A small bend from a local muffler served as our discharge tube from the turbo to the carb bonnet. We welded a fitting to secure an inexpensive blow-off valve. A small bend from a local muffler served as our discharge tube from the turbo to the carb Before subjecting the Demon 454 to some boost, we made one final change: swapping the dual-plane RPM Air-Gap for a single-plane 454R. We were concerned about proper fuel distribution with the dual-plane and opted for the single-plane. The single-plane would naturally hurt power down low, but we figured there would be more than enough power to go around once the boost came up. Besides, the reason we assembled the turbo kit in the first place was to test the strength of the internal components in the Demon 454. With everything hooked up and some extra insurance present in the form of Lucas Oil octane booster (with our 91-octane premium unleaded), we started making partial power pulls. A few jets here and there to lean out the mixture, and we were eventually rewarded with peak numbers of 776 hp and 732 lb-ft of torque. Torque production with our quickie turbo kit exceeded 650 lb-ft from 3,500 rpm to 6,200 rpm. There was plenty of power left with even greater boost pressures, but we were satisfied with the results of this exorcism. Obviously, 20 to 25 dyno pulls cannot simulate the years of abuse with a turbo kit, but they do indicate that the Low-Buck 454 should last almost indefinitely at the lower power levels. DEMON 454-NA VS. TURBO N/A TURBO GAINS RPM HP TQ HP TQ HP TQ 3,500 355 533 443 665 88 132 4,000 406 533 527 692 121 159 4,500 461 538 619 723 158 185 5,000 507 533 696 731 189 198 5,500 540 516 743 710 203 194 6,000 562 492 776 679 214 187 6,400 551 452 767 630 216 178 It is amazing what 7 to 8 psi of boost does to a big-block. Already impressive at 564 hp and 542 lb-ft of torque, the low-buck turbo kit improved the power output to 776 hp and 732 lb-ft of torque. Despite the use of a single-plane intake that reduced low-speed power production compared with the Edelbrock Performer RPM Air-Gap, boost response from the 74mm turbo from Comp Turbo was impressive. Of course, the stationary load on the engine dyno is never simulated in the real world, but we had a solid 8 psi of boost available at just 3,500 rpm. DESCRIPTION PN SOURCE PRICE Comp Turbo 74mm NA eBay Motors $895.00 Hyper Gate 45mm wastegate TS-0504-1001 Turbosmart USA 300.95 Edelbrock 454R 2907 Summit Racing 299.95 Hedman shorty headers 68370 Summit Racing 59.95 T4 and wastegate flanges N/A Local muffler shop 30.00 Carburetor CSU850BT CSU 1,050.00 Carburetor bonnet CSU1001 CSU 149.00 Miscellaneous fittings and hoses N/A local hardware store 29.95 TOTAL $2,814.80 The dual-plane RPM Air-Gap was replaced with a single-plane 454R from Edelbrock. CSU supplied an 850 Holley specifically designed for use in a blow-through application. These carburetors work well on both blow-through supercharged and turbocharged applications and cost considerably less than converting the big-block to fuel injection. CSU supplied an 850 Holley specifically designed for use in a blow-through application. Th The turbocharged 454 from Demon Engines produced 776 hp and 732 lb-ft of torque. Torque production exceeded 650 lb-ft from 3,500 rpm to 6,200 rpm. More power was on tap with higher boost levels (beyond 8 psi), but the homemade turbo kit definitely served its purpose. Remember, these power numbers came from a short-block equipped with a cast crank and stock rods. The turbocharged 454 from Demon Engines produced 776 hp and 732 lb-ft of torque. Torque pr SOURCES Comp Cams 3406 Democrat Road Memphis TN 38118 800-999-0853 www.compcams.com Probe Racing 2555 West 237th Street Torrance CA 90505 310-784-2977 www.probeindustries.com Holley/Hooker 1801 Russellville Road Bowling Green KY 42101 270-782-2900 www.holley.com Comp Turbo 221 West Allen Avenue San Dimas CA 91773 909-599-5757 www.compturbo.com Turbosmart 11650 Mission Park Drive Suite 103 Rancho Cucamonga CA 91730 909-476-2570 www.turbosmartonline.com Carburetor Solutions Unlimited 17367 Reed Street Fontana CA 92336 909-851-6955 www.camresearch.com Demon Engines Sante Fe Springs CA 562-694-2559 www.demonengines.com Dr. J's Performance 436 S Montgomery Street Orange CA 92868 714-808-9780 www.j-performance.com L&R Automotive 13731 Bora Drive Sante Fe Springs CA 90670 562-802-0443 www.lnrengine.com Procomp Motorsport Rialto CA 909-605-1123 www.procompelectronics.com « | 1 | 2 | 3 | View Full Article By Richard Holdener Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!