VERY Low Airflow at WOT

[4G63 For Me]

Mods are in profile.

I'm seeing around 30 - 31 lbs/min of airflow with DSMLink at ~24PSI, which seems extremely low for this setup. I have a stock 2G intake manifold and stock unhacked 2G MAS. I don't understand why my airflow is so low (even considering my altitude is ~5000 ft). Is there something I'm missing? Any guesses as to why it's so low?

Thanks in advance for the assistance.

 

[Dan7040]

Thats definitely too low for your setup. I have a B16G and its flows ~30 and my altitude is pretty much the same. If you PM me your log I can take a look and offer some advice. You should also try posting this over at www.dsmlink.com/forums if you haven't already.

 

[4G63 For Me]

Would this more likely be a monitoring issue or an actual airflow/component issue? I guess that's what I'm confused about. I can't fix something if I don't know WHERE it is broken.

Would a boost leak and/or intake leak cause low airflow?

I posted some logs over there. I have to get some more, though. Tonight I maxed out at 34lbs at 22PSI.

 

[Dan7040]

Would this more likely be a monitoring issue or an actual airflow/component issue? I guess that's what I'm confused about. I can't fix something if I don't know WHERE it is broken.

Would a boost leak and/or intake leak cause low airflow?

I posted some logs over there. I have to get some more, though. Tonight I maxed out at 34lbs at 22PSI.

It could most likely be a combination of things. Most likely you do have some boost leaks. So make sure you test the intake tract. You may also have a leak in you exhaust manifold (either where the manifold bolts to the head or the turbo). Is your WG sealing all the way (granted it may or may not reduce airflow # depending on the severity)? Timing? A/F Ratio? BOV leaking boost? All of these component need to be in check to recieve good airflow numbers. As I mentioned before anyone of these may not be the sole problem especially with such a high flowing turbo such as the GT-12. Its more likely a combination of things. A log will give a better picture.

 

[4G63 For Me]

I will start giving all these things a look at. But if the airflow is metered at the MAS, then why would a leak AFTER that affect the readings? Am I misunderstanding something?

Here is a log from last night on DSMLink forums. I don't know how to post them here.
http://www.dsmlink.com/forums/showthread.php?s=&postid=32441#post32441

Thanks for the help, Dan

 

[Dan7040]

Yes the airflow is measured at the MAS, but the problem is most prominent if you had a leak in your exhaust manifold. I would give extra attention to your exhaust side of the engine (Wg and manifold gaskets). Any significant leaks here would result in less then average airflow numbers and decreased spool. I would really like to see what your fuel values, timing, and A/F looks like in your log, but for some reason I keep pulling an error message when opening. Ill reinstall DsmLink tonight and see if it will work then.

 

[4G63 For Me]

That makes sense. I will check the exhaust manifold area and bolts. They LOVE to come loose (I usually end up finding them LESS than finger tight), and it probably doesnt help that I have to have a spacer between the manifold and head just to be able to BARELY fit the turbo in. Spool up is quite slower than I expected so I won't be surprised if this is (at least part) the problem.

Thanks for the suggestions. If you have more trouble opening the log after you reinstall, let me know and I'll relog or repost.