Mythbuster: continuing project thread of my 1303 '75

[70Turbobug]

The other downfall of more duration is less torque down low.
If you can lessen both downsides of more duration, you optimize the engine's efficiency.

Another way to compensate for that and have an aggressive ramp,prolonging valve open timing is to use a smaller base circle and a wider lobe center.If you can use a higher compression ratio also.Wally mentioned picking up 40hp just by changing rockers.One reason is not only the extra lift but with the higher ratio the valve opening rate in mm per second also rose dramatically.Basically the same effect as having a steeper ramp on the cam.
Wally is running a pretty big turbo with relatively small displacement.Most of the ricers that run these large turbos don't have much power below 4500rpm but therefore rev easily 8500rpm.What's the point? Wally's cam may be too mild and the lift too low to spool the turbo sooner, making the whole set up less responsive.Sounds like the opposite of what Wally said above, but it's not really.If you have a typical drag race cam an NA engine may be a little sluggish in the lower rpm range.That's due to lack of airflow actually airspeed causing a lower inefficient cylinder pressure.This is where the efficiency of the turbo and the rest of the system i.e twin scroll,static compression ratio,tuning etc. come into play.
True a turbo engine does not need a high lift high duration cam to make power,but if you want high boost and responsiveness that low lift low duration will become more of a restriction especially if you want a lot of power out of a small displacent engine.