schorvitz
Viper Owner
I heard through the grapevine that the guy who makes Hennessey's air boxes sells them directly out of Canada. Does anyone know how to get in touch with him. I need one for my new car 
Hennessey Air Box
- Thread starter schorvitz
- Start date
Anthony - 98 GTS
Enthusiast
GTS Dean
Enthusiast
They are built in Oklahoma. Do an airbox search for posts in the past 9 months or so.
jp
Enthusiast
FACTORY TEN COMPOSITES are the ones doing the box.
Talk to Gary Smrtic
Talk to Gary Smrtic
Maverick The Electrician
Enthusiast
We used the Hennessey box for a year, it is a very nice piece. We talked to factory ten about getting a few more for our customers. The new box was going to be out several months ago and never came out. We kept getting the run around, then no return phone calls. We then put some tubes and filters back on the car and ran faster than we ever have. If you plan on buying this box for looks, then great. If you think it is going to be a performance factor, save your money. We picked up a little on the dyno, but not worth 500-700.00 more.
Prashant
Enthusiast
Here's the way I look at it: it looks great and now its been proven with a 9.56 ET on the RSI car.
And now its been proven?????? What the heck does that mean???? Sounds like a sales pitch if I ever heard one. That airbox is not going to pick up ANY horsepower and you are not going to see any gain in ET or MPH but the **** factor is the only thing going for it. So before you talk to soon, I have one on my car but its for LOOKS only and dont try to sell it for anything more.
Mark H.
NO sales Pitch just the TRUTH!!!!!!!!!!!!
Mark H.
NO sales Pitch just the TRUTH!!!!!!!!!!!!
HouseofSpeed
Enthusiast
Mark and Albert are correct....before you claim a piece as proven, make sure that nothing else on the car could have played a role in the record setting pass.
Basic scientific method, pull the airbox off and run the car with a stocker or K&Ns with tubes...record the number...then run with the box and see the difference.
Its really hard to make a sweeping claim like that when you provide your own atmosphere....I doubt that the airbox had any effect on the ET or the trap speed, at least not as much as the HUGE shot of gas on the car...
Basic scientific method, pull the airbox off and run the car with a stocker or K&Ns with tubes...record the number...then run with the box and see the difference.
Its really hard to make a sweeping claim like that when you provide your own atmosphere....I doubt that the airbox had any effect on the ET or the trap speed, at least not as much as the HUGE shot of gas on the car...
DEVILDOG
VCA Member North TX
Sounds like HMS bashing to me. The same people claiming that you must run tests to prove a gain are bad mouthing the HMS carbon fibre box without testing it and claiming it results in no HP gain. Test it then run your mouth!
treynor
Enthusiast
For the record, I tested my H+C car with the stock and Hennessey airbox. There was no difference on the dyno.
To his credit, John told me before I bought the airbox that I would be unlikely to see any gains on a static dyno, but he opined that it would help a little bit at speed. I did not have the opportunity to test that assertion. The HMS airbox however (a) looked very nice and (b) did not interfere with the stock fan mounted on a big Fluidyne radiator, as the stock airbox had.
To his credit, John told me before I bought the airbox that I would be unlikely to see any gains on a static dyno, but he opined that it would help a little bit at speed. I did not have the opportunity to test that assertion. The HMS airbox however (a) looked very nice and (b) did not interfere with the stock fan mounted on a big Fluidyne radiator, as the stock airbox had.
HouseofSpeed
Enthusiast
Its been tested...and no one was bashing the now defunct HMS.
Ease up Jim, loyalty is a good thing...but obsession is not.
Ease up Jim, loyalty is a good thing...but obsession is not.
V10 MOJO
Enthusiast
ok, so where do you get one? (the original question here)
Relentless
Enthusiast
Id like to know where to get one too....can anyone help?
Mike Brunton
Enthusiast
Mike,
I have to disagree with you. Ram air is a marketing fad and nothing else. The ZX-12R does not gain anything from Ram air, anymore than the Viper does from it's NACA duct.
Before everyone jumps down my throat, here is a full explanation. If any of you guys took fluid dynamics or works with aeronautics and wants to argue, I'm game
http://www.vetteguru.com/ramair/
I have to disagree with you. Ram air is a marketing fad and nothing else. The ZX-12R does not gain anything from Ram air, anymore than the Viper does from it's NACA duct.
