Can't control boost for the life of me...

[exile]

Alright, just to let everyone get the basics of my situation: I have a WHOLE lot of supporting mods to support a 16g @ 18-20psi, including the knowledge on how to get it to work. At this point in time I have gone through ~3 boost controllers and I have a good feeling the problem MAY lay somewhere else.

If you check out my profile you'll see I have a 16g. It was said to be ported when I bought it, and it was.. however is it ported enough to keep it at 11psi? No. Not a big deal, if I set it somewhere near 18-20 I shouldn't have any problems. However, I can't control my BOOST AT ALL!

Before you read what I've tried, please understand that I understand THROUGHLY how a boost controller works, and how to properly install one. It's not a hard concept and I am an expert at it at this point in time. No. god NO it is not on backwards. (Don't say it.)

1.) I have tried (1) Ebay BC.. (2) Joe-P MBC (3) Brand new out of box Turbosmart boost controller.
2.) I removed the actuator and tested it with my air compressor (along with my t-25 to compare) it appears to fully open @ 11psi as the t-25 opens fully @ 18-20psi.
3.) I did a straight loop from my boost source and the actuator (o2 dumps at 11psi but it creeps after 5k+, but still holds firm from 3k to 5k at 11psi.

I have a boost source DIRECTLY after the turbo. I have also removed the source hose and tested to feel if air is coming out and yes it is.

Only thing I can think of is I have the boost controller set too low and the actuator isn't seeing air at all. I am currently using the Turbosmart and I have it set like 3 clicks passed the lowest setting.

Thanks in advance.

 

[Quasimondo]

Unported and even improperly ported 16G's can creep up to around 23 psi. The problem may not even be with your boost controllers. It's all about process of elimination here. Run a line directly from the boost source to the wastegate. If the boost is not under control, that leaves either the wastegate itself or boost creep. Since you've already tested the wastegate and it opens up at 11 psi on your compressor, that leaves us with boost creep, and the exhaust housing may not be as well ported as you believe it to be.

 

[exile]

3.) I did a straight loop from my boost source and the actuator (o2 dumps at 11psi but it creeps after 5k+, but still holds firm from 3k to 5k at 11psi.

I have already tried that. What it says there is I did that, and yes it does creep.. okay, but it holds at 11psi for quite a while before it creeps, okay.. So I can tell very well whether or not it's creeping anything passed 11psi and 18psi is where I want it. So, if it holds at 11psi for a few seconds, then it should hold at 18psi for even longer before it creeps so I'd be able to tell.

I have all of this stuff on my car, everything ready to tune.. I really need help eliminating this issue so I can finalize this car before it gets warm out.

 

[oldman]

The turbo needs to be properly ported like the wiseman said.

http://www.dsmtuners.com/forums/showthread.php?t=186525

 

[Quasimondo]

I have already tried that. What it says there is I did that, and yes it does creep.. okay, but it holds at 11psi for quite a while before it creeps, okay.. So I can tell very well whether or not it's creeping anything passed 11psi and 18psi is where I want it. So, if it holds at 11psi for a few seconds, then it should hold at 18psi for even longer before it creeps so I'd be able to tell.

I have all of this stuff on my car, everything ready to tune.. I really need help eliminating this issue so I can finalize this car before it gets warm out.

If you have your wastegate set for 18 psi, and you're creeping at something higher than that, by the time that wastegate opens up to bypass the exhaust gases it'll be too late for the wastegate to properly regulate the exhaust it sees.

 

[exile]

I understand. I agree, it needs to be ported *more* than it is now, however when I loop it directly through it doesn't creep until 5-6k, it holds for over 3k rpm's. I can sorta tell where it's "trying" to set itself even if its for a second or so. I'm not getting any kind of response like that's it's a straight on flight from 0psi to 25psi+

 

[TurboChrged93]

Exactly. That is boost creep. Quit playing with internal gates and upgrade to either a manifold mounted external or an o2 mounted external. Going o2 dump still with your internal gate never works. What really needs to be done is port the hole for the wastegate flapper and use a larger flapper. Which IMO is not worth all the trouble, time, and effort. You can find makeshift homemade 2g manifolds with a flange welded on it for under 200 or even under 150 bucks.

