Video: Getting Project LS5.0 Ready For The Engine Dyno

The LS5.0 engine project has been a long and drawn-out process. Thanks to things like a global pandemic, parts shortages, and a general lack of free time, the project has taken way longer than it should have. However, we are nearing the finish line, as we have the short-block complete along with the top end ready to go. So now, all that is left are a few important loose ends to tie up, and we’ll be ready to turn hydrocarbons into horsepower.

Gimme Fuel, Gimme Fire

One of the most important parts of an engine project is making sure it has enough fuel. There is nothing worse than being oh-so-close to your power goals and running out of fuel. When it comes to such a critical component, we tend to err on the side of caution and familiarity. We’ve run Deatschwerks injectors in several other EngineLabs projects, and they have our full confidence to perform under the stresses of our testing.

With the brand selection out of the way, it was time to dive into the specifics of the injector needed for this project. The first, and probably most important parameter to figure out is the size of the fuel injector. You might remember a video we published a while back where we ran through the math of determining what injector size you need for a given horsepower goal. DeatschWerks has an online calculator that takes all the long-form math out of it and makes life easy.

One thing to remember when you’re trying to figure out how much injector you need, is to first, be honest with yourself. If you think you’re shooting for 500 horsepower, is that really how much you want to make? Secondly, you should look ahead and plan on where you are going with the project in the future. In this day and age, it’s no big deal to have larger injectors than you need, but it will always be a problem if your injectors are too small.

For LS5.0, we know that there will be not only several phases to the project, but that we’ll be doing some testing for the magazine along the way. So, we added up all the biggest variables (the most power we expect to see, using the fuel type that requires the most volume that we might use), and got our final required flow number for the injector. Then saw a small hiccup.

Our calculations came up with an injector size for LS5.0 that was right in between two sizes of injectors offered by Deatschwerks — 630cc/min and 800 cc/min. In that scenario, you have three options. The first being to reduce your power goals to meet the capabilities of the smaller injector size. For most of us, that just isn’t an option. Secondly, depending on how close you are on the low end, you push the injector duty cycle envelope and play with base fuel pressure. We ran all of our calculations at a nominal 85 percent duty cycle at 58 psi, so there’s not a ton of meat on the bone there. While we’ve done it before in the heat of battle with decent success, it is far from an ideal solution. The third option is to simply run larger injectors.

There’s No Such Thing As Too Big

It used to be, in years past, that you never wanted to run “too big” of an injector, because you could run into idle and drivability issues when not demanding the injectors’ full capacity. These days, that just isn’t the case. We ran 78 lb/hr DeatschWerks injectors throughout our Retro 5.0 project at configurations from 250 horsepower all the way through 830 horsepower and never once had the slightest issue with the injectors being “too big.” Since the price between the two injectors was identical, there wasn’t even a financial consideration to be had in the decision. That made the choice between the two injectors easy in our mind, go with the bigger 800cc/min injectors.

Of course, we also wanted to get DeatschWerks’ input as well, since they do this kind of thing for a living. Reaching out to Dakota Bowman, DeatschWerks Technical Product Specialist, he not only agreed but gave us some additional parameters to consider in the future. “Your window of operation for the injector is smaller the higher the RPM, which means there is less time to deliver the fuel. Running a slightly larger injector would be more ideal in that case,” says Bowman.

Bowman also shared his personal experience with the whole “too big” of an injector situation, which we’d heard anecdotally in prior conversations. “Newer injector technology allows for much better drivability even at some ridiculous injector sizes,” Bowman explains. “For instance, I am running 1,500cc/min injectors in my car that makes 350 horsepower at the wheels, and it still drives like an OE car. I am not recommending you follow suit, but you can go slightly larger without concern.”

With the sizing out of the way, the next step is to properly choose the physical characteristics of the injector. For an LS engine, there are both tall and short injector options, along with a number of connectors available. Since this is a custom application, we have a lot of flexibility with the physical characteristics. Our Holley fuel rails will accommodate either tall or short injectors, so that’s not a concern. Also, as you’ll read more about as you get further down in the article, there are multiple fuel injector harnesses available with the Holley Terminator X kit.

