Ported Blower Install - Swap And Speed

We should consider our-selves lucky that Ford stuffed our beloved Gen 2 Lightning's engine bay with a supercharger. If they hadn't, we would be left chasing our tails and having to upgrade the engines for a belt-driven boost-maker.

The Eaton supercharged engine responds well to modifications and makes enough grunt to keep most Lightning owners happy for a while. A quick swap of blower pulleys and your truck picks up power. Add headers and an exhaust system and your truck picks up power. Add this or that and the results are usually noticeable, and a low-13 or high-12-second truck is usually the result. But what happens when the list of the easily swappable parts is finished? Time to turn to a ported Eaton supercharger from Stiegemeier.

A ported Eaton is a great way to jump horsepower without breaking the bank. We turned to a Stiegemeier-ported supercharger and recruited Shawn Andrews' Lightning truck as our test mule. The Stiegemeier crew starts with an Eaton supercharger and works their handcrafted magic using grinders, cutters, and years of experience. Porting a supercharger is more than just opening its ports. It's a delicate balance of flow before and after the rotors. The ports are enlarged, increasing volume, and the air moves more efficiently through the Eaton.

"Our ported superchargers work best at about 153/4 psi of boost," says Bob Stiegemeier. He continued, discussing the finer points of over-spinning the rotors to the point where the air cavitates and is turbulent. When that happens, horsepower and torque decreases. It is all about the balance of flow, and Stiegemeier equated it to the balance between the intake and exhaust ports of cylinder heads. The ported blower is undetectable from the outside and provided our test truck with a kick in the pants that helped it run in the mid-12s.

Our test was conducted at Maple Grove Raceway during the NMRA Ford Motorsport Nationals presented by Toyo Tires. Johnny Lightning Performance handled the blower swap and subsequent computer tune and chassis-dyno test on location at the track. Thanks to DiabloSport's portable dyno, we were able to do a before and after dyno-test, and Johnny Lightning was able to tune the pickup before we headed back on the track.

Andrews' truck was mildly modified with the typical bolt-on components and blower-pulley swap. The engine was making 16 psi of boost, and it spun the DynoJet chassis dyno to peak numbers of 397.65 hp and 493.98 lb-ft of torque at the rear tires. Those are fairly average results for the given modifications. On the track, Andrews had some Hoosier tires out back to help traction. The truck ran 13.03 at 104 mph with a 1.89 60-foot time. Johnny was the wheelman, and when he rolled back to his pit spot, his right-hand man, Mason Lefever, got to work swapping the superchargers. It felt like only moments later when Lefever completed the mechanical portion of the swap, and it was time to run the truck on the dyno.

Our testing parameters were quite simple. The transmission was locked up using the DiabloSport software for accurate dyno testing. The coolant and air-temperature sensors were monitored and equal throughout the dyno runs. The air-fuel ratio was kept consistent as well (roughly 12.5:1). A decision was made to swap the lower blower pulley because initial dyno pulls showed a drop in boost. A JLP quick-change, 8-pound lower pulley was installed, and the boost was consistently at 16 psi during our dyno-tuning sessions, the same boost as our baseline testing. Later bench-racing sessions with Stiegemeier revealed that our test truck was possibly suffering from belt slippage or a bypass-valve problem. He has added an FAQ section to the company's site to help answer questions about swapping to a ported supercharger.

It took a few runs on the dyno for Johnny to set the tune, and he used DiabloSport software to accomplish the computer modifications. The truck then spun the dyno to peak numbers of 416.27 hp and 505.85 lb-ft of torque. "It is very important to look closely at the overlay runs of the two dyno pulls. Remember, it's not just the peak numbers that net good e.t.'s, but the entire dyno run. You will see how the ported-blower run not only had higher peak numbers, but more importantly, a substantial difference throughout the entire run. The peak gains weren't huge by any means, but the gains throughout the entire run were huge," comments Johnny. Those mid-range gains were upwards of 30 rwhp in some cases.

The robust and aggressive mid-range power is what we saw on the dragstrip. Every increments from the 60-foot clocking to the quarter-mile result was better. Andrews' truck nailed down a 1.83 60-foot, and on the big end, the Lightning threw down a 12.64 at 108 mph, 0.39-second quicker and

4 mph better than our baseline run. That was quite an impressive performance gain for a few hours worth of work and some tuning on the chassis dyno, and the modifications won't break your piggy bank.