YEAH, IT’S A BLOW… HUH? YEAH, A BLOWER CAR!
NO… YEAH… HA… DRAG RADIAL!
JOE… WAIT ’TIL YOU SEE IT RUN!
If we were discussing this particular C5 Z06 in person, that’s pretty much how the entire conversation would go. You see, this is quite possibly the loudest LSX Drag Radial car ever built, and once the 427 cubic-inch LSX engine fires up and the fender well mounted headers start screaming, you can pretty much forget about talking within a two-mile radius of this beast. Truth be told, it’s probably unsafe to be around this Z without earplugs and, even then, it’s really loud. Like the type of loud that I can still feel in my eardrums a full month after the Z’s inaugural trip down the 1320 at the LSX season opener in Bradenton, Florida. And while the car still needed some fine-tuning to really show its potential on the track, potential is the key word here. Well, that and loud.
But loud is awesome. And so is a crank-driven ProCharged widebody Corvette pullied to some 38 pounds of boost, built specifically to compete with the best of the best for all of the LSX glory. But what’s also amazing about this particular build is the story, as this Z06 didn’t come out of some high-dollar shop as a blank check build, although it would be difficult to tell that from these photographs. In fact, this build began as something much more subdued, with owner Joe DeDona and madman builder Mark Mastrojohn of Tire Craft Racing setting out to set a couple of simple records before everything spiraled out of control. “Through the years I owned many sports cars, but they were all automatics. Then one day I purchased a manual ’08 C6 Z06. This was a night and day change for me. I took it to a track rental at Atco in 2008 and the rest was history. I drove that all stock C6Z for two years and managed a personal best of 10.98 at 128 mph. It was a far cry from my first pass of 12.26 in the same car. At this point, I wanted to go faster and so I partnered up with a local Corvette builder Mark Mastrojohn of Tire Craft Racing. At first we decided to go after the elusive 8-second C5/C6 IRS six-speed record, and when we were at 95 percent completion, we looked at each other and said, ‘Let’s just go faster and all out.’”
All out, as it were, meant building a blown combination that had never been tried before in LSX Drag Radial, combining the raw power of a massive centrifugal supercharger with a serious bullet from Virginia Speed, and putting it all together in a chassis riddled with cool tricks. The main attraction is obviously the crank driven ProCharger F-3R supercharger unit, which is capable of producing roughly 2,500 hp on an optimized engine combo at full-tilt, and is the first centrifugal supercharger to ever run in the 6-second zone at over 200 mph. Attached directly to the front of the billet Bryant crankshaft by the ProCharger RaceDrive, this whistle is spun hard and feeds all 38 pounds worth of compressed air into—get this—the factory framerail before sending it into the air-to-water intercooler stuffed in the passenger seat area. “We were concerned that the frame would be a restriction or issue with boost, but we have seen 38 pounds of boost in the manifold so it looks to be working fine,” said Mark Mastrojohn, the brains behind this framerail as a charge pipe operation.
And working fine means that all of that compressed air finds its way into the massive 125mm throttle body hidden under the windshield and into the gorgeous Marcella sheetmetal intake manifold without any issue. Stuffed with eight massive 275 lb/hr Moran fuel injectors fed by a mechanical Waterman pump and enough Q16 to run the space program, this hand-fabricated and TIG-welded beauty is optimized for the Mast Motorsports LS7 cylinder heads that it’s bolted to, as well as the top secret solid roller camshaft that commands the trick Jesel valvetrain found within those ported heads. Compressed air enters the chambers through a set of titanium 2.200-inch intake valves, where it is further compressed by a set of custom coated JE pistons before heading out the Inconel 1.600-inch exhaust valves and into the 2.5-inch long-tube exhaust manifolds. We’ll get to those in a second, but first let’s take a look at the rest of the engine.
