The head actually has a lot to do with the blow by in that it is the relief point for the excess pressure. as the pistons create pressure that escape past the rings the excess pressure finds it's way throught the block an out the only way it has to go, the valve cover. This is never more important than when your pushing high boost.

when you made the 240 number how long did you drive on it? the reason I ask is becuase like I said before with the MINI ecu you don't command boost, you comman "load" albeit not my favorite style effective none the less. however I noticed that when you tuned for max eff. we would have the problem of hitting boost cut. This is because it was a cold day with the fans blowing on the car when we tuned and as it would get to be less optimal conditions the car would require more boost to hit the same "load" thus pushing us past 20 psi and into boost cut.

Tuners (like Jan I suppose) can turn off the boost cut feature, however this can be sketchy as it requires the car to rely solely on it's requested load numbers and disregards boost levels. this is a problem because it's like tuning old ALPHA-N cars, a real shot in the dark.


The G-pop turbo was quoted at right around 300. This is a safe bet seeing as the same turbo that comes stock on the audi tt's has been proven to right around those numbers.

I guess I am just curious as to what a setup like yours have could really go to. The bottom end you have is probably able to hold close to 500 with out to much worry. If you had a snail, induction path, and fuel system sorted out to support it you could probably flirt with the low mid 4's with out to much hassle. I just want to see someone go for it.


Cheers!

 

Your head theory still doesn't quite make sense to me. Weather the head be stock, or have oversized valves, during the compression stroke and power stroke the valves are closed. It won't make more or less blow by depending on wheat head is on the car. That all has to do with piston to wall clearance. Could you clarify what you are talking about?

Lets see I got the tune in October, 2011 and drove it till December, 2012 so probably about 10k with no boost cuts.

Trust me I want to find out too. There are 2 WRC cars running the same block as our cars have so there is potential. One day when I have a real job and another daily driver I will work on the mini more

 

I think you're doing fine so far finance wise as far as how much you've thrown at it. I personally would purchase a second vehicle if I was trying to take on the mission you are though.

 

I was saving up to buy a Ducati since last summer. Only reason I was able to do this.

 

You know I was thinking to myself earlier today weather or not we were on the same page. I even intally started to explain my self when I wrote the first response but stop thinking that I had explained my self well enough. my apologies.

A stock head has an in-direct effect on pcv emmissons. due to the fact that in order to make any useable power your going to have to crank the boost. As with the theroy of a straw if you want to blow x amount of cfm through a straw you either have to make the straw wider, or blow harder.

seeing that you haven't made your straw (cylinder head flow) any bigger you will have to crank up the boost. this is what I meant about a stock head. sorry for the confusion.

what was your orignal tune on Jan or AP?

 

Ah yes, the stock head will have an effect on the fluid dynamics. Will it make more blow by? Probably not. I'm only boosting like 8 lbs. We were thinking of blow by in two totally different ways.

Well I had ap then jan tuned it

 

Sorry for the poor grammar/spelling it was during a long day's work.

forget I ever mentioned anything about the head it is all irrelevant. either way I look forward to the rest of the build.

 

Thanks a head is next on the list.

I suck at spelling and grammar all the time, don't feel bad.

 

Talked to the turbo shop and they said that the turbo was completely within spec, and looked good. Receiving oil and all that good stuff, and that that amount of shaft play was normal for a single journal bearing type turbo. Not believing them I talked to a few other places and having some side to side shaft play is normal. The oil pressure is what makes the bearing and shaft not move during operation. Anyway, They are going to replace all the bearing and seals and send it back to me.

 

I talket to Garrett and Borg Warner and they say for the single journal bearing system we have in our turbos having shaft play on a dry turbo is completely normal. When there is oil in the system is essentially "squeezes" the bearing and this keeps it stable during operation. The cold clearances are larger due to thermal expansion of the metal as well creating more play when cold then when at running temp. I still don't think that mine was within spec. But it is good to know that some shaft play is expected with this system.

 

Thanks, that is really useful information to know

 

Did you get the turbo back? Having better luck with it this time?

 

Yeah I got it back a few days ago. It's on the car. I haven't pulled of my intake tubes yet to check for oil. An I happy? Sure I would rather have a double ball bearing turbo but its not that big of a deal

 

So I am no longer leaking oil out of the compressor housing. Now its coming out of the exhaust housing. I am going to hook up the stock PCV system and see if that fixes it.

 

Hope that solves your problems.

 

It probably wont. But I will give it a try. It didn't do it before the only variable is the turbo.

 

Here's a long-winded explanation of what I've just finished doing for a similar problem. I plan to start a new thread on the subject in a couple weeks, after I put some more miles on it ---

My original OCC install consisted of the catch can connected to the line feeding the turbo inlet, nothing else. This means the hose from the valve cover to the intake manifold is still in use. After several months of driving with the OCC, there was still no oil showing on the OCC dipstick. After seeing several online posts with pics of their catch, I did some research.

According to the Bentley manual, the line to the turbo is used when manifold pressure is “under load”. The line to the intake manifold is used during “deceleration or idle”. Since most of my driving is not under load (I use a lot of cruise control), the OCC wasn’t getting used. So, the question is, should I cap the manifold line, or route it to an OCC? Because of cost and ease of installation, I took the cap option. Bought two vent caps from my local Audi dealer, part number 036131510, removed the hose, and installed them. Didn’t take long to catch oil in the OCC. Peugeot also sells them as #0361.S4, and ECS Tuning sells them online, all for about $10 each. Hard part is figuring out how to remove the hose without breaking it. Once you see how the vent cap is designed, it’s pretty easy to figure out.

