Who you calling fat?

 

screw the milkshake, gimme a BIG MAC!

 

I want a Baconator.

 

Now here's the other caveat, an N/A engine that is not seeing any boost won't take in more air than it needs. Meaning, wherever the greatest restriction is, be that TB, intake manifolds, the air filter, or heads, that is what the engine will breathe.

I do not yet know if the filter is the point of greatest restriction. If there is enough surface area on the filter to cover what the 50mm TB can pull in at WOT at it's peak HP RPM, then a larger filter will not help.

K&N used to have a CFM per square inch of filter somewhere on their site but I can't seem to find it right now.

F&B claims that the stock TB flows about 635 CFM @ 25" and their 50mm TBs flow 760 CFM @ 25" . I would guess the Fastman 50mm I have won't outflow that.

Ray has a 318 in a '92 Dak R/T with ported heads, a 1.97 intake valve, M1 2bbl, Fastman 52mm and a Hughes HER1418AL cam. He obviously has the potential to flow way more than me. If he's not seeing losses, I doubt I will. However, I am trying to be as diligent as I can about checking.

 

Well, I contacted K&N about their filter.

Here's what I wrote:

Hello,

Is there any data on on the CFM flow of the K&N filter E-1100? This filter should be a stock replacement for the 92-96 Dodge Dakota 5.2L engine.

I am trying to figure out what it flows @ 25" H2O as a comparison to the reported CFM of throttle body I currently run that has been flow benched @ 25" H2O. I thought this data used to be available on your site, but I cannot seem to find it anywhere.

Also, is there a rough estimate of the CFM at a specific pressure per square inch of your filter material, or does it vary by filter style?

Thanks,


And the response:

Thank you for your interest in K&N products. Our filters are tested at 1.5” H2O restriction, and your filter, E-1100, will flow 479.49CFM at that level of restriction. By my calculations, your motor requires around 440 CFM (assuming a 6000rpm redline), and around 400CFM (assuming a 5500rpm redline).

If you have any further questions, please feel free to contact our customer service department at 1-800-858-3333.


Thank you,

Matt Smith
Product Specialist
K&N Engineering, Inc.
mattsm@knfilters.com




I'll have to hit him up with the real specs to see what he says. I think my email left him thinking I owned a stock '92 Dak.

 

I am gonna try to find something to where i can have the filters just after the scoops. THen I can keep the air hat empty.

I am working on a few ideas that do not involve spending $200 on filters that go inline with the ducting. Damn spectre.

 

If you have filters pre-hat, you have make absolutely sure that everything post filter is perfectly sealed, or you risk unfiltered air/tiny debris going straight into the TB. Not a good idea, IMHO, given the hat's snorkel construction.

 

Here was a second response:

The conversion from 25” H2O to 1.5” H2O isn’t a straight linear conversion (and I don’t know what it is off hand), but the logic behind restriction and air flow is fairly straight forward. Imagine sucking a soda gently through a straw. The soda will flow slowly up through the straw until it reaches your mouth. Now imagine sucking the soda very hard. It’s going to move much faster through the straw. That same logic applies to flow rates of air filters, throttle bodies, carburetors, and cylinder heads. A restriction rating is essentially the pressure drop created across a component given a certain amount of air flowing through the component – the pressure differential between your mouth and the soda cup. The higher the pressure drop created, the higher the restriction, the higher the CFM rating. The lower the pressure drop, the lower the restriction, the lower the CFM rating. If you were to rate our air filters at 25” H2O restriction, they would show a lot more airflow. Conversely, if you were to rate a throttle body at a lower restriction, it would show less air flow.

Our air filters are tested at a lower restriction and guaranteed to provide the specified CFM rating at that 1.5” H2O restriction, so the throttle body (or cylinder head) is going to be the point of restriction in your application. Our air filter, part number E-1100, will flow more than enough air for your needs.

Please let me know if there is anything else I can do for you.

Sincerely,

Matt Smith
Product Specialist

 

I can easily get the 14x3 in the hat. THere is about 1/8 inch of space between the lid and the lip with the 14x3 in there. If I put some weather stripping around the rim of the hat, it will seal perfectly.

No issues. I will use a 14x3. Also good...I can swap to my mopar air cleaner if there is heavy rain and I am on the HWY.

--Dan