luke Bogacki.

Based on what I grew up using this is actually nuts in how much it can do.

Yes, it can tell you a reaction time, change rollout settings, use a delay box, change between five- and four-tenths full and pro trees. It can use the included buttons, or you can purchase foot petals or special connectors to your car. Most table top boxes can do all this.

But a couple things really stand out to me after using these types of devices for over two decades now.

Like for one thing, you can put batteries in it instead of needing a wall plug. Granted, it’s four C batteries (who buys C batteries?) but it’s an option anyway.

It’s also the best table top box I’ve ever used for a crisp on/off of the lights, which is true to life. Other drag race practice trees for sale have a slight fade in and out of the bulbs. But not this one.

What I like most though is the ability to look back at your exact runs during your session. Most other trees show you an average reaction, number of red lights, best and worst. But being able to also see the exact lights in order (plus calculating your spread) is really neat.

Run log and session recap

The picture above also hints at another really neat thing: it can save up to 15 user profiles. Most do save the settings you last used, but if you have multiple people using it or different cars or whatever, you’re not needing to change every setting every time. Just change the profile and the variables are saved in there.

Next, it has a shift light feature. For drivers that shift by hand (like me), there’s really no easy way to know how well you’re hitting your shift light on track. For me, a difference of just 200 rpm for my two shifts can be worth up to five hundredths on track, so getting it just right is important.

React to the tree, then react again to up to four “shift lights” on screen. See your R/T and the average time after the shift lights.

Keep in mind what we said about Human Reaction Time above. Knowing your own rough RT will give you clues as to how much you jumped the shift light or were late.

Another really cool setting is the ability to adjust the brightness of the lights. The tree I was using had four brightness settings from low to high, but this is pretty cool. It does not affect the brightness shown on a large tree however.

This is really awesome for when the room lights aren’t that bright. Otherwise you’re seeing spots for days.

My one complaint about this box is that it is not very intuitive. Generally I have the ability to quickly learn and understand any new program or device, even if I’ve never seen it before. It’s like how some expert mechanics just “get” cars, no matter what kind it is.

The menu navigation is a little sloppy and tedious, but I suspect that’s just a result of a first generation touch screen tree. Knowing how users use it, I’d expect the second version to have much better navigation.

All that means now is expect to spend some time the first couple of uses learning where certain buttons and settings are. After that things speed up a bit if you need to adjust on the fly.

But some other features:

  • Every configurable option for any kind of tree you could ever see, like Full, Pro, or “Blocked” tree (a full tree that doesn’t show first two yellows)
  • Adjustable tree speed from .100 to .900 (so you can set your .370 if that’s your thing)
  • All delay box settings including double tap
  • Save and load your stats later (versus pen and paper)
  • Practice focusing with the “Distraction mode” (flashes random lights on the screen as the tree comes down)
  • Set which kind of perfect light you want, newer .000 or old .400/.500
  • Use the computer connection cable and upload it all to the free software for further analyzing
  • Universal 1/8″ stereo jack ends for input buttons/switches
  • Universal 3.5mm center pin positive tip AC adapter (110-220v AC to 12v 1A DC output)
  • Cute little prop stand


A drag racing Christmas tree is the backbone of all forms of drag racing.

The Christmas tree lights are not a suggestion. Intimate knowledge of how this works is absolutely required for anyone involved in drag racing.

Is there something I missed? Leave a comment below and let me know!


  1. Gary Hatch

    What is the time from when you light the bottom bulb in staging before the tree starts?? We are having an awful time with this!! It starts the minute the last driver lights the bottom bulb. I’ve always thought you had 2 seconds from when the last bottom bulb came on before the tree started??

    • Jacob Murphy
      Jacob Murphy

      Hi Gary. The average I’ve seen is more like one second, but it depends a lot on where you are and the series. Usually, it’s a random range the computer decides, set by the series/track, anywhere between 0.6 and 2.0 seconds.

      To find out, call/write your track and ask them: “Could you tell me what your AutoStart settings are?” It might take some time to find someone that knows what that means, but then you’ll know!

      (If they don’t use AutoStart for whatever reason, it could mean the starter is randomly choosing when to start the tree. In your question you might also add, “The tree seems really quick, so I wanted to figure it out.” Finally, the NextGen practice tree allows you to set your own AutoStart to practice quick or slow trees!)

  2. Jennifer

    Hey! Thank you for this. Other than some serious calculus, do you have any ideas for calculating the rollout of my car so I can set it up in the Port A Tree?

    • Jacob Murphy
      Jacob Murphy

      That’s some serious math that no one’s really ever figured out without actually putting your car on a track (and even some tracks are different). If you’re top bulb, just hit the tree with your common delay and adjust rollout until it’s close (the point is to be consistent there anyway). If you’re bottom bulb, I’ve done a combination of a) hit it the same at home and adjust the rollout until I get the same-ish lights, and b) blocked the top two bulbs at the track and go on the third flash, repeat at home and adjust rollout. You’re supposed to always be able to go on the third flash and adjust the car to make the RTs you need, but in my experience that’s not always possible. Your goal is just acquire consistency and mimic real-life close as possible at home.

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