2002 Chevrolet Corvette Z06 - After-Cat Fever

Mission: To Build The Fastest Street-Legal, Naturally Aspirated 427 In The World

Jerry Heasley Dec 1, 2004 0 Comment(s)

Engine* GM C5R 7.0L race block (installed at 1,249 miles)* Lunati rotating assembly* All internal friction surfaces coated* All heat exchange surfaces coated* Cam, custom grind* Valves, Ferrea one-piece steel, 2.100-inch intake/1.670-inch exhaust* Isky 295D Gold Series Tool Room springs* Ferrea titanium retainers* T&D 1.7:1 shaft-mounted roller rockers* New LS6 head castings, custom hand-finished porting* ATI Super Damper* FAST 90mm intake manifold* TPIS 90mm throttle body* Holley 36-pound injectors* VaraRam* Breathless Performance air bridge* Meziere electric water pump* Katech belt tensioner* Katech tall valve covers with coil relocation kit

Interior* Modified red parts by Vette Essentials (steering wheel, door pulls, console lid, shifter knob and boot, brake handle and boot)* Custom partitions by Twisted Interiors (modified red front panel with raised panel, Plexiglas inserts and C5 logo, black rear panel with raised panel and red neon Twisted Interiors logo, and custom formed wheelwell covers)* Vinyl lettering on steering wheel, dash, and door sills

Headers & Exhaust* Bassani 171/48-inch tri-Y headers* Bassani high-flow catalytic converters* Bassani 3-inch exhaust from catalytic converters back

Clutch* Fidanza aluminum flywheel* Ram 910 disc* Ram 402 pressure plate* McLeod billet adjustable clutch master cylinder* B&M Ripper shifter

Wheels & Tires* Kinesis K18R, Front: 18x9.5-inch* Kinesis K19R, Rear: 19x12-inch* Michelin Pilot Sport, Front: 275/40ZR18* Michelin Pilot Sport, Rear: 345/30ZR19

Brakes* Wilwood Superlite six-piston, front* Wilwood Superlite four-piston, rear* 13.8-inch replaceable, slotted rotors front and rear with red anodized hats* Goodridge stainless steel, Teflon coated lines* Speed bleeders* Motul brake fluid

The Bassani ConnectionHave you heard of tri-Y headers? They've been around for 40-50 years. "Tri-Y" means the primary tubes, four per side, dump into two tubes then into the collector. That's "four into two into one."

In contrast, typical C5 performance headers are traditional long-tube style, even on a setup like a naturally aspirated C5-R. The four primary tubes dump into one collector. That's "four into one."

Apparently, there's a power advantage with the tri-Y style. However, this advantage hasn't been fully exploited on the 427, which Gary Greenwood has gotten into with help from Bassani.

"At first, we tried Bassani's 131/44-inch tri-Ys with 211/42-inch exhausts, which was way too restrictive for the 427ci engine," Gary says. "It really cut us down on power. Then they built a prototype set of 171/48-inch tri-Ys with 3-inch-diameter exhausts. The tri-Ys go into a 211/42-inch collector, then into cats, and on the back side of the cats is a 3-inch pipe. From there, the exhaust is 3-inch all the way back." Gary would rather see the 171/48-inch tri-Y pipe merge with a 3-inch collector and 3-inch diameter pipes on either side of the catalytic converters.

He adds, "I think we'll pick up a significant amount of torque. We're working with Bassani on it now. We're gonna make this thing breathe!"


Balch Springs, TX


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