Engine Upgrade For Our 5.0L Stock-Block - Back To Basics

Makin' Mods
Sticking with our plan to kick it old school, we headed back to the dyno to make our changes. We started with ignition timing. First, we cleaned the harmonic balancer with sandpaper and marked the crankshaft at 10, 14, and 16 degrees before top dead center (BTDC). Then we removed the SPOUT connector (located in the ignition harness near the distributor), and using a timing light, we found the timing to be set at the base timing of 10 degrees BTDC. Removal of the SPOUT (for SPark-OUT) allows timing adjustments while the engine is running without the ECU interfering. Ensuring we had 93 octane in the tank, we rotated the distributor clockwise until we achieved 14 degrees of timing advance. We reinstalled our SPOUT and spun the rollers with impressive results of 219 rwhp and 254 rwtq, a 14 hp and 32 lb-ft gain. We then advanced the timing another 2 degrees to 16, yielding 221 rwhp and 255 rwtq, a gain of another 2 hp and 1 lb-ft of torque.

The results of our timing advancement left us stoked and hungry for more power. We had a stock airbox on hand with the silencer removed, so we threw it on with a fresh K&N air filter. The dyno results were good, but surprising: 224 rwhp and 260 rwtq, an improvement of 3 hp and 5 lb-ft. We attributed the gain to cooler air from outside the engine compartment.

The next order of business included a few simple bolt-ons, so we gave BBK Performance a call. Being a leader in Mustang performance, BBK knows a thing or two about making power. Its prices are very competitive, fitment is great, and the components look nice. Our stock airbox experiment gave us the idea for our first product: BBK's fenderwell mounted cold-air kit. After a quick installation, we went back to our chassis dyno for the results. We noticed a gain of 3 hp, but a loss of 6 lb-ft off peak torque, which brought our output to 227 rwhp and 254 lb-ft, however, it was impossible to realize the gains offered by such a system while the car was stationary on the dyno, as it's designed to work best at speed. And even though peak numbers weren't impressive, average horsepower and torque increased with the cold-air kit.

A new BBK 76mm mass air meter was our next weapon. The meter is calibrated for our 19-lb/hr injectors, and the stock wiring harness plugs right in. With our engine temperature still warm (175 degrees) from the previous step, we made another pull on the dyno. The mass air meter upgrade gave us an extra 6 hp and 11 lb-ft of torque, bringing our running totals to 233 rwhp and 265 rwtq.

Next, we removed our stock throttle body to make room for BBK's 65mm version. At just 5mm larger than stock, it fits the opening of our Cobra intake perfectly. Like the mass air meter, the TB connects easily and bolts on in minutes; it even comes with the necessary gaskets. After warming the engine to 175 degrees, we made another pull and were pleasantly surprised to see an increase of 3 rwhp (to 236) and a gain of 6 rwtq (to 269).

Even though we just gained 31 rwhp and 47 rwtq in a couple of hours (including dynamometer runs), we wanted to push it a little further. Don't we always? Having spent less than $600 on our parts, we ran down to the local parts store and picked up a 71-inch engine drive belt for about 30 bucks so we could bypass the power steering pump (the air pump was already bypassed). We installed it and made another run. Peak rwhp and rwtq were essentially unaffected, but we saw a gain of about 5 rwhp and 5 rwtq down low, which tapered off around 4,000 rpm. The gains would be closer to 10 or 12 had the air pump been in place.