Cam: FP 4R Peak Power: 537...
Cam: FP 4R
Peak Power: 537 whp
Power Curve: 3
Notes: Another good camshaft with respectable power delivery and idle. Trades off slightly lumpier idle than GSC S2's with a bit more power up top.
Cam: Kelford 272 Peak Power:...
Cam: Kelford 272
Peak Power: 544 whp
Power Curve: 4
Notes: Average idle of the bunch with manageable street behavior. Great midrange to top-end power with a slight sacrifice at spool-up and low-rpm performance. About the best-performing cam for street/strip daily driver.
As you can see from the acceleration graph on the right, one cam has much higher acceleration forces than the other. Guess which cam will be easier on the valvetrain?
This parameter is very important because if the valve is closed too fast, premature valve seat and valve wear will occur. We can actually go further and derive acceleration into jerk, which is the rate of change of acceleration. The car in my previous example that was accelerating at 2 mph per second isn't going to keep accelerating like that, it will eventually start to slow its acceleration as aerodynamic drag takes its toll. Jerk is also critical in calculating valvetrain loads and harmonics. I'll stop there as it can go even further than that. Cam lobe design is complex and many things need to be taken into consideration. Ideally, we want the valve open for as long as possible but to do so we need to open and close the valve quickly. It's a big game where the designer optimizes the lift profile to maximize gains while ensuring the valvetrain holds together. If the engine is designed for only drag racing, we can push the limit further as the operating time is much less than a road race engine for example. A purpose-built drag race engine might only see 30 trips down the dragstrip before a tear down, while an endurance engine might have to last the 24 hours of Daytona.
It's difficult to compare all of these camshafts and pick a winner. If I were drag racing the winner would be either Tomei 280's or the Crane's. If my car took me to work everyday and I did a few track days throughout the year I'd go with something more mild like the Forced Performance 4R's or the Kelford 272's. The very mild cams like the GReddy Easy Cams and HKS 272 would be more suited to the stock Evo turbo rather than the GT35R that I used.
BC Brian Crower
Cam: Crane 272 intake/264...
Cam: Crane 272 intake/264 exhaust
Peak Power: 559 whp
Power Curve: 10
Notes: The bark matches the bite. Rough idle comes with degraded low-rpm street running, but she zings up top! Peak power checks in roughly the same as the Tomei 280's but makes more power at redline with a slight sacrifice of midrange power. Great camshafts for drag racing.
Cam: Tomei 280 Peak Power:...
Cam: Tomei 280
Peak Power: 560 whp
Power Curve: 9
Notes: Race car-like idle with rough low-rpm running. Idle quality is a little better than the Crane cams due to less overlap. Another peak power cam that pulls great in the midrange and up top. Just like the Cranes, the spool-up and lowrpm power suffers. Another great set of drag race camshafts.