Adjustable Actuators Vs Ebc

[RB2600]

So I've been having some issues with getting over 1 bar on the greddy profec b-spec 2. At one stage it was getting over 1 bar but did not do it very well

(misfires, flat spots etc). Now I have reverted back to the stock boost control system on my R33 GTR with -9s (Garrett 1 bar actuators) and it hits 19psi with no issues.

I'm sure if I spent some more time on it, the ebc will eventually work fine. The funny thing is, it was boosting over 1 bar

on one day and with nothing else changed it wasn't on the next drive. All hose clamps, vac lines etc have been replaced.

The reason I bought it in the first place was to chase extra response over the actuator setup. Supposedly these EBCs are capable of

keeping actuators shut until desired boost (which I set at 3psi under max boost to prevent spiking) and bust open at that point.

So my question is, how far behind (in terms of response) would off the shelf garrett 1 bar actuators be, compared to an ebc setup correctly?

Or allow me to ask, will the actuator setup alone allow me to have at least 1 bar of boost by 3700-3800rpm like the properly working -9 setups are getting?

My setup includes stock 33gtr dumps, 2x 2.75" to 3" front pipe, 3" straight pipe and 3.5" catback. Stock airbox, adjustable cam gears and will be tuned on

Haltech platinum pro with or without afm pending.

The car is not tuned yet (stock ecu) and feels quite laggy. It almost feels like a -5 setup atm. The ignition timing is currently set at 20-22 degrees BTDC

getting a pickup from a high tension lead on #1 cylinder. There seems to be 2 degrees variance depending on which timing light I use.

[SargeRX8]

Doesn't sound right at all with your ebc. Ive got the same thing and I hold 19psi just fine on a 15psi actuator. Are you sure its not faulty?

I see a problem with running only on wastegate and that's from heatsoak. When the actuator gets hot how well will it still behave? Would the spring soften up at all and open prematurely? I don't know if they're affected but I know I'd want a boost controller there so I can have full control of what I want my curve to do.

Also thats alot of boost you're running untuned.

[RB2600]

I almost suspect that I've plumbed the controller incorrectly..

I never imagined actuators suffering from decreased performance through heatsoak?

Yes, it does seem like a fair bit and I may drop it down 2 psi through the actuators before heading to the tuner to get AFR checked and timing double checked.

Do remember R31Nismoid mentioning that 18psi on -9s with a stock ECU is safe, given that the standard pump is up to the task or have aftermarket fuel pump.

I have a Nismo drop in and have rewired it already. Seems to be spiking to 19psi but doesn't hold that boost to redline.

[RB2600]

To draw it out clearly, I have blocked the hoses from plenum to factory boost solenoid with bolts and clamped the ends. Removed said boost solenoid and left it unplugged at the loom.

Had a spare vacuum tube hard line so chopped it close to the fitting and ran the boost pressure source there as can be seen in the diagram (I think this is where my problem lies?)

Other side of Greddy boost solenoid was plumbed into a Tee and equally diverted into the actuators.

The vacuum control tube was also blocked off at the end of the hard line and at the bov return side.

Legend:

Red // are items removed

Red dots are blocked with bolt and clamps in the line.

Blue rectangle is greddy solenoid

[Shoota_77]

One common drama with RB's is the vacuum hoses at the back of the engine cracking with age and leaking (on the far right side where it says 'clamp'. Might pay to pull the hoses off under the manifold where they originate from and run a replacement hose straight over the engine to test for a leak in the standard hoses.

Worth a try anyway!

Although knowing you had your head off recently you may have picked up on that if it was an issue.

[RB2600]

Thanks Ewan, will try and give that a go.

Any ideas on whether the pressure source for the greddy solenoid is correct or not?

[Shoota_77]

Only problem I see (if I'm reading it right) is that unless you've joined the hoses at the boost control solenoid then you would have no boost signal to the new solenoid.

[RB2600]

So the top part of the pic where the 2 red dots are. These two hoses need to be joined together?

Because both were blocked off with a bolt in each when I still had the boost controller in.

[Shoota_77]

I'm pretty sure that's how it should go. Unless another hose from the manifold has been connected to the hose that runs around the back of the engine.

[RB2600]

Sorry, not too sure what you mean by the last part.

But after doing some more research, looks like we might be onto something.

Since my system runs internal actuators, I'm to use the COM port for the actuators and the NO port for the pressure source.

The instructions do say to unblock ALL plastic plugs on the valve unit and makes no mention of plugging back up the unused NC port which is used for external gate.

Some say this is for the solenoid to bleed the air that the gate is seeing.

So I will remove the plug on the NC and hope for the best!

[scotty nm35]

Yes, the unused port needs to bleed off pressure, rip the plastic plug out.

You can stick a muffler on it, or even plumb it back into the intake...

[RB2600]

Can it just be vta?

[GTSBoy]

If you want insects and shit to be able to get into it, then yes it can.

[XKLABA]

The two hoses that join to the stock boost controller CAN NOT be joined and have to be blocked, other wise it will bleed off boost from the signal line as one of the lines runs back to the intake pipe of the back turbo

I pick up the signal from the hose that come off the plenum run it to the boost solinoid which I put next to the steering shaft then run the wastegate line back up to the steel line that runs around the back of the head to the wastegates, which means I don't have to muck around the turbos and there is less heat on the intake side and the controller is near impossible to see

[RB2600]

I can appreciate your method, but doesn't that mean the waste gate lines will be a hell of a lot longer?

So given that the two hoses going to the stock solenoid are blocked - which they were, would it be ok to block the signal

Line leading back to the intake as well? When I had the greddy setup on there, I had blocked it from the intake pipe nipple

And from the hard line side too obviously.

And would the location of where the actuators gets its standard feed from (that water and air divider thing on the back of the head with

Two fittings) be an appropriate location for a pressure source for the new solenoid?

[XKLABA]

Better having the wastegate line longer then the signal line, either way one is going to be longer

Yeah that's sound ok, just block anything that's not used so if you ever want to reconnect it its not got dust and shit in it

Yeah that works, only thing I would do is bypass the T by picking up signal at the plenum and running a hose to the steel one that goes around the back of the head, in the pic it's at the top on the right side where it has "clamp" and four arrows running off it

[RB2600]

Sounds good, for the time being I'll stick to feeding the solenoid off the standard wastegate feed location. If that doesn't work, I'll look into picking it up from the plenum.

I'll report my findings back here once I'm done and will also comment on my experience between running straight off the actuators and having a boost controller keeping the gates shut for as long as possible.

Cheers for all your help guys