SOCKS_old

do NOT run the pcv and vent to a TEE. go outside right now, and seperate them.. i thought that would be a good idea also, and somehow it ended up getting clogged and pressurized my valve cover, causing my turbo to start leaking from the seals. once i went back to seperate vent lines, had no more issues.

Enthalpy

Assuming you are sure your wastegate spring is actually as low as 7-ish psi, there's something else to consider. As you advance the timing to the appropriate levels, the exhaust enthalpy goes down, which means you don't have boost creep AND you have more power!

If you don't want to go down the ignition tuning road just yet, then a bigger wastegate would fix this issue, once again, assuming you have the correct spring rate.

Yes, a higher-flowing head can definitely increase the size requirement of the wastegate. Sorry, I forgot about this!

As boost increases, the gate size required to maintain boost actually decreases. You are right. The reason? Pressure drop, plain and simple. You have to force more air through the turbine to spin it faster, and you also have a greater pressure differential across the wastegate to play with, so you have a bigger potential waste flowrate.

Turbos definitely take a little bit to spin down. Journals spin down a little faster, but both take 10+ seconds, especially if you have a super fast idle. Obviously, the colder (and thicker) the engine oil, the faster it spins down.

SOCKS is absolutely RIGHT about the PCV! The manifold tap should remain on the manifold. Most PCV valves have a built-in check valve that prevents excessive pressure from reaching the crankcase. Make sure your PCV valve is in good shape and can do this for you. Then, simply run the BREATHER (low-pressure line) to a catch can (if you desire) and then a filter to ambient air (or pre-turbo intake, if you prefer this look).

If you look at the line sizes, the manifold line is usually much smaller, especially inside the PCV valve, when compared with the breather. This is done on purpose. The breather is meant to "make up" for any flow differences going through the PCV valve and ultimately keep the crankcase as close to ambient pressure as possible.

This can only happen if your engine is healthy (minimal blow by) and if you don't do things like tee the two lines together. wink1.gif

tdonnell

Hey there guys,

As far as the tee goes, I still have the PCV valve threaded into the valve cover, then I run the lines individually for about 8", then tee them and run them 1' to the catch can, and from there 1.5' to the breather.

I can't see how this would damage anything really, I mean they are both vents, the likelyhood of them getting clogged seems minimal, must have been your PCV valve socks? My pcv valve is in perfect condition so I really don't see what could go wrong. Worst comes to worst, I will have to run two seperate catch cans and breathers correct? Unless I want to run the vent into the intake piping and get oil in the intake tract and manifold.

This is interesting damon, I didn't know that about timing! Here is a question though, say my timing is 4 degrees retarded from where it could be while keeping the engine knock free (that is likely a favorable amount right? Or no?). Will advancing timing 4 degrees make enough of a difference in the exhaust enthalpy to eliminate my boost creep that begins at 5000 rpm and needs to stay gone until 7500? I don't think it would, but you are the expert so your advice is needed.

As for the replacement gate, should this one do it (LOL)?:

http://www.atpturbo.com/Merchant2/merchant...egory_Code=WGT2

I need to find the external dimensions of that to make sure I can get it to fit, but there are a number of ways to route the gate feed pipe so I don't think I will have a problem.

If that one is WAYYY overkill (which I think it is), what do you guys think about this one:

http://www.atpturbo.com/Merchant2/merchant...egory_Code=WGT2

I REALLY like the v-bands on those gates, and I hope the 44mm will be enough, but the last thing I want is to do all this work AGAIN and still have a boost creep issue. I know the 60mm seems like way overkill, but you can never be too safe. How much more air could the 44 mm flow vs the 38? It IS $200 cheaper so I could save a lot of money and would like to, I just want to be SURE I will have NO boost creep issues.

If I have to comprimise the v-band I could also go with this gate:

http://www.atpturbo.com/Merchant2/merchant...egory_Code=WGT2

But if you ask me, if I am doing that one, I might as well just go with the 60 mm and be super safe. It is only and extra $100 bucks AND I would get the NICE advantage of the v-band's adjustability.

What do you all think in regards to gate size?

And just so you know, above 5000 rpm, I can creep to 8 psi on a .4 bar gate spring in less than a second after mashing the pedal from 0% to 100%, so the creep is more of a slam if you know what I mean. That is really when my engine starts to flow a ton of air. I might try changing my cam timing to help solve the issue for now...

As far as confirming that the current gate spring is 6 psi (.4 bar - 5.8 psi to be exact), the gate opens around 3000 rpm and holds 6 psi all the way to 5000 rpm, and the box has .4 bar written on it from tial (although I got it from ebay, but the head bolts haven't been touched).

I might try for one or two pulls advancing the timing a couple of degrees to see what happens, I am really hoping changing the cam timing a bit will help as well.

