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Greddy Profec B Spec 2 Grief

donut_kng

By donut_kng,
in Engines & Forced Induction

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donut_kng Experienced

donut_kng

Posted
Posted

Hey people,

Extremely frustrated at what was supposed to be an 'upgrade' from a Turbosmart dual stage is turning out to be a bastard of a thing. What I have is a Greddy Profec Spec 2 ebc which I thought would make the thing a bit more snappy with the right settings, this is installed on a externally gated setup (turbosmart pro gate 38),

I have tried plumbing it up in 3 different ways all delivering similar results - 1 like the EXTERNALLY gated way in the ebc manual, 2 the INTERNALLY gated way in the manual, and 3 another way which I had found through searching on through other threads - after 3 goes at it I thought I deserve my own thread!

All the setups I have tried have used different combos of the COM and ON ports on the solenoid. Also tried it removing the little filter which runs on the vacuum line going to the incabin unit. Just so you know, + and - is taken from the cigarette lighter/headunit ACC power and the vacuum line is T-pieced of a Vacuum line going to the ECU which was already T pieced of the fuel prssure reg (as instructed in the manual).

Now, I know its no other part of the setup (cooler piping, FMIC) as the old dual stage boost controller worked fine, and I also chucked in a turbotec $30 thing off ebay which also worked a treat boost past 20psi+, so I have ruled out any other causes. Also the Greddy unit I am using was brand new so I doubt there could be any faults with the unit.

The problem? Basically the bloody thing just wont boost past 15psi. I have a good idea of tuning the thing and with values set to 'as high as it can go' I still dont see anything past 15psi which is painful. I have also had a mate look at it who has the same boost controller on his relatively standard setup who is also baffled on what the problem is!

The next weird thing which has really headf***ed me?... as I said... I have a turbosmart progate 38 which has a 14psi spring setup in it - so you would think that with the boost controller turned off I would see 14psi max as it would be just running off the gate - but no, with the controller TURNED OFF I only get about 9psi out of it - yes, less than the spring setup - how this is possible? I have No idea.

So from what you have read christmas isnt all that merry for my forced induction.

If anyone has any suggestions, it would be greatly appreciated as I am about 4 minutes away from saying f** ebc and bleed valve ftw! which I dont want to as I have seen what these things can do when they actually work.

Any help appreciated PLEASE PLEASE PRETTY PLEASE.

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donut_kng Experienced

donut_kng

Posted
  • Author
Posted
take some pictures or show exactly how youve plumed it all up

will do mate

Have you changed the high peak value (boost cut)? The EBC has a safe function where you can set it from spiking above the value set.

Eg. I have mine set to 16psi and boost cut at 18psi to prevent it spiking above that value. Does that make sense?

yeh man i haad it set way over what i need it to be so to rule it out of being a cause

RBwhatever Veteran

RBwhatever

Posted
Posted

COM needs to go to the wastegate, NC needs to receive a pressure source, NO goes to nothing so leave it blank.

Use the NO port for actuator setups, Use the NC port for external wastegate setups. I'm sure you've read that already though.

Ummm, turn your limiter off altogether, which is switched off from factory anyway.

I'm thinking you may have to check your wastegate. From what your explaining it sounds like its stuck open and bypassing exhaust therefore not producing the boost you want. Well that's all i can think of if it's boosting under the spring pressure.

And in theory if this was the case, any boost controller would have trouble to hit your desired boost, which is strange because you say the MBC's were ok......that baffles me.

Do a couple of swaps. If it was me:

Plumb a pressure line directly to the wastegate and see what it boosts to.

Hook up a MBC and see what it boosts to.

Reconnect the prefec B and see what boost you can set.

I don't know if any of that is going to work, you've probably already tried all that.

donut_kng Experienced

donut_kng

Posted
  • Author
Posted
COM needs to go to the wastegate, NC needs to receive a pressure source, NO goes to nothing so leave it blank.

Use the NO port for actuator setups, Use the NC port for external wastegate setups. I'm sure you've read that already though.

Ummm, turn your limiter off altogether, which is switched off from factory anyway.

I'm thinking you may have to check your wastegate. From what your explaining it sounds like its stuck open and bypassing exhaust therefore not producing the boost you want. Well that's all i can think of if it's boosting under the spring pressure.

And in theory if this was the case, any boost controller would have trouble to hit your desired boost, which is strange because you say the MBC's were ok......that baffles me.

Do a couple of swaps. If it was me:

Plumb a pressure line directly to the wastegate and see what it boosts to.

Hook up a MBC and see what it boosts to.

Reconnect the prefec B and see what boost you can set.

I don't know if any of that is going to work, you've probably already tried all that.

Ok done a direct line from the wastegate to the pressure side of the turbo to see what boost i get - after giving it a bit of a squirt the most i saw was the same 9psi. This tells me that the wastegate spring either is 9psi not 14psi like i thought it was, or something may be leaking as Keymaker said.

But, if something was leaking, wouldnt that make the thing reaaly sluggish and laggy al the way?

... in the meantime im gonna go hook up the turbotech..

Turbo Dave Collaborator

Turbo Dave

Posted
Posted

If the Gate was stuck open it would be sluggish the whole way, but if it is low spring pressure it would explain why its still responsive but only getting 9psi, and with and BC it can only acheive 15psi before the gate cant close any harder.

donut_kng Experienced

donut_kng

Posted
  • Author
Posted

ok peaople an update.. got the Manual BC back in and funnily enough i can only get the thing up to abotu 16 17psi! and thats with the thing screwed up the whole way.

so i mustnt be boost controller after all... thinking maybe a flange/exhaust leak somewhere around the wastegate?

Any other ideas ?

Richieb Collaborator

Richieb

Posted
Posted

Yeap. Turbo might not be producing any more pressure. This depends on work done. Mine wn't go over 18.5 PSI since I worked the head, and cammed it. Still, it now produces mountains of torque over previous build, which is what turns the wheels, and no more peaky output waiting for RPM to develop.

BTW, it did run 23 PSI before on same turbos, but less power.

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