Short Ram (Warm Air) Intake?

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chubbusket

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Hello, this is my first post on the forum. I know enough about engines to get myself into trouble, but I am not an expert by any means. I did some searching before posting but I didn't really find an answer to my question.

The vehicle in question: 1997 K2500HD, 5.7L V8, 4L80E

I just got it last year I am currently stripping it bare and rustproofing the frame. Unlike most trucks in the northeast, it is relatively rust free and I want to keep it that way.

When I started searching for information on short ram intakes, what I found was threads about cold air intakes and people who were concerned with getting more power. I'm not going to venture into that debate, since my question is the opposite. I would like better fuel economy, not power. The 4.10 gears already use enough gas as it is. My thought is that having the air filter pretty much right off the intake manifold will probably lose ~10hp, as compared to the fancy airbox that goes into the fender, for some efficiency gains.

The reason I am considering installing a different intake is that I want to remove the stock airbox and use that location as a place to attach a plow motor and pump. I live in Maine. It gets very cold. Having a warm air intake will probably help some with fuel economy when I am plowing at ~0F, right? I already tried mounting the plow motor where the "storage box" sits above the windshield washer reservoir but it didn't work very well last season. There just isn't enough room in that area for the valve body and hydraulic lines without interfering with the serpentine belt or all of the other gadgetry.

Mostly, I am looking for opinions as to what potential negative EFI impacts this might have, and whether or not it is just a really bad idea and I should try something else.

Thanks.
 

454cid

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I thought the motors were mounted right on the plow frame outside the truck?

Your idea sounds like a bad one, to me.
 

LC2NLS6

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So far from 0F to 85F outside air, my open element air intake on a hot engine only sees about +30F change in air temp in the throttle body. I wouldn't worry about it.
 

b454rat

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You need cold air, regardless. The colder the air, the better it will run, and, and, will get better mileage.
 

chubbusket

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I thought the motors were mounted right on the plow frame outside the truck?

Your idea sounds like a bad one, to me.
Nice plows have motors on the plow frame. I bought an old plow that came with a beat up 1995 K2500HD with a broken frame around the leaf springs for free. When I was looking crappy plows were around $1k and that was what I paid for the combo deal. The nicer plows also have harder to find push plates and the wiring harness will set you back even more if you can even find it. So I am using the same plow setup on this truck and the motor / pump / valve body go in the engine bay since it is cable actuated and not all electronic. Hopefully not a too long story. And thank you for the input that you don't like my idea. I just wish there was more room in the engine bay. I guess I could always try the firewall somewhere.
 

chubbusket

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You need cold air, regardless. The colder the air, the better it will run, and, and, will get better mileage.
I have considered a cold air intake just to save space but I frequently use my truck in high water so that really isn't an option. Thank you for your opinion.
 

JeremyNH

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You need cold air, regardless. The colder the air, the better it will run, and, and, will get better mileage.
Nope. The ECM maintains an optimal AFR for engine speed. Colder air means higher density air means more fuel necessary to maintain a constant AFR. That's why motors are more powerful in the winter but by consequence less efficient. With regards to the OP though these aren't particularly efficient motors to begin with and they're in heavier vehicles so likely you won't see much of a difference in either performance nor fuel economy. I don't see why it wouldn't work to draw air direct from the engine bay if you know what you're giving up. Just make sure whatever you do that you keep all air intake going through the MAF else it will run very poorly. This includes keeping the PCV intake after the MAF.
 

454cid

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Nope. The ECM maintains an optimal AFR for engine speed. Colder air means higher density air means more fuel necessary to maintain a constant AFR. That's why motors are more powerful in the winter but by consequence less efficient.

I believe that's what the IAT sensor is for.... to determine air density by calculation from temperature.

Also, mileage goes down in the winter becasue of winter blend fuel.

...This includes keeping the PCV intake after the MAF.

It's not in the valve cover on small blocks?
 

PlayingWithTBI

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Colder air means higher density air means more fuel necessary to maintain a constant AFR.
Yes, to a certain extent. You can also run a higher SA when you have lower IAT (Intake Air Temps) without detonation. With speed density (MAP) systems it won't compensate enough for higher temps, MAF can help somewhat. What you need to look at is air flow compared to temp. If your OE cold air set up is constricting flow, you may be losing performance/efficiency. I have yet to see any data which shows temp vs flow peformance. In my TBI with speed density, I do see loss of power in 100* plus ambient with full flow 14" filter but, don't see it in the winter time, ~70*. Some day I will compare it with the OE CAI which has to go through a little snorkel (red arrow) behind the right turn signal housing.
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JeremyNH

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The OP isn't asking about how intake air is measured or controlled only whether he can take it direct from the engine compartment vice the fender well and, considering that the SBC took intake air from the engine compartment for most of its' very long life, the answer to that is yes. He will lose some power due to drawing warm air. Theoretically he would gain somewhat on fuel efficiency but real world it won't be seen. I put a Volant CAI in my 1998 K1500 5.7L since it was supposed to be the best available and from my experience there was absolutely no change in either power or fuel economy. With regards to the PCV intake on Vortecs (OP has a 1997 5.7L so same as mine) that comes off of the TB elbow into the passenger side valve cover. Exhaust is into the intake manifold via the drivers side valve cover. He just needs to ensure whatever he does that the PCV intake remains after the MAF otherwise it will run like it has a vacuum leak.
 
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