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Is a BHAF really better?

1181 Views 8 Replies 6 Participants Last post by  illflem
Found testing that someone had done.
Decide for yourself.
Coolest intake temps (dark blue) are from a mod described here http://www.cumminsforum.com/forum/general-diesel-discussion/127696-modify-stock-airbox.html


from http://www.psmdiesel.com/prod.php
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It may be cooler air but will it flow as much air as some of the aftermarket intake systems. Both temp and amount of air is important
the way i see it, temp of the air don't really matter too much on our trucks because of that big a$$ thing in front of the rad that cools down the intake air after the turbo.....



which one is the BHAF on this?:confused013:
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the way i see it, temp of the air don't really matter too much on our trucks because of that big a$$ thing in front of the rad that cools down the intake air after the turbo.....



which one is the BHAF on this?:confused013:
Not true. The intercooler is a constant for both cool and warm air, meaning it reduces the temp about the same regardless of air temperature, so your have an advantage to feed it the coolest air possible.

Cooler air is denser air so it is more volume for a given CFM rate. Restriction becomes an issue for a stock air filter at higher HP/Tq numbers because it requires a specified CFM of air to create those HP/Tq numbers. I'm not sure what the max CFM a stock air filter is, but it is considerably higher than most people think. The best set up would be a cowl induction BHAF so cold air can be ingested through that massive filter.

ps... That graph is from PSM. I have that setup on my '98. Cruising at highway speeds it bumped my MPG by about 1. Reduces IAT about 100 degrees across the board.
which one is the BHAF on this?
Red line on the top.

It may be cooler air but will it flow as much air as some of the aftermarket intake systems.
You are 100% correct but how many folks here are putting out enough hp where they even come close to maxing out the flow of a stock airbox style filter?
whats psm air filter?
Not true. The intercooler is a constant for both cool and warm air, meaning it reduces the temp about the same regardless of air temperature, so your have an advantage to feed it the coolest air possible.

Cooler air is denser air so it is more volume for a given CFM rate. Restriction becomes an issue for a stock air filter at higher HP/Tq numbers because it requires a specified CFM of air to create those HP/Tq numbers. I'm not sure what the max CFM a stock air filter is, but it is considerably higher than most people think. The best set up would be a cowl induction BHAF so cold air can be ingested through that massive filter.

ps... That graph is from PSM. I have that setup on my '98. Cruising at highway speeds it bumped my MPG by about 1. Reduces IAT about 100 degrees across the board.
Where are you measuring this? My Edge JwA tells me my intake air temp and I rarely see that number more than 20* warmer than the temp outside. If I reduced my IAT by 100* my IAT would be 20* when it is 80* outside!
BHAF good for volume/flow but junk for the cool dense air our engines want.
Where are you measuring this?
Think he meant EGTs.
Your 20° number is right on, the intercooler does an excellent job but the airbox mod lowered my egts about 100° also.
Probably because of denser air.
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