Cold Air Viper intakes-Its a no win

[GR8_ASP]

So, is someone going to use that handy dandy temperature sensor that is built right into the airbox to ascertain the difference in inlet air temperature. A check at a few higher speed points with similar ambient air and coolant temps would suffice. I am betting on less than a 10 degree F difference ( I am betting on a 20 degree delta T across the radiator when at speed). Worth in the neighborhood of 5-10 RWHP, but only due to the temperature. No ram effect at Viper speeds.

But, since it is so easy to measure the temps, why are we speculating on a web site? Just make a few measurements and post the results. The horsepower effect can quickly be calculated once you know the temperature difference.

 

[Newport Viper]

Stop it Ron! You are trying to take the fun out of this!! LOL!!!

 

[vipah]

Ron, keep reality out of this. The people posting here clearly want to buy and sell based on potential, not fact.

You may be infringing on my magic HP bean sales to Devildufus and the good people of Texas.

 

[REDSLED]

This thread is so funny. Reminds me of when I was 5 years old. What good is any Viper mod if it's put on "Garage Queens?" LMAO Where did I put that "Ferrari wind breaker?" I sure hope this thread gets put to rest soon. Aren't we all on the same team?

 

[joe117]

jrkermode,
I'm standing by the article.
You say the air isn't moving but the car is moving. I don't understand why that is going to change anything.

Testing is often done in wind tunnels. If it made any difference what was moving, that wouldn't be valid data.

Your claim that,
"pressure on the nose of the car can be greater than the prevailing atmosphereic pressure"
Has no basis.

If you disagree, tell me why.

 

[jrkermode]

Joe117,

The vetteguru article is basically a detailed description of Bernoulli's equations of a closed system where the air has a fixed amount of energy which it can possess as Pressure or Velocity. The article further describes how trying to increase one of these must result in a decrease of the other. This is absolutely correct, in a closed system. However, the case of a moving vehicle or a wind tunnel is not a closed system.

A moving vehicle's engine, or the big fan in the wind tunnel, impart additional energy into the system. So, now you actually can increase Pressure or Velocity beyond prevailing atmospheric levels.

Think of it this way. A supercharger or turbocharger does not change the prevailing atmospheric conditions around the car, but they certainly change the intake pressure on the motor. That works because the supercharger or turbocharger is adding energy to the air. The motion of your car can do the same thing, only not nearly so efficiently.

If you want to prove it to yourself, it is actually quite easy to do lowbuck aero testing. Just make a manometer using a yardstick and some vinyl tube. Tape the tubes to your chosen sampling sites, fill the U-tube with water and off you go.

 

[joe117]

I don't think the manometer you speak of would give clean results due to air flow over the end of the tube.

The air going over an airfoil increases velocity and the pressure drops. That's an open system isn't it? That's Bernoulli.

 

[jrkermode]

An airfoil at a fixed speed is actually a closed system. There is no net flow of energy into or out of the system.

In the case of ram air, the vehicle is adding more and more energy to the system because it is accelerating. So, at rest, the most pressure the car can get is ambient. At speed, it can get higher pressure air thanks to the work being done by the car.

There is no question you must be careful with tube placement when doing the el cheapo windtunnel routine. That is why it is usually referred to as "tufts and tubes". Where the tufts are little strands of wool used to confirm the direction of flow near the tube (you want the flow perpendicular to the opening on the tube).

P.S. I noticed in your sig, you have a vette. Are you vetteguru?

 

[joe117]

No, I'm not.

 

[Mike Brunton]

An airfoil at a fixed speed is actually a closed system. There is no net flow of energy into or out of the system.

In the case of ram air, the vehicle is adding more and more energy to the system because it is accelerating. So, at rest, the most pressure the car can get is ambient. At speed, it can get higher pressure air thanks to the work being done by the car.

There is no question you must be careful with tube placement when doing the el cheapo windtunnel routine. That is why it is usually referred to as "tufts and tubes". Where the tufts are little strands of wool used to confirm the direction of flow near the tube (you want the flow perpendicular to the opening on the tube).

P.S. I noticed in your sig, you have a vette. Are you vetteguru?

The "ram air" effect is so negligible it's irrelevant compared to ambient temperature, etc.

There *may* be a handful of horsepower to be had at high speed (like above 100mph), but at any sort of speed you will see on the street - even on the highway, you're not going to see anything that will be noticeable.

Furthermore almost all "ram air" systems are designed entirely the wrong way, and don't give any sort of "ram air" effect.

having said that, I don't know whether "Vipair" works or not - it's not meant to be ram air, and I do think that cold air induction is certainly a benefit over sucking in hot air. It seems that the test that was done is entirely valid (Russ's test), but he didn't test vipair, so the only test we do know of Vipair showed it worked pretty well.