Before everyone jumps down my throat, here is a full explanation. If any of you guys took fluid dynamics or works with aeronautics and wants to argue, I'm game
http://www.vetteguru.com/ramair/
Mike Adams
Enthusiast
Some things cannot be tested on a dyno. Kawasaki is the king ram air. Their ram air add to a Motorcyle doesn't add anything on a static dyno but take it down the dragstip and WOW huge difference.
I Kitchener their is Motorcycle dyno which has a huge fan in front of it that pickup and the dyno speeds up but it cannot keep up with the acceleration. It has shown improvements with ram air set ups on R1's .
John's original claim was that it added 2 - 4 mph to the quarter mile. How much horse power is that who knows ? I don't but some will be able to tell.
I can get you air boxes but only if you have large throttle bodies.
I Kitchener their is Motorcycle dyno which has a huge fan in front of it that pickup and the dyno speeds up but it cannot keep up with the acceleration. It has shown improvements with ram air set ups on R1's .
John's original claim was that it added 2 - 4 mph to the quarter mile. How much horse power is that who knows ? I don't but some will be able to tell.
I can get you air boxes but only if you have large throttle bodies.
HouseofSpeed
Enthusiast
Maybe 1 psi of manifold pressure at 130 MPH if ducted and sealed properly.
jrkermode
Enthusiast
Mike,
I think Vetteguru misses something. The argument assumes the air is moving. It's not. The air is quite happily at rest until a car crashes into it. The cars motion imparts additional energy into the air mass, energy not accounted for by Vetteguru. Using this added energy is what ram air is about. Is the gain big enough to justify all the hoopla? I estimate the gains due to increased intake pressure to be about 5% (similar to HouseofSpeed's number). However, ram air systems also tend to give you cooler air, in which case the overall gains may be closer to 10% (a very rough rule of thumb; 10 degree F decrease in intake temp = 1% gain in HP).
I think Vetteguru misses something. The argument assumes the air is moving. It's not. The air is quite happily at rest until a car crashes into it. The cars motion imparts additional energy into the air mass, energy not accounted for by Vetteguru. Using this added energy is what ram air is about. Is the gain big enough to justify all the hoopla? I estimate the gains due to increased intake pressure to be about 5% (similar to HouseofSpeed's number). However, ram air systems also tend to give you cooler air, in which case the overall gains may be closer to 10% (a very rough rule of thumb; 10 degree F decrease in intake temp = 1% gain in HP).
Mike Brunton
Enthusiast
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by jrkermode:
Mike,
I think Vetteguru misses something. The argument assumes the air is moving. It's not. The air is quite happily at rest until a car crashes into it. The cars motion imparts additional energy into the air mass, energy not accounted for by Vetteguru. Using this added energy is what ram air is about. Is the gain big enough to justify all the hoopla? I estimate the gains due to increased intake pressure to be about 5% (similar to HouseofSpeed's number). However, ram air systems also tend to give you cooler air, in which case the overall gains may be closer to 10% (a very rough rule of thumb; 10 degree F decrease in intake temp = 1% gain in HP).
<HR></BLOCKQUOTE>
You guys are both wrong
If you read through the explanation, you'll see what I mean.
You're saying that the speed of the car puts "energy" into the air which is shown by an increase in pressure in the intake tract? That's not what happens. Intuitively, you'd think thats what happens, but it's not. As the site (quite correctly states), in order to trade kinetic energy for pressure, you need to slow the air down, not speed it up, which requires a divergent nozzle (if it were a cone, the air would come in the small end and the airbox would be at the big end). You could put a scoop the size of a megaphone on the front of your car, and even at 80mph, you won't see a single ounce of gain.
As is also stated, below around mach 0.5, air is pretty much incompressible, so the "ram air" effect doesn't happen until that speed level. Check out the air intakes on a jet fighter... if you look at the diagrams and see what happens to the air when it enters the engine to produce the "ram" effect, you'll see what I mean.
Mike,
I think Vetteguru misses something. The argument assumes the air is moving. It's not. The air is quite happily at rest until a car crashes into it. The cars motion imparts additional energy into the air mass, energy not accounted for by Vetteguru. Using this added energy is what ram air is about. Is the gain big enough to justify all the hoopla? I estimate the gains due to increased intake pressure to be about 5% (similar to HouseofSpeed's number). However, ram air systems also tend to give you cooler air, in which case the overall gains may be closer to 10% (a very rough rule of thumb; 10 degree F decrease in intake temp = 1% gain in HP).