What you are experiencing is boost creep. When you run a line directly from the compressor outlet pipe to the wastegate actuator and it holds 11 psi til about 5-6k ... and then shoots up to around 18-19 ... that is boost creep. Your not going to solve it from switching controllers.

The little wastegate passage can't keep up once it gets to that high of RPM. Therefore... it creeps. Go external or go home

 

[oldman]

The little wastegate passage can't keep up once it gets to that high of RPM. Therefore... it creeps. Go external or go home

I disagree completely. Using an external to run less than 22psi is a waste when porting has proven to work time after time. An external setup becomes import when running 22psi+ where internal flappers are being blown open.

 

[exile]

Yeah I have the 34mm over-sized flapper and it's ported, still having issues. I'm not trying to fix my boost creep with a different boost controller. I'm not even going to worry about this little turbo anyway, it's ridiculous all of the trouble it takes to make this thing hold boost. =\

I'm just having trouble understanding why I can't get it to stick at 18psi like it sticks at 11psi even for a second, it's just something that I wanted to get working before I moved on to something else I guess.

 

[Quasimondo]

I understand. I agree, it needs to be ported *more* than it is now, however when I loop it directly through it doesn't creep until 5-6k, it holds for over 3k rpm's. I can sorta tell where it's "trying" to set itself even if its for a second or so. I'm not getting any kind of response like that's it's a straight on flight from 0psi to 25psi+

When you have it direct to the wastegate, how much boost are you seeing at redline?

When you have a boost controller hooked up, what is the lowest you can set your boost to?

If you have your boost controller installed and set to 18 psi, will it hold that setting at 5K or will it start to creep at an earlier rev range?

 

[exile]

Okay, I'm going to get a new manifold and a new o2 housing with the external waste gate that reroutes back into the exhaust, if I get that and I remove the flapper door, will I need to port the hole out anymore or can I just leave it where it is? It's a 34mm flapper door so I'm assuming the hole is somewhere near 32-33mm. Thanks.

 

[oldman]

Okay, I'm going to get a new manifold and a new o2 housing with the external waste gate that reroutes back into the exhaust, if I get that and I remove the flapper door, will I need to port the hole out anymore or can I just leave it where it is? It's a 34mm flapper door so I'm assuming the hole is somewhere near 32-33mm. Thanks.

An O2 mounted will not be a guarantee unless the turbine inlet is ported as if you had an internal because the biggest contributor to boost creep is the transition from the turbine inlet to wastegate, not the size of flapper, wastegate path or o2 housing, rendering an O2 mounted external pointless, unless you're running 22+psi.

 

[jpbrazill]

This sounds a little weird. When I built my 2.4 and retained the stock 14b, with the wastegate all the way open, (unported housing...basically your run of the mill 14b) I was hitting 20psi and there was nothing I could do about it. It crept up to 22psi by 7K. 1 week later, the 14b was toast.

I understand that you know how to install a boost controller, however this is an unusual thing you are describing.

I agree that you should run a boost source (post intercooler) directly to the wastegate actuator and diagnose from there.

 

[exile]

Okay, I've gathered all the info from this post but you guys are still ignoring that I've already did that. Please stop suggesting that.

I removed the turbo this weekend (reluctantly, especially after finding 2 turbo bolts seized up) and found that when I bought the turbo "ported" they simply installed the larger flapper and ported the inlet of the turbine housing slightly. They did NOT port the wall that requires porting to force air into the wastegate. It makes sense now, and if I had known that before I put the turbo on I would of ported it =(

I appreciate everyone help, I am still going to order an tubular manifold and an ext. wastegate recirc o2 housing since I have to order new bolts anyway and everything is off. I plan on going bigger in the future I don't see why I can't get that stuff now anyway.