XRTypeRS

I have recently replaced my amal valve as my previous one was faulty.

With the control wire pulled off my new amal valve full boost is 8psi held as should be expected with a -31 actuator.

With new Amal powered up boost holds at 10 psi.

For the last few months while I had the old faulty Amal disconnected I increased boost to 10PSI held with a bleed valve in the pipe between the Amal "C" control outlet and the actuator (the bleed was placed in this pipe by a pro tuner who appears to be highly respected on here )

I now want to up the boost slightly from the 10 the Amal gives to about 12 psi. I want to keep the Amal in circuit as it gives the ECU some control (I have an Ahmed chip which I believe still drives the Amal ??) and the because the Amal does not seem to give the same gearbox straining boost spike as the bleed does (long stoke CVH already gives plenty of torque so boost spikes arent wanted).

So this morning I reconnected my bleed valve in the Amal to actuator pipe and opened it to give a held boost of 9psi with the amal control wire disconnected. I then plugged in the Amal expecting to see about 11 psi, but instead boost shot up to about 16PSI!! - it was only there for a fraction of a second so no harm done.

Im guessing that the fact that the actuator control pipe is effectively meant to be sealed means that when the Amal it is not designed to provide any"flow" to the actuator and hence any bleed off from this pipe has a MUCH bigger effect when the Amal is operating.

Therefore where is the correct postition for the bleed valve :-

1). In the control (C) pipe to the actuator (current position).

2). Inline between the turbo nipple and the Amal valve??.

3). In "Parallel" with the Amal Valve??.

What does everyone else think?.

Cheers,

Stu

P.S. I also notice that the new Amal has a white plastic restrictor in the actuator control output (C) port whereas the old one had nothing?? - any ideas why that might be?? should there be one there and whats it for??.

PP.S I have a wideband and Im being sensible so dont worry Im not planning to break anything playing with this!

XRTypeRS

bttt

CosRush

Stu,

The Amal works as an electronic bleed valve. it is a 2 way switch effectively which either sends the boost pressure to atmosphere/back into the in box or to the wastegate to open it (its actually pulsed open and closed by the ecu).

The jets you refer to are to control both the Peak and held boost figures.

The jet between the Compressor and the actuator (marked C) alters the boost spike, smaller hole bigger boost spike/ bigger hole smaller boost spike.

The other jet (as there should only be 2 fitted) is the bleed and is between the compressor and the airbox (marked R), this controls the held boost, smaller hole lower boost/bigger hole higher boost.

Basically i would imagaine that if your standard setup using a -31 gives you 10psi with the new amal, you should be able to add a small amount of reload to the actuator to get it to 12psi easily. provided that is you've started off with only a half a hole of preload.

or you could alter the jet sizes to get the correct boost you require.

My engine is running a stage 3 conversion and to get the 26psi peak and 24psi held, ive got an enlarged jet in my R port, and have a couple of turns of added preload over standard.

hope this helps...

in summary...ditch the bleed valve completely if you want the safety via the Ecu.
you dont need it to get what you want....