944 Performance Idealist Thread ;]

[Craig944]

So many "make my 944 go faster" threads these days, but here are a few ideas that I pondered on the duration of 15hours 30minutes worth of driving I did this week.
1) Cold air is denser than hot air, so could there be a way to have an area of the engine compartment cooled to be very cold and have the intake take from that area?
2) Maybe running tubes from the intake to an area of the car where there is alot of pressure, maybe SOMEHOW running them to cut into the sunroof or something ( i've heard there is ALOT of down pressure on the sunroof ).
-This thread is for thinking out of the box or previous/recent ideas.
-No flames please, if you don't like this, just PM me w/ all your hate please.

[1.2gees]

It's hard to have anyplace too cold in the engine compartment. 2/3rds of the engergy extracted from burning the fuel is transferred into waste heat.

Running long tubes is likely to add more restriction, unless a ram-set up is used. An engine sucks in A LOT of air. Let me give you an example, the avarage car is likely to gain less than 3% supercharging, from a 'ram air' set up put on the hood, with an intake size of the throttle openning, and 0 theoretical resisstance at 150mph.

As for the air being dense on the roof, the air is most dense at the front bumper compared to anywhere on the car, not only that, but a steady supply of high pressure air can be expected at most times. (Unlike wind buffeting at the sides or rear forexample). That is where the factory set up already draws the air from on most models, even on others the intake is placed at a relatively cool/high(er) pressure area of the fenderwell.

There's a reason why all those treads conclude=0, there's no free lunch
Ahmet

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It's all the driver...
My page over1g@hotmail.com
Porsche owners Gallery.../My 944

[Bob's944]

I've been thinking about what you want to do, and think that the pressure collected up by the sunroof would be lost by the time it was channelled back to the engine. My ideas of increasing air to the intake was more focused at the front air dam. There is an area just below the driving lights on my 85.5 NA that looks likes it's made to collect air, but it's closed off and doesn't go anywhere. Here is a pic of where I'm talking about...
The idea would be to drill holes and pipe the high velocity air to the fenderwell where the air intake is, only about 10" or so from the area I'm talking about. It looks like 5 or 6 holes could be made. If you were to get fancy, the whole area looks like it could be opened up, and a custom collector made to rout the airflow to the fenderwell.

[AMCPorsche924Powerhaus!]

I wouldn't spend a lot of money/time on cold air...if it is easy to do and fun, and not much money, do ti, it helps reliabilty, etc.

Performance wise, it is not going to do jack, you would have to have a really cold temperature air to make a real difference...same as turbos, they run at very high rpms, 20000 or something...an electric fan that you make up from yoru cooling fan is not gonna turbo charge your car, only a turbo is...so a freezer would maybe help your performance enough to make a difference, but a freezer is heavy, and draws electricty...
Cold air is not gonna be detrimental, so do it if its easy, but don't expect anythign more than maybe 1HP that you gain only at high speeds since cold/ram air doesn't do anything unless ur at high speeds.

[wolfrpi]

Rule of thumb is 1% horsepower for evey 10 degree change in temp (farenheit).

Air in your engine compartment at idle can be over 150 degrees and maybe more in a turbo. Knock the intake air down to 70 degrees (ambient) by using a cold air intake and you've got 8% more power. Big difference in intial pick up at a stop light (1st gear). But then again these cars aren't supposed to be drag cars lol.

The difference will go away at higher speeds because of airflow through the car.

[AMCPorsche924Powerhaus!]

hmmm...somehow i find that a little fishy,...if i go buy a tube from home hardware and run it off my air intake inlet thing down to say the spoiler near the fog light where the air is outside temperature (say 80 degrees), im gonna get 30 more HP on a 300 HP car?

[Dave's 944]

For a temporary boost you can use an old drag racers trick. They install something called and ice box. the fuel is then routed trough this box. cooling it off before it hits the intake. this cools the entire intake charge down. You could also modify your resevoir to allow addition of ice. Of course this only works till it melts. Not a problem for a 1/4 mile run, and maybe a short autocross. but useless pretty much anywhere else.


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If you drive it, Race it
Dave
'87 944

[Dave's 944]

Ya know bob is i was venting any air from the front air dam. expecially from around the fog lamps. I'd route it to my brakes. Otherwise dont drive through any big puddles if your sucking air from 5 inches off the ground.

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If you drive it, Race it
Dave
'87 944

[ae1969]

....uhmmm you know....my neighbor has a 90 mustang gt.....and he has this KN filter set up........and it does exactly what you guys are talking about...

Except his sticks out of the bottom of the car.....black ugly piece of plastic that gets funnelled up to the intake....he swears by this thing......and the KN filter that is....

Uhmmm maybe I will visit home depot...get some pvc pipe and duct tape.....and a jig saw and hack away... uhmmm all I want is 50 HP anyways...LOL....

