Top 10 Tuner Secrets to Free Horsepower
WE FOUND 45 HORSEPOWER AT THE WHEELS WITH OUR SR20 TESTER
Something for nothing. Is it possible to produce additional horsepower from your engine without spending a dime? Yes it is. In fact, we put 10 of our favorite tricks to the test on our 1989 240SX and we found an extra 45 horsepower at the wheels. To be completely honest, we never expected to get so much for so little. Not all 10 tricks produced more power on this car, but all 10 tricks have proven to produce horsepower on different platforms.
1. Correct Plug Type & Plug Gap for Power
Cost: $0.00 (buy the right plugs the first time)
Average Horsepower Improvement: 0 to 5 horsepower
Our SR20DET Results (@ peak): + 2.1 horsepower / + 2.5 lb-ft of torque
No-Cost Solution
Spark plugs have two design parameters that directly influence voltage requirements: center electrode diameter and the air gap distance. As the center electrode is reduced in diameter voltage requirements are lowered making it easier for a spark to be produced. The same reduction in voltage requirements occurs when the air gap size is reduced.
Our Dyno Experience
Before starting the bulk of the testing, we wanted an engine in good running condition so a tune-up was performed. Since the factory NGK PFR5ES (a small-diameter center electrode design) plugs were not available, we substituted a set of NGK BCPR7ES plugs (two steps colder in heat range along with a standard size center electrode). Just for kicks we tested these plugs against the used original PFR5ES plugs. The old original plugs outperformed the BCPR7ES plugs by over two horsepower. What does this mean? We would venture to believe that the voltage availability of the factory direct-fire, coil-on-plug system is near its maximum even at factory horsepower levels. The small-diameter center electrode plugs are a must to get the party started with the cylinder.
For a Fistful of Dollars
Distributor-based ignitions often benefit from an ignition amplifier and coil upgrade. The pair usually runs for under $200 while dramatically increasing the spark capabilities of the ignition system as a whole. On direct-fire applications (especially coil-on-plug systems), multi-channel ignition amplifiers or voltage step-up transformers (like the B&M NewVolt) can also ensure that there is plenty of spark available to get the job done.
2. Remove The Air Filter
Cost: $0.00
Average Horsepower Improvement:
0 to 15 horsepower
Our SR20DET Results (@ peak):
+ 5.1 horsepower / + 0 lb-ft of torque
Engines ingest air and fuel and deliver horsepower through the process of combustion. Removing the air filter removes the primary restriction before the intake of the engine. Try breathing with a pillow over your face and try breathing without and you get the point. The engine takes a deeper breath of air allowing it the ability to burn more fuel and produce more power.
No-Cost Solution
We yanked the entire air box and filter assembly leaving the mass air sensor as the entry point of air flow into the engine. During the test, we crafted a make-shift air deflector to be sure the engine cooling fan (switching on and off and blowing hot air) didn't upset the airflow to the meter.
Our Dyno Experience
Oh yeah! Five horsepower for nada. Let the games begin.
For a Fistful of Dollars
Buy an aftermarket air filter system. Your can't drive around on the street without an air-filter system on the car. Too much dirt and debris enters the engine and causes exceptional wear and tear. Pricing varies per model from $35 to $350. Drop-in high-performance filters do not generally offer the horsepower improvements of a high-performance, aftermarket air intake system.
3. Advance Ignition Timing
Cost:$0.00
Average Horsepower Improvements:
0 to 10 horsepower
Our SR20DET Results (@ peak):
0 horsepower / 0 lb-ft of torque
The exact point when the spark is fired within the cylinder affects horsepower
output. In most cases, the factory sets the ignition timing on the conservative
side. Advancing the timing from two to five degrees (on most applications)
can deliver a few extra horsepower.
No-Cost Solution
We hooked up the timing light, loosened the sensor and added in two degrees of ignition timing.
Our Dyno Experience
It lost power. We ended up back at the factory setting. Why? Well, we think we have the answer. Fuel octane and ignition timing are critical factors that work together to establish the exact time to fire the ignition. In Japan, the origin of the SR20DET ECU, fuel octane is three to six points higher than in the U.S. (depending on where you live). The factory ignition timing which was probably conservative for Japan's higher-octane gasoline was just right for the low-performance 91 octane that flows from California pumps.
For a Fistful of Dollars
Aftermarket engine management systems allow the ignition timing to be optimized for different engine speed and load levels.