But as far as the 60mm goes, I think I am going to run that one, reason being is it is the safest way for me to go to try and prevent boost spikes, it has the v-band flanges and I THINK I can fit it (dimensions - thank you full-race customer service! Opened one up and measured it for me! - 7" long, 4" in diameter at the head, and 5" diameter at the outlet flange area.)

Going with that gate will make sure I don't kick myself in the ass for going with the 44mm and still having boost creep issues saying (I SHOULD HAVE BOUGHT THE 60!!!) LOL.

I know it sounds like overkill, but in my book a little overkill can't hurt in the boost control department. wink1.gif

yamaha

I still can't see why your having crazy boost creep. I run a Tial 38mm with no issues. Where the pictures!?!?! lmao.gif

tanc

Do not T your PVC, you need vacuum. I have mine PVC ---> catch can---> intake elbow. The breather you can do breather ---> catch can---> filter or w/e


Also are you nuts? LOL I say that kindly. A 60mm gate? That is WAY overkill for the size turbo your using. 44m is PLENTY. If your having boost creep with a 44mm gate and 8psi than its not your gate. You have to have smooth flow from manifold to wastegate to dump.

Enthalpy

4 ignition degrees, if you are already a fair bit off the idea timing, can definitely spell the difference between creep and no creep. Making the AFR richer can achieve the same thing.

Don't tee the PCV. It's beneficial to introduce a vacuum source to suck in fresh air into the crankcase. Besides, the tee could provide restriction, which might back-pressure (yes, it's a verb!) the crankcase enough to blow oil seals. Yes, I realize systems used to be made like yours. That's what they call progress. wink1.gif

That 60mm gate was designed for cars that can make HUGE power on LOW boost (read: huge displacement or redline). LOL!

I kid. 60mm is overkill, and overkill can be bad in the case of wastegate sizing. If your gate is so freaking huge that the entire range of control happens with the first 10% of gate movement, then your boost winds up "twitchy" and over-shoots all the time. Setting boost control can be difficult to say the least.

Cam timing can have an ABSOLUTELY FREAKING HUGE impact on boost creep! If you start blowdown (exhaust stroke with valve open) early, then you are WAY over-energizing the exhaust stream! This is a common trick for variable cam turbo cars to introduce earlier boost.

tdonnell

Back again and thanks to everyone for their input!!

I will re-route the lines into the manifold I suppose, I will need to do two more T's though! I don't like running that many T's!

I am going with the 44mm gate. Yamaha, the reason you don't have creep issues is because you are running 18+ psi. I on the other hand are trying to run 6-10, so all that exhaust gas you are using to spool the turbo to get 18 psi must be bled out my gate for me to run less boost.

If I wanted to build the bottom end NOW, then I could certainly keep this gate and be fine running 15-20 psi, but I am not doing that for a while once I have more $$$.

So for now the 44mm will hopefully flow enough to get me to at least 6000-7000 rpm where I can actually capitalize on those nicely flowing camshafts. Speaking of cams, I changed the timing from where I had it 4 degrees retarded and 2 degrees back positive from the start position and it made no difference so sad.gif

I have another issue, the oil smoke/burning coming from the exhaust when I was running 11 psi wasn't from the additional boost. I think the oil in my pan is covering up my drain causing oil to back up in the turbo and get into the exhaust!!! This is very bad for the turbo correct?! I don't want anything to happen to it, it cost too much money! Only when I let the car idle for more than 5 minutes (it's happened twice now), smoke starts coming out the exhaust! I can be boosting 10 psi with NO smoke at all so that tells me when under boost and oil is being pulled away from the drain bung, there is no problem. Someone told me my -3 an oil feed line was too large and I needed a restrictor; I told him that's why I ran it from the head, because the head already has a restrictor for the hla's (what is the restricted pressure BTW?). He told me BB turbos only need drips of oil; frankly I don't see anything wrong with more oil flow as long as the pressure is regulated. This intel is coming from a guy with a journal bearing turbo though, he has never owned a BB turbo in his life so can someone just confirm for me this is BS?

As far as the oil backing up, does it sound like what I described could be the problem? I am thinking of running 1/2 quart low to see if that solves my problem. I am running full synthetic amsoil and will be changing the oil every 3k so I shouldn't have a problem doing that should I? That should lower my oil level about 1/2" or so?? Sound like it will work?

Hey what could I increase my fuel cut to if at all? I am at 11 psi now but was thinking of trying 15 for a couple of pulls to see if my boost will still creep that high from the 6 psi spring in the gate. I am running into the 10:1 range once I get into the 10+psi range so it is definately safe, and I am running just about 0 degrees of timing advance as well so the only issue could be breaking a rod but I doubt that will happen with only a few pulls right? Opinions welcome here please.

I think that is everything, thanks for the continued help guys. smile.gif

Thanks everyone!

