Unknown turbo issue

Hello,

 

I am having an issue with the turbo that neither myself nor the professional shop that I got it tuned at could figure it out. So what is going is under light acceleration the turbo spools up fine up to 10-12lbs then from 12-14 bounces all around but never lower than 10lbs then it smooths out around 15-16lbs. So I would say anything from no throttle to half this happens but any thing above half to full it doesn't do it

 

I think it maybe some type of compression stall or something along those lines

Or it could be the air flow that is making a "vortex" and here is why:

I have the k and n typhoon intake that comes with 2.5" pipping then I have the 3" Avo inlet hose that goes to the turbo that goes into the stock 2.5" down pipe into a 3" that tapers into 2.5" magna flow exhaust

 

There car also has a Perrin tmic, new timing belt water pump etc...new stock turbo it now has 5k on it Cobb ap with custom stage 2 map And a dw265c fuel pump

 

 

The guy who tuned worked on the car for hours and logged many runs/pulls on the dyno and on the road to see what was causing it and found nothing, the car is running very well. So any input would be great

Manual or EBCS?

Have you tried running it with the stock air box? Several members had issues with the K&N on the stock turbo.

It is a 5eat.

 

No I have not, when I bought it that's what was in it, I was thinking about switching it out any ways for the cobb or perrin one but will have to get it retuned no mater what I do. That is why I'm trying to get as many opinions as possible. But thank you for the advice

Manual or EBCS?

 

It is a 5eat.

 

Manual or Electronic Boost Control System?

 

The reason being, if your boost is swinging about, it could be a boost control issue.

 

Although, if you're running stock DP, I'm gonna guess you're also running stock boost control?

Oh sorry about that man as soon as I saw "Manual" just jump to the conclusion that you were asking it it was mt or at and Yes it is the stock boost controller

If you can get a stock air box, put that back on. May be the junk yards would have one.

 

Both my car's have Perrin or K&N filters, lightly oiled. My wagon has had the same Perrin Panel filter since it had about 2000 miles on it, way back in Aug 04.

 

Just guessing, how's the MAF sensor, clean or dirty ?

The maf and the sensor are fine I cleaned it when I did the inlet hose and the shop checked it when it was getting tuned and it was fine

 

Would the stock airbox work with the Avo inlet hose?

Yes.

I wonder if you have a crack in a vacuum hose, that opens under pressure.

 

Can you do a vacuum leak test ?

 

Plug the hose off the air filter with a paint can. give the small vacuum hose off hte BOV a quick blast of air. Put your thumb over the hose, listen for leaks.

Yeah ill def check that out this weekend, but when they did the pre dyno inspection that was part of it and it all passed, but your right it could be possible that with more pressure it opens up

But then again when it was on the dyno under full throttle it wasn't doing it, its like it only does it under lite/ half throttle acceleration and only when it gets to the 10-12lbs rang once it hits 15lbs it smooths out and will hold at 15 and or 16

Can you post a data log. A few guy's here are pretty good at reading them.

 

My Tuner www.tuningalliance.com is pretty good, he is a vendor on here in the Vendor Forum. May be ask him for help.

Wastegate actuator

Can you post a data log. A few guy's here are pretty good at reading them.

 

My Tuner www.tuningalliance.com is pretty good, he is a vendor on here in the Vendor Forum. May be ask him for help.

 

Okay thank you very much ill do a log either tonight or tomorrow am and post it up

Wastegate actuator

 

Hmm didn't think of that with the turbo being new, is there really any way to check the actuator?

Mityvac-see if it holds at pressure or if it leaks down. Stock VF40 is 13psi I believe.

Okay ill check on how to do that thanks for your help

While I'm checking for leaks and the actuator anyone have some more suggestion on what else might be causing this issue?

 

And thank you to who have helped so far!!

So no leaks any where. The actuator was checked out before going on the dyno, spoke with the guy who does all the tunes and he is also the owner of the shop and swears up and down on it being the air flow and how its almost making a "vortex" if you will. So looks like I'm going to try a 73mm intake and custom maff and see if that works

think I may have found the problem but I can not I find any diagram that show were it goes. but its the only thing that is not connected to anything. when I first did the inlet hose nothing was connected to it in the first place, the guy that own the car had taken everything off to do the turbo and given what I have found so far probably forgot about this hose back on

 

this is the only diagram I could find http://legacygt.com/forums/attachment.php?attachmentid=167975&d=1384657978 but I called Subaru and some other tuner shops in the area no one is sure, so what do you all think

http://realmshades.com/car/3.jpg

 

http://realmshades.com/car/1.jpg

 

http://realmshades.com/car/2.jpg

any Suggestion?

???

I think the line 1 from the grimmspeed controller goes to the T on the inlet tube. Where that light green line goes to item (6).

 

Is that what your asking ?

 

Or can you tell us where your open line is coming from ? If you have a picture there, I can't see here at work.

I think the line 1 from the grimmspeed controller goes to the T on the inlet tube. Where that light green line goes to item (6).

 

Is that what your asking ?

 

Or can you tell us where your open line is coming from ? If you have a picture there, I can't see here at work.

 

 

the pictures of what im talking about are in this post, are they not working?