SS CAMARO ULTRA Z !!! THIS IS THE 427ci PROTOTYPE CAR FOR SLP!!! ULTRA RARE!!!

This is one of those "we knew it when" stories. That's because we knew SLP Performance Parts' Camaro Ultra-Z when it was "only" a pewter, 550hp street car. Back then (all of two years ago), the car sported a stroked LS1 and would lay rubber until either your right foot got a cramp from pressing the pedal to the floor or the seesawing hind end threatened to snap a 180-at 50 mph.

So, after a brief life as an on-the-edge street car, Reese decided to take the car off the highway and get serious. Certainly, the car has proved itself a worthy rolling tested for SLP Performance Parts, but it also is an in house project that keeps morale pretty high. Think of it this way: Where you had to fill out an expense report for a taxi ride from the airport to the hotel, Reese turned in an expense report for, say, an NHRA-legal rollcage. Is Ed Hamburger a helluva boss or what?
"The funny thing is, it's a lease," says a grinning Reese, about the now-Laser Red F-body (sprayed by Richfield, Ohio's Northcoast Jet Clean). "We'll either have to return it to stock or buy the car. You might see a 'For Sale' sign in the window someday, too. But I don't even know where the back seat is right now." It doesn't matter. The strip-bred Ultra-Z now packs a 650hp Gen III engine (548 to the ET Streets), providing enough yank to pull the front wheels and zip down the track to a best e.t. of 10.37 at 130 mph.

Displacing 427 ci (7.0 L), the motor powering the Ultra-Z started out as the ultimate Gen III foundation- Corvette racing C5R aluminum block. For the unfamiliar, the C5R block was developed for the LeMans-winning GTS
Corvette team, and though it has the same outward appearance and dimensions as an LS1 block, that's about where the similarities end.
The dry, pressed-in cylinder liners on each bank of the block are different than the regular production LS1, and the C5R block has Siamese water jackets. This allowed adequate room to overbore the cylinders to 4.125 inches (max 4.160). Combine that with a 4.00-inch stroke and you've got 427 big-block-style cubes. Bottom-end beef includes a Callies Magnum Plus 4340 forged crank, Callies Pro- (by Oliver) 4340E forged conrods, and Diamond/SP forged pistons delivering 12.0:1 compression.

But while the stout bottom end delivers the displacement, making power is all about moving air. The cam is a Comp Cams/SLP hydraulic roller with 256/256 and 0.621/0.603 specs. The heads are SLP-modified LS6 parts, with CNC-ported intake runners and exhaust ports and 64cc chambers. The lightweight LS6 valves measure 2.00 inches on the intake side and 1.55 on the exhaust. The rockers are SLP's own 1.85:1 parts. "They're the same heads we include with the 382 and 427 engine packages," says Reese. "The whole idea with this car was to build something reflective of the capabilities we offer 'over the counter.' Anyone can order the same engine combination from us." Well, almost anyone-at $25.500, the package isn't exactly cheap.
SLP's heads flow like the wind across Nebraska, with the air stream generated in a ported LS6 intake manifold capped by a prototype 85mm throttle-body. Thirty-eight-pound injectors, fed by an SX pump and regulator, ensure a more-than-adequate fuel supply. The fuel tank was replaced by a trick fuel cell setup, and the stock fuel lines were scrapped in favor of half-inch teed and return lines. The Camaro's stock quasi-returnless fuel system, says Reese, is totally inadequate for the engine's needs.
As for exhaust, SLP's 131/44-inch, tuned-length, stainless steel long tubes feed a pair of custom collector mufflers with dumps. The remainder of the car's drivetrain is fairly straightforward strip stuff: a Yank-built Turbo 400 with a 3,200-stall 9-inch converter. The obligatory transbrake and Hurst Quarter-Stick are in place, as is one of SLP's Moser-built 12-bolt rearends. Again, it's one of those "out of the catalog" parts SLP installed. For the Ultra-Z, the rearend boasts stronger axles, 4.11:1 gears, and a spool. The whole assembly turns a set of 15-inch Weld Wheels with Mickey Thompson ET Drags (28.0x11.5) or ET Streets (26.0x11.5).Keeping that rubber planted at the Tree is a bunch of SLP suspension parts, including the company's adjustable torque arm. HAL shocks are used at all corners, while the modified, but stock, rear springs house airbags. To stiffen the F-car's notoriously flexible chassis, SLP's subframe connectors and shock tower brace were also added, and SLP scratch-built the car's rollcage.
In a nutshell, the Ultra-Z is prepped for one thing: launch. "It's pretty sick." says Reese. "It comes off the transbrake around 3,200 and just blasts off-the tires stick like glue. It tracks super straight thanks to a heavy preload of the passenger-side suspension, as well as proper shock valve tuning and airbag biasing."
Thing is, 10.30s are just a first blush. "The Ultra-Z was in pieces two days before we had to leave for one of SLP's customer-appreciation events, and we promised the car would run down the track," says Reese. "When the car got back from the paint shop, it was a thrash to assemble it. Hank Daniecki, Tony Kalapach, and Ken Estelle deserve most of the credit for putting the car together-and making it run." As a rolling laboratory, the form and function will continue to evolve. "We'll be in the 9s shortly," says Reese. "We just need to put the car on a diet. I'd like to get it down to about 3,250 pounds, but without completely tearing out the interior. We're going after hidden
weight."