Articles written by Richard Holdener
Articles written by
Richard Holdener

1,197 Horsepower from a ProCharger-Blown Big Block

The third installment of the Mad Adder series puts a ProCharger F-1A-94 centrifugal supercharger on a BluePrint Engines 540 big block - reaching 1,197 hp and 953 lb-ft of torque at 11.8 psi on the dyno.

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Multipurpose Power: A 496ci Big-Block Built for NA, Nitrous, and Boost

A 496ci big-block stroker built to perform across three configurations - naturally aspirated, nitrous-injected, and supercharged - reached 1,144 hp on just 11 psi of boost from a ProCharger F-1A-94, with capacity still in reserve.

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5.0L Fistfight Part 4: Adding Boost With a TorqStorm Centrifugal Supercharger

In the fourth instalment of the 5.0L Fistfight series, both the Ford 302 and Chevy 305 receive TorqStorm centrifugal superchargers. The Ford produces 619 hp, but the Chevy's stronger block may tell a different story long-term.

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Speedmaster Downdraft IR System Adds 29 HP and 49 Lb-Ft to a Modified 5.7L Hemi

A back-to-back dyno test on a modified 5.7L Hemi crate motor shows the Speedmaster downdraft individual-runner system producing 512 hp and 452 lb-ft - a 29 hp and 49 lb-ft improvement over the factory single-plane intake, with gains across the full curve.

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Boost Theory Tested: LS3 vs. 427 LSX on the Dyno

A controlled dyno comparison of a cam-only LS3 and a built 427 LSX tests a foundational boost principle: the stronger the naturally aspirated baseline, the more power you make under pressure.

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Intercooling a Twin-Turbo 540: Dyno Water vs Ice Water

A back-to-back dyno test on a twin-turbo 540-inch big block from Blue Print Engines measures the real-world power difference between ambient dyno water and ice water flowing through an air-to-water intercooler - 28 hp and 48 lb-ft at 10.4 psi.

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EFI vs. Dual Plane on a 5.0L Ford: A Dyno Comparison with the Speedmaster Eliminator

Richard Holdener puts the Speedmaster Eliminator dual-plane intake head-to-head against a Trick Flow Specialties Street Heat EFI system on a modified 5.0L Ford, with dyno results revealing where each configuration delivers its advantage.

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Carb Spacer Testing on a 302 Ford: Open vs. Four-Hole on a Speedmaster Eliminator Intake

Using a junkyard 5.0L Ford topped with Trick Flow 11R heads and a Speedmaster Eliminator dual-plane intake, Richard Holdener tested 1-inch open and 4-hole carb spacers from Wilson Manifolds - measuring where each design adds power and where it trades torque.

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939 HP From a Blown 540-Inch Big Block

Richard Holdener puts the BluePrint Engines 540 big-block Chevy through a progressive boost test using a Speedmaster 8-71 supercharger kit, reaching 939 hp and 866 lb-ft of torque at 11.1 psi.

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What Happens When You Run an Engine Without Oil: Lessons from the Dyno

What actually happens when oil pressure drops to zero and you keep driving? Richard Holdener and Chad Reynolds put it to the test on The Wheel of Death, combining controlled destruction with real failure analysis.

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Boost vs. the Block: Why More PSI Is Not Always the Answer on a 5.0L Ford

Running a 331 Ford stroker to 761 hp on a factory 5.0L block revealed a critical lesson: boost is a multiplier, not a solution. Building normally aspirated power first delivers more output at lower, safer boost levels.

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The Pecking Order: How Much Are Cylinder Heads Worth on a 331 Ford Stroker?

On a 331 Ford stroker equipped with Speedmaster forged internals and a COMP cam, swapping from stock E7TE iron heads to Edelbrock Performer RPM aluminum heads delivered an 85 hp gain. The results reinforce why the order of modifications matters.

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Dyno Tested: Speedmaster Stack Attack Individual-Runner Intake on a Gen III Hemi

On a mild 5.7L Gen III Hemi, the Speedmaster Stack Attack individual-runner intake system produced 461 hp and 412 lb-ft of torque, outperforming a Mopar Performance single-plane intake by 35 hp with gains throughout the entire rev range.

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The Great Equalizer: Vortech Supercharging a Modified 4.8L LS to 799 Horsepower

A modified 4.8L LS equipped with Speedmaster rods, JE forged pistons, and a Vortech Ti supercharger produced 799 hp at 15.8 psi, nearly doubling the 438 hp naturally aspirated baseline. The results demonstrate the value of building NA power before adding boost.

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Big-Block Chevy 454 Top-End Upgrade: Edelbrock RPM Heads, Intake, and COMP Cam

A Gen VI 454 pulled from a wrecking yard produced 369 hp in baseline trim. After installing Edelbrock RPM 454-O aluminum heads, a Performer RPM Air Gap intake, and a COMP XR271HR12 hydraulic roller cam, output climbed to 481 hp and 527 lb-ft of torque.

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Speedmaster 6-71 Blower Kit on an LS 383 Stroker: From 527 HP to 753 HP

A 383 cubic-inch LS stroker built around a 4.8L iron block produced 527 hp naturally aspirated. After installing the Speedmaster 6-71 supercharger kit with a dual-quad carburetor setup at 7.3 psi, output reached 753 hp and 625 lb-ft of torque.

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383 LS Stroker Exhaust Test: Measuring the Cost of a Full Street System

A full-length 2.5-inch Hooker Blackheart exhaust system was tested against open headers on a 383 LS stroker to measure the actual power cost of running a street-legal exhaust. The results showed a difference of just 9 hp at peak, with the street system delivering 542 hp at 6,000 rpm.

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LQ4 6.0L LS Build: Compression, Cam, and Ported Heads to 549 Horsepower

A stock LQ4 6.0L truck engine was upgraded with LQ9 flat-top pistons, a COMP 54-454-11 cam, Stage 2 ported 317 heads from Total Engine Airflow, and a FAST LSXR intake. The result: 549 hp at 6,700 rpm and 481 lb-ft of torque at 4,900 rpm.

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427 LSX Throttle Body Test: Measuring the Difference Between 4150 and 4500

A throttle body comparison on a 427 LSX equipped with Mast Black Label LS3 heads and a CNC-ported single-plane intake showed a 12-hp gain when stepping from a 4150 to a 4500-series unit. The results confirmed that the high-flow Mast intake was being restricted at the throttle body.

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LS7 Downdraft Intake Dyno Test: 32 HP and 34 LB-FT Over the Factory Manifold

Tested back-to-back against the factory LS7 intake on a 427-inch engine, the Speedmaster downdraft individual-runner intake produced 673 hp and 605 lb-ft of torque - gains of 32 hp and 34 lb-ft across the full rev range.

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