special plugs to make it worthwhile, diablo.

It is similar to saying, ok, let's all go for a run at -40 degrees ferenheight....there is more oxygen in the air, correct?

But your lungs will have a very hard time pulling this oxygen out of the cold air, and the drawbacks are limitless! u freeze your ass off too.

Of course you're not going to get 30hp. The air from the stock inlet is not going to be engine bay temperature. You might get 5hp though, which could be worth it considering the cost is pretty low. You might also lose power if the temperature/flow gains are not significantly better because there are some benefits (which i cannot explain) to having an airbox especially on NA engines.

only in a closed system, which an engine operating in an atmosphere is not. Every time you put gas in the car you are adding "energy" to the system http://www.pelicanparts.com/ultimate/smile.gif

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'86 951 Graphite Metallic/Tan

I have to agree with AMC.....cold is good.....but not too cold.....

It can be flippen cold where me and AMC live....and you know...I have not seen an the extra 8% in HP from the cold winter air.....

Although I must admit....in the cool summer mornings ...the car does seem quite peppy.......and if I have been driving around for awhile in a hot day....my car feels like its dragging its ASS.....

uhmmm...how about we run an air conditioning coil over the intake.....that way I will turn my A/C on and get another 10HP LOL....and a 12 volt fan....that could run at about....uhmmmm 20,000 rpms...

ALex


P.S. AMC: yah I have seen the red 944 turbo around.....only in the mornings when I am coming into sherwood park......there is another pharmacist in the park....he has a 356 convertible.....nice one....but doesn't drive it to work....Haven't seen the gold one around....

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http://www.alta.net/944/alexs944na.jpg

86' 944
79' 924 (R.I.P)

Well, you probably are getting about 8% more in the winter if it's 80 degrees colder (won't be quite that much of a difference at the inlet since the engine keeps the area warm). You've got an NA, so 150hp base. Standard for measuring that is around 70F? (I know there's a standard but don't remember what it is.. dyno operators?). Lets say it's 30F out.. 4% difference, 6hp. Are you really going to be able to tell 150hp vs 156 when you're freezing your ass off? Or 150hp vs 144 when you're sweating to death at 110F? Probably not. Now, ask someone with an 800hp SupraTT if they can see a difference in there strip times between january and august.

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'86 951 Graphite Metallic/Tan

Remember also that having any type of cone filter pretty much negates any type of ram air set up unless the cone is in an air box that is sealed so that it can build up pressure. Air is simply a fluid, and will take the path of least reisitance. We use ram air on our race bikes by making sure that the air box is sealed. But you also have to understand that to build up ambient pressure, you need to be ramming air faster than the carbs or throttle bodies are pulling it in. On our GSX-R's @ 12 to 15,000 rpm the throttle bodies are pulling air in at over 90 miles an hour, so ram air only increases HP above this speed. Running a intake from the front spoiler will bring more air into the enigne bay, but without ducting to keep it where you want it it will simply pass around and through.

no no no no, i was talking about the cold gas and air...you require more enenrgy to get it up to the temperature that goes out the exhaust pipe...requires more energy

sergio is right about the closed system thing..

I would put a tube thats open and then ram it into a cone that is enclosed, or a square filter...

it's not only the fact that air takes its easiest path, its the harmonic waves that happen in the system, drill holes in your exhaust pipes and headers, and you will lose horsepower, just as you will lose hp if you ram air into a tube that faces a cone filter, but isn't a closed system...drill holes in your air box, lose hp.

Err.. I don't think so.. The colder/denser fuel/air mixture will release more energy when it combusts. You are not heating it, you are compressing and then combusting it. Because it starts out denser, when the cylinders compress it you will have more air molecules. Just like increasing compression.

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'86 951 Graphite Metallic/Tan

Which may be even more beneficial since it will lower engine bay temps, right? You get cooler running and longer life of the rubber bits in addition to any sort of additional power. I don't think anyone's looking for ram air benefits since no one spends the bulk of their time accelerating into tripple digits.



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'86 951 Graphite Metallic/Tan

I am absolutely loving this. Keep up the arguments guys many many good points are being made!!!!!! - Would it be smart to convert my car to work w/ a cone filter?
I think it'd be to exposed myself and get to much moisture or heat from the engine...

