Bracket racers are creatures of habit that stick with proven parts and systems that provide consistent results. When you take a stroll through the sportsman pits you’ll find mostly carburetors and ignition boxes controlling the engines racers use. But we wanted to do something different and opted for EFI with our Project Number Cruncher bracket car build using an ECU, wiring harness, and supporting parts from FuelTech.
Project Number Cruncher is our first purpose-built bracket car here at DRAGZINE. We wanted to do things differently with this build, so we opted to use an LS-based engine and an EFI system from FuelTech to control the mill. Now, this isn’t the only way you can attack a build like this — a junkyard LS with a factory ECU would still get the job done, but we wanted this build to show off some of the cutting-edge technology that’s available. Hopefully, this project will encourage others in the bracket racing discipline to dip their toes into the EFI and LS engine pool on their future builds.
Getting Wired Up
Fuel injection scares a lot of people because it conjures up mental pictures of spaghetti plates of wiring that you have to figure out on your own. While that might have been the case in the past, these days every ECU manufacturer has pre-made wiring harnesses that can easily be finished by most users.
For our LS build, we used the LS550 V8 complete harness that FuelTech offers. This harness is designed to work with the FT550 ECU that’s controlling an LS-based engine. Luis De Leon from FuelTech explains why a harness like this is the perfect product for someone who’s adding an LS engine to a racecar.
“The LS550 harness is great because it removes a lot of the guesswork from an installation like this. You get a nice manual with the harness that’s easy to understand and will help you with any troubleshooting you might have to do. It’s great because if you don’t feel confident in your ability to create a harness from scratch this will take care of that; it also spares you from having to schedule a wiring guy or dealing with crazy lead times. All you need to do is follow the directions, connect everything to the engine’s sensors, and you should be good to go.”
FuelTech put a good amount of thought into the design of the LS550 harness. A pre-made harness like this will significantly cut down on your installation time since it uses OEM-style connectors. The harness is also designed to be universal, which means you don’t have to worry about it not working on your engine in your chassis. You might only have to lengthen a sensor wire based on your specific build, but outside of that, everything you need is included.
“We offer the LS550 harness for different engine generations as well, so it’s compatible with 24x and 58x reluctor wheel versions of the LS engine. This harness is focused on the ease and quickness of installation. The quality is way above average for this kind of wiring solution, and vital sensor connectors are not the OEM style, so things like fuel and oil pressure are wired for performance-grade sensors. The coil harness is fully finished, so no need to use the last part of the stock harness, as well…so it’s a full harness solution. You can even use low- or high- impedance injectors with this harness,” De Leon says.
Watching The AFRs
Every internal combustion engine needs a specific amount of air, fuel, and spark to operate. The air and fuel portions of the equation need to be combined in a specific amount to create the most horsepower possible — this is known as the Air/Fuel Ratio, or AFR. In a carbureted application, you might monitor AFRs for performance, but in an EFI application, AFRs not only need to be monitored for performance, but they’re also a critical piece of data the ECU needs to control the engine.
Now that we’ve established what AFR is and why it’s so important, it’s time to look at how the FuelTech ECU monitors it. The AFRs are seen by the FT550 thanks to FuelTech’s CAN-based WB-O2-Nano.
“The WB-O2-Nano is an oxygen sensor conditioner that works with an O2 sensor. The Nano basically talks to the sensor, conditions what it’s saying, and translates it so the ECU can understand the data. This allows the ECU to know what’s going on with the exhaust gasses in a very precise way. The ECU will use this information to determine if the AFR is too rich, too lean, or right where it needs to be based on the values commanded by the tuner,” De Leon explains.
The EFI system can make adjustments during a run by itself, this means you will get more than just the base tune-up like you would with a carburetor. -Luis De Leon, FuelTech
So, you can see how important it is to accurately collect AFRs in an EFI application like this. Depending on how much horsepower your engine combination is making, you could need more than one Nano to provide data to the ECU. Thankfully, our naturally-aspirated engine will only need to use a pair of Nanos.