I just ordered a .7 bar (10.15 psi) 44mm gate. Since the car has no problem handling that much boost now being that my fuel cut is at 11 psi and I can feather the pedal and keep it at 10 til about 6500 I figured this would re-assure there will be no creep at all after the installation of this gate. Now I can run 1.75" pipe instead of 1.5", it should flow MUCH more air and hopefully ELIMINATE my boost creep issue. The higher spring rate will allow me to bleed off less pressure to get to 20-25 psi as well, damon you mentioned no more than double your gate spring with a BCS bleeding off boost pressure, so I will be able to run 20 psi with no worries. I think that will be the limit of pump gas? I will likely need methanol injection to run upwards of 20 psi without knock right?

As far as the electronic boost control, if I have creep, won't that affect the bleed off of the boost control causing a higher boost level than you should have? Or is creep something you can factor in?


Thanks again.

tanc

You always have essays as your posts LOL. I only have time for one of your concerns, the -3 line. In your earlier posts you state that you have journal bearings now from your last post I'm under the impression you have BB bearings? Anyhow, with journal bearings you can run oil from the head, it won't hurt. There is a bit of a restriction, you'll probably only see 60psi at the head. If your using a BB turbo I would use a inline oil filter with a restriction. I BB turbo's can run on 5-30psi of oil thats it, any more and you'll slowly start causing more harm than good.

Also, if you want your turbo to last longer, esp since it's BB, use a inline micro oil filter with a restriction or get the oil from the oil filter with a restriction. Basically you don't want dirty oil thats been flowing through the motor, and you don't want more than 30psi.

I'll get back to your other concerns when I get some time tomorrow.

Enthalpy

I use a -3 on my journal bearing turbo, and have for years. My nominal pressure is 60-70 in the block, and I directly tap the block. If you have a BB turbo, it's true, you need less pressure. This should be addressed preferably before you go boosting again! This has the potential of hurting internal seals in the turbo.

I love the filter idea. Come to think of it, turbo BBs have more strict requirements in the area of oil contiminants than the engine does anyway.

When you changed your cam timing, I was advocating leaving the intake and retarding the exhaust. Try 2-3 degrees at first to see if it helps.

The burning oil can be explained by excessive drain pressure, but there are a few other evil things that can explain it. One is engine damage. Another is seal damage from excessive oil pressure or excessive EGT (exhaust gas temp) from lack of spark timing.

As far as the oil backing up the drain, isn't the oil sloshing AWAY from the drain during boost, unless you are boosting in REVERSE?

Don't increase your boost to 15 until you solve your issues at 11. You are asking for broken parts.

The limit on pump gas will be determined by careful study of your individual engine on the dyno. The limit is usually indicated by safe timing (which quickly drops off above the limit) and a lack of a regular hp/psi figure being achieved with each bump in boost above the engine's max.

GOOD GOD! You are running 0 degrees of timing at 10 psi?!! There's your creep! You need more timing. I'm staring to like proper ignition calibration for you before you go buying (or breaking) parts.

As for boost control, if your wastegate can handle the boost without the controller, and the addition of the controller brings creep on at higher boost levels, it's 100% your controller. Let's jump off that bridge if you come to it. wink1.gif

tdonnell

I don't remember ever saying that I have a journal bearing turbo, I stated it was a GT3071R and assumed everyone knew it was BB.

I was unaware that 60 PSI was too much. My block oil pressure is 80 psi at startup, and after warm is about 60 psi. I didn't know the head didn't restrict that much!

Something like this would suffice I think: http://www.full-race.com/catalog/product_i...b770b02991a220b

Is there anything I could run at the head connection instead of at the turbo?

Yes oil sloshes away from the turbo under boost, that is why I am saying it doesn't burn oil when under load, only when idling for a long time.

I think my timing is 0 at 15 psi, I need to check, like I said I might try advancing timing a couple of degrees and seeing what happens, either way I will be needing the 44mm gate.

Please don't tell me my oil seals are shot already, how much would it cost to replace them? It requires dis-assembly of the turbo by a specialist and rebalancing correct? I've only got 230 miles on the car with turbo, they cant be blown out already can they?

BTW the 60 psi is revved out to about 6000 rpm, its only around 20 at idle, which has me wondering how too much oil flow can be causing my oil consumption problem since it only does it when oil pressure is at 20 psi?

And as far as the restrictor goes, it seems like since I am running off an already restricted head fitting so I figured the .050" would be fine instead of a .035"?

Here is the .035": http://www.atpturbo.com/Merchant2/merchant...tegory_Code=BCS

Thanks.

Actually, I was thinking of removing the 1/8 NPT to 3 an line adapter off my head, welding it shut, and then drill a hole to any size I want.

Of course I could only get the smaller diameter hole to be about 1/8" long (however deep I weld it), but that shouldn't matter.

What do you guys think?

I like the idea that it is free!