Advice from hereon? wastegate tuning

[barracuda]

Hi,

I recently installed synapse WG001 to my dsm with larger valve seat and stiffer spring (that came with the package). the vacuum lines are hooked to port D % A. The wastegate dumps the exaust gas to athmosphere.

I can hear the wastegate opening approx 15psi and slowly creeping to 21-22psi at redline which is fine by me for I intend to run 25psi anyways. For that I have an EBC provided with the engine management I have installed - I can control boost for every gear and every rpm with 250rpm intervals.... not operational for now.

BUT I have question

1. Do you think the pressure of the gas is opening the gate prematurely? How do I check?
2. Should I try to level the boost curve first before doing anything with the EBC? (remember, I can control the solenoid the way I please)
2b. Could changing back to the originally installed spring and adding preload level the creep?
3. Should I switch from using ports D+A to D once I begin using the EBC? Is there anyway using both with EBC is a bad Idea?
4. um... I forgot


Thanks!

[Rally_Blue]

Typically DSMs are a very high backpressure engine. The force of the gasses in the manifold are blowing open the gate early. In an ideal situation you should be able to hear the gate crack open within a few psi of target boost pressure. I would find out what the mechanical limit of the current spring combo would yield. My guess is it will be lower than your target, meaning you need to apply pressure to the top of the gate to help it stay closed. Your creep issue may be coming form the valve not getting enough lift. here is a rough guide to setup an ebc for interrupt style much like a mbc


http://synapseengineering.com/smf/index.php?topic=434.0

[barracuda]

Yeah, A really rough guide 

Anyways, I figured I could do one of the following:

1. adding more tension to the preload spring, thus increasing the exhaust manifold backpressure threshold, to level the boost steady and then adding EBC to interrupt style boost managing. But doesn't tensioning the preload spring also increase the max boost pressure? Or should I put the boost source line from D to C or C%D and then adding preload?

2. adding EBC to regulate ports A&B while boost goes to ports C or D or both, uninterrupted... like this: (?)

[Rally_Blue]

Adding more tension to the preload spring will delay the initial gate crack, but raise max boost. Only by one or two psi overall depending on what preload spring you have installed. By adding more preload pressure it will also limit valve travel possibly causing creep in upper rpms.

Adding boost to both C&D will help raise the gate more than just C or D alone.
I would set it up like you have pictured but attach a uninterrupted boost signal to C only and have the BCS pressure going to A.
This will ensure that you will not overboost as A has a much smaller surface area than C. If this does not work for you then try BCS pressure going to B. Be sure to properly set up the gate for running B, plugging the port located on the top of the gate near the preload screw if you have one and attaching a fitting to B as it does not have one installed out of the box.
More BCS duty cycle means more boost
Any more questions you have feel free to call the office and one of us can explain more to you.

[barracuda]

yeah.. so option #2 it is.. I already have D+A tested so we can skip usin port A (or only A) alltogether even with bcs.