“The number of WB-O2-Nanos you need will be determined by the engine and power-adder you’re using. For example, a single turbo combination would need just one, and a twin-turbo setup would need to have two. Now, for a nitrous application with zoomie-style headers, you’d want to run one Nano for each cylinder to give you the most accurate reading possible,” De Leon says.
Controlling The Engine
We’ve covered how you can wire up an EFI build like this, and how you can monitor the AFRs, now it’s time to look at the ECU that runs the show.
The ECU is the brain of any EFI system that controls the engine, monitors multiple sensors, logs data, and helps with power management. When EFI was first introduced to drag racing, the ECUs and the software that managed them weren’t very user-friendly, but that’s changed and opened the door for this technology to be used in bracket racing.
Before we dig into why the FT550 is an excellent fit for bracket racing, let’s take a look at the ECU to see what it offers.
The FT550 is great because it’s packaged as an ECU, digital dash, and data logger all in one unit. That means you don’t need to purchase a separate dashboard or data-logging system. The ECU has 14 separate inputs and outputs available that you can configure how you like through the FTManager software. These inputs and outputs can be used to gather data from sensors or activate different devices in your racing vehicle. You can see all the features this ECU offers right here on the FuelTech website.
There are a lot of racers who won’t give up their carburetor jets and floats…you’ll have to pry them out of their cold, dead heads. That thought process circles back to bracket racers being creatures of habit that want to use what works. The thing that could help racers make the switch to EFI is how they look at fuel injection. You really can treat it like you’re tuning with more precise jets that are electronic.
The FT550 is easy to use and brings all the systems required to run your race car to one location. Luis De Leon, FuelTech
“EFI is different from a carburetor because all of the changes the racer makes are with a keyboard and not with a set of hand tools. The system can make adjustments during a run by itself — this means you will get more than just the base tune-up like you would with a carburetor. As you make a pass, the ECU is going to be making the changes in real-time, so if you were off a little bit it will make corrections. The data analysis and engine control is also more robust…this gives you a better understanding of how and when your engine is making power,” De Leon states.
The FT550 is obviously packed with all kinds of neat technology and can do a lot of stuff, but why would a bracket racer want to make the switch to EFI and use one? We briefly covered the FT550 from a high level earlier, and one of the things we touched on was the fact it has so many features stuffed into one unit. That goes beyond just the physical side of things, the FT550 also has a built-in delay box, nitrous controller, boost controller, time-based outputs, wheelie control, and much more.
All of the features the FT550 offers cut down on the electronics you need to purchase and wire up into your racecar. This is another reason the FT550 is a great fit for bracket racing: it brings everything into one ecosystem for the racer.
“The FT550 is easy to use and brings all the systems required to run your racecar to one location. The FTManager software lets you make changes to everything at one time in one program. You don’t have to jump from the software you use to change timing in your ignition box to a nitrous controller or other systems. Everything you need is right there in FTManager and can be seamlessly adjusted at one once,” De Leon explains.
Another advantage that the FT550 and EFI in general will bring to a bracket racer is consistency. The ECU is going to be looking at a huge amount of data from all the sensors it’s connected to when the engine is running. That means the FT550 will be able to add or subtract fuel and spark as needed to make sure the engine is producing as much horsepower as possible. As a bracket racer, you won’t have to worry about the car falling off nearly as much at times because of this real-time tuning.
The FT550 isn’t a one-trick pony, the ECU offers users the opportunity to expand what it can do based on your needs. For our application, we’re using the basic sensors you would need to run an LS engine along with a pan vacuum sensor. What if there was something else you wanted to monitor for data purposes? Well, FuelTech offers a wide range of pressure sensors you could use to make that happen. You can also add travel sensors to your shocks, or a driveshaft sensor to your vehicle too, along with other types of sensors that can be wired into your FT550. How much you expand the ability of your FT550 is literally just limited to your imagination and wallet.
Technology is a wonderful thing and it’s allowed racers to set numerous records in the world of drag racing. Project Number Cruncher is going to benefit from all the features FuelTech’s FT550 offers. Make sure you follow our build progress with Project Number Cruncher right here on DRAGZINE — we’re going to be doing some cool things with this project and plan on doing a lot of bracket racing in the future.