secondry turbo actuater

[Pappu1]

have a mates TT GTB BH shape and the secondry is not boosting at all

how we know:"

1 - after a hard run, the secondry downpipe is just mildly warm (from engine bay heat perhaps) but u can fully hold it and not get burnt - lol try that to the primary pipe which radiates heat from a few cm away telling how hot it is

2 - logged the boost and its fairly flat not like the tell tale TT dip and secordry chime in

3 - the secondry actuater duty cycle - starts to climb to abt 50% and the drops down to zero (shutting the secondry off)- normally, it climbs all the way to 100% like in normal secondry boost

car has massive knocks (stock ecu)...my theory is that

1 - the knock sensor picking up a lot of knock and shuts secondry from openinig

2 - (less likely) the secondry turbo is toast and ecu somehow realises it and shuts the actuater..

question:

the secondry actuater has 2 vac hoses. to run the secondry in parallel (just for testing purposes of secondry thats all) - do i pull out the bottom hose and block off?

also do i have to block off the under intercooler bypass valve thing or leave that alone?

i wana ensure secondry running fine before get started with the timing map tuning

[soopersubaru]

 pappu said:

have a mates TT GTB BH shape and the secondry is not boosting at all

how we know:"

1 - after a hard run, the secondry downpipe is just mildly warm (from engine bay heat perhaps) but u can fully hold it and not get burnt - lol try that to the primary pipe which radiates heat from a few cm away telling how hot it is

2 - logged the boost and its fairly flat not like the tell tale TT dip and secordry chime in

3 - the secondry actuater duty cycle - starts to climb to abt 50% and the drops down to zero (shutting the secondry off)- normally, it climbs all the way to 100% like in normal secondry boost

car has massive knocks (stock ecu)...my theory is that

1 - the knock sensor picking up a lot of knock and shuts secondry from openinig

2 - (less likely) the secondry turbo is toast and ecu somehow realises it and shuts the actuater..

question:

the secondry actuater has 2 vac hoses. to run the secondry in parallel (just for testing purposes of secondry thats all) - do i pull out the bottom hose and block off?

also do i have to block off the under intercooler bypass valve thing or leave that alone?

i wana ensure secondry running fine before get started with the timing map tuning

Actuator flap jammed? check for freedom of movement.

[Pappu1]

hmm that could be..

to check for jam - i push down/away from the actuater body yea?

how hard should it be to push open the actuater flap manually?

[soopersubaru]

 pappu said:

hmm that could be..

to check for jam - i push down/away from the actuater body yea?

how hard should it be to push open the actuater flap manually?

disconnect it...check for free movement

[Pappu1]

Wats the easiest way to disconnect it as have never done that before

 soopersubaru']

[quote name='pappu said:

hmm that could be..

to check for jam - i push down/away from the actuater body yea?

how hard should it be to push open the actuater flap manually?

/quote]

disconnect it...check for free movement

[D-Style]

Abit off topic.. This thread reminded me.

There use to be a member who was installing a Butterfly type valve setup for the change over actuator. Anyone know whatever happin to this memeber or the project?

[telemekas]

I have done a slightly different ECV modification:

2.5"( 63mm) butterfly valve located low down in the 2nd turbo dump pipe.Vacuum operated via No:6 port.

A further extension to this:

The ICV has also been replaced with a 50mm passive one way check valve.

This has improved timing of the valves and allowed removal of the supercharger pressure relief valve.

[Jord]

 pappu said:

how hard should it be to push open the actuater flap manually?

1+ Anyone know? Im having secondary issues since installing new secondary and was wondering if its ECV related. The actuater was way to stiff to move by hand, only just able to move it using some pliers. Normal? It has pretty large diafram area so im guessing it is.

[soopersubaru]

 Jord']

[quote name='pappu said:

how hard should it be to push open the actuater flap manually?

/quote]

1+ Anyone know? Im having secondary issues since installing new secondary and was wondering if its ECV related. The actuater was way to stiff to move by hand, only just able to move it using some pliers. Normal? It has pretty large diafram area so im guessing it is.

It is also possible to supply air to it and cause it to open, 1 bar only! should open all the way.

Best to check free to move first, can become stuck!

[Pappu1]

Is the secondry actuator like a external wastegate pressure difference between top and bottom To operate type actuator

What's the spring tension on them

[telemekas]

The two ports on the ECV actuator have different functions.

The top port (pretransition postive pressure only) will only partially open the valve at high engine loads and boost.

Therefore bleeds exhaust like a wastegate and aids secondary prespool. A smoothing effect during hard acceleration runs or climbs.

The bottom port (post transition negative pressure (vacuum) only) will open the valve fully at the predetermined RPM (transition point) set by the ECU regardless of what is happening with the top port.

The sequential system will still operate without the top port being active.

[Pappu1]

 telemekas said:

The two ports on the ECV actuator have different functions.

The top port (pretransition postive pressure only) will only partially open the valve at high engine loads and boost.

Therefore bleeds exhaust like a wastegate and aids secondary prespool. A smoothing effect during hard acceleration runs or climbs.

The bottom port (post transition negative pressure (vacuum) only) will open the valve fully at the predetermined RPM (transition point) set by the ECU regardless of what is happening with the top port.

The sequential system will still operate without the top port being active.

so at point of secondry boost the lower one supplies vac to the canister to get it to open..

assumiong uses vac from the vac store?

what will happn if u unplug the botton amd only supply manifold pressure to top - will it then work like a standard wg actuater and open at 1 bar etc?

[telemekas]

I pressure tested the ECV using the top positive pressure port.

Begins to open at 120 Torr or approx 2.5PSI and fully open at 160 Torr approx 3.5 PSI