Airflow limits of various components

[Calan]

I started doing some research for a document I was thinking of putting together, and surprisingly there isn't a lot of specific information that I can find. (maybe I'm just not looking in the right places...I dunno. I'm getting old).

What I'm looking for is max airflow information for various components, in lbs/min. (nice standard unit that everyone is used to). I'd like to come up with something that shows things such as "2.5 inch IC piping will flow x lbs/min.", for example. The goal here is to provide a reference that can be used to determine when components may start to become a restriction as airflow is increased.

For a lot of these, there may not be a practical upper limit, or at least not one that has been found. In that case, I'll just go with the highest number that has been supported with good results. So for example, if someone flowed 79 lbs/min while running the FP race exhaust mani, that's what we would use for it. Please note that I purposely left max airflow for turbos off this list...that discussion could (and has) gone on for years. This is just for related components of interest.

Before I get flamed, I understand that there is interaction and countless factors at work here. Please don't over complicate this; I'm just trying to get some ball park numbers to look at.

Anyway, if you have solid lbs/min numbers for any of the following, please post it up. We don't need opinion or hearsay...just numbers that you have seen (and logged), or a link to these numbers. Please feel free to add any components I missed that may be of interest (Please make them bold if you do).

Copy the list from the post immediately above yours and change any numbers that you have data for that are larger than previously recorded (that you can back up with a good log in case someone calls BS. ). I'll get it started with a typical airflow (38lbs/min) on my current 16g setup. The values are in red to make them easier to see, so just make any changes between the font tags. Once this has run for a while, I'll compile the data and post it up somewhere.

BTW - If this already exists somewhere, well...then nevermind.

EDIT:

Please do not post any numbers unless you are sure that airflow was fairly accurate and is repeatable. This isn't a contest; we're just trying to get a feel for how much airflow different components have supported.

 

[Calan]

Note: All listed values (in red) are in lbs/min of airflow.


Air filters

1). Typical 5" K&N cone type: 38
2). 5" x 10" cylindrical: 0

Turbo Inlet Pipe

1). 2.5" ID: 0
2). 3.0" ID: 38
3). 3.5" ID: 0
4). 4.0" ID: 0

Exhaust manifolds

1). Stock 2G: 0
2). Stock Evo III: 0
3). FP Race: 38

O2 Housings

1). Stock: 0
2). Stock (ported): 0
3). Stock EvoIII: 0
4). Stock EvoIII (ported): 0
5). MAPerformance Recirculated (ext gate): 38

Downpipe

1). 2.5" ID: 38
2). 3.0" ID: 0
3). 3.5" ID: 0
4). 4.0" ID: 0

Exhaust

1). 2.5" ID 0
2). 3.0" ID: 38
3). 3.5" ID: 0
4). 4.0" ID: 0

Mufflers

1). Stock 1G: 0
2). Stock 2G: 0
3). 5" x 14" Magnaflow: 38

LICP

1). 2.5" ID: 38
2). 3.0" ID: 0
3). 3.5" ID: 0

UICP

1). 2.5" ID: 38
2). 3.0" ID: 0
3). 3.5" ID: 0

MAS

1). Stock 1G: 0
2). Stock 2G: 0
3). Evo 8 MAF: 0
4). 3.0" GM MAF: 38
5). 3.5" GM MAF: 0

Throttle Body

1). Stock 1G: 0
2). Stock 2G: 0
3). Ported 60mm 1G: 38

 

[mike96]

just curious where you are getting your airflow numbers from, are you using a flow bench of sorts?

edit: ok i see where you are going with this or rather where you are getting your numbers from if i am not mistaken... basically what i am looking in your post is basically the max airflow for the setup you are running as of right now... example would be bone stock car, if you were to log your bone stock car and were getting say 30 pounds of air flow that would be the max airflow someone would expect to get across the board. now if you took that same car and say changed out the stock SMIC for a FMIC and were now logging say 32 pounds of air than that's basically what you could expect from a FMIC. correct?