 

[BigCarrot]

http://www.prestage.com/Car+Math/ET+and+Horsepower+Calculators/Correct+ET+To+Standard+Conditions/default.aspx

This might help with the temperature argument.

 

[Anthony - 98 GTS]

All I know is if you are relying on an air intake to make your power you are SLOW - period!

Please stay at home and stick to the Zaino posts.

 

[scottgf]

I would still like to know what the formula,
or actually what the answer is,
to how much does the air temp have to drop to gain 10 hp....
Cheers,

 

[jimandela]

my vipermed airbox and vipair part will arrive tomorrow.
i will install it on my nonSC car and let you know what seat of pants results i get.
sorry i have no access to a dyno for before and after ...
I love the looks of there product and not having a rain baffle has to be good for
at least some gain!

great thread the bickering made it fun

 

[GTS-R 001]

From the Kennebell.net website in FAQ

------------------------------------------------------------------------------------------------------------------------
What is the most ridiculous aftermarket product? Right there on the list has to be those "underhood exposed filters" that **** in 200° underhood air instead of ambient (70°-100° air from the fenderwell). 10° air temp rise is -1% HP. That's how dynos are calibrated for temperature changes. Does anyone really believe that all those OEM manufacturers designed expensive plastic inlet systems - for the last 20 years - that pull cool air from the fenderwell, hood or grill because they didn't have anything else to spend their money on?
------------------------------------------------------------------------------------------------------------------------

Therefore .45 ( 45% airflow from under hood )x 120 degree difference = 54 degrees increase in intake air temp from the stock airbox over the VIPAIR™ based on an ambient outside air temp of 80 degrees

Therefore if 10 degrees equals -1% then this equals -5.5%, therefore .055 x 435hp (Average viper with simple bolt ons)= 24 hp savings with VIPAIR™ ( theoretically speaking, based on Kennebell ( James Bell's ) thinking.

 

[phiebert]

Re: Cold Air Viper intakes-Its a no win

I just put one of those K&N cone filters under the hood on my Durango and pulled out the front rubber deflector in front of it. It definitely made a difference. The rubber deflector removal allowed cool air under the hood and the K&N filter put right against the hat on the intake allowed much easier access to air than the 40 miles of tubing it had before. So I'd debate whether the comment ' "underhood exposed filters" that **** in 200° underhood air ' are bad is valid. The air isn't 200 degrees under there when your moving at 60+ mph! Put a temp probe under there (see my earlier post) and you'll see.

 

[GTS-R 001]

Re: Cold Air Viper intakes-Its a no win

Patrick,

On the Gen 2's the Naca duct flows 55% of the intake air and the remaining 45% comes from the sides of the stock airbox which ***** in hot under hood air. People have been asking for a qualitative " how much does temp affect HP?" ie why do cold air devices give more power

 

[phiebert]

Re: Cold Air Viper intakes-Its a no win

Patrick,

On the Gen 2's the Naca duct flows 55% of the intake air and the remaining 45% comes from the sides of the stock airbox which ***** in hot under hood air. People have been asking for a qualitative " how much does temp affect HP?" ie why do cold air devices giove more power

Sorry, all I was saying is that a general comment on cone filters under the hood isn't valid and that one can make mods to get cool air under the hood. I have no experience with a Gen II under hood situation and I believe your product will definitely help. It's really a no brainer, regardless of what people say, cool air is more dense and that will increase compression...a.k.a. horsepower.

 

[GTS-R 001]

Re: Cold Air Viper intakes-Its a no win

Patrick,

Where were you yesterday? We could have used your opinion on this post!!

 

[Roadkill]

Re: Cold Air Viper intakes-Its a no win

Ok I am tired of the name calling and theoretical yeild BS that this thread has turned into.. ***.. 1. How hard is it to just mount a thermometer in the smooth tube to measure air temp..?? Once you have mounted the thermometer, do a normal drive using the Vipair product and a normal drive using just the naca duct.. If you have not done this then post the results, otherwise go sell your snake oil to some other sucker. EASY REAL WORLD TEST is what i am asking for, not some pumped up controlled condition (and when i say controlled it means controlled in your favor) dyno test.

 

[joe117]

Re: Cold Air Viper intakes-Its a no win

I think this has already been done. The results are addressed in some earlier posts.

Even the most optomistic claims from the manufacturers of intake boxes would not yield enough hp to give a seat of the pants feel.

