Holding boost: Problem Solved (I think)
 

File this under 'I have no brain'... :wallbash:

I'm using the GReddy bleed valve that came with the E-01, although not the E-01 since the XEDE has a built in boost sensor/controller.

It's hooked up as follows: a vacuum hose from the IM is T'ed to the wastegate actuator and the NC (normally closed) port on the bleed valve. So, when the bleed valve opens, it takes pressure off the wastegate actuator. Duh. One could also call this a MASSIVE BOOST LEAK? THen again, can enough air flow out of the nipple on the IM to make boost drop off?

So, by connecting the wastegate sensor to the COMM port and the IM vacuum line to the NO (normally open) port on the bleed valve, less signal is sent to the wastegate sensor as duty cycle on the bleed valve increases. This assumes the NC & NO ports are linked and operate the same way (one opens by the same amount the other closes), which might be a bad assumption.

We might have to restrict the flow from the bleed valve as an alternative.

Huh? I'm not so sure I understand what you are saying.

First, the WG signal should be plumbed to the turbo outlet, not the IM as per https://www.rx8club.com/showpost.php...09&postcount=2 and https://www.rx8club.com/showpost.php...20&postcount=1
Second, The solenoid valve that comes with the E-01 is NOT a bleed valve. When it is closed, it is closed. When it is open, it simply ports the signal to the output.

Sorry, lack of sleep makes me sub-coherent.

I haven't done the turbo outlet fix yet...it's on my to-do list.

There are 3 ports on the solenoid, labeled COMM (goes to wastegate actuator), NC (Normally Closed), and NO (Normally Open). In the E-01 config, COMM goes to the wastegate and NO is plumbed to the turbo outlet/IM.

On my car, the XEDE is controlling the GReddy solenoid valve. The boost signal is coming off the intake manifold, where it is connected to a T-fitting. One side of the T goes to the wastegate actuator, the other side goes to the NC port on the GReddy valve.

The XEDE is sending a signal to the GReddy valve that opens the NC port, thereby bleeding pressure from the wastegate actuator.

My hypothesis is that this amounts to a big boost leak that the turbo can't keep up with at high RPMs. If the NC and NO ports on the GReddy valve work in unison (as the NC port opens, the NO port closes), I should be able to plumb the wastegate actuator to COMM and NO to the turbo outlet/IM.

If it *doesn't* work that way and/or the XEDE can't control boost this way, I at least need to limit the amount of boost leak by constricting the flow to the NC port.