But hey...if it gives me 10 HP.....I would be soooooo happppy.....(gotta get one of those G-tech gizmos)!!!!


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

[AMCPorsche924Powerhaus!]

hey Ae, i saw a red 951 at canadian tire yesterday in sherwood park...u don't know who he is do u?
i think it was a turbo because i heard a turbo spooling down, either that or somethign was wrong with the engine.
also saw a gold platinum 944 at canadian tire with one wheel on it that looked like it was off a mazda, a shorter older guy owned it.

[This message has been edited by AMCPorsche924Powerhaus! (edited 08-10-2001).]

[eimkeith]

Bob - a buddy and I are working on a collector for that soon to be vent! (we are using it for brake ducting) That area was definitely designed for an opening...

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keith
'86 951 redNeckarsulm

[Bob's944]

My idea was to simply have that additional airflow enter into the fender where the air intake is located, not necessarily directly to the intake. At high speeds it would add positive air pressure into that space for the air intake to feed on. I was figuring that any water that comes in would drain out the bottom of the fender, maybe requiring some holes to be drilled? The quick brainstorm idea was drilling holes in that area just under the fog lights and glueing some kind of stem in to accept a tube that would travel the short distance to the fender where the air intake is. Drill holes into that compartment and feed the other end of the tube thru it. Might need to have enough excess to point the ends downward in that compartment so water channels out faster. Do that about 5 or 6 times, or maybe make some kind of custom collector and drill the whole area out. I wouldn't expect to get alot of power from it, but i can image that each 3/4" hole at speed would produce about as much air as you could blowing through the tube as hard as you could, them multiply that by 5 or 6 tubes and add that to the way it is already working OK at. Just an idea..

[AMCPorsche924Powerhaus!]

One other thing about cold air and cold fuel and why maybe it doesn't give as much HP gains as the facts say it does (30 HP on a 300 HP car?? i don't think so), is that colder air and colder fuel have tighter bonds in them, less surface area for the molecules to react.
Hotter substances have larger spaces inbetween the molecules, allowing the reaction to occur quicker.

Also, your fuel and air have to get the energy from somewhere that they lost (when u cooled it)to get hot after they explode, so you would need a more powerful spark to explode colder air maybe, and speical plugs...You need to heat the cold stuff up more somehow now, so where are you going to get this extra energy from? your gonna rob your horsepower while doing it, the spark will have to be more powerful and your overall explosion may not be hot enough to burn the fuels off (less combustion, more nburnt fuels, less power) that you were before when you weren't running with cold air and fuel.

NOW, if your engine is already running very hot, then it will help yes.

conservation of Energy; energy is never lost or gained....well new information says it is but the amount is so little that it doesn't matter (ie sound, won't get into it tho)

[Bob's944]

the reason you want cold air is that there is more oxygen in it, more oxygen is more power.... i have a diesel suburban, that principal is very evident in the 'burban, loves the cold air, dog in the hot florida summer. It's the same is gas engines, you just don't feel it as much, but it's definately there.

AMC. me thinks yer drinking to much. I'm sure we all understand your point but did you go to school to learn this. special plugs my a$$

[This message has been edited by el Diablo (edited 08-10-2001).]

[Sergio]

Bob, instead of drilling mutiple holes which will disrupt the airflow with turbulence, why not hollow out the whole space there and use the nice smooth rounded edges that are already on the front of the valance.

[951carter]

it is 1hp per 10 degrees. you would have to lower the intake air 100 degrees to get 10 hp. have you seen the factory solution to cold air on the 968 turboRS? it draws air from a naca duct in the hood.

[Bob's944]

you any good at fiberglass work? make me a custom collector to fit on the back side of the spoiler? hmmmmmmm have it connect to a pvc pipe that travels to and thru the fender and a angle fitting pointing down once inside to allow water to escape.... hmmmmm

[AMCPorsche924Powerhaus!]

no doubt, just like the reason you get a k and n cone filter is for more flow.
that is not the full story. there is more than just flow, there is the other factor of sucking hot engine air into your car.

In this case there is also another factor.
more oxygen but like i said the molecular bonds are tighter in colder air, cold substances don't mix easily they don't blow up as easily (incomplete combustion)...and when your injector sprays gas into your engine, what are you doing? trying to mix air with fuel with a nice spray of fuel...cold fuel will not mix with cold air as well as hot air will with hot fuel!
So with cold air you will get a mixture of air and fuel that isn't mixed as well, and with hot air and fuel you will get a mixture that is more unified.

im just repeating my previoius post in different words, point is that there is drawbacks with cold air, and that is why you may only get 1HP rather than the theoretical 30. In certain situations, like hot running engines, cold air is much more efficient, becase they are hot running engines.

[MAS]

Um... correct me if I'm wrong... but don't we already have a form of cold air intake already? In my 87 924S the intake is at the far left hand bottom corner of the car. Is this not a cold air intake? (I know that this is what the RX7 guys call a cold air intake)

-MAS