Tom Wilson
May 1, 2009
Just fitting, a lightly modified Vortech Power Cooler is slid into position in the Saleen's crowded Windsor engine compartment. By providing cooler intake air, the cooler allows more ignition timing, and therefore, power.

Horse Sense: It's a shame more people can't sample the relatively rare S351 Saleens. Especially in today's sub-300ci context, the blown 351 Saleens rage with a raw-power, big-block personality.

In a bolt-on world, it's fun to see some old-fashioned parts-shuffling and smoke-wrench engineering. That's just what the JBA Performance Center resorted to when a customer had them upgrade his Saleen S351's engine, including fitment of a Vortech charge cooler.

Charge cooling was not original equipment on the burly S351 Saleens. With a generous 351 ci of displacement, a few pounds of Vortech boost was enough to put 500-plus horsepower in the hands of a few in the mid-'90s, and that was plenty in those days. But with power levels gaining by the hundreds in the last decade, this S351 convertible owner decided more was better. Thus JBA rebuilt the core engine to a lusty 393 cubes utilizing a 4.0325-inch bore and a 3.850-inch stroke in the stock 9.500-inch deck-height block. Little money was spared on the innards. (For a more thorough accounting of the engine internals see the nearby sidebar). However, the crux of our story surrounds the induction.

Starting with a Vortech cooler for an '04 GTO, JBA modified it by welding in a bypass-valve hose nipple just below the Vortech logo, along with an air sensor hiding behind the large discharge outlet. And yes, that's a Ford oil filler cap riding high on the water vent that Vortech fits facing upward. The oil cap was a temporary debris-stopper during fabrication; it was eventually replaced with Vortech's standard cap.

As an SN-95 with pushrod power, the S351 Saleens use an upper intake with a forward curve to the throttle-body mounting. This swept intake entry is an SN-95 signature item aimed at keeping a low hood profile, but it doesn't leave room for a water-to-air charge cooler. Because cooling the intake air is now a requirement in the quest for power, JBA opted to replace the SN-95 intake with an earlier Fox version. It offers the traditional Fox intake entry and throttle-body mounting location, plus-you'd think-enough room to shoehorn in a charge cooler.

Even so, with the wide Windsor taking up plenty of space between the Saleen's shock towers, the JBA crew had to wander through the Vortech catalog before discovering the '04 GTO Power Cooler is the right size and shape to fit the crowded Saleen scene.

With the main players set, JBA fabricated the necessary cooler mounting bracket, along with a Fox throttle body, throttle cable, and throttle-position sensor. A three-wire harness connector has the SN-95 engine wiring harness and the Fox TPS playing nice together. The rest of the charge cooler hardware-hoses, brackets, front-of-car heat exchanger, and so on-came straight from Vortech's standard charge-cooling kit.

JBA sets up its blower customers with an air-charge-temperature sensor downstream of the charge cooler to ensure the engine management software senses the temp of what's actually passing through the throttle body. Furthermore, the crew at JBA also prefers two bypass valves, one before and one after the charge cooler, as the arrangement that guards best against surging and driveability issues.

In this Saleen fitment, the air-charge-temperature sensor screws into the Power cooler itself, as does the single bypass valve (there isn't room for two). This involved drilling a hole in the side of the charge cooler housing, and TIG-welding an aluminum tube for the bypass hose to slip onto.

Another issue was placing the Power Cooler's water reservoir. Normally this usurps the battery's location in the front right corner of the engine compartment. On this car, however, there was no room in the diminutive convertible trunk for the battery as the rear locker was already filled with stereo gear. So the battery remained in its stock location; a tall, narrow cylinder more typically used as a radiator overflow tank was selected. This aluminum vessel is custom-fitted to just behind the radiator fan shroud on the driver's side using custom brackets and hoses. Again the TIG welder was required to smoke on a pair of 1/2-inch pipe fittings to the 13-inch tall tank.

The final bit of mechanical wiggling was reclocking the Vortech V-1 so its outlet aligned with the charge-cooler intake. Fitting the rest of the charge-cooling system-notably the heat exchanger in front of the radiator-followed standard Vortech practice. We should also note a higher cowl hood-with a few clearance mods even-was required to help clear the now filled-to-bulging engine compartment around the charge cooler.

Tuning the now charge-cooled 393 was done in-house at the JBA Performance Center using an SCT four-bank chip. A conservative tune that ignored peak power and concentrated on cold start and normal speed driveability was installed, the idea being to rack around 1,000 break-in miles before strapping down on JBA's chassis dyno for a final power-building tuning session.

The break-in dyno tune was the latest word at press time as the car hadn't built up the needed mileage for its final tuning session. Still, clearly the owner has a torque monster on his hands. Running conservative air/fuel ratios in the 10:1 to 11:1 range and slightly stunted ignition timing, the blown 351 stroker laid down 499.8 rwhp at 4,400 rpm and 655 lb-ft at 3,300 rpm. In fact, there was over 600 lb-ft of torque from 2,700 to 4,300 rpm.

When tuned past safe mode, we guess this one will put down 525 hp and 665 lb-ft of torque at the tire. That ought to be enough to keep the veteran Saleen in the hunt. As for the rest of us, we've now seen what it takes to add charge cooling to a stroker Windsor.

Nice Inside
Engine building is one of many capabilities the JBA Performance Center offers, and when it came time to build the Windsor stroker in our subject car, they used a quality set of hot-rod parts. In the bottom end, a SCAT 4340-forged-steel crank, SCAT H-beam rods, JE forged pistons, Clevite race bearings, and Total Seal piston rings went into the short-block. Upstairs, a pair of 205cc Air Flow Research cylinder heads set the torquey tone, backed by a Professional Products intake, an Edelbrock phenolic spacer, a 75mm Professional Products throttle body, and a 90mm Lightning mass air meter. Given the mid-600 lb-ft of torque at the tire from this 393ci combination, the medium-sized 205cc Air Flow Research heads seem a smart choice.