Let's say you picked up 25hp. That's 5.5%. Think you could feel 5.5%?
I think 25hp might lower your ET by .2seconds, think you could feel that?
if you were running 12.3sec ET and you then ran 12.1 sec ETs you would be running 1.6% lower ETs, think you can feel that? I don't.

Can you feel 1.6% of anything else?

And remember, for this discussion we are giving the airbox 25hp!

The man said,
"All I know is if you are relying on an air intake to make your power you are SLOW - period!

Please stay at home and stick to the Zaino posts."

He's right.

 

[Catwood]

Re: Cold Air Viper intakes-Its a no win

ok..ok... I have proof to the following theory although not on a Viper but on my F-Body.

Hot intake air makes more power....period!

On that car it draws in cool intake air low from the front facia. Air temp at the TB was the same as ambient.

When I heated it from 70* to about 115* through the Strim power greatly improved. RWHP went from about 225 to 492.

I'm now heating it more and I think it's over 550 RWHP.

Carl
2000 GTS
1993 Blown/Intercooled 355 Trans Am
1999 Jeep Grand Cherokee
2001 Chrysler Van of some sort

 

[joe117]

Re: Cold Air Viper intakes-Its a no win

And if you pipe the exhaust right into the TB you get a supercharging effect and less green house gas emission.

I think we're on to something here, where's torquie when we need him?

 

[Russ M]

Re: Cold Air Viper intakes-Its a no win

ok..ok... I have proof to the following theory although not on a Viper but on my F-Body.

Hot intake air makes more power....period!

On that car it draws in cool intake air low from the front facia. Air temp at the TB was the same as ambient.

When I heated it from 70* to about 115* through the Strim power greatly improved. RWHP went from about 225 to 492.

I'm now heating it more and I think it's over 550 RWHP.

Carl
2000 GTS
1993 Blown/Intercooled 355 Trans Am
1999 Jeep Grand Cherokee
2001 Chrysler Van of some sort

Carl,

How many psi of pressure did that warm air come in with.

 

[Catwood]

Re: Cold Air Viper intakes-Its a no win

ok..ok... I have proof to the following theory although not on a Viper but on my F-Body.

Hot intake air makes more power....period!

On that car it draws in cool intake air low from the front facia. Air temp at the TB was the same as ambient.

When I heated it from 70* to about 115* through the Strim power greatly improved. RWHP went from about 225 to 492.

I'm now heating it more and I think it's over 550 RWHP.

Carl
2000 GTS
1993 Blown/Intercooled 355 Trans Am
1999 Jeep Grand Cherokee
2001 Chrysler Van of some sort

Carl,

How many psi of pressure did that warm air come in with.

Only ten or eleven, but that wouldn't increase power would it? Had to be the heat.

 

[GARY J]

Re: Cold Air Viper intakes-Its a no win

This has been a cool thread. I have laughed several times. One point I wanted to make was I seriously doubt that the air the motor ***** in from around the naca duct is 200 degrees. I would bet, at anything but a stand still, it isnt that much hotter that ambient. I dont know where all of you guys' naca ducts are located but mine is way out in front of the motor. I'ld be willing to bet that the air that is sucked into the airbox from the front part of the engine bay, at speed, is just a little hotter than outside temps. Of coarse in the end I am just guessing. Lets get someone to independently test before and after on the dyno and at the track. That will put this one to bed.

 

[vipah]

Re: Cold Air Viper intakes-Its a no win

So has anyone done any tests? Anyone? Anyone?

 

[GTS-R 001]

Re: Cold Air Viper intakes-Its a no win

Bump!

 

[Torquemonster]

Re: Cold Air Viper intakes-Its a no win

And if you pipe the exhaust right into the TB you get a supercharging effect and less green house gas emission.

I think we're on to something here, where's torquie when we need him?

I'm needed?

And I thought no one cared!

Didn't Saab Scania in Sweden perfect a way of scavinging some unspent exhaust thru their turbo systems? I think they called it a compound turbo system - by all accounts it is quite efficient - they're certainly the top truck here, the only rig that is up there with them is the Signature Series 600 Cummins - they too are very efficient - by using fuel pressures well into 5 figures in psi!!!

 

[joe117]

Re: Cold Air Viper intakes-Its a no win

An example of a turbo compound engine is the 18 cylinder R3350 aircraft engine. It was first used in the B-29.

This engine was a radial with two banks of nine cylinders each. The engine had 3350 cubic inches.

There were a number of turbo units on the engine. I can't remember how many cylinders fed into each turbocharger. They worked as any turbocharger works.

The neat thing was that after the exhaust left the turbos, it was routed into a turbine that helped turn the crankshaft.

This grabbed the last bit of energy available from the exhaust.