Under those JE slugs are a set of GRP aluminum connecting rods, which spin around a center-counterweighted billet Bryant crankshaft clamped tight to the RHS aluminum block with a set of ARP main studs. At 427 cubic inches, the motor isn’t massive, but the cubes are almost perfectly matched to the flow characteristics of the F-3R supercharger and the heads and cam combination. Flow brings us all the way back around again to those massive 2.125-inch to 2.5-inch stepped long-tube headers, which exit through 5-inch Vibrant race mufflers stuffed in the modified C5 front fenders. “We didn’t want to hide the beautiful headers, so the decision was made to go through the frame…” And so it was. Truth be told, the headers are one of the coolest parts of this entire project and easily one of the most talked—well, yelled—about pieces on the car.
As for the remainder of the drivetrain, well, it’s all GM-based race stuff, with hard parts coming from RPM Transmissions. Backing the blown beast is a TH400 three-speed automatic transmission spun by a Neal Chance bolt-together 5500-stall converter, which drives power through an upgraded torque tube assembly and into an RPM-built ZR1 rear end housing. Drive Shaftshop axles take power to the wheels, which are still independently suspended and controlled. That’s right, this C5 Z06 is still IRS and, well, who says an IRS can’t wheelie?! Of course, power transfer has a lot to do with getting off the line quickly, and Joe’s ’vette is full of tubular suspension parts to make it all work.
Out back, custom tubular lower control arms by Farks Supercars in Brooklyn, New York, allow the massive 15-inch Weld Racing Alumastars to bolt in place, which wear a set of 275 or 315mm drag radial tires depending on the day. A Pfadt drag race spec sway bar handles the side-to-side load, while AFCO rear coilovers control the dampening and rebound. Up front, it’s all TRZ and Strange Engineering, with a TRZ tubular front K-member supporting the TRZ upper and lower control arms, which are controlled by a pair of Strange coilovers. Speaking of Strange, we should probably introduce TJ Strange, the hot shoe responsible for piloting Joe’s car in its DR debut, but we’re running out of room, so we’ll have to leave that introduction for another day.
With Joe behind the wheel during initial testing, he only had to say, "there is no way to explain what the difference is in acceleration between a 10.9-second car to a 7-second [capable] car.” Despite issues at the track, the crew was able to run as fast as 8.10 seconds at an incredibly slow 135 mph on a half-track pass with an early shut-down. That pass would have been well into the 7-second zone based on the early incrementals, which included a back breaking 1.24-second 60-foot time on the back tires. Of course, if you saw it in person, you would probably only remember having to cover your ears and duck for cover as the C5 came up on the transbrake and tried to deafen the entire LSX field before making its 8-second run. So, yeah, come—what?!— come check it out at the next race!
Car: 2002 Corvette Z06
Owner: Joe DeDona
Block: RHS, 427cid
Compression Ratio: 9.6:1
Heads: Mast Motorsports LS7, 2.200-inch titanium intake, 1.600-inch Inconel exhaust valves
Cam: Custom solid roller
Rocker Arms: Jesel, 1.8-ratio
Pistons: JE, forged and coated
Crankshaft: Bryant, billet
Rods: GRP, aluminum
Throttle Body: Marcella 125mm
Fuel Injectors: Moran 275 lb/hr
Fuel Pump: Waterman, mechanical
Ignition: MSD Digital 8, ProGrid, Jesel distributor
Engine Management: FAST XFI 2.0, tuned by Ed Huchings of HiTech Tuning
Exhaust System: Custom 2 1/8-inch to 2.5-inch stepped long-tube headers, 5-inch Vibrant mufflers
Supercharger System: ProCharger F-3R, Supercharger Store gear drive
Intercooler: Bell, air-to-water
Blow Off Valve: ProCharger race, twin
Transmission: TH400, built by RPM Transmissions
Converter: Neal Chance, 5500-stall
Front Suspension: TRZ K-member, upper and lower control arms, Strange coilovers, removed front swaybar
Rear Suspension: Farks Supercars custom lower control arms, Pfadt sway bar, AFCO coilovers
Rear End: GM ZR1, 3.42:1 gear, Driveshaft Shop axles, Quaife differential
Brakes: Strange, front and rear
Wheels: Weld Racing Alumastar 15x3.5 front, Champion CWI-X double beadlock 15x10 rear
Front Tires: M&H Front Runners 26/3.5-15
Rear Tires: Mickey Thompson Drag Radial Pro 275/50/15
HP: 2000 (est.)
Best 60-ft: 1.24