You've probably read or heard it someplace before that nitrous systems have been around for a very long time, and in that period, they've proven themselves as reliable power adders time and again. However, until now, most basic nitrous systems haven't advanced much past their original beginnings. The guys at Wilson Manifolds have changed all that by adding a whole new nitrous division to their lineup. Wilson's Nitrous Pro Flow system is much more than just another carb spacer with spray bars stuffed in it. What Keith Wilson, owner of Wilson Manifolds, and his team set out to do several years ago, when development of the Pro Flow systems began, was to re-engineer the way nitrous and fuel gets sprayed into the engine.
One of the biggest problems with some of the older nitrous plate designs is that they had trouble getting an equal amount of fuel and N2O into each runner. Of course, a lot of that has also to do with how well the intake manifold works, so don't expect a Pro Flow system to solve your problems if you're putting it on a swap-meet-special intake manifold that looks like two chipmunks tried porting it with jackhammers. Ideally, you'd want to match up a Nitrous Pro Flow system with a specially CNC-ported Wilson intake manifold, as we've done here. They're available from either Edelbrock or from Wilson, directly, to fit many performance applications. Check out the chassis dyno test we performed using a single-stage Pro Flow plate and some of the plate's features we've highlighted here.
Nitrous Pro Flow Single-Stage Jet Settings
Flowing fuel pressure: 7.5 psi on race gas, 8.5-9 psi on pump gas
Timing retard: 2.5-3 degrees per 50 hp
Bottle pressure: 950-1,000 psi
Recommended fuel: 116-118 octane with any hit above 175 hp
Pro Flow Single-Stage Plate Test
We tested the single-stage Pro Flow plate on our 531-cid Max Rat (see buildup: August '02 issue, page 70) installed in a heavy Chevelle strapped onto Westech's Superflow chassis dyno. The plate added an estimated 364 hp at the flywheel and 300 hp at the tires. The horsepower gain was attained using the recommended 350hp jetting (110-nitrous, 110-fuel) and burning 76 Racing's 118-octane race gas at 7.5 psi. The Chevelle also featured a progressive nitrous controller, which is why the nitrous power increases mildly first, then rises sharply above 6,000 rpm.
Test 1: Corrected Rear-Wheel Horsepower (CRWHP) on motor only
Test 2: Estimated Flywheel Horsepower (EFWHP) on motor only
Test 3: Corrected Rear-Wheel Horsepower (CRWHP) with Pro Flow plate
Test 4: Estimated Flywheel Horsepower (EFWHP) with Pro Flow plate
Max Motor Only CRWHP 717hp @ 7100
Max Motor Only EFWHP 918 @ 7100*
Max Pro Flow CRWHP 1016 @ 7300
Max Pro Flow EFWHP 1282 @ 7300*
Superflow's chassis dyno estimates flywheel power based on vehicle data and the corrected rear-wheel power. However, we think the chassis dyno's estimate is a little low based on the fact that this very same engine made 980 motor-only hp (vs. 918 estimated) on Westech's Superflow 901 engine dyno weeks before. That's about 6.5 percent more power than estimated in the chassis dyno test session. This is most likely due to the fact that the chassis dyno software cannot possibly know exactly how much the inertia drag of items like the flywheel, torque converter, transmission, drivetrain, and even the wheels and tires is. So the computer is extra-conservative in its estimate, but since this figure is only an estimate, we won't loose any sleep over it.