What we ended up deciding on is a set of 800cc/min tall injectors with the truck-style EV6 (USCAR) connectors (P/N: 18U-00-0078-8). These injectors are dynamically flow matched as a set, and come with individual injector performance data in the box. All of the tuning data is available right on DeatschWerks’ website, making it a breeze to plug into the Holley Terminator X when we get to the dyno. Not only does having accurate injector data at your fingertips speed up the setup process, but it also gives you far more precise tuning control. Plus, if we ever get really stupid with this engine, we still have some room to grow.

Putting A (Carbon Fiber) Lid On It

The next part for LS5.0 actually came about thanks to the comments section of our social media channels. Many of you asked how we could run the Performance Design carbon fiber valve covers, but not one of their intake manifolds. What you guys didn’t know, was that not only was Performance Designs reading the comments, but that we already had some intake lid testing planned for the project. That led to them sending over one of their Carbon HR intake manifold lids designed for the Holley intake manifold base.

The Carbon HR lid was originally designed to fit Holley’s Hi-Ram base, but as they released the different runner-length bases with the same lid pattern, the fitments expanded. Since we’re running the Lo-Ram intake, the Carbon HR lid is a perfect fit. Performance Design’s carbon lid design not only shaves weight, but thanks to the carbon fiber material’s thermal properties coupled with the high-temperature aviation-grade epoxy, the lid reduces heat soak compared to the cast-aluminum lid.

The plenum flange is also made from carbon fiber twill, but wrapped around a foam core, for a lightweight, structurally sound piece, that will withstand severe use. On the front of the lid, is a billet aluminum 105mm throttle body flange, available in either black or red anodizing. While all this combines into a killer piece, there is another benefit, and that is that the plenum isn’t just a copy of the aluminum lid’s geometry. The plenum is larger and reshaped, and the angle of the throttle body is altered.

So, besides the fact that the Carbon HR looks absolutely amazing on LS5.0, and offers some thermal benefits of a cast aluminum piece, the altered plenum size and design might yield even more benefits. So, it will make for some solid testing on the dyno.

Controlling The Chaos With A Terminator

Controlling an 8,000-rpm engine is no small ask for an EFI system. At those elevated engine speeds, you are really asking for a lot from the ECU, electronically. Not only does high-RPM demand lots of data, fast, it requires incredibly precise control, as a misstep at those speeds is no small hiccup. For LS5.0, our choice from the start was a Holley Terminator X fuel injection system. Not only is it powerful enough to handle our combination, but it’s simple enough (as we proved in the Retro 5.0 project) for someone with little to no experience in Holley’s software to get decent results.

The Terminator X is available in a huge variety of plug-and-play configurations for the LS platform. As it turns out, our configuration was far less complex than we imagined. By simply opting for the Gen-IV truck engine system, it checked all of the boxes we needed while making no compromises in capability. P/N: 550-905 is designed for 58x crankshaft reluctor wheels and 4x camshaft position sensors. Additionally, it comes with an EV6/USCAR fuel injector harness, although it is available with an EV1 harness if you prefer to use LS1 injectors.

The Terminator X ECU itself is an incredibly powerful and feature-rich piece of hardware that will not only handle our naturally aspirated combination, but do so much more than this engine will ever utilize. What LS5.0 will use, however, is the built-in 1-Bar MAP sensor and the included Bosch LSU 4.9 wideband oxygen sensor. Besides creating exceptionally precise adjustments on the dyno, the ECU’s self-learning capabilities love all the data provided by the high-resolution sensors, and will come in incredibly handy for developing the maps for the engine once it’s in its eventual home.

Additionally, the ECU has advanced on-board diagnostics allowing for easy troubleshooting, and has plug-and-play compatibility with a whole host of Holley EFI accessories, once it’s in the car. The Terminator X kit also comes with a 3.5-inch handheld touchscreen controller that not only contains a startup wizard that will generate a solid base map to get started, but can also act as a small gauge panel and data logger. We’ll likely be using the touchscreen more once the engine is in a car, but for the dyno, Holley’s Terminator X Windows software will be our main source of tuning.

So, with these final components here and ready to go, there is nothing else to do but load the engine up in the truck and head to the dyno. We know you have all been eager to see the results of this project, and we can assure you, no one is more eager than we are. But, just a reminder, we have some fun testing in store for this engine beyond just aiming to beat the original Coyote engine from LS Vs. Coyote Part 1. And, we’ll let the cat out of the bag here and now – there is already an LS5.0 version 2.0 in the works in the background, where things get even more insane.

So, stay tuned, as the proverbial rubber is about to meet the road for the LS5.0 project.