Here's a copy of the email I sent / received from K&N.

-AR

Dear customer,
I would not worry too much about air temp. If you isolate the filter
too much, you are no different than stock. It is also possible to locate
the filter in a place where it can be susceptible to water ingestion. Cool
air accounts for only a small horsepower gain. Adding a heat shield (cold
air chamber) to some of our kits raised the horsepower gain by 0.5 % This
is great if you are racing and need every advantage possible for that extra
tenth of a second but in everyday use, it is not much. Once you are moving,
there should be plenty of outside air entering the engine bay. Air flow
gives you the ability to deliver more fuel and this is what makes power. A
few months back 4 Wheeler magazine did an article on intake air temp vs.
horsepower. Our FIPK had the highest temps but also made by far the best
horsepower gain. As it has always been know, volume is more important than
air temp when it comes to making power, ask any racer, NASCAR is a perfect
example. In fact, temperature is not even considered when calculating
horsepower. The formula is:
Atmospheric pressure x compression ratio x volumetric efficiency x cubic
inches x rpm / 150 / 5252. Our filters and kits increase the volumetric
efficiency and therefore increase horsepower.
Thanks for asking, Rick

> ----------
> From: JAC/<AL[SMTP:arobbins@mail.liberty.k12.mo.us]
> Sent: Thursday, October 12, 2000 3:55 PM
> To: tech@knfilters.com
> Subject: Open Elements vs. Cold Air Intake
>
> Hello, I have a 2001 F-150 4.6L V8. I belong to a message board,
> http://www.150online.com Their has been a lot of talk about open element
> filtration (FIPK), and cold air intake (stock setup.) It seems that many
> guys are turning in their FIPK's and going back to the stock setup, with
> some mods that we have come up with. (Replacing the restrictive 1 3/4"
> snorkel with a 3" snorkel, and removing the 2" "air silencer" inside the
> "throttle body box.") I guess I'd like to hear your thoughts on the FIPK,
> vs. modified airbox's with no smaller restriction than 3". It seems as
> though the colder air, is worth the sacrifice of greater, warmer, air.
> Some guys have put a "real time" thermometer near their FIPK's, and the
> filtered air temperature is amazingly greater with the FIPK than with the
> stock setup. I always replace my stock filter, but I question the use of
> an FIPK for all setups. True, the FIPK replaces the whole stock setup,
> which is very restrictive, however, I feel a properly modified stock setup
> using cold air, is the better option, especially in warmer climates. I
> think K&N should offer stock airbox modification parts, while utilizing
> the cold air intake. I greatly appreciate any feedback. Thank you.
>
> -AR
>

------------------
2001 F-150 XLT 4X4 Off-Road, S/C, FS, Black
- 4.6L Triton V8 (Romeo, 20 HP Increase)
- 5 Speed / 3:55 Reg. Axle
- Keyless
- Premium Audio CD
Mods.
- K&N Cold Airbox / Throttle Body Mod.
- Flowmaster 40 (Stock Setup with 3 1/2" x 10" Gibson Tip)
- Cranked Torsion Bars
- Bugshield
- Bedliner
- Ventshades
Build Date: 8/23/00 (Kansas City Plant)

arobbins@mail.liberty.k12.mo.us

 

Should be just the opposite man. Also, the colder air has more molecules in a given area than warmer air does. Not arguing the point, it's just a pretty well-know topic around here, and everyone seems to say that colder air is better. I like hearing all opinions on this topic however.

-AR

 

Right on Jackal dude,
Lower air temps will produce more power by volume than warmer air. Any time you compress air you generate heat. This is why intercoolers are used in conjunction with turbos and blowers, to get a cooler more dense intake charge.

However, I do belive that the sensors on our trucks calculate air temp and volume when computing ratios and timing.

On antique vehicles, with carbs, I could allways feel the difference when it was cooler outside. The older tricks with ice buckets and shaker hoods should not have that much of an effect on the new breed of sensor controlled performance.

After all, both fresh air (not cold air), and open filter devices get their supply air from about 3 feet up from the highway. I feel comfortable saying the difference in temperture is not great enough to outweigh the difference in sheer volume that the open filter provides. Not to mention the ease of draw.

Course dats just my pinion.....Ah could be wrong.

------------------
Terry Deaton
99 F150 XLT, 2WD, 4.6, S/C, S/B, Superchip, K&N FIPK, FMS 9mm, +4s, Nerfs, Leer Top, Cow Catcher W/Bright A$$ Lights, True Duals with hi flow cats, 275 Dunlops with 3.08 gears, fat swaybars, Steeda front and Hellwig rear. Coming soon: Fabtech 3" and 4.10s.
96 SVT COBRA
98 AERO
Speed Kills, drive a Chevy and live forever.

[This message has been edited by TREADMARKS (edited 10-13-2000).]

[This message has been edited by TREADMARKS (edited 10-13-2000).]

 

Ya know, I'd really like to run an open element, but when I did, I really wanted to run modified. I wish there was more solid evidence to prove one way or the other. I bet FIPK takes the cake in most conditions, but on a hot summer day on Texas, I'd much rather have a modified airbox.

