What should I be looking at to confirm increasing airflow to redline? MAF signal?

Doesn't seem to make a difference since you can see that the WGDC is maxing at 100.

Sadly, yes it is. I live at 3200 feet and work at 2500 - so I split the difference

I pressure tested after I replaced my leaky throttle body shaft seals and that eliminated most of the leak - I did notice air leaking out of the tube that connects the head cover to the intake. Also, there is a little hole in my Greddy RS BOV that leaks air like as well - I just plugged it for the pressure test.

I was afraid of that. I have a custom drilled #58 pill in there, but only in the line between the compressor outlet and the T. I don't have the OEM pill in the line between the T and the BCS (previous owner had no pills in the lines). Could that be making the difference?

 

If you are leaking out the valve cover vent, then replace your PCV valve. Under boost pressures, the PCV should be shut closed. The extra port on the Greddy BOV shouldn't leak. Your diaphragm has a tear in it. Airflow is logged via 2-byte airflow data - seach the ECUFlash forum.

 

+1, the only way air gets in the crankcase is one of 3 ways:

• past the piston rings
• past the valve guides
• PCV valve not fully closing

The best way to combat the first two on the list is to make sure the engine is warmed up to normal operating temp before doing your boost leak test and to put your #1 cylinder at TDC.

If the BOV is leaking, the BOV is probably being forced open while boosting, creating your leak. At your boost levels I'm pretty sure you can use a stock MR BOV.

 

What's the easiest way to put cylinder #1 to TDC? Removing the timing cover and rotating the cam gear?

Unfortunately I don't the OEM BOV (bought the car used). I do have a 1g DSM BOV (uncrushed) - I could install that and see if that solves it.

Thanks all for the help so far. I've been tempted to just scrap the whole ECU boost control idea and install my MBC, but I'm giving up yet!

 

#1 cylinder at TDC makes no difference for pressure testing since if 2 of the cylinders are closed, the other 2 cylinders are open. Leakage past ring seals is a very very slow leak (unless your motor is shot and has no compression).

 

I usually pull the timing cover and turn the crankshaft clockwise with a 1/2" ratchet with extension (I make sure the car is in neutral with the e-brake on so I'm not getting resistance from the tranny) until the crank pulley is lined up at TDC with the timing mark on the lower cover. Then I confirm the cam gear timing marks are correct to be sure its at TDC.

An uncrushed 1G BOV should be able to hold that much boost, if not, it will only require SLIGHTTTT crushing to do so. Do you have an aftermarket UICP with a flange on it for the greddy BOV now?

If you REALLY want to take advantage of the ECU controlled boost, step up to a reputable 3 port BCS and you'll be much happier overall.

 

This makes more sense to me - you can't close them all so why close any (at least on purpose).

I do have an AMS short path upper IC pipe, but it's flanged for the OEM bov - so to use the GReddy, I just installed the recirc attachment. I also have the recirc attachment for the 1G, so I can very easily sway the two BOVs.

I was hoping that I could stick with the OEM BCS based on the fact that I'm only aiming for 24 PSI on 91. I suppose it could be a good investment though... what's the cheapest source of these?

 

Having the engine at TDC ensures that either the INTAKE or EXHAUST valves are as close to being closed as possible to minimize the air path towards the exhaust system. And a cold engine WILL have significant blow-by past the rings. I've done hundereds of boost leak tests and trust me, have the engine warm. WHy chase phantom 'hisses' when u don't have to? Plus, I prefer to not hear my compressor turn on twice as often as it needs to when searching for leaks. Every bit helps.

 

Since I didn't have a whole lot of time yesterday to experiment, I just simply replaced the GReddy BOV with my 1G as suggested. Here is the result!



I'll post my log up here in a bit - finally I'm getting somewhere! This weekend I'll look into replacing my PCV valve and see if that helps even further. Thanks all for the help! I actually hit my boost-load limit, so I now it's time to tweak

EDIT: Added Datalog

Could someone help explain to me why my WGDC Correction falls off like? I was under the impression that WGDCCorr was only affected by the BEC table, which I currently have zeroed out. Am I missing something?

 

So it was a leak then. If you open up the Greddy BOV, I bet you will see a tear in the rubber diaphragm.

 

lol my stock BOV was leaking @ 10 psi. hopefully, i will see some more power, i got a HKS BOV in there, car pulls stronger but still untuned

 

Yeah, I plan to crack it open this weekend and see what damage is in there. I can't believe they want $80 for a replacement piece of rubber!

 

Well, the prognosis was correct. The rubber diaphragm of the GReddy was torn a little and folded down on a side, not sealing. Thanks for the help!

 

Not sure but I noticed your scaling only goes to 7000 RPM, same place that the WGDC correction falls off. Plus, you have the % over 100%. I highly doubt that either should be an issue but its the first thing I noticed. Not sure why its correcting if the table is zero'd out.

 

But it's not correcting as his WGDC is still at 100 even though WGDCC is at -25+ and doesn't follow what boost error is reporting.

Sure you are logging the correct item?