Stage 3 Methanol Injection - Spray and Play

Horse Sense: The steady progress we've made with our project car's rear-wheel horsepower/torque certainly has been amazing. In our quest for more performance, we've gained a greater appreciation for the enthusiasts we've endearingly chastised for racing the dyno instead of racing their 'Stangs on the dragstrip. While blasting 'Stangs down the quarter-mile will always be our favorite performance evaluator, the work we've done on the dyno has given us a better understanding of just how good it feels when an engine in a dyno-tested 'Stang goes to full scream, the rollers spin furiously, and the graph shows more power than originally thought possible.

Although Editor Turner's feature story on our '86 T-top coupe LX (Top This," Jan. '08, p. 102) gives the impression that we've reached a closing point for a wonderful project, the saga of our latest flagship 'Stang continues.

To tell you the truth, we really don't know exactly when we'll stop reporting on our exploits with the project ride, as it seems there are countless modifications that can still be made, including the project we're embarking on in this report. There are other upgrades on the horizon to further solidify our T-top coupe's status as one of the baddest Fox-Rod project Mustangs in history.

One thing we're learning as we continue using the dyno to fine-tune the 'Stang's engine is that there's definitely a mountain of difference between a combination's actual power output and something we call theoretical horsepower. That's horsepower that gearheads believe their Mustang's bullet should make based on its internal components, power adders, and so on.

For example, based on an assessment of its parts, we originally forecasted (hoped) the supercharged 347 stroker in our coupe would throw down 600 to 650 rwhp; all the parts to accomplish this goal were in place. However, we didn't reach the milestone with the original bullet due to its unfortunate early demise (Full-Throttle Meltdown," Jan. '08, p. 68) during a dragstrip test. The best horsepower/torque achieved with the 347 was 473.34 hp/476.51 lb-ft at 5,000 rpm, with the torque converter locked, barely 8 psi of boost (thanks to a slipping blower belt), and 91-octane pump gas.

A freshened 350ci bullet now rests between the fenders of the project 'Stang. With the corrections we've made in the blower department (a larger-diameter main idler pulley and the addition of a second idler pulley for improved belt tension to create 20 psi of boost), the addition of higher-octane fuel (VP Racing Fuel's MS 109E instead of 91-octane pump gas), an Aeromotive A1000 fuel pump, and spot-on FAST XFI tuning by Harv of HMS Performance, the coupe stands high and mighty with 811.28 horses and 700.25 lb-ft of torque available at the back tires.

One interesting but completely unscientific theory on horsepower is that it always seeks and usually finds the weakest link in an engine or drivetrain. While there may be some truth to this idea, the real deal is that a high-performance Mustang should be outfitted with parts that are designed and manufactured to make, or support, a specified amount of power.

This became blatantly clear for us during our last dyno session, when we discovered our original engine's 650cc (approximately 65-lb/hr) fuel injectors are far from capable of supporting the 800-plus horsepower that the rebuilt bullet produces.

While injectors typically run at and should not exceed 80- to 85-percent duty cycle (0.80/0.85) at 60.5 psi of brake specific fuel consumption in a supercharged application, we're now experiencing 100 percent duty cycle at 5,500 rpm (762.33 hp). Duty cycle refers to the amount of time the injectors must remain open and flowing in order to feed the engine its required amount of fuel. With the injectors maxing out so soon, we're asking for serious trouble if we continue trying to eke more performance from our engine. The blown stroker gives every indication that once it has fuel, it will put up even bigger numbers.