Yes there are two pills.

Here is how I look at the system......the pill at the turbo is the main control over the boost. Think of the line as being a boost leak....removing the pill allows a lot of air to escape, limiting boost. Why only ten psi ??? thats what the wastegate actuator spring pressure is..

Place a tiny pill ( small ID ) next to the turbo and you can buld a lot of pressure quickly because the small pill wont allow much pressure to escape.

OK on to the solenoid pill....why does removing it or making the pill ID bigger allow for more boost? the line after the turbo pill splits and goes 2 ways...one to the BCS and the other to the wastegate ( WGA ) . OK then pressure applied to the WGA opens the wastegate.....so reducing the air pressure to the WGA allows it to stay closed longer. To do this you need to bleed off the air quickly. The BCS does this by staying open more ( WGDC ) Having a pill at the BCS allows the air pressure to build up at the WGA and open it. So you have to increase the duty cycle to get rid of it. Having no pill allows more air to be bled quickly so you may spike higher.

It is a balancing act...small pill at turbo ( #60 drill size ) and a #56 drill pill at BCS allows 24-27 psi. If you then take the BCS pill out, you can easily hit 30 psi ( not recommended ) crazy overboost . Putting a #60 at turbo with a #58 at BCS limits boost to 20-22 psi. This is because the pressure is diverted to the WGA and helps open it. You can use the WGDC to increase the bleed off and stabilize the boost more.

For example using a #58 turbo pill and a # 54 BCS pill you would start out at 10-20% WGDC at 2500 rpm and increase slowly to get peak boost. Make all cells same from 2500 up to 7500. If you hit 22 psi at say 40% duty cycle at 3500 and the boost tapers to 15 psi at 7000 , then increase the WGDC above 3500 to remove some of the taper. ie 50, 60, 70 , 80 , 90 100 going up to 7500 rpm.

You must use a boost gauge and log to do this safely. Also you must log knock load and timing advance. Keep the boost below 22 psi on the stock block and head bolts, 'cos you dont want to bust a head gasket . You should also be using a wideband to do this right.

milburn

 

Bottom line is dont dick with boost control unless you have a boost gauge.

 

... or better yet, a boost gauge and a JDM MAP sensor to accurately log boost.

While I have been able to control boost well using the "Max Waste Gate Duty Cycle" item in EvoScan and logging "Calculated Load", I'm still worried that there might be boost spikes that I'm not seeing. So until I get my JDM MAP sensor and can accurately log boost I'm gonna put the pill by the BCS back in. It's just not worth the risk.