By Steve Turner
Photos by the FSC Staff
An injector solenoid pulses, releasing fuel pushed out by over 2,000 psi. A cloud of fine droplets hangs in the air. It’s an impressive sight to behold, but for John Urist it was a eureka moment for his NMRA VP Racing Fuels Street Outlaw racing program. The idea of the magic those micro droplets might unlock inside the combustion chamber of his turbocharged Coyote racing engine. The light bulb went off and he set off on a course toward mimicking the latest production Mustang’s dual-fuel system in the competitive environs of heads-up racing.
“That’s how I got John in the boat with direct injection because when he picked up the car last year in March when I put a Bosch controls system on for the first time, I had him at my shop and I did the demonstration of how this spray vaporization looks like with a DI injector,” Uwe Ostmann, of Xtreme-DI, enthused. “I showed him port injectors spraying and I showed him the DI injector spraying and his reaction was just, ‘Oh look at this mist because it’s so light. It actually, it actually floats up. It doesn’t fall down.’ You just need to picture that you have that in your port, right? So you just have a mist of fuel, not a shower. There are no drops. It was just a mist. And that helps with your air/fuel mixture.”
The Bosch controller in question is the vaunted MS6.4, which made a name for itself in the rigors of endurance road racing. Like the factory systems, this robust, fully programmable unit is designed to actuate both port and direct fuel injection. It had never been deployed in a gas-burning, drag-race application until Ostmann and Urist began working together after an introduction by a mutual friend.
Germinating this collaboration was a mutual desire to push the envelope of the dual-fuel Gen3 Coyote under the hood of the latest Mustang GTs. Urist’s company, Hellion Power Systems, has long created turbo systems that push street and race Mustangs to impressive performance levels, but he really wanted to maximize the output of a 2018 Mustang GT fitted with one of his turbo systems, so he tried out one of Xtreme-DI’s high-pressure pumps do deliver more fuel on the direct-injection side of the fuel system with impressive results well over four digits at the rear wheels.
“John put some nice numbers down on that and that triggered a little bit the discussion of ‘What else can we do?’ Then he brought up his race car and I told him what I could do if he were interested in the standalone stuff,” Uwe said. “I explained everything to him, what we could do down the road, and that we might as well be able to do direct injection. He liked that idea, but we started with just putting the Bosch Motorsport kit on.”
The duo began by converting the existing port-injection setup to the Bosch controller. With it in place, they were able to optimize the extant combo for better performance, and engender the confidence to pursue a dual-fuel strategy similar to the factory 2018-and-newer Mustang arrangement.
“Ford engineers obviously spent X amount of dollars and hundreds of thousands of hours of engineering to come up with this technology. So we mimicked it. They obviously paved the way. We just followed them and then we’re increasing the volume,” Urist explained. “So the port acts as high pressure. The difference is, that the port injection in the ’18 Mustang is low-pressure, whereas the port injection in this car is high pressure. It’s 3,000 psi in the port and it’s a supplement.”
“So the first step is to install a Bosch MS 6.4 ECU, which has the capability of running the DI. So we installed the Bosch controller on the car with the port injection, got it tuned, and got everything working right with normal racing over the winter,” Urist added. “Then we converted to four belt-driven pumps and converted to high-pressure port and DI. We spent the first two races this year sorting through the fuel. With that complete, it’s about getting this power down. The car runs fast. It’s one of the top mile-an-hour cars in the class and is making a ton of power. Plus, it still has hydraulic cams and they could drive down the street if it had a radiator.”
Of course, making the leap from a traditional port system to dual-fuel arrangement with both high-pressure port and direct injectors from DeatschWerks was not something that had been attempted in this world. Fortunately, Ostmann has a long history with both Bosch controllers and these types of fuel systems. He spent time working at Bosch and these days his company offers a variety of a direct-injection fuel system upgrades for street and race vehicles. As such, he had been plotting just such an undertaking for years while seeking just the right opportunity.
“The fuel system existed in my mind five years ago,” Ostmann elaborated. “And it was pretty much just about getting to the point of actually having parts. The first step in that direction was actually my cooperation with Katech. We came up with an external, belt-driven DI fuel pump that we developed for the Corvette and the LT1 and LT4 engines.”
He took that pump design and quadrupled it for Urist’s max-effort, Street Outlaw S550. The car runs a quartet of belt-driven versions of Xtreme-DI’s HPFP35 high-pressure pumps. There are two pumps mounted on each housing, which includes its own pump camshaft the sensors necessary to tell the ECU where said cam is positioned.
“We have two high-pressure pumps feeding into two rails on each bank of direct and port injection. And then we have the other two high-pressure pumps feeding into two DI rails for the other bank,” Uwe explained. “And it’s all based on the way the control strategy works with the MS6. So the MS6 is capable of running up to two DI pumps, one per bank, and it can run two independent rail pressure sensors. So we have one rail pressure sensor on each DI rail.”
Where the factory system uses the dual-fuel arrangement to drive efficiency and lower emissions, this setup is all about feeding the turbocharged beast. Running on pure direct injection would make more power, but there aren’t injectors big enough to support this level just yet. Until then, the high-pressure port system allows supplementing the DI with a fuel mist that is almost as fine.
“We are actually using the ’18 Coyote DI system in our port setup, including the rails and the injectors. We pretty much modified the billet intake that he had already and added some special injector bungs that fit the DI injectors,” Ostmann said. “The advantage of running high pressure on the port is purely vaporization and droplet size. So we are running 2,000 psi right now. The system is capable of 3,000 psi, but we were still sneaking up to it …”
“Those droplets all have the same size now between the DI and the Port injectors. That’s a compromise that we have to make now but the closest to DI-only that you can get. It’s high-pressure only. There aren’t large enough DI injectors to make these power levels yet with DI only. DI only has a couple of other advantages,” Ostmann added.
Running pure direct injection delivers the best vaporization, and it allows shoving more air into the combustion chamber because fuel doesn’t take up space in the inlet tract. However, this setup gets pretty close, and Ostmann optimized the injector placement on an engine not originally designed for DI to minimize puddling and maximize the cooling effect of fuel in the port to mimic the benefits of a carbureted arrangement in this regard.
Of course, having the Bosch MS6.4 controller in place and sorted before making the leap made the change easier. The team had familiarity with the hardware and software, and the ECU was built for applications just like this, as it supports both port and direct injection, as do the controllers the company makes for many of the OE automakers.
“We have 16 injectors — eight DI injectors, and eight port injectors — and the Bosch ECU controls them. If you take the ’18 Coyote ECU, it is a Bosch ECU. If you would strip all the emissions stuff and you just focus on what makes power, it’s probably 90-percent identical,” Ostmann said. “And with the way the fuel pressure’s controlled on the DI side, with the way the fueling is controlled between DI and port via the blend tables, that’s pretty much identical. It’s just that we, of course, have a different focus. We want to make power and are not concerned about emissions.”
Making power would not be a challenge, but as we noted before, this powerful engine control system was initially created with endurance racing in mind. It is run on vehicles like the Mustang GT4 that runs in IMSA’s Michelin Pilot Challenge class. Therefore, its software was not originally programmed to include some of the features drag racers take for granted.
“Bosch always did road racing, it is big in Le Mans and now IMSA. Race-specific little features like having a two-step or having a bump box or having a line lock or having an actual timer that shows me events that happened during my four seconds or five seconds or 10 seconds,” Ostmann explained. That is stuff that the Bosch did not have before. We had lap times, we had fuel consumption per lap. We had predicted lap times we didn’t need. We don’t turn here. John goes straight.”
Thanks to the work of Ostmann, Urist, and a growing number of straight-line end users, the company continues to add features to the software geared toward the drag racing endeavors we cover here.
“We actually had some Bosch representatives at the track in Las Vegas last year, and then at Bradenton. We are still talking about getting the actual developer to the track so that we can do firmware development at the track,” Uwe said. “That’s working for us. It’s not exclusive to anybody. Everybody can get that, but John is pretty much the number one tester and I’m with him.”
“They didn’t have drag-specific software, so we’re working through the software side and I’m helping Bosch in designing a full drag pack software tailored to these cars,” Urist added.
Developing the software is just a side-effect of the team’s continued refinement of the combination, which continues to respond with better performance as indicated by its trap speeds.
“I think we have all the hardware. Now it’s about actually harnessing the advantage. We saw already that you gain power even without direct injection,” Ostmann said of the setup’s progress. “We gained the 180 horsepower just by firing everything at the right time. Precision is key. We made power like that, and when we added direct injection, and we made even more power.”
In addition to the benefits of the high-pressure dual-fuel system controlled by the Bosch ECU, it also offers a robust suite of up to 720 datalogging channels for the team to analyze, and the Hellion crew is utilizing most of them.
“I mean John has pretty much almost maxed out he MS6 now with the amount of sensors that we have on there,” Uwe said. “We have, we have shock sensors, strut sensors, we have pretty much pressure sensors on everything that’s in the car and before and after everything.”
Data is exceptionally useful to tune all aspects of a race car, but the huge volume of data can be overwhelming for a small drag racing team.
“Right now it’s human resources. We have all the technology that you can have on the car. I am processing everything. I would usually have a chassis engineer and an engine engineer and then we’ll have a crew of three people that are wrenching on the car all the time,” Uwe said of his usual road-racing crew. “We have to do that with John, his crew chief Mike King, and I. So I do all the data and I am teaching John to work with it. The goal is at the end of the year, he can run it himself.”
There is potential for this cutting-edge effort to push the performance envelope in drag racing, and it may inspire others to venture into new technologies like direct injection.
“I don’t know how much people are willing to learn and try things. What I see and why I do that is the technology on the street cars is so far ahead now of everything drag racers are using. So the MS6 is the one standalone controller that can handle all of these new technologies that come with every new street car,” Ostmann said. “but it offers you full access, datalogging, no limitations, full documentation — everything is described and every table is described — and motorsport features.”
Continuing to try new things keeps the frenetic Urist driving forward, but he believes that continuing to innovate is a key to keeping our sport viable for years to come.
“This is the final bridge and our link to a clean combustion and to keep combustion engines around it will take efficiency. The only way to add more efficiency is with high pressure,” Urist said. “This is the most advanced gasoline-direct-injection Mustang in the world. We’re going to try to keep it that way, and hopefully it’ll keep us relevant for a little bit longer.”