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2G 2g B16g LB/MIN Questions??

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1slowhatch

Proven Member
172
2
Mar 5, 2014
Reno, Nevada
What kind of lb/min are you guys getting on OEM B16g turbos? Mine has been ported on the turbine side, wastegate, o2 housing, manifold ( opened 7 cm gasket, and slight port match @ head). I have stock exhaust except removing the rear most muffler. The intake side is a VRSF intercooler kit, fenderwell intake 3" w/filter.

I have seen a peak of 27.5lb/min on a cool night at 19 psi. Is this right..?? Low???

It seems like the FMIC install did get me a little bit more airflow.. before on 22 psi on a cool night I'd see maybe 26.5-27lb min MAX.

Also, how much power should this be good for? I've heard 1 lb/min is roughly 10 crank HP?
 
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Seems about right to me. Changing air density properties makes exact calculations hard but a B16G practical flow is around 30lbs/min. Pushing may get to around 33lbs/min.
 
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1slowhatch said:
I just ordered one of the $75 15 PSI 16g actuators. I'll report back with hopefully good news (I'll be sad if the $75 is a waste).
Click to expand...

Dstarperformance01 said:
38/40/42 in lbs/min for small/big/EvoIII respectively, IIRC. Something is wrong. 14b has a compressor map of 34/lbs a min.
Click to expand...

At what boost pressure? I'm only seeing 19ish on a cool night, 18 during the day. Will exhaust raise the lb/min significantly? I'm also at a relatively high elevation (very dry air). We are 4500 ft, but air density is usually 6k+during the summer.
 
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Mello said:
Ditch the stock exhaust will help flow & response.
Click to expand...

Yeah, that's next. I've got a 3" down pipe, going to be 3" crush bent everywhere else. 2 straight through mufflers. Hopefully I can get another lb or 2 out of it.

How critical is the air filter setup? I have a 3" 90' elbow and a 6" long cone filter where the stock side mount went.
 
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Intake is probably as good as practical. The cooler air with it in the SM is more than worth hassling with trying to improve the flow. Match your pipe & muffler size. Get a 3 inch instead of 2 in or just do your whole exhaust 2in.
 
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1slowhatch said:
Will exhaust raise the lb/min significantly?
Click to expand...
Absolutely.

Logged lb/min isn't just how well a certain compressor is working on your setup- it's more a reading of how well your setup is responding to a compressor. You're going to see the highest airflow rating the closer you are to sea level as air is less-dense as the elevation increases. A turbocharger helps an engine remain efficient at various elevations as a naturally-aspirated engine will lose a significant amount of power (which it has no way of getting back) as the air becomes less dense where a forced induction engine basically generates it's own atmosphere in a round-about way. However, airflow ratings on compressor maps are calculated at sea level (14.7psi) so if you climb to 10,000ft where the air is far less dense it will effect the turbo's ability to compress air efficiently.

Now regarding the exhaust- every little aspect of the engine's intake and exhaust system effects how the turbo generates airflow and the engine uses the airflow the turbo is generating. So running intercooler piping that is too small, or a tiny throttle body, or a restrictive intake manifold, or a low-duration cam, or too much exhaust manifold restriction, or too small of a turbine housing a/r, or too small of exhaust piping will ALL effect the turbo's airflow numbers. Your guys that are matching the compressor map's highest airflow rating per boost level have their setup on point where the guys that are running the same boost pressure but are 6-8 lb/min lower have a restriction somewhere....meaning the turbo is still generating pressure just fine but the engine's not putting the pressure to use to the point where the load factor is increasing airflow demand.

I could go on and on to the point where I completely lose the majority of those who read this, but your exhaust system absolutely effects the positive airflow the turbo is generating.
 
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JusMX141 said:
Absolutely.

Logged lb/min isn't just how well a certain compressor is working on your setup- it's more a reading of how well your setup is responding to a compressor. You're going to see the highest airflow rating the closer you are to sea level as air is less-dense as the elevation increases. A turbocharger helps an engine remain efficient at various elevations as a naturally-aspirated engine will lose a significant amount of power (which it has no way of getting back) as the air becomes less dense where a forced induction engine basically generates it's own atmosphere in a round-about way. However, airflow ratings on compressor maps are calculated at sea level (14.7psi) so if you climb to 10,000ft where the air is far less dense it will effect the turbo's ability to compress air efficiently.

Now regarding the exhaust- every little aspect of the engine's intake and exhaust system effects how the turbo generates airflow and the engine uses the airflow the turbo is generating. So running intercooler piping that is too small, or a tiny throttle body, or a restrictive intake manifold, or a low-duration cam, or too much exhaust manifold restriction, or too small of a turbine housing a/r, or too small of exhaust piping will ALL effect the turbo's airflow numbers. Your guys that are matching the compressor map's highest airflow rating per boost level have their setup on point where the guys that are running the same boost pressure but are 6-8 lb/min lower have a restriction somewhere....meaning the turbo is still generating pressure just fine but the engine's not putting the pressure to use to the point where the load factor is increasing airflow demand.

I could go on and on to the point where I completely lose the majority of those who read this, but your exhaust system absolutely effects the positive airflow the turbo is generating.
Click to expand...

Awesome. I'm curious to see how much difference there will be.

Do cams make a big difference as well? I would think they be able to extract more airflow from the turbo, but also quickly reach the airflow limit of a smaller turbo (16g. etc).

On a side note, I'm now considering adding a 3" high flow cat to remain emissions legal. Will this be a noticeable obstruction in flow?
 
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Probably. There are different types of cats & dont all restrict equal. If you want a cat that won't restrict get a Vibrant GESi I think model 7803. Flows like having a test pipe.
 
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Just a quick update to this thread. Same turbo/hardware/car... DSMlink, DIY E85 tune up, 1120cc injectors. The boost controller was then maxxed out (about 24psi on a cool night). I was logging about 33 lbs/min max.. which still seemed a little low.

For the heck of it, I pulled the air cleaner off the stock 2g mass air flow and drove to work. My car picked up over 3.5 lb/min just by removing the air filter!??

How is this possible? What time/size of filter should I be running? I was using one of those ebay 6" or so conical ones.. with the filter element in the end. Foam filters?? Cut a hole in the fender well and buy a much longer one?
 
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Vegas smith said:
Damn, that's like 30hp.
Click to expand...

I know, right..!? Is there any way that it's not accurate.. like maybe the mass air's don't read correctly without an air filter restriction?

I just logged 37.1 lbs/min on the way home from work (45 degree air), no changes anywhere..
 
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pauleyman said:
Ebay airfilter. I question those two words together.
Click to expand...

I'm not sure if it's the quality of the filter material.. or maybe the size of the filter.

Do you have a recommendation? I still have the confines of the stock mass air+tubing and a homemade cold air box. I think I might be able to go to an 8" long conical filter. Or cut a hole in the fender and go longer.
 
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So I upgraded to a 6"x9" conical filter brand new, and lost all the airflow, right back to where it was (tops of 32 lb/min). What could be going on here? With no air filter: 36-37lb/min, my tune goes super rich (11's AFR). With an air filter I get 32 lbs/min, goes lean (13+ AFR).
 
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boostdawd said:
Have u tried a K&N filter? The one your using is causing a restriction.
Click to expand...

I'm starting to think the lack of air filter is causing a false airflow reading. Did you read the part about what my AFR's did without a filter? They went very rich... like the MAF is counting air that's not there..

This new air filter I just purchased and put on today, is plenty big enough for someone with a V8 with more power. I have the same style but smaller on my nitrous 5.0 mustang (made 450 rwhp).
 
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