The Built-In Bracket & Index Racing Features Of FuelTech’s ECUs

On the surface, bracket racing looks simple: declare a dial-in and run the number. But there’s so much more to it than that. There are plenty of strategies and tricks that go into bracket racing, especially the classes that allow technological driver aids. Today, we’re going to talk about how bracket racing aids work and, specifically, those that are built into FuelTech’s line of ECUs to appeal to the sportsman drag racing crowd.

We’ve built our Project Number Cruncher Firebird to be an EFI bracket racing machine. The FuelTech FT550 ECU we’re using to control the engine is packed with some great features to help bracket racers. Displaying a commitment to FuelTech-the-world, FuelTech has consolidated a delay box, throttle stop, starting line enhancer, and even a practice tree all into a single package.

Delay Box

The delay box is a piece of technology that’s used by every top-bulb bracket racer the world over, but what exactly does it do? Some think a delay box runs on black magic and does the work for you, but in reality, all it does is insert a pre-programmed delay into your starting sequence. When you’re using a delay box, you don’t have to wait for the tree to run through its full sequence and leave off the bottom bulb. Instead, you react to the first bulb in the tree’s sequence, and the delay box will hold your car in position until the amount of time you have input expires.

Andre Nunez from FuelTech provides a great real-world example of how a delay box actually works.

“So, let’s say you cut a .020-second light with the delay sequence you have in the box. If you have one second of delay, that’s probably low, but it makes a nice round number for this example. So to be perfect, you’d have to take the .020 out of your delay, assuming you hit the tree consistently each time. That means you’d have to change your delay to .980 to be perfect each time. Technically, if you stage the car the same, and hit the tree the same, your reaction time should improve by the same amount you pulled out of your delay number.”

A delay box allows you to change a number in the box, versus making a physical change to the car to alter the reaction time. –  Andre Nunez, FuelTech

A modern delay box will have bump-up and bump-down functions. You would use the bump-up function to add time to the delay you set, and bump-down to subtract. You can use the bump-up and down functions from the time your delay starts, right until your vehicle launches. Why would you want to use the bump-up or down functions? Well, if you think you missed the tree, whether red or really green, you can quickly bump numbers in or out before the car launches.


Now that we’ve established some delay box basics, let’s talk about what the FuelTech ECU brings to the table. A typical delay box will have a primary delay function, a secondary delay function, where you can hit the tree again, bump-up and bump-down options, and timers available, as well. The FuelTech system has all of these built into one package.

The FuelTech system goes beyond the common bump-up or bump-down, with a super-bump option. This lets you bump up or down by a larger number than the bump-up or bump-down you already have programmed. The super-bump makes it easier to make larger adjustments at one time versus hitting the bump up or bump down multiple times. This saves you from hitting the bump-up or down button multiple times if you’re confident you really missed the tree.

How you manipulate the delay box functions with a FuelTech ECU through its screens is straightforward and easy. You can access everything with a few touches or swipes. All of the numbers are big and easy-to-read, and it’s simple to change them on the fly from inside the vehicle while it’s running. The FuelTech system can also be configured to make changes to the delay box inputs through additional buttons, that way you don’t even have to touch the screen. You can customize how everything is laid out on the dash based on what works for you and your specific vehicle.

The FuelTech ECU pulls all your critical racing systems into one unit. It will control your vehicle, take care of the delay box functions, act as a dash, and can even be your shift light.

“One of the great things about the FuelTech system is that it’s one product controlling everything, so it limits the number of devices that need to talk to each other. If you have a car that you race box and no box on the same day, where you’re required to remove the delay box to race, you might want to think about running an external box. The reason is that the firmware change to go from box to no box takes about 15 minutes. It’s purposely slow to load so people can’t change their firmware on the return road,” Nunez says.

FuelTech made sure it added the customary Crosstalk functionality to its internal delay box, too. Nunez explains what Crosstalk is and how it’s incorporated into the FuelTech system.

“Let’s say I’m racing somebody who’s dialed 5.00 and I’m dialed 6.00. I’m going to have a one-second headstart. When we stage, both top bulbs will come on at the same time, and the other racers’ bulb will stay lit as mine falls through the sequence. The other racer’s bulb will stay lit for one second before it falls. The delay box allows you to enter your opponent’s dial as well as your own. It will calculate the difference, and add it to your delay number. Once you let go of the button, the total delay will now account for that difference and let you react to the first thing you see.”