 

[Calan]

just curious where you are getting your airflow numbers from, are you using a flow bench of sorts?

I wish.

This is just logged airflow, assuming a pretty well calibrated tune of course.

I'm not looking for any empirical scientific data here, as that would be way beyond what most (or any) of us have access to. This is geared more towards fulfilling a statement like "A stock O2 housing has been used successfully on a setup that flowed 65 lbs/min", or "Nobody has logged 90 lbs/min on a stock 1G ehaust manifold". While this type of info is scattered all over these and other forums, I haven't found it all in one place and organized in this way.

It's mostly just for my amusement at this point, but there may be some useful info to come from it.

As another example, if you have logged an accurate 50 lbs/min and are running a 3.5" downpipe, copy the list and change the 3.5" downpipe entry to "50" ...since that is larger than the previous value. Do this for any components that apply to your setup and that you have flowed more air on. If your particular piece isn't listed (different muffler for example), add it!

 

[turbosax2]

Note: All listed values after colon are in lbs/min of airflow.


Air filters

1). Typical 5" K&N cone type: 38
2). 5" x 10" cylindrical: 0
3). Stock: 0
4). 4" K&N cone type: 39

Turbo Inlet Pipe

1). 2.5": 0
2). 3.0": 38
3). 3.5": 0
4). 4.0": 39

Exhaust manifolds

1). Stock 2G: 39
2). Stock 1g: 0
3). Stock Evo III: 0
4). FP Race: 38

O2 Housings

1). Stock: 39
2). Stock (ported): 0
3). Stock EvoIII: 0
4). Stock EvoIII (ported): 0
5). MAPerformance Recirculated (ext gate): 38

Downpipe

1). 2.5": 38
2). 3.0": 39
3). 3.5": 0
4). 4.0": 0

Exhaust

1). 2.5": 39
2). 3.0": 38
3). 3.5": 0
4). 4.0": 0

Mufflers

1). Stock 1G: 0
2). Stock 2G: 0
3). 5" x 14" Magnaflow: 38
4). Tanabe 2.5" G Power Medallion: 39

LICP

1). 2.5": 39
2). 3.0": 0
3). 3.5": 0

UICP

1). 2.5": 39
2). 3.0": 0
3). 3.5": 0

MAS

1). Stock 1G: 0
2). Stock 2G: 0
3). Evo 8 MAF: 0
4). 3.0" GM MAF: 38
5). 3.5" GM MAF: 0

Throttle Body

1). Stock 1G: 39
2). Stock 2G: 0
3). Ported 60mm 1G: 38

 

[99gst_racer]

Note: All listed values after colon are in lbs/min of airflow.


Air filters

1). Typical 5" K&N cone type: 38
2). 5" x 10" cylindrical: 0
3). Stock: 0
4). 4" K&N cone type: 39

Turbo Inlet Pipe

1). 2.5": 0
2). 3.0": 47
3). 3.5": 0
4). 4.0": 75

Exhaust manifolds

1). Stock 2G: 39
2). Stock 1g: 0
3). Stock Evo III: 0
4). FP Race: 38

O2 Housings

1). Stock: 39
2). Stock (ported): 0
3). Stock EvoIII: 0
4). Stock EvoIII (ported): 0
5). MAPerformance Recirculated (ext gate): 38

Downpipe

1). 2.5": 38
2). 3.0": 75
3). 3.5": 0
4). 4.0": 0

Exhaust

1). 2.5": 39
2). 3.0": 38
3). 3.5": 0
4). 4.0": 0

Mufflers

1). Stock 1G: 0
2). Stock 2G: 0
3). 5" x 14" Magnaflow: 38
4). Tanabe 2.5" G Power Medallion: 39

LICP

1). 2.5": 75
2). 3.0": 0
3). 3.5": 0

UICP

1). 2.5": 75
2). 3.0": 0
3). 3.5": 0

MAS

1). Stock 1G: 0
2). Stock 2G: 0
3). Evo 8 MAF: 0
4). 3.0" GM MAF: 47
5). 3.5" GM MAF: 0

