Max Vane

[catdiezel]

how much boost are you running on the stock turbo cats. also take a look at the max vane position table for your elevation. this table makes a huge difference in achieving your requested vane position. i hope you are not wanting to get 50 psi out of your stock turbo

WAY too much....I should have clarified what i said alittle more. I see now my last post to be a bit confusing.

What I was trying to say was I am trying to back off ofthe 45psi (this is measured with a mechanical gauge) and if i REALLY want to lay into it I can easily achieve 50+psi. I know its VERY unhealthy. I dont hold it there and it doesnt get there hard, I usually lay into it soft and i can gradually rise the manifold pressure.

The only problem with a soft rise is that once you finally look back down at the speedo its reading close to double the posted limit. LOL



On a side note, I made a few changes, started fresh off a stock tune and THIS time I was in fact able to maintain a NICE and steady 35~lbs manifold pressure. I in fact changed the desired boost down a good bit---even though im making more than its "desire" it worked(I think lol). It wont throw any codes for me either, I turned up the fault rate in the diagnostics to 655 seconds for everything relating to boost/map/maf/ect.



This thread seems to be very informative.!!

Thanks Alot

 

[catdiezel]

I'm not. I feel I have very respectable spoolup. Just always working on something better.

BTW, as an aside, the IOH kit requires 15-24% less vane (factual) to be used for a typical stock boost setting. What took 68% before, now only requires 48%, etc. Steady state, constant load observation.

I cannot open your links to your IOH--bad pages-- feel free to PM me the info...Thanks

 

[Killerbee]

if i REALLY want to lay into it I can easily achieve 50+psi. I know its VERY unhealthy.

I really don't think so. Maybe a gauge issue? I don't think anybody has actually done this to a stock compressor, and admitted it.

Where is your sensor

 

[catdiezel]

Well, Killer--I honestly thought so as well, SO I have two 60lb gauges, one is a old school isspro plain jane and the other is a Autometer PhantomII. Both were very close to each other. I pulled the Isspro out of my ford and install it in place of the phantomII results were basically the same.

Now I DID NOT run both at the same time.


My Boost gauge is installed DIRECTLY after the compressor housing in the ATAAC pipe. I know that it should probably be on the other side of the cooler but I like to see what is going on right at the compressor housing were it matters the most as far as the turbo is concerned. Im thinking about running one on both sides after I determine that they are both accurate with each other. I will put a tap in the pipe right next to the other one. and then make a run with probably my wife watching them lol.

Im not kidding about being able to hit 50psi. I did it once--then did it twice just to make sure my eyes were not reading false numbers. Then did it again with the isspro gauge. The scary thing is I RARELY ever hit 100% throttle most of my testing is done with respect to my stock-for-now allison.

Keep in mind when It was pushing the high numbers I felt Absolute no power gains at all. I know that something was up---I unfortunately was NOT data logging at the time.

 

[catdiezel]

I really don't think so. Maybe a gauge issue? I don't think anybody has actually done this to a stock compressor, and admitted it.

Where is your sensor

....for the record im not proud of it.... But I am never ashamed to post something I did stupid either. And if indeed both of my gauges are wrong i will be the first to admit to it....I am actually headed to Lowes in a minute and will indeed pick up another feral fitting for the pipe to run both at the same time.

 

[beach_33]

dont take offense to it cat. i dont think killer meant anything by it. but i dont think you will find anyone on this board that will advise you that it is ok to run the stock turbo at anything over about 37 psi

 

[catdiezel]

OH no offense taken at all!!!

Im here to learn!! I realize I am near death LOL at 40+ I just re-did my tune, now I am producing too little....somewhere around 30ish WOT. But I am getting it under control.

Thanks for the help!

 

[Killerbee]

no, no critisism intended. What I was trying to say, is that since most attempts to make this kind of boost end up in a memorial service, they might be embarrassed.

50 it is then. But it does make more sense where you say you tapped. Pressure will be higher there than downstream, maybe 5-8 psi (guess) higher at those levels. I agree with your choice of location, it is the only choice IMO.