<HR></BLOCKQUOTE>
You guys are both wrong
If you read through the explanation, you'll see what I mean.
You're saying that the speed of the car puts "energy" into the air which is shown by an increase in pressure in the intake tract? That's not what happens. Intuitively, you'd think thats what happens, but it's not. As the site (quite correctly states), in order to trade kinetic energy for pressure, you need to slow the air down, not speed it up, which requires a divergent nozzle (if it were a cone, the air would come in the small end and the airbox would be at the big end). You could put a scoop the size of a megaphone on the front of your car, and even at 80mph, you won't see a single ounce of gain.
As is also stated, below around mach 0.5, air is pretty much incompressible, so the "ram air" effect doesn't happen until that speed level. Check out the air intakes on a jet fighter... if you look at the diagrams and see what happens to the air when it enters the engine to produce the "ram" effect, you'll see what I mean.
GTS Dean
Enthusiast
Brutonius Minimus, if Ram Air were a sham, why is it that NASCAR, ALMS, IRL, F1, NHRA Pro Stock, etc. waste valuable engineering $ and time on optimizing the shape of the inlet tract?
The main problem with the NACA duct on the Viper's hood is that it's too small. The inlet of the air box itself is right around the "magic" 30 in^2 area that is frequently used as a rule of thumb for automotive applications. Despite a favorable aero profile, the NACA duct provides less than half of the required frontal area. A number of the Viper Days racers have closed off the hood duct and pick up air from the radiator inlet. Perhaps if someone would bother to cut a big hole in the hood and put *2* NACA ducts in parallel ahead of the airbox, you would measure a useful static pressure increase. Regardless, the cooler air does increase charge air density slightly and is worth persuing. I picked up a consistent 3-4 mph on the front straight of TWS with the HMS air box vs stock with K&Ns and tubes.
The main problem with the NACA duct on the Viper's hood is that it's too small. The inlet of the air box itself is right around the "magic" 30 in^2 area that is frequently used as a rule of thumb for automotive applications. Despite a favorable aero profile, the NACA duct provides less than half of the required frontal area. A number of the Viper Days racers have closed off the hood duct and pick up air from the radiator inlet. Perhaps if someone would bother to cut a big hole in the hood and put *2* NACA ducts in parallel ahead of the airbox, you would measure a useful static pressure increase. Regardless, the cooler air does increase charge air density slightly and is worth persuing. I picked up a consistent 3-4 mph on the front straight of TWS with the HMS air box vs stock with K&Ns and tubes.
HP
Enthusiast
I'm not going to speculate on the numbers claim, but
some of the physics logic is a little off.
First whether the air has a velocity of 100mph and the car
is standing still, or the air is standing still and the car
is going 100mph- it's all the same. That's why a plane with
a 100mph stall speed, going 100mph, will fall if it encounters
a tail wind at 100mph. And why a glider can fly standing still.
Another point necessary for taking advantage of ram air, is
to have all the air molecules going in the same direction, that's
what gives air horns there power gain. The same principle applied to light gives you lasers, or in the case of water
gives you water canons. So air flow that is not organized will
tend to cancel out the effect you are looking for.
Air velocity and air pressure, of course cannot be confused
It's like comparing air compressors and air tools, a HVLP paint
gun needs a compressor that moves a lot of air, but little pressure, on the other hand a conventional paint
gun requires high pressure to work, and volume of air is less
important.
some of the physics logic is a little off.
First whether the air has a velocity of 100mph and the car
is standing still, or the air is standing still and the car
is going 100mph- it's all the same. That's why a plane with
a 100mph stall speed, going 100mph, will fall if it encounters
a tail wind at 100mph. And why a glider can fly standing still.
Another point necessary for taking advantage of ram air, is
to have all the air molecules going in the same direction, that's
what gives air horns there power gain. The same principle applied to light gives you lasers, or in the case of water
gives you water canons. So air flow that is not organized will
tend to cancel out the effect you are looking for.