Throttle Body

1). Stock 1G: 75
2). Stock 2G: 47
3). Ported 60mm 1G: 38

Intake manifold

1). Stock 1G: 0
2). Stock 2G: 47
3). Magnus street 2G: 75


Valves

1). Factory diameter: 75
2). 1mm oversize: 0



_____________________________________

I'll try to add more later when I can find time. -P

 

[Calan]

Now we get some numbers that mean something! (Glad to know I'm covered on my TB and ICPs)

Thanks Paul

 

[99gst_racer]

No problem, Craig. Neat idea, BTW.

 

[Calan]

No problem, Craig. Neat idea, BTW.

Thanks...now if we could just get more people to jump in...

 

[Boosted98gsx]

Thanks...now if we could just get more people to jump in...

Just like with electronics, you can squeeze 20,000 amps through a 14 ga wire, you're just going to get a little heat in the process.

Just because someone has squeezed a compressible fluid through an orifice, doesn't mean it was done efficiently. You will NEVER see a "Max" airflow through an orifice until the airflow hits the speed of sound (becomes choked). Even then, you can always increase airflow through a choked orifice by increasing upstream pressure.

 

[Calan]

Just because someone has squeezed a compressible fluid through an orifice, doesn't mean it was done efficiently. You will NEVER see a "Max" airflow through an orifice until the airflow hits the speed of sound (becomes choked). Even then, you can always increase airflow through a choked orifice by increasing upstream pressure.

Yeah I know, which is why I said:

Before I get flamed, I understand that there is interaction and countless factors at work here. Please don't over complicate this; I'm just trying to get some ball park numbers to look at.

Come on Andrew...work with me here and play along.

 

[Boosted98gsx]

Yeah I know, which is why I said:



Come on Andrew...work with me here and play along.

I'm not over complicating, I'm informing you that you will NEVER see a limit to the airflow of these components. Someone could put a 1000 lb/min turbo on their car, and a 2g throttlebody would flow 500lbs/min (if it could stay on the car and not detonate).

It's not about flow capabilities, it's about impedances (how much each component restricts maximum possible flow) for your argument.

 

[Calan]

Ok... so has anyone flowed 500lbs/min while running a 2g throttlebody? That's what I want to know. If so, then there would be no reason for anyone to ever upgrade their 2G TB (from an airflow perspective anyway), and there would be a lot less discussion about bigger TB's and port jobs.

However, if the highest airflow we have for a 2G TB is 45 lbs/min (just throwing a number out there), then maybe I would start asking questions about my 2G TB if I was planning on making more than 400whp with it.

I know what you are saying, and I understand that the effectiveness of each component needs to be considered in reference to it's effect on the related setup. Unfortunately, I can't think of an easy way to collect data from a large and varied source of setups while doing that.

I'm going for the approach that if someone successfully put together a 500whp car and stayed with a 2.5" downpipe (again just tossing a number out), then a 2.5" DP is probably good for around 55-60 lbs/min (or whatever they flowed to make that power).

Flawed? Somewhat.

Usable info? Maybe

 

[bjones18]

Interesting topic. Even if you could get data from guys getting x.x lb/min using a 2g TB, I'm not sure others would use the data correctly. You and others have identified the flaw in this venture. I compare it to my "old neigbor" who estimated his Firebird at 410HP because he added up the HP gains advertised by the companies from which he bought products. I didn't bother trying to inform him.

Besides CFD modeling different system restrictions; maybe the best way estimate this is to look at OEM flow for different vehicles and look at the respectively sized components. They optimize their systems with mutiple engineering groups. The red hering would be commonization of components between different models.

I know a guy who made an outstanding estimater of vehicle cg height based on - basic vehicle architecture and dimensions from road & track magazine (some measured/scaled with a ruler!)