 

[Killerbee]

As for the LLY from a dead stop mine won't build full boost into more than halfway through second.

would you mind emailing me this log, or posting it here in allowable format, zip maybe. beekiller at cox net

 

[Brayden]

for the purpose of spoolup, not concerned about DP.

Coming from the engineer that seems a bit odd.

Vane angle not only affects the pressure rise in the exhaust but the angle of incidence on the turbine which affects spoolup. At anything over 85% vane position over 1000rpms you're not helping your spoolup any IMO.

Vanes that have a smaller profile can flow well at high vane angles and have an angle of incidence that is right at the tip of the turbine where the moment arm is the greatest.

Brayden

 

[[email protected]]

Hey kb, im the one who just ordered the intake from you and it looks like I will get it monday from ups. Anyway I always thought my spoolup was the slowest thing ever, but then I just started thinking it was normal.

Anyway hopefully tommarow I can get my intake put on, but another thing how much will a dirty airfilter effect airflow? My restriction gauge just started to move to where it is just touching the red zone, but I can't find any AC delco filters around so I guess ill have to go to the dealer. Once I get everything on ill take another log and see what is going on.

 

[catdiezel]

take the top of your air filter lid off and see how it runs then...

You can get a pretty good air filter from Napa for these things.

 

[Killerbee]

Anyway hopefully tommarow I can get my intake put on, but another thing how much will a dirty airfilter effect airflow? My restriction gauge just started to move to where it is just touching the red zone,

at high cfm's it can be tragically reduced. Just depends. Red is a bad thing, and it also ups your turbo shaft rpm. Remember, don't settle for less than the 1618C element. It is reinforced to keep it from getting ingested.

 

[[email protected]]

What do you think of the log?

 

[Killerbee]

The spoolup is not as bad as the zoomed chart above led me to think.

But there is something wrong. If you look at the run from fame 1360 to 1400, 50% throttle, your vane stays at 95% thropugh the end of the 6 second accleration. This is way more than my experience suggests is necessary, but with the lower rpm, it might be correct for having a stock induction mouthpiece. I just don't see numbers like that any more, like stated earlier, they will reduce by around 15-22% after you fix it. MAF looks great, spoolup time is not bad, and you obvioulsy need a lift pump. Other than that I see no issues.

 

[[email protected]]

Ok I got it put on after about 3 hours, I finally had to cut the PCV rubber thing to try to slide it over the hole in the mouthpiece.

Spoolup time seems shortened pretty good, at high rpms I can feel it better as the transmission is shifting harder now which is making me think the trans learned the shifts before the mp and now it has to relearn again. It makes me feel like my stock trans is finnally going to give out now.

What looks wierd in the logs is that from idle to WOT the ecm no longer commands 100% vane but only 75-80% boost looks to come a little quicker but the boost is running away worse. It is going 40,41,42pis when it is only commanding 37psi peak while vane position in these areas looks to be lower.
Boost when the tc is locked looks to be better too but I don't won't to push it to hard in the weak 5th gear with the tc locked.

I wonder if 90-100% vane position in the WOT low boost areas? Maybe a little less timing?
I know I need a liftpump and a transmission but thoes are too expensive.

 

[Killerbee]

...

What looks wierd in the logs is that from idle to WOT the ecm no longer commands 100% vane but only 75-80% .

this is the result of lower compression loads from losing that MP restriction.

If you feel as though you are having a boost control issue, it may be time to replace the MAP sensor. I have a few of these here.

 

[othrgrl]

Start pulling out max and desired vane position to get the boost down where you want it.

 

[Killerbee]

vane position is controlled by controller logic coded in the ECM. Only hard limits (stops) can be defined. You control boost in the desired boost tables. My guess is that is where you will find your overboost problem.

 

[[email protected]]

Before I tried lower the max vane position but never datalogged to see what happend.

Ill try it again, but it dosent seem like that should fix the problem why dosent the ecm see the overboost and start adjusting the vanes more open? But then it seems like opening the vanes would actually make more boost at high rpms high fueling?

So i guess this is where there is a problem because there is no wastegate on a vvt? So is there any way else to limit boost pressure?