There are more turbochargers and superchargers on cars than ever before, and if you’re looking to make more power with one of those engine combinations, a boost-friendly camshaft can improve the efficiency of your combination and increase power and torque.

“Turbocharging and boost is the only way to go these days,” says Howards Cams’ Luke Bandt. “It’s free horsepower. You’re not refilling a bottle and not doing crazy things to the cylinder heads to make power.”

Bumpsticks For Boost

With the ever-increasing popularity of boosted engine applications, Howards Cams developed a line of boost-friendly camshafts to provide enthusiasts with additional horsepower.

“A common thought is that any cam is a boost cam,” Bandt continued. “You can get any cam to function in that application, but it comes down to how efficient you want it to be with the turbocharger or supercharger. We looked at small-block and big-block Chevy and small-block and big-block Ford, and of course LS engines, and we picked a couple of grinds that fit various combinations and put them out as shelf numbers. If someone has a D-1SC ProCharger on a small-block Chevy, we have cam for that. If you have a turbo LS, we have a shelf cam for that and it will keep the power in the right spot.’’

Calculating The Camshaft Specs

Increasing the efficiency of the cams for boosted applications comes down to making changes to the camshaft’s specifications, such as lobe separation for the valve events.

“Generally, what we see on a boosted application, be it a turbo or supercharger, is that the wider we can get the lobe separation, it generally means you’ll get a more efficient charge,” Bandt explains. “The further away the intake and exhaust events are from each other, the more power you can make.

“A tighter lobe separation means that if you have 25 psi of boost, you’re going to be blowing it out the exhaust. The wider the gap, you’re trapping that charge longer and you have a cleaner, higher density charge of air in the cylinder, which is going to make more horsepower.”

Bandt also notes that the camshaft’s duration figures play a part in turbo applications, as well.

“As far as duration goes, you see a wider split on a naturally aspirated application, but when we put them closer on a turbo cam, it creates more heat, which helps with spooling the turbo faster.”

Building more heat has additional effects that Bandt points out.

“When you move to a turbo setup, you’re going to create more heat and higher under-hood temperatures in general, and when we do that with a cam, the higher heat energy drives the turbine. Single-pattern camshafts were a big thing back in the day, and those cams were notorious for heat, but they work well in a turbo application. With the increased heat, you need to make sure the rest of the engine components can handle the heat, so having the right radiator and fans to support that combination is important.”

One other thing that Bandt pointed out was that if a customer doesn’t see a cam that fits their application and/or has the RPM range they desire, they should contact Howards Cams.

“Every time you increase boost, you are increasing efficiency,” Bandt says. “Say you have a typical 5.3 LS and our turbo cam says its good from 2,000-5,500 rpm, that’s assuming it’s a basic 5.3 with 5-10 psi of boost. If you change the cylinder head, that may change the efficiency of the engine. If you use 20 psi of boost instead of 10, that takes the head flow that we calculated the RPM range for a given combination and increases it. Increasing the boost makes the air charge more dense, which makes the bottom of the engine think it has a larger head. This, in turn, will increase the RPM window until we reach a choke point such as the camshaft, the hot-side turbo routing, or the turbo itself. The best way to know for sure what is happening is to monitor back pressure in the exhaust. If you want to use a cam that doesn’t fit the RPM range you want, never hesitate to call us to verify.”

Howards Cams’ boost-friendly bumpsticks are available in hydraulic flat tappet and hydraulic roller configurations, and the company will also manufacture solid rollers on a custom basis.

“When you’re going to a solid roller, you’re generally at a different performance level and we want to make sure those camshafts are specific to their applications,” Bandt noted. He also mentioned that along with the solid rollers, Howards can also produce boost-friendly cams for other applications, such as small-block and big-block Mopar, old and new HEMI, Oldsmobile, Buick, and Pontiac, on a custom basis.

Supporting Components

We also queried Bandt regarding any accompanying components that might be required to use Howards boost cams and he said that there is a huge misconception about spring pressure with boosted camshafts.

“Everyone thinks they need a ton of spring pressure to hold the valves closed. The reality is you have hundreds of pounds of pressure in the cylinder that you have pushing on the front side of the valve. A boosted application might require a little more pressure, but not as much as many think. If they want to call us and go over their application, we can spec something for them.”

Additionally, Bandt noted that it is important to have a hydraulic roller lifter that can handle the additional spring pressure, as well as stand up to the 1,000-plus horsepower that people are making these days.

For more information on Howards Cams’ boost-friendly camshafts, visit them at www.howardscams.com.