-AR

 

jayf, another very good reason you're getting better mileage in the summer is that the gas in winter is modified to lower emissions (this also lowers the energy content, lowering your mileage and power).

 

K&N e-mailed me basically the same information. They said that their system (breathing hot air) vastly outperformed any cold air/factory intake mods. A person that I trust stated the K&N or Airaid adds 12-14 HP. These are not my opionions, just FYI. I won't even bother responding to the cold air issue..lol

------------------
2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
Class III tow/Payload #3/Convenience pkgs.,
4-wheel disc/ABS,Chestnut/Parchment 40/60,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification, Superchip,
Dynomax ultra-flow welded 3" cat-back,
3" exit Y-pipe, Hellwig rear anti-sway bar,
Rancho RS9000s.

 

Strictly from a thermodynamic standpoint, I would think it more efficient to have warm air entering the intake the cold, you don't waste energy heating it up. Real life tends to support this theory, since I get better gas mileage in the summer than in the winter.

Just my $.02,

Jay

------------------
1998 F150 Lariat 4x4 Extended Cab. 4.6L Auto
Mods: Superchip
Planned: Airforce One

 

If you compare the change in density of air (1atm) from 0°C to 80°C with the change in enthalpy (h) over the same temperature range you’ll find that its enthalpy increases approximately 50% faster than its density decreases. I guess that’s why we pre-heat rather than cool the air entering the boiler at the power plant.

------------------
'00 5.4L 4X4 Lariat (Black/Silver)
'99 Ranger 4.0L 4X4 XLT

 

Cool air is great, but it seems like volume is the ticket. From tests I have seen, the FIPK or Airaid type setups gain from 7 to 12 HP.
When I was stationed in Okinawa, Japan, there were a lot of modified cars using sidedraft carbs. Many (if not most) of them used an open velocity stack, or one with a screen. The intake point was only 8-10 inches from the block.

 

Been in the Boiler Business for over 20 years, we have over 500 Boilers/HTHW Generators on board base with the largest being 20,000,000 BTU HTHW Generators, absolutely none preheat air before it enters Boiler, some do preheat FeedWater but not Air.

------------------[list=a][*]All Black 2K F-150 XLT[*]5.4 Auto, 3.55[*]Super Cab, BedLiner[*]Class III Tow Package, Rear Slider[*]Keyless Remote, Cruise, A/C, CD Player[*]Tinted Windows[*]Bug Guard[*]Black Step bars[*]Billet Custom Grill[*]K&N Filter,Air Box Modified & inlet increased to 3" from Fender[*]Flow Master Force II Exaust with Single in, Dual out Behind rear Wheels[*]Stainless Hide-a-Hook Tie downs[*]HellWig LP 25 Overloads[*]Front & Rear Color Matched Light covers[*]Dash Cover[*]SuperChip[*]White Light Fog Lights(remote controlled)[*]80/100 watt white light Headlights/Smoke covers[*]Still on to do list: Electric Fan(s) Rancho 9000's,American Racing 16 X 8 Baja's,Snug Top or Tonneau,B&M Shift Kit[/list=a]

 

Gee, lets not muddy up the waters any further. HAHAHAHA!!! Well, it seems as though the warmer air is favored this time around, last time, it was cooler air. GO figure.

-AR

 

Well, we only have 14 units (80MW~180MW) but all of them pre-heat the air entering the boiler. They have a large steel mesh drum (half in the path of the inlet air, half in the path of the exhaust gas) that rotates, thereby exchanging heat between the exhaust gas and the inlet air. Another thing, for the power cycle, if you increase Delta T, T(hot) - T(cold) you increase the efficiency and therefore the power produced. In the winter when the outside air is much colder T(cold) is significantly lower, therefore increasing efficiency. There probably isn’t as much difference in air inlet temp, summer vs. winter, due to all of the heat transfer occurring as the air enters the cylinders. So why do superchargers come with inter-coolers? Mostly to avoid pre-detonation. If the air entering the cylinders has too much energy the fuel will ignite prematurely.

------------------
'00 5.4L 4X4 Lariat (Black/Silver)
'99 Ranger 4.0L 4X4 XLT

 

And another thing, I guess that 20,000,000 BTU/hr sounds like a lot but that’s only 5.86MW. Our smallest unit is 80MW, our biggest almost 200MW, and that’s nothing compared to some utilities that have in excess of 500MW units.

------------------
'00 5.4L 4X4 Lariat (Black/Silver)
'99 Ranger 4.0L 4X4 XLT

 

Considering there is actually no such thing as "cold", only an "absence of heat", which is denser?

180 degree air or 100 degree air?

Technician A says 180 degree air.
Technician B says 100 degree air.
Technician C says they are the same.
Technician D says it doesn't matter.

Which is right?

------------------
BLOWN 4.6 5-speed

Where we started.
After a facelift.
Latest MOD!

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crash@f150fanatic.com

MAGNACHARGER
ALLEN





[This message has been edited by crash1 (edited 10-20-2000).]

 

Allright, guys!

Is anyone going to give it a shot? It's a typical ASE certification test question.

I am leading up to something here...