One Question: Greg Caloudas Of GSC Power Division Details Turbo Cam Selection
Images Courtesy: GSC Power Division
The science of camshaft design is simultaneously intricate and elegant; the mathematical equations used to determine the ideal camshaft for a particular engine are unforgiving and exact. If the measurement is off just slightly, you can end up with an engine that most definitely does not perform up to expectations. If it’s off substantially, the result can be far worse; lackluster performance which doesn’t even equal that of a stock version of the same engine.
Perfecting the details of turbocharged-engine camshaft design and manufacturing in the automotive performance world is the realm of few companies, of which GSC Power Division is one. Helmed by Greg Caloudas, the company is world-renowned for its quality and precision in the camshaft design and manufacturing arena.
As camshaft technology is voodoo to most enthusiasts, the horror stories of cars running terribly after a cam swap—both on the street and at the track—are many. So how do you get the right camshaft, the first time? We recently had the opportunity to talk with Greg, and this seemed like the perfect time to ask the question.
Front Street: What’s the most common mistake you see people make when they select a performance camshaft for their turbo build, and do you have suggestions to prevent them from making it?
First off, it’s important to always buy parts for the build you’re doing RIGHT NOW, not for the build you’re dreaming of doing when you hit the jackpot. And, as it usually goes, bigger is not always better. We’ve seen off-the-shelf 2JZ S1 profile cams make 1,200 horsepower and off-the-shelf 2JZ S2 profile cams run 6-second quarter-mile passes. The fastest EVO X in the country ran a set of off-the-shelf S2 profile cams. Now that that’s out of the way…
Simply put, the biggest mistake is not matching your cams to your turbo. Our cam profiles are created to step you through the RPM band to better match turbo size for the best power curve possible. Running a smaller profile cam allows you to push a lot harder and maintain drivability and low-end power, while making great peak power. When you get into too large of a cam, you end up with a high peak power number, but you lose that drivability and low-end power. You end up sacrificing area under the curve for that high peak number.
Another point to make is, if you’re adding cams, make sure you have the correct matching components to support them—turbo, valvetrain components, cylinder head modifications, and ECU programmability. There is a huge misconception that a set of cams is just a drop-in mod; but outside of a 4G63, cams require matching springs, replacing mating components, checking valve lash, and some larger profiles require machining of the cylinder head for fitment.
The takeaway? Know and have realistic goals and shoot for what you’re capable of now. Be prepared to invest in everything you’ll need to support your cams—don’t expect to drop a set of S1 cams in your Subaru and make tons of power without upgrading from your stock turbo and upgrading your valve springs.
Thanks to Greg for taking time out of his busy schedule to answer our question! Check out previous installments of One Question content right here.