jimmydanny

Also, halfway back to the topic.

My turbo now only charges to 0,4bar, 0,6 is stock I think. 0,7 is fuel cut.

Now this is not the solenoid as I have taken the hose to the solenoid and connected it straight to the pre-turbo intake, like stock but without the solenoid. So now it should in theory get the 0,6 bar, right? Nope.

So the actuator arm, how can it fail on me? Can it be adjusted on the stock turbo? Or is it something like the FD that the C-clip falls off?

Molotovman

iTrader: (49)

Get your head out of your ***.

Stealth 316 - Turbocharger Compressor Flow Maps

There's some compressor maps on that page in CFM. take a look at a few different ones.

Different turbo's flow a different CFM at the same PSI.

RotaryEvolution

iTrader: (30)

removing the wastegate solenoid and venting it back into the intake pipe results in no pressure building to open the wastegate actuator and an overboost condition. plug the line off and you should be seeing roughly stock boost. if not then your intake systems is leaky, intake/exhaust restricted or turbo itself is having issues like worn journal bearings/worn wastegate bushing allowing exhaust to push the wastegate open via backpressure.

AGreen

iTrader: (11)

Don't think of it as a defined volume with a compressor on one end.... because that's not what the system is.

Keep in mind there's an engine that still consumes this air. So if the stock turbo makes x.x psi at x.x rpm under x.x load condition, the engine will consume what it can out of the turbo. A larger turbocharger will allow the engine to consume more air. However, because there is still an inherent restriction in the system, that will explain why there's a pressure. It's not just static pressure when talking about compressors, it's pressure, volume, density, and velocity. There are multiple factors you're not taking into consideration.

So in a nutshell, the larger turbo will allow the engine to consume more air at a faster rate, expelling more air (exhaust), making room for more air, faster, which will increase the HP, and at the same time prevent the pressure from building up inside the engine. More flow rate means you will need more fuel to keep the air/fuel ratios the same. So the pressure DOES NOT MEAN ANYTHING without a flow rate. Stock injectors will not work for almost anything other than a stock turbo.

There's also a point at which a turbocharger no longer pumps air efficiently. With the stock turbo, going above 10-12 psi it won't flow more air, but instead superheats the incoming air, making it so much more susceptible to knock, or detonation. This is deadly for an engine.

jimmydanny

That is the problem. I don't see more boost. 0.4 bar... 1 bar is 14.7, no overboost at all. Intake is not leaky the vacuum is fine.

Is the actuator arm adjustable at all on this turbo? Can I feel the slack if the diaphragm is very bad, for instance? That is the two main things I can think of right now. Wouldn't bad bearings often show signs with blue smoke and oil consumption?

The turbo can when the wastegate is not connected give over 10psi, tested it once last week and once today, it peaks even higher than 10psi, maybe 12 (watching the road, don't wanna die). Connected the wastegate vac line, and same thing as before, 0,4 bar, whatever that is in PSI. So I'd say it's probably not the bearings, probably not anything else but something with the actuator arm, or the actuator itself.

Just been out driving, so the turbo is too hot to handle right now, so I gotta wait till later tonight or tomorrow before I do any feeling of the arm (sounds nasty)

Also

I found this line very interesting in the bottom of the page, in the summary:
Which is kinda what I said here. If it is 9psi, 20 degrees celcius, and 6000rpm, I got X amount of air going into the engine with the stock turbo. With the bigger turbo, it is still X.

RotaryEvolution

iTrader: (30)

.4 bar is 5.8psi.

check the wastegate arm for slack, it should be tight and difficult to move by hand. sounds like your bushing is worn and allowing exhaust to bypass lowering boost and dropping too much when the actuator is moving the arm.


not going to argue the turbo differences anymore.

jimmydanny

Is that bushing replaceable, and/or can it make that amount of exhaust to bypass through the wastegate?

And that quote I gave was from the link Molotovman gave. Funny, isn't it, giving me the one sentence that says I'm right, when trying to prove I'm not?

jimmydanny

Okay, the actuator arm seems fine. No slack in it, so bushing is okay I guess.

However, holding the hood up with my neck, pulling in the arm with my left hand(right handed), I could pull the actuator arm out without any real trouble, so with the right hand I would probably pull it without any effort at all.

Is this normally doable? I have never touched the arm so I don't know at all.

RotaryEvolution

iTrader: (30)

it shouldn't be that easy to pull, no.

for the other comment, as i mentioned many posts ago: do what you want, it's just advice. but when you see AFRs start to spike and can't explain it. *shrug*

Molotovman

iTrader: (49)

The compressor maps say it all, and the information is in the article. I just did a quick google search and found that.

Since you can't get your head out of your *** and trust others who have experience, do it yourself. Put a larger turbo on, keep it at 8 PSI or whatever you want, blow you engine. We won't have to say "we told you so" and rub in your ignorance. You'll be doing that to yourself when you have an expensive rebuild.

jimmydanny

I will prove you wrong. But as RotaryEvolution said, he is done, and so am I. It's word against word.

So, back to my current turbo. Actuator and arm (I guess), is this hard to swap if I fetch a HKS uprated actuator, holding 0,6 which is the stock level anyways? A clip and some bolts I would guess, without having taken a real good look on it yet.

Is maybe that something I take when I get my new exhaust, just taking the turbo off and doing it then?

Molotovman

iTrader: (49)

Key word. Temperature.