Was working with a lad I am quite pally with on friday

He runs a civic B18 with a turbo conversion 350 bhp 400 lbs

Anyway we were talking about spool up etc and he was saying that he has an electronic boost control instead of an actuator

Says his engine gets boost and holds has no leakage at all

I presume he runs an external wastegate which I presume helps (thhough I have to say I was ill (still am) and don't think I took it all in)

Can this be be run on a YB @ reasonable cost

Thoughts?

 

Yes can be run, but ecu dependant most ecu's have better boost control.
tabetha

 

so would that be a stand alone jobbie ie an emerald or can the l6 or l8 do it

what exactly opens and closes the wastegate?

i should realy have a look at his engine i spose

 

The pressure from the inlet(usually taken from comp housing) opens the wastegate by operating the actuator.
My boost control is one of the best aspects of my K3, so vastly better controlled than the L6 I had, as it is linked both the tps and rpm.
tabetha

 

the wastegate is held closed due to a hard spring, pre-tensioned to only allow opening of the gate after a certain boost can force the spring enough to allow the wastegate to open. this movement on the wastegate happens via a daprhragm in the actuator/external wastegate actuator which opposses the spring fed from the compressor side of the turbo.
you can get more boost by allowing a bit of the air going to the actuator device to "bleed" off, therefore reuding the effective pressure forcing the spring back, therefore holding the wastegate shut longer and allowing more boost.

the ecu or in some cases an electronic standalone controller will be causing the bleeding to be metered to attain certain boost levels.
in crude setups a mechanical bleed valve is used and that allows a fixed amount of air to be bled off with no user control in the car, and can be prone to failing and big boost occuring momenterily causing damage.

in all cases there needs to be an actuator of sorts to keep tension holding gate shut, that can move quickly enough, most mechanical solenoids would burn out holding enough tension on a wastegate for a long time i would have thought.

p.s. wrote this a bit sleepy, just a guide on how it all works and feel free to correct and fundamental errors.