EJ1B18c

At my local tuner there ss a customers car. A B18c with jackson racing supercharger. On the dyno dynamics print out looking at the power and boost curves the power curve is very straight and nice. The boost curve is 5psi all the way on the low cam on cross-over the power continues to rise in a very linear curve but the boost curve drops to 3psi till redline. The customer is using ITR cams. Would gsr cams help.
Can soneone help me understand why the boost drops on high cam yet power is still linear. would a less overlap cam selection help this motor?

HiProfile

There are 2 reasons boost drops:

First, the vtec lobes have more duration, so more overlap. During overlap, there is very little backpressure to prevent intake air from flowing straight through the cylinder out the exhaust valves during overlap.

Second, the extra lift and duration allow more air into the cylinders. The airflow through the SC rises linearly. When vtec engages, the airflow through the SC isn't enough to hold 5psi, so it drops to 3psi.

When a turbo is used, the compressor wheel just spins up paster to maintain boost level.

Garage 808 Hatch

Belt slip

EJ1B18c

ok, Understood would a set of gsr cams having less duration help gain more power/torque ? belt is not slipping the modified idlers prevent that.

94dxcoupe

Use a set of the JDM/EURO? b16 automatic cams If you can't find any of those, use a set of auto GSR cams.

azandford

why would it matter if it was an automatic? ^^^

Natural Aspirations

GSR intake and ITR exhaust is the favored cam setup for JRSC

i-VTEC_do_you

why is that?^^^^^^

Natural Aspirations

It has been found to work the best on the dyno time and time again