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1991 GMC Syclone - Tycoon

Will This be The World's Fastest SY?
From the October, 2005 issue of GM High-Tech Performance
By Scott Parker
Photography by Rick Jensen
0510Htp Sy 01 Z
0510Htp Sy 07 Z
The PT-91 turbo utilizes a... 
   
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0510Htp Sy 07 Z
The PT-91 turbo utilizes a 7-inch inlet, 3.5-inch outlet, and an Innovative Turbo 51mm Indy-Gate wastegate.
0510Htp Sy 05 Z
The rear window was replaced... 
   
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0510Htp Sy 05 Z
The rear window was replaced with Lexan in order to cut it around the rollcage; meanwhile, the rest of the glass is factory, including the electric windows. All of the sheetmetal is factory as well, repainted and massaged by Golecki Customs. The only addition to the exterior is the adjustable wing created by Competition Fabrication for high-speed stability.
0510Htp Sy 02 Z
This award-winning engine... 
   
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0510Htp Sy 02 Z
This award-winning engine bay features coated headers and intake tubing from LO-KO Performance Coatings. The splashes of red come from an MSD distributor and 10mm spark-plug wires. The flawless paneling and firewall can be credited to Competition Fabrication, who also fabricated the headers and tubing. And by the way, the 311-inch V-6 should make about 1,200 horses!
0510Htp Sy 03 Z
The carbon-fiber inserts and... 
   
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0510Htp Sy 03 Z
The carbon-fiber inserts and Creative Auto Tops & Interiors fabric helped Jason win Best Interior at the Detroit Autorama. Autometer Pro Lite gauges, a B&M Hammer shifter, and an Innovative Turbo boost controller also did their parts in addition to being quite functionally necessary. All the standard safety equipment for an 8-second race truck is still present though, including RJS five-point harnesses, a window net, a Simpson 10-foot chute, and a Safecraft 3-pound billet extinguisher.
0510Htp Sy 08 Z
Nestled under the carbon-fiber... 
   
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0510Htp Sy 08 Z
Nestled under the carbon-fiber bed cover and aluminum wheeltubs are three Derale 10x16 engine and trans coolers with 650-cfm fans.
0510Htp Sy 04 Z
The rolling stock consists... 
   
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0510Htp Sy 04 Z
The rolling stock consists of Weld Magnum wheels measuring 15x4 and 15x15 with Mickey Thompson Sportsman skinnies and 33x19.5 tires for the street.
0510Htp Sy 06 Z
Competition also fabricated... 
   
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0510Htp Sy 06 Z
Competition also fabricated this scoop for the turbo to feed it fresh air, and another scoop can be found underneath the car to channel more air onto the intercooler. A custom Griffith aluminum radiator, Spal 2,200-cfm electric fan, and Mezeire 55-gpm remote electric water pump were all used to keep the monster at bay and circumvent the tight confines created by the front mounted turbo and intercooler.
0510Htp Sy 10 Z 0510Htp Sy 09 Z 0510Htp Sy 11 Z
0510Htp Sy 12 Z 0510Htp Sy 13 Z 0510Htp Sy 14 Z
0510Htp Sy 15 Z
Owner: Jason Leach
Truck: 1991 Syclone
Block: GMPP Bow Tie Racing, 311 ci
Compression ratio: 8.0:1
Heads: GMPP Bow Tie, ported and polished by Flow Technologies Inc, 2.15 intake, 1.625 exhaust valves
Cam: COMP Cams roller, 262/267 duration at .050, .673-/.673-inch lift, 112 LSA
Pushrods: Howard's Cams custom chromemoly 3/8-inch
Rocker arms: Jesel 1.6:1
Pistons: JE forged
Rings: Total Seal
Crankshaft: Moldex forged, 3.875-inch
Rods: Oliver forged, 5.85-inch
Throttle body: Wilson 90mm
Fuel injectors: Bosch 160 lb/hr
Fuel pump: Weldon 2025
Ignition: MSD Digital 7 controller, MSD coil and distributor
Engine management: F.A.S.T. tuned by Rockford Racecraft
TURBOCHARGER Precision PT-91
Boost: 30 psi
Intercooler: Custom air-to-air from Precision Turbo
WASTEGATE Innovative Turbo 51mm
Exhaust system: Competition Fabrications custom 1.75-inch equal-length turbo headers, 5-inch downpipe, Borla XR-1 muffler
Transmission: 400 built by FB Performance
Torque converter: FB Performance 3,600-5,000-stall (variable stall control)
Driveshaft: Midwest Driveshaft custom 3-inch chromemoly
Front suspension: Competition Fabrications custom control arms, Strange coilover struts
Rear suspension: Competition Fabrications custom four-link and antiroll bar, Strange coilover shocks
Rearend: Strange 9-inch, 4.56 gear, 40-spline gun-drilled axles, spool
Brakes: Strange front and rear
Wheels: Weld Magnum 15x4 front, 15x15 rear
Front tires: MT Sportsman Pro 26x4.5
Rear tires: MT Sportsman Pro 33x19.5 (street), Goodyear 33x15 (track)
Fuel octane: 116
Race weight: 2,800 pounds
Best ET/mph: N/A
Best 60-ft. time: N/A
Current mileage: 8,900
Miles driven weekly: 1


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