After a couple tanks of gas, I noticed crankcase oil level was down a quart. This is the first time this has happened - this engine hasn’t burned oil in the 20K miles / 2 years I’ve driven it. First guess is crankcase pressure is forcing oil past the valve stems into the combustion chamber. This implies the vent plugs I just installed messed things up. So, I ordered a Dual Boost Tap, bought some hose and a “tee” fitting, and connected the other valve cover outlet to the existing OCC. While in there, I disconnected the turbo air inlet hose for a quick look. Worst fears realized --- oil puddle in the air chamber!

Made a couple calls about turbo repair / replacement. One shop that knows Garrett turbos, told me that high crankcase pressure can cause oil to “backflow” thru the turbo oil drain line, and cause the symptoms I’m seeing. Resolve the high pressure issue, and the oil consumption problem will go away. Then there’s an oily mess to clean up --- from the turbo outlet to the intake manifold. This is several months after the initial OCC install. I’ve created the very mess the OCC was installed to prevent!

After reading some of the various threads on OCC’s, oil consumption, and bad smells, it’s my guess that they have a similar problem --- 2 vent caps installed, or a dual boost tap adapter connected with the plug installed.

I still don’t understand how this adapter can read boost when it’s connected to the crankcase / valve cover vent line. Maybe if installed at the manifold end of the hose and then plugged, but I don’t know what’s happening inside that “control box”. So much to learn ---

Hope this helps.

 

I just wanted to give you a quick reply. But I can explain the boost tap to you and my issue is actually opposite of yours. I'll go into detail when I get off work

 

First the boost tap. I think that is what you referred to as the "control box" anyway it is just a sealed pice of aluminum. If you hook up the manifold line then you would be able to get boost from the tap. None of the gasses would go either way through the BHS part because it is solid.

I do have the two back ports blocked off and have had them like that for at least 20k and never had an issue. Maybe with the new turbo the tolerances are not as tight as when the turbo was stock or my oil pressure is higher then before for some unknown reason. I am going to return the PCV system to almost stock when I put on my new intake and see what happens. Oh yeah I got a new intake. It looks like it gets most smokey when boosting so we will see what happens.

 

My "control box" was referring to the throttle body --- where the vent hose connects. There must be a valve of some sort inside it to keep high boost pressure out of the valve cover area. So when this valve is closed, how does the boost tap read boost pressure?

My throttle body vent connector is capped with the Audi vent cap. My BSH Direct Dual Boost Tap (#20201102) has the two small side ports blocked, with only the main center opening in use. It's connected to the passenger side, rear-facing PCV vent, with a hose running to a "tee" in the "traditional" OCC inlet connection to the turbo air inlet. Eventually, I'll update the photos in my "garage" --- verbal descriptions just don't cut it!

 

Let me try this again --- back-pressure from the crankcase can cause the turbo oil drain line to flow backwards --- into the turbo compression chamber. Having the rear, passenger side vent capped can create enough back-pressure to cause this.

Before investing in another OCC or "tee" connection, try reconnecting the hose to the vent and just dumping it under the car --- without connecting it to the throttle body. No blocked vents!

Mop up the oil residue in or near the turbo, then monitor that area after a few runs to check for oil again. Just watching for smoke at the exhaust is futile until all the post-turbo lines have been cleaned.

 

I don't think it would work that way. The oil pressure is anywhere from 40 to 70 psi, where the crankcase, with a functioning PCV system is going to be at a slight vacuum to zero psi.

the oil drain from the turbo is not going to flow backwards. Yo can easily test if your PCV system is not operating, just take the oil fill cap off of the head cover, when the engine is running and put your hand over the oil fill hole, you shouldn't feel any pressure.

Dave

 

I agree with you - oil pressure should exceed crankcase pressure. I was surprised to hear the turbo oil drain line is gravity feed. The following is an excerpt from my emails to a garrett dealer / repair shop ---

"The way that the OCC affects the leak is it can prevent proper crankcase ventilation. Because the crankcase can't vent, the pressure is trapped in the crankcase and rises. As excessive pressure rises, the pressure actually goes up into the oil drain hose up into the turbo. Remember oil is trying to gravity drain/drip out of the turbo via the drain hose back into the crankcase. If the crankcase itself is resistant and "blows" pressure up into the drain hose, the incoming oil inside the turbo bearing housing has nowhere to go, but leak into the housing(s). It's by design.

The good news is, only the "forced" oil is in the housings and nothing is blown or damaged. If you resolve this plumbing issue, the problem (and leak) will just go away. You do have to clean off or burn off the oil residue though."

Maybe this is unique to Garrett, or maybe they don't want to mess with a repair job? Hard to believe the leak is coincidental with blocking the 2nd vent. More likely blocking the vent caused the leak. At any rate, I'll find out for sure after I drive it for awhile.

 

Ok, I dont know what you two are trying to say. Oldbrokenwind, the valve you are referring to is built into the valve cover. So if you have the BSH part in, that valve is already blocked. Now for the rest of what you said I am fully aware of how the PCV system works. I did a write up from my inspection and information Czar has provided. It is in this thread. My complaint is simply with the stock turbo I was not burning any oil with the back ports blocked off. Now I am and it is coming out of my exhaust. So I am going to return the PCV system to stock and see if that solves the problem. For our turbos we don't actually have "seals" they are more like piston rings.

 

I have a G-Pop turbo with a blocked off rear PCV system and also had a problem with oil consumption for a long time. Now that I think about it I do believe it started after blocking off the rear PCV. I plan to vent the rear under the car as I have the front to see if this helps. I wonder if venting to the exhaust might be an option for us using something like this.