Seven Cams, One Blown LT4, One Day: What Flag and Griffin's Shootout Showed

A $100 camshaft from Facebook Marketplace made 1,003 hp on a supercharged LT4. That is the line everybody will repeat from the second installment of Flag Motorsports and Griffin Motorsports' LT4 camshaft shootout, which EngineLabs' Jimmy Stray broke down on Oct. 13. It is a fun headline. The more useful lesson is in what happened to the boost gauge.

TORQFOLIO did not run this test. This is a read of EngineLabs' report on part two of a three-part video series. EngineLabs said a planned third video will dig into which cam suits which kind of build.

How they built the mule

Gabe from Griffin Motorsports and Evan from Flag Motorsports spent five days at Westech Performance in Mira Loma, California. They started with an LT4 as close to stock as practical, with a slightly overdriven ATI balancer and some parts covered in their first video. Then they built it up one change at a time, and EngineLabs reports the gains for each step.

A large cam on an otherwise mild engine added 76 hp and about 500 rpm of usable range, while boost fell from 12.2 to 8.7 psi. A 10-inch, 25 percent overdrive lower pulley added 29 hp but gave back some of that rpm. Flag-ported cylinder heads added about 100 peak hp, and about 150 hp at 7,000 rpm, along with another 500 rpm of range. The ported Kong X-Port 1.7-liter supercharger was the biggest single gain of the whole project at 161 peak hp, pushing the engine past 1,000 hp on 15.5 psi. That was the final test configuration.

The method is what makes this worth reading. Same engine, same dyno cell, same blower, same day for the cam swaps. Most cam comparisons you see online pull numbers from different cars on different dynos in different weather, which makes a 20-hp difference almost meaningless. EngineLabs notes that controlling the variables is the point of a test like this, and the team's step-by-step buildup also shows which parts mattered most before a single cam was compared.

The cam results

With the mule finished, they ran the remaining six cams on the same calendar day to keep conditions as close as possible. EngineLabs did not publish final-configuration numbers for the large cam used in the buildup, so the comparison below covers six cams.

The BTR Stage 0.5 is the mild one. It works with stock springs, uses a 38 percent fuel lobe and made 950 hp at the highest boost of the group. BTR's new Stage 1 V3 made 981 hp with one of the flattest torque curves, and Evan said it carried power higher in the rpm range than he expected. The Summit Pro LT made 983 hp with a strong torque average but fell off earlier, and Evan considers it a strong street cam to about 6,500 rpm. The LMP Apex gave up some low end and pulled cleanly to 7,000 for 999 hp.

Then the two oddballs. The Zucker, the $100 Marketplace cam the team picked because it has more than 230 degrees of intake duration, made 1,003 hp and pulled cleanly to 7,000 rpm, a little softer down low. Rick Crawford's Slick Rick won peak power at 1,006 hp on the lowest boost of the test, 15.8 psi. EngineLabs says three of the cams made peak power at 7,000 rpm, the Crawford grind among them.

The boost lesson

Look at the boost column next to the power column and the pattern is obvious. The cam that made the least power, the Stage 0.5, made the most boost, and the cam that made the most power made the least. EngineLabs spells out why. On a supercharged engine, boost is partly a measure of restriction. A cam that lets the engine move more air through the cylinders flows more and reads less pressure on the gauge. The same thing showed up in the buildup, when the first big cam dropped boost from 12.2 to 8.7 psi while adding 76 hp.

That is the most useful takeaway for anyone with a blown LT4 or LT4 swap: chasing a boost number tells you little about power. One small editing note for readers checking the math: EngineLabs' text says the Stage 0.5's 829 lb-ft led the group, but its own figures show the Summit cam and the Zucker at 837 lb-ft. The peak torque spread across all six is only 8 lb-ft either way.

The blower that outran the cams

After the cam test, the team swapped the Kong 1.7 for a Whipple 3.0-liter and ran it with the Zucker cam. It made 1,101 hp and 845 lb-ft on 15.6 psi, more than 100 hp over the Kong setup. EngineLabs reports the Kong was spinning about 28,000 rpm at the end of a pull and the Whipple about 17,000 rpm at similar boost, and post-compressor charge temperature fell about 40 degrees. The biggest cam difference in the test was 56 hp. The blower swap was worth roughly twice that.

TORQFOLIO's read

This shootout ranks the cams on peak power, but EngineLabs is clear that peak horsepower is only part of the story, and the team is saving the which-cam-for-which-build discussion for part three. Reading the numbers now: if you want a mild street LT4 on stock springs, the BTR Stage 0.5 gives up power but keeps things simple. If you want the most top end, the Crawford, LMP and even the bargain Zucker all made about 1,000 hp. If your build is still on a stock blower, the buildup data says heads and a better supercharger will move the needle more than any cam on this list.

And the Zucker result is a reminder for the LS and LT swap crowd that a cam's specs matter more than its box. Just know what you are buying before you install a mystery grind.