zinx

iTrader: (3)

So i've been running 21 psi for what seems like forever and decided to run a few more psi for the end of the season, but i'm having trouble getting the boost controller to go up. I've read the manual front to back several times and that nice write up on the Evo forums too.

With the controller off, i get about 16 psi. With my normal setting of 80% SET with 10% gain and 16 psi START, i get 21 psi. No matter what i turn the GAIN to, its always 19-21 psi (The extreme highs and lows net less boost). I turned the SET all the way to 100% and set the gain to 35%, same outcome. The controller and valve seem to be working properly since i can turn the boost down to wastegate and everywhere in between 16 and 21, but can't go any higher. I'm thinking i should be able to take the boost up to 30 psi or so if i actually wanted to.

Anyone have any ideas why it won't go any higher?

jg13b

If i am reading your post correctly it sounds like you are adjusting all the settings when you hit the set button and go through those but that's not where the main boost control % is to adjust total boost. When the controller is in normal operating mode (not going through the "set" stuff) just turn the big ****. Then when you have the % where you want to increase or decrease the boost push it in to lock that setting. If you don't push it in at the end to lock it (may have to hold a few sec i forget) after a bit it will show your vacuum/boost again on the main screen but revert back to what % it was before.
The stuff you are messing with is to refine when the boost comes on and falls off but is not the main PSI setting.

chohakai

iTrader: (1)

Rotary god is trying to tell you something.. Duck!

zinx

iTrader: (3)

The manual refers to the SET value as the main boost ****. It is currently set at 80%, If i lower it, it will drop the boost. It i set it at 0%, i get the same results as running with the controller off. However, If i turn it up past 80%, it does not increase the boost past 21 psi which is the same as the 80% setting.

zinx

iTrader: (3)

Btw, the controller itself is getting the boost source from the back of the UIM near the TB. The wastegate is getting signal from the nipples at the top of the LIM. A friend suggested changing the wastegate source to a spot near the compressor. I've got one blocked off there so i'm going to give that a shot.

Trots*88TII-AE*

iTrader: (11)

are you using both ports on your wastegate? you might be getting backpressure overcoming spring/boost pressure.

zinx

iTrader: (3)

I have the COM port on the valve going to the top of the wastegate, and the NC port going to the side of the gate. I like your thinking though that the exhaust pressure is just too much for the controller to overcome.

Trots*88TII-AE*

iTrader: (11)

Sorry, I'm not familiar with the Profec. Is it a 3 port solenoid, and while building boost, does it supply manifold pressure to the top port, working against the exh manifold pressure?

zinx

iTrader: (3)

The manual has a drawing on page 11 exactly how its installed in my FD. Its probably easier to look at the image than it is for me to explain it.

http://www.alamomotorsports.com/gred...EC_B_SPEC2.pdf

arghx

iTrader: (3)

You can only crank up the boost controller so much before it will no longer respond; the solenoid duty is going to be capped at some value to prevent the coil from overheating. The factory wastegate solenoid for example is usually capped at 89 or 95% according to the FSM and my Datalogit logs.



try hooking it up this way (this is based on the instruction manual diagram):



because there is a pressure drop after the intercooler, more force will be acting on the top port of the wastegate, pushing the spring shut.

I sure hope that was a typo, or at least lacking in clarity.

Trots*88TII-AE*

iTrader: (11)

I'm not sure how the solenoid works on the Greddy, but this is from my E-Boost manual. when the solenoid is not activated and you're building boost, the manifold pressure acts on the top port, keeping the WG shut against exh pressure. And then when the solenoid is activated, boost is switched to the bottom port to open it.

arghx

iTrader: (3)

3 port solenoids are all basically the same. Port 1 is the equivalent to the COM
("common"?) port, Port 2 is NC (normally closed), and port 3 is NO (normally open). You will notice that in the Greddy etc. diagrams, the COM port is the one that goes to the wastegate. It doesn't really matter, air can flow in either direction. Air flow from COM to NO (or vice versa) when the coil in the solenoid is disengaged and from COM to NC (or vice versa) when the coil is engaged.

Here's an example of a 3 way solenoid with the coil disengaged (solenoid off). COM would be on the left, NO would be upper right, NC would be lower right.



solenoid engages (air does not necessarily have to flow in the direction pictured):



Now let's go back to the TurboSmart plumbing.



The second plumbing setup (which was just posted) would work, but I think there is some misunderstanding about how that plumbing system functions. When the coil is cycled off, pressurized air flows through the normally open outlet (NO port aka port 3) of the solenoid to the side port of the wastegate. This pushes on the spring to open up the poppet valve if there is enough pressure. Then every time the coil engages as it is duty controlled, pressure is vented from the side port (back out port 3/NO port) and pressure is added to the top port (through port 2/NC port). The pressure to the top port pushes on the spring and the poppet valve will close more. What makes it confusing is that boost controllers usually run at almost 100% duty until a certain pressure ("START BOOST" etc) is reached, which does in fact push the wastegate spring shut whether you plumb it with the 1st or 2nd option depicted here. This can be a little confusing, and it's easy to give yourself a headache thinking about it.

Anyway, this type of plumbing would likely require much less solenoid duty. I would use this setup as a last resort, as it will increase the chance of uncontrollable boost. External boost controllers really don't have the precision of the ECU-controlled ones that have very precise duty cycle maps, closed loop parameters, and ambient condition correction tables.

I have found that the most stable boost control is achieved by not trying to go too much higher than the rated spring pressure. You rarely/never see OEM boost control systems going 3 times more boost than the spring pressure on a gas engine, and factory boost controllers (on factory cars) are more consistent by far than most aftermarket setups.

zinx

iTrader: (3)

Thanks for the help guys! I switched the top port to the compressor and the side to the IM. I got to tinkering with a few other things on the car so i didn't take it out and see, but i will soon and I'll post results.

sk8world

iTrader: (5)

Have always heard issues with the spec 2. When Ray was down this past year we ran into this one of the cars being tuned. Ended up putting in a manual valve as it wouldnt go any higher. But this was not the first time I have heard of this on a spec 2. Get it fixed soon or I am bumping your time...

zinx

iTrader: (3)

haha, we'll if i can't get the boost to go up, i'll just have to resort to mixing nitro in with my meth.

zinx

iTrader: (3)

So it seems as though its gotten worse, now i can't get it to boost above 18 psi after messing with it. I've tried all the methods in the chart, but nothing will increase the boost. I even set it up like i had it originally and can't get back up to 21 psi. I've tested the valve and it is clicking when it gets pressure, If i give it too much and hit the boost limit it clicks like crazy. Blowing though a vacuum line, it is closed, and after it clicks it opens up, which seems to be like it should since its running through the NC (Normally closed) port. I'm wondering if it is a problem with the wastegate itself? I'm not really sure.

blitzboy

What wastegate spring do you have, is it 10psi 14psi?

zinx

iTrader: (3)

1 bar spring, i believe, but i get 16 psi with the controller turned off. I'm going to take the wastegate off the car and double check which spring is in it. Its a GReddy 47 mm gate.

arghx

iTrader: (3)

if you've got the ***** for it, run straight wastegate pressure to the top port and leave the side port vented. if it still won't boost then you've got a mechanical problem with the wastegate or perhaps a restriction in the intake or charge air system.

zinx

iTrader: (3)

lol I was talking to a supra guy last night that has used the profec B in the past and that's what he did when he was having issues with his.

A friend is going to let me borrow his controllers (manual and electronic) and I'm going to start testing things and narrowing down the problem. Driving the car with only 16-17 psi sucks, Its slow.

arghx

iTrader: (3)

the problem with these types of external boost controllers is that usually you cannot actually set the solenoid duty directly, nor can you log the duty. Among the external EBC's, only the AVC-R lets you set duty precisely. And only boost control systems built into standalones let you log the duty in a useful way (haltech, PFC, AEM EMS, etc). I use the PFC and a factory wastegate solenoid to control boost on my T04R. It's a lot easier to troubleshoot because I can actually see what the boost controller is doing by looking at the logged solenoid duty curve.

Trots*88TII-AE*

iTrader: (11)

I would run a MBC before running a vented sideport. It may not control boost accurately, but at least it will control boost to some extent and save your motor from blowing! What turbo are you running anyways?

zinx

iTrader: (3)

I'm going to try the MBC first, its the easiest swap and lowest tech. I'm running a greddy T88 34D.

arghx

iTrader: (3)

the problem with an MBC is that it is hooked up to the side port and the top port is vented. Less pressure is applied to the side port, which makes the wastegate open later (just like on a single port internal wastegate actuator). But without pressure on the top port, the wastegate poppet valve may be pushed open by the exhaust pressure up top.

this depends on many factors though. if your EBC was messed up in the first place then the MBC may indeed let you boost higher.

zinx

iTrader: (3)

I borrowed a friend profec B (non spec 2) and hooked it up in my FD with the same results. It looks like the problem may be in the wastegate? I'm waiting for it to cool down and them i'm going to take it off and check it out.

Anyone have any ideas?