The FuelTech ECUs might have all of the best delay box features built-in, but these functions aren’t available unless the user selects the correct firmware. FuelTech designed the ECUs to function this way so they can be used in multiple types of sportsman racing.

“We have multiple firmware options for the ECUs that are legal for different kinds of racing. We have a full version that has every single feature available, and others that are specific for a given class. For sportsman racers, we have a box and no box version of the software. What that means is you can turn off all the delay box functions and they won’t work,” Nunez says

Throttle Stop

Throttle stops are something you’ll see in index class racing like Super Street, Super Gas, and Super Comp. The goal of these classes is to run the designated index. A throttle stop is a mechanism that’s used to control how much and when the throttle blade(s) opens — this slows the vehicle down so it can hit the target index. The throttle stop is typically activated right after the vehicle launches and is engaged for a set amount of time that the racer has selected to ensure the vehicle will run on the index. That’s not to say you can’t use a down-track throttle stop, though, as some tricky racers have experimented with.

Throttle stops are commonly used in NHRA super class index racing. They require an additional timing system to control them, the FuelTech ECU can eliminate the additional devices used to control a throttle stop.

Currently, the FuelTech ECU has an NHRA-legal throttle stop built in that works with drive-by-wire throttle bodies. The ECU controls the electric motor inside the throttle body to act like a throttle stop based on input from the user.

One of the great things about the FuelTech system is that it’s one product controlling everything, so it limits the number of devices that need to talk to each other.- Andre Nunez, FuelTech

Since the two major types of throttle stops either attach to the throttle linkage or are installed under the baseplate of the carburetor, the drive-by-wire function of the FuelTech isn’t going to be useful. FuelTech is currently beta testing a software enhancement that will work with these types of throttle stops.

The next FuelTech firmware upgrade will include throttle stop control options.

“The FuelTech system already has plenty of timer functions built-in, and now we’re working on applying those to a throttle stop. This will work with just about any standard throttle stop, since it will be controlled by the FuelTech software. That means you won’t need any external timers or controllers to run the throttle stop. You can move over one screen and have access to the timers for the throttle stops on the FuelTech dash. You’ll be able to configure the throttle stop in the FTManager software to activate at a specific time (from the launch) and then disengage at another specified time,” Nunez explains.

Starting Line Enhancers

Consistency is absolutely paramount in bracket and super-class racing, as you’re dealing with thousandths of second and very tight margins of victory. Tire pressure, starting line RPM, and how you stage your vehicle all play a role in attaining consistency.

Bracket racers started using what’s known as starting line enhancers to improve their staging consistency. These enhancers are typically some type of device that uses hydraulics or air to limit an engine’s RPM. Racers like to use these enhancers to keep their starting line RPM level low and consistent when they stage. FuelTech has added its own version of a starting line enhancer control, known as a pre-launch enhancer.

A FuelTech ECU can control a starting line enhancer with its pre-launch enhancer function.

“You can activate the pre-launch enhancer before you go in to stage and it will drop your RPM to a pre-determined level. It will allow you to maintain that RPM so you can stage in a consistent fashion each run. That way, the car always has the same amount of bump when you’re going through the staging process. When you release the transbrake it releases the throttle enhancement and lets the two-step kick in. It removes variables from your staging process, and that’s a big help,” Nunez states

Practice Tree

Races are won and lost on the starting line, and if you want to improve your chances of picking up a victory, you need to sharpen your reaction time skills. The only way to whittle away at those reaction times is by practicing as much as you can. FuelTech didn’t invent the practice tree, but it has found a way to improve how racers interact with it.

“The practice tree is a standard feature that’s built into the FuelTech ECU. It allows you to set up a practice session with a .500 or .400. tree. You can sit in the vehicle and practice using any delay box functions and the practice tree will recognize it. This type of tree lets you practice in your vehicle in the environment where you’re going to be hitting the tree. You’re getting the physical reps in the car just like you would at the track, and that will help your consistency since you’re using the same routine,” Nunez says.

The FuelTech line of ECUs offers everything a bracket racer could ever need. These ECUs have been designed to work with both carbureted and EFI applications, so every racer can use them if they choose. Make sure you follow along with our Project Number Cruncher right here as we hit the track and start to explore all of the bracket racing features our FuelTech FT550 has to offer.

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Brian Wagner

Spending his childhood at different race tracks around Ohio with his family’s 1967 Nova, Brian developed a true love for drag racing. Brian enjoys anything loud, fast, and fun.
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