I think some of you guys missed something in Chemistry/Physics 101. There is NO more O2 for a given MASS of cold air vs hot air. Note that mass (not the Catholic type) is a physical property of a substance used when gravity is factored out. Add gravity and presto- weight. (Ever wonder what the English unit is for mass?? Stay tuned.) When a substance is heated, the energy causes the molecules to vibrate more rapidly, causing them to be further "apart". The converse is also true, remove enough heat energy, and the molecules slow down, allowing them to stay closer together. This effect continues until molecules get close enough to form a liquid and you begin to precipitate out liquid N, O, He, Ar, and so on. Also called a phase change. The reason that colder air produces more hp is that for a given VOLUME, there are more O2 molcules per volume to support combustion. (See Boyles Ideal Gas Law P1T1V1=P2T2V2.) Like most processes, you can reach a point of diminishing returns because of the volumetric efficiency capacity for a given displacement and design. Therefore 10deg=1%hp is NOT a linear function. The "Cool Can" that dragsters use works somewhat as does NOS. NOS works partly on the same principle of colder=more dense, in addition to other factors.

Craig- your only real options here are to:
1) NOS on your 944na
2) Chevy power
3) Get a 951
4) Turbo or Super charge your 944na
If you do a $/hp analysis, the 951 will usually win, even though there is a lower cost for NOS, it has some drawbacks. There are benefits to drawing cold air when you can, less stress on the engine cooling system for one. Go ahead and try a cool can with dry ice instead of water ice, that way, there's no water mess to deal with. Let us know how you do.

Dave951M
The rest of the story- the English unit of mass is the --- slug

Cone filters are good as long as you can supply fresh air to them. You've heard of all of the complaints about replacing the standard box filter with a cone, it ends up suckin hotter air and that defeats some of it's free breathing advantages. I've seen K&N cones that are located in the nose of the car, just in front of the hood and between the 2 headlights that require their custom plumbing and are alittle pricey. It would go inside there... in front on the hood release..http://www.pelicanparts.com/ultimate...nose plate.jpg

Ok, so the only disadvantage with cold air/fuel then, is that the fuel and air do not mix AS thoroughly and unified, so you don't get as efficient as an explosion in the engine.

IT wouldn't be true if fuel was in the air already and we didn't have injectors.

I remember reading an article in- I think it was Hot Rod magazine, where a couple of guys were experimenting with refrigerating the intake manifold. It seemed to have worked to a point when the dewpoint of the mixture was reached and the fuel started to condense on the intake runner walls. If there has been any other research done along these lines, it would be interesting. Anybody ever hear of this?

Dave951M

Well, that must have been a carbuerated car. Wouldn't happen on a fuel injected motor since the only thing flowing through the intake manifold is air.

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'86 951 Graphite Metallic/Tan

yup only in a carburated, or your cold start valve wouldn't work when the car is cold, because the manifold is cold lol

WEll with injectors it is very important to have the fuel spray evenly, and with cold fuel and cold air it is harder for the fuel to uniformly mix for the most effecient combustion.

BTW how do turbo cars' injectors spray fuel in properly if they are sprayign under pressure that the turbo has created??just a higher pressure injector?

Injectors on turbocharged engines are no different than those on NA engines. It's easier to think of what the turbocharger is doing in terms of flow as opposed to pressure in this case.. it's working the same as a NA motor just with greater flow into the cylinder. It still mixes fine because the air flows by the injector as it is spraying no differently. You would have the same effect if you increased the displacement of the NA motor.. more air being forced into the cylinders. The injector doesn't care whether the flow is from the cylinder pulling air or a turbocharger pushing it.

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'86 951 Graphite Metallic/Tan

My 2cents would be to simply forget about the cold air induction and hust route the air from those lower vents onto the engine block since these engines seem to run hot anyways...energy is never destroyed but changes forms....and dave951s right no more oxygen in cold air than hot air...-chris http://www.members.aol.com:/fty9999/...ftypelican.jpg



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"Faster,Than,You"
"Wish I had a 951....."
"Ive tried so hard and got so far but in the end it doesnt even matter"
http://www.members.aol.com:/fty9999/944land/944land.htm

You guys need to start reading some more car rags. Try SCC or Turbo for the latest on hp improvements with cold-air intakes. I believe Hot Rod TV tested a C5 vette and got almost 20hp from the FIPK K+N filter kit. They had a dyno there while they were doing the mods. To install the FIPK they cut out the air filter housing underneath the front of the car. The C5 probably has around 330 hp stock. So 20hp more is beleiveable if the temps are lowered accordingly. Believe it or not guys cold air makes a big difference. Do searches anywhere on the web and you'll find that 10 degrees colder increases output by 1%, not 1 hp. If it equated to 1 hp, my 5 hp briggs and stratton motor would vary from 1-10 hp depending on the temperature!

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Erick

86 951

http://www.pelicanparts.com/cgi-bin/pmpre/pm.cgi?action=display&login=aka_951

There's no debate over cold air helping to make more hp, just some misconceptions as to why and the point that this is not a linear function. Any way you can lower intake temps is beneficial- to a point.

Dave951M