Air velocity and air pressure, of course cannot be confused
It's like comparing air compressors and air tools, a HVLP paint
gun needs a compressor that moves a lot of air, but little pressure, on the other hand a conventional paint
gun requires high pressure to work, and volume of air is less
important.
Mike Brunton
Enthusiast
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by GTS Dean:
Brutonius Minimus, if Ram Air were a sham, why is it that NASCAR, ALMS, IRL, F1, NHRA Pro Stock, etc. waste valuable engineering $ and time on optimizing the shape of the inlet tract?
The main problem with the NACA duct on the Viper's hood is that it's too small. The inlet of the air box itself is right around the "magic" 30 in^2 area that is frequently used as a rule of thumb for automotive applications. Despite a favorable aero profile, the NACA duct provides less than half of the required frontal area. A number of the Viper Days racers have closed off the hood duct and pick up air from the radiator inlet. Perhaps if someone would bother to cut a big hole in the hood and put *2* NACA ducts in parallel ahead of the airbox, you would measure a useful static pressure increase. Regardless, the cooler air does increase charge air density slightly and is worth persuing. I picked up a consistent 3-4 mph on the front straight of TWS with the HMS air box vs stock with K&Ns and tubes.
<HR></BLOCKQUOTE>
Dumbo Dean,
There is a big difference between "optimizing the flow of the intake tract" and "ram air". The latter is physically impossible at car speeds. We can go back and forth about this all you like, but if you have some factual data to present, I'm all ears. Until then, I'll fall back on my engineering and fluid dynamics courses and keep on believing the effect is negligible or nil at vehicle speeds. Wanna make a bet on it? Of course the fallback is always "well you can't measure it on a dyno so therefore you can't prove I'm wrong". P.S. not trying to be confrontational, just extremely confident about being right on this one - which would be rare when I disagree with you
Regarding "optimizing intake tract"... minimizing flow restrictions and pressure drop is an entirely different animal than creating pressurization at the intake due to "ram air". If you really think that you can increase the pressure above atmospheric by using a decreasing radius scoop, then I have some nice oceanfront property in Utah I'd love to sell ya!
Brutonius Minimus, if Ram Air were a sham, why is it that NASCAR, ALMS, IRL, F1, NHRA Pro Stock, etc. waste valuable engineering $ and time on optimizing the shape of the inlet tract?
The main problem with the NACA duct on the Viper's hood is that it's too small. The inlet of the air box itself is right around the "magic" 30 in^2 area that is frequently used as a rule of thumb for automotive applications. Despite a favorable aero profile, the NACA duct provides less than half of the required frontal area. A number of the Viper Days racers have closed off the hood duct and pick up air from the radiator inlet. Perhaps if someone would bother to cut a big hole in the hood and put *2* NACA ducts in parallel ahead of the airbox, you would measure a useful static pressure increase. Regardless, the cooler air does increase charge air density slightly and is worth persuing. I picked up a consistent 3-4 mph on the front straight of TWS with the HMS air box vs stock with K&Ns and tubes.
<HR></BLOCKQUOTE>
Dumbo Dean,
There is a big difference between "optimizing the flow of the intake tract" and "ram air". The latter is physically impossible at car speeds. We can go back and forth about this all you like, but if you have some factual data to present, I'm all ears. Until then, I'll fall back on my engineering and fluid dynamics courses and keep on believing the effect is negligible or nil at vehicle speeds. Wanna make a bet on it? Of course the fallback is always "well you can't measure it on a dyno so therefore you can't prove I'm wrong". P.S. not trying to be confrontational, just extremely confident about being right on this one - which would be rare when I disagree with you
Regarding "optimizing intake tract"... minimizing flow restrictions and pressure drop is an entirely different animal than creating pressurization at the intake due to "ram air". If you really think that you can increase the pressure above atmospheric by using a decreasing radius scoop, then I have some nice oceanfront property in Utah I'd love to sell ya!
Greg Good Cylinder Heads
Enthusiast
Mike, I have a set of audio tapes and the literature that goes with them from a Superflow convention held back in the '90's at which George Bryce spoke on the subject of NHRA Pro Stock Motorcycles. In the literature was a copy of the computer printout from a run. It showed every monitored reading, except for the clutch graph. He wanted to keep that secret.
There was a g-force meter on the bike to measure acceleration as well as a pressure transducer mounted in the airbox to measure airbox pressure as the bