Montego

iTrader: (1)

Like I said I'm stumped on what could be causing my issue hopefully someone can shed some light on the subject.

mods that pertain
GT35R single turbo
Profec B spec II boost controller
Tial 44mm Wastegate with a 10lb spring (real not fake)


Ok out of the blue I lost total boost control. My wastegate dumps to the atmosphere so it's quite obvious that it's not opening.

Things that I have done:

Called up greddy for advice and they told me to completely disconnect electronic part of the controller so the car would run off the wastegate. If nothing happened then to proceed to disconnect the solenoid for the controller as well. Both yielded zero results so the next thing was to take a look at the wastegate.

Easy enough called up tial and they had me send it to them for inspection. Tial checked it out and they found zero issues but they rebuilt it as a courtesy (damn good customer service ). Hooked it back up and as expected problem is still there.

I have checked my hoses that lead to the wastegate and they are all connected.

So what gives? any ideas are greatly appreciated.

M-

arghx

iTrader: (3)

vent the top port on the gate to the atmosphere. run a hose from the compressor housing to the side port of the gate. this will bypass the boost controller completely. See if the gate opens then.

Montego

iTrader: (1)

Thanks I'll give that a shot

DCrosby

You could do this with a bicycle pump as well, the wastegate should open once you overcome the pressure of the spring (10 Psi Spring) 11 PSI of Pressure, wastegate should open, the top part is to keep it closed longer, so that you can make it go higher than what the spring was designed for. It's a mechanical beast, the electronics / solenoids etc... just regulate the mechanics of the system.

AEM used to have a great writeup with diagrams on how to plumb a wastegate, and there are two ways of doing it, one is to fake the wategate into thinking the pressure is lower than what it actually is, by releasing some of the pressure before it gets to the wastegate (bottom), and the other way is to keep it shut by applying some of the pressure to the top (opposite side) of the spring, to keep it shut longer. Both ways have their advantage / disadvantage in case of failure of the regulating solenoid. Depending on weather the solenoid sticks open or closed in case of failure...

But be careful runaway boost without fuel = broken motor.

Montego

iTrader: (1)

Thanks for your suggestion.

Even though I performed the test that greddy recommended I have my doubts about it. The top of the wastegate was not vented to the atmosphere. The only thing that was "jumped" was the controller.

Thanks I'll will also give this a try if arghx's recommendation yields negative results.

ha ha no kidding. I've been a victim of that scenario before. Back when I had stock twins the wastegate line came off and "boom" 23 psi on stock injectors...

DCrosby

Well like I said the top shouldn't be vented to atmosphere if you're using a boost controller, which will hold the valve shut until you reached whatever max boost you had set on the controller. Regardless with or without a controller, a common guide is that
1) you can't go (dial in) lower (boost) than the spring.
2) Going higher than 2X the capacity of the spring (Spring =10 psi, Max Boost = 20 psi) is dangerous to the controller and solenoids and or the wastegate, but that might be an old wives tale...
I never tested that theory. But it makes sense why get a 10 psi spring, when you plan on running 30 PSI, your low boost at 15 is probably sufficient, unless you have radically different setups between track and road use... and then swapping springs in a wastegate might not be your biggest problem.

Montego

iTrader: (1)

Just to clear something up: I meant when I bypassed the solenoid. All I was told to do was to bybass the solenoid by hooking up the hoses together (instead through it) and go for a drive.



Agreed that's why I chose a10lb spring: My Low boost is 12 and high is 15. After AI I might push a little harder (depending on how much fuel I got) for the occasional fun. But never up to 20... I certainly don't have the fuel for that

DCrosby

[QUOTE=Montego;10270410]Just to clear something up: I meant when I bypassed the solenoid. All I was told to do was to bybass the solenoid by hooking up the hoses together (instead through it) and go for a drive.




That makes no sense, since the only way for the wastegate to know how much boost you're making is to have a reference from the manifold, as the exhaust pressure that the spring pushes against has nothing to do with what boost you're seeing. The wastegate has to have some idea of what boost is in the intake for it to do its job.

Montego

iTrader: (1)

the more i think about it:
it mimmics the function when the controller if off by bypassing the solenoid. As you are aware in a properly working set up when the unit is off, the wastegate works off the spring.

Im gonna test it again today I'll report my findings.

Montego

iTrader: (1)

double post via cell phone

Montego

iTrader: (1)

Ok I just wanted to give an update:

Most of my free time goes into fixing up my house and my car is in the low low priority list. Besides these days I force myself to take the car out so if put 30 miles a week, it wouldn't surprise me.

So I tried what was suggested to no avail so I got under the car again. Took out the wastegate and hooked up a bicycle pump (thanks DCrosby) to the nipple. Yep it worked. So the next step I decided to take out my hoses which are steel braided. Son of a B... As it turned out the hose had wedged itself in a spot that was hard to see, not only that, it rubbed off the thermal wrap on the DP on that particular spot. So what happens when a HOT DP is wedged with a steel braided line... Yep melted the hose inside melted.

BTW yeah I cut off the piece and rerouted the hose and *BAM* instant boost control.

G's 3rd Gen

iTrader: (11)

yikes! Sometomes findng little splits and holes around the wastegate lines can be tedious. Glad you got it sorted

arghx

iTrader: (3)

wow that is the first time I have seen a stainless wastegate line compromised

Rawbz08

iTrader: (7)

Mine just started doing the same thing. I'm gonna go thru the lines today. I'm thinking of re doing my entire vacuum system with pneumatic fittings and Teflon hose. With running them thru a high heat sleeve down around the wastegate.