Well sort of...

on a cossie, I want to temporarily run with 0 boost to see if my misfiring problems are boost related (I am thinking overboost at the moment).

Is there an easy way without tweaking the actuator ?

Thanks in advance
Greg

 

just remove the actuator rod from the wastegate. really east to get to
hope the misfirs is at low revs though because it will be like driving a micra

 

It's a 4x4 and the misfire is at high revs...

 

I had the same thing, i ran mine on axle stands and it redline in all gears smooth as silk with no misfires.........

Different kettle of fish on the road, once it hit 4200rpm it would miss, cough splutter.......

At least running it this way made me realise it was boost related.

hth

 

Thanks cosRush, now that's an idea - as long as the car doesn't jump off the axle stands !!!

any other ideas peeps, can't I just disconnect a pipe somewhere ???

 

you can go to a lower boost setting by taking off the connector from the amal valve, but not to 0 boost. this may well be low enough for your test.

the only way to go to 0 boost is to open the wastegate completely. you can either do that by pressuring the actuator somehow, or as suggested, removing the actautor rod from the wastegate spindle. that is the easiest way, as you just have to remove the clips and pull it off. refitting is the reverse of removal.

 

Removing the actuator rod is probably the best bet then - I didn't realise it was open by default, thought it was the other way and the actuator opened it to let boost off, not the other way round.

CheeRS
Greg

 

the wastegate is just a disc on that pivot that covers a hole that allows exhaust gas to go straight from the manifold to the downpipe bypassing the turbine. the spring and preload in the wastegate holds it closed to build up boost, but the boost pressure then pushes against a diaphragm in the actuator to overcome the preload and spring force and push the wastegate open. this allows exhaust gas to bypass the turbine and not spin it any faster to not make more boost.

hth.

 

Nick, from what you are saying, removing the actuator rod will close the wastegate, not open it so I will get loadsa boost, not 0 ?

Is that right ?

Thanks again.

 

no, removing the rod will just allow the wastegate to swing freely. the pressure of the exhaust gas in the trbine will easily be able to psh it open and most of the exhaust will take that route as it is the path of least resistance (compared to going thru the turbine).

try it.

 

That makes sense - thanks nick.