1-Inch HVH 4-Hole Carburetor Spacer
The Test
More often than not, a spacer will do the trick and add power-and we proved it. The 9.8:1 iron-headed 396 big-block was topped off with a performer Edelbrock intake and a Holley 650-cfm carburetor. It made good, reliable power in almost stock trim on the engine dyno but made more with the spacer added.
Before
Max power: 381 hp @ 5,000
Max torque: 442 lb-ft @ 3,100
Average power: 328 hp
Average torque: 427 lb-ft
After
Max power: 391 hp @ 5,000
Max torque: 451 lb-ft @ 4,200
Average power: 338 hp
Average torque: 439 lb-ft
Difference: +10 hp; +9 lb-ft
HVH
865.573.9151
highvelocityheads.com
Holley 1050 HP Carburetor
The Test
Swapped out Holley's 850-cfm carburetor for a heavier-breathing 1,050-cfm on (both HP series) on a 378ci race small-block. It was obvious that the increased cfm and added availability of fuel bumped up power and also increased torque across the board on the Superflow engine dyno.
Before
Max power: 694 hp @ 7,900
Max torque: 485 lb-ft @ 6,500
Average power: 640 hp
Average torque: 478 lb-ft
After
Max power: 705 hp @ 7,800
Average power: 494 lb-ft @ 6,500
Max torque: 652 hp
Average torque: 486 lb-ft
Difference: +11 hp; + 9 lb-ft
Holley
270.782.2900
holley.com
HP Tuner's VCM Suite, Version 2.1
The Test
Z06 Corvette with FAST intake manifold, cold air intake, and throttle body with stock headers and exhaust. We hooked up HP Tuner's newest software to correct fuel and air mapping and ran the car on Westech Performance's chassis dyno.
Before
Max power: 442 hp @ 6,024
Max torque: 478 lb-ft @ 4,298
Average power: 352 hp
Average torque: 412 lb-ft
After
Max power: 460 hp @ 6,330
Max torque: 484 lb-ft @ 4,423
Average power: 379 hp
Average torque: 419 lb-ft
Difference: +18 hp; +6 lb-ft