At the recent SEMA show, we ran into Borowski Race Engines‘ owner, Ken McCaul, who raved about one of the company’s newest engine packages, an LS3-based nitrous bullet that’s been designed for an unnamed customer.
For years, street racers (and we don’t condone that) have been looking for ways to hide their “on the bottle” performance from unsuspecting opponents.
We’ve seen systems hidden that would need the entire car disassembled by a team of trained mechanics to find even the slightest hint of a system; since this particular engine has that type of competition in its future, stealth performance was at the top of the list when designing the combination.
The engine in question is based around one of Borowski’s prepped stock LS3 engine block and CNC-ported cylinder heads, with a hidden nitrous system on board from Nitrous Outlet that’s been selected for its simplicity and performance.
“We were the first ones to buy this puck from Nitrous Outlet machined specifically to be a dry nitrous system. They sell it to the public as a wet system, but for this engine we let the Holley HP EFI system handle the fueling. Since everything is all tied into one program that’s controlled by the box, it makes for a cleaner installation and is better for disguising the kit. If you have to run fuel to it, then it’s harder to hide,” says McCaul.
“There’s a small 90-degree fitting for the nitrous feed underneath the manifold that you can’t see, and we’ll be disguising it further upon installation,” says McCaul.
The LS3-based engine checks in at 416 cubic inches or 6.8L – a large bump over the 376 cubic inch standard LS powerplant. To reach that displacement, the Borowski team selected a SCAT forged crankshaft, forged H-beam connecting rods, and a set of AutoTec pistons by RaceTec. On top is a set of stock, Borowski CNC-ported factory LS3 cylinder head castings, fed by an Edelbrock intake manifold plumbed with the Nitrous Outlet puck, and topped off with a FAST billet throttle body. The Holley HP engine management system controls both the engine and nitrous system.
In this power range, the factory LS3 block is sufficient, but to step up to the next level, McCaul recommends the customer step to Dart’s LS Next block, which we’ve covered extensively here on EngineLabs. “We really like the aluminum LS Next block, but it’s four times the cost and isn’t needed in this application,” he notes.
Although the intent of the engine is to be a street race brawler, quite a bit of technology is at work behind the scenes to maintain harmony between the engine and the nitrous system; most importantly, the aforementioned Holley HP.
“We’ve programmed the system where the nitrous only comes on above 4,000 rpm, then turns off at 6,500 rpm – it’s totally adjustable. Once you arm the system, at 4,000 rpm above 90% throttle position, it’ll control the nitrous, deliver the fuel, and retard the timing,” says McCaul.
The Holley EFI system’s ease of use with nitrous oxide is a large part of why the Borowski team selected it for installation on this engine – with the customer’s blessing, of course.
“If you run out of fuel, it will kill the nitrous program so you don’t torch a piston. If you run out of nitrous, it will show the wideband that the engine is running too rich and again, kill the whole nitrous program. The system is smart enough to turn off the program and default back to the regular naturally-aspirated program.
The system is also programmed to shut the nitrous off and return the engine to naturally-aspirated conditions if there’s an unforeseen issue. The engine needs to meet all of the parameters to activate the system; should those parameters change during operation, the HP shuts off the nitrous flow as it monitors all of those conditions every five milliseconds. Running the system this way can prevent catastrophic failure.
The engine made even more power on the dyno than expected – while it cranked out 620 horsepower naturally aspirated, it started to shine once the squeeze was turned on.
“The combination came together, and it was just a real efficient setup with the piston design and hydraulic roller camshaft we specified; the engine picked up 225 horsepower on what was jetted to be a 150 shot, for a total of 845 streetable horsepower,” says McCaul.
Tuning on the dyno was handled by a partnership of Borowski’s lead engine builder, Dave Livesey, and lead machinist, John Zapp.
“It’s so easy you wouldn’t believe it. It did not miss a beat on the dyno; we did a handful of pulls on the engine naturally-aspirated, then activated the nitrous side. John figured out how many pounds per hour of fuel we wanted to add – we weren’t even pushing the button. It just worked flawlessly, it never spit or sputtered or anything. This was the first time I’ve had the opportunity to use the Holley EFI system on the dyno as the nitrous engines we dyno are usually carbureted,” explains Livesey.
We have to wonder how quickly the new engine’s owner will win back the funds it took to build this beast, and if the reports we hear coming out of Chitown are true in terms of the amounts that exchange hands on any given Sunday, it won’t be long at all.