Power is not a piñata. You can't string up some effigy to performance then flail about madly swinging a stick, hoping to get lucky and bump the output of your engine. Making power is strictly science and experience. Science in that burning more fuel at the proper proportions will generate more horsepower. Experience in the enlighten-ment of knowing what parts will make a particular engine burn that extra fuel and produce those extra ponies.
Beyond basic bolt-ons, camshafts represent the next step in the modification chain. While capable of doling out dramatic gains it takes experience to select the right camshaft for the intended usage of the vehicle. It's not about peak power; it's about peak performance on the road where drivability and acceleration trump a big dyno number.
Test Platform
The test mule for this shootout is a 1995 Honda Civic with a D16Z6 SOHC VTEC engine. This is a great combination to run. EG Civics are cheap and the D16 single-cam engine is often overlooked as a powerhouse in favor of the more glamorous GS-R swap, so stock parts are plentiful. Speed Factory, a Honda savvy tuning shop in Tacoma, Washington, set out to test a bevy of D16 turbo cams and we followed along to chart the progress. Speed Factory modified the D16 in a manner representative of most commonly built turbo D16 setups in use by D16 enthusiasts today:
Vitara 75.5mm pistons
Eagle rods
Stock sleeves
Stock-port head
Skunk2 valve springs & retainers
Skunk2 Intake Manifold
60mm throttle-body
RC Engineering 750cc injectors
Walbro 255-lph in-tank fuel pump
Mini-ram turbo manifold
57-trim T3/TO4E .63 A/R turbo
3-inch downpipe and exhaust
Chipped P28 ECU, Crome tuned
Test Parameters
Testing was performed on Speed Factory's in-house Dynapack chassis dyno. The D16 was rev-limited to 8,500 rpm because most street driven cars do not rev higher. Testing was performed at 19 psi of boost as this is a common, safe boost level for this setup and 92-octane pump gas was used throughout.
Speed Factory started with the stock camshaft in place, and tuned the car with the GReddy PRofec B electronic boost controller. Speed Factory's James Kempf used the low boost setting with the low boost knob maxed out. This resulted in 16 psi of boost at 4,750 rpm, climbing slightly to a peak of 19 psi of boost at redline. James then changed camshafts and retuned it at the same 19 psi of boost for all cams. The boost curve remained the same for all camshafts; run time was kept the same for all camshafts. Engine coolant temps and intake air temps were kept consistent at the start of every pull on all camshafts. All cams were at 0-degrees unless otherwise noted.
Test Subjects
Speed Factory decided to test the most commonly used, readily available camshafts on the market for this test. No one-off custom grinds, only mainstream available goods here:
Cams Tested:
(T)=turbo grind; NA=naturally aspirated
Stock
ZEX (Comp Cams) 59300 (T)
ZEX (Comp Cams) 59500 (T)
Crower 2 Turbo (T)
Blox Stage 3 (NA)
Bisimoto Engineering Level 2.4 (T)
Bisimoto Engineering Level 3.6 (T)
Stock Cam
300 whp/254 lbs-ft torque
(baseline)
Comments: Great idle quality, okay power; you gotta start somewhere.
Test Conclusions
Speed Factory put the hurt on their Dynapack, logging more than 150 dyno pulls during the test, and came to an easy conclusion after pouring over the data: the Bisimoto Engineering cams absolutely dominated. They sacrificed practically nothing to the factory cam other than stock idle characteristics, and delivered mind-blowing 70 to 80-plus-whp gains on the top end. These are the ultimate cams for Turbo D16 enthusiasts.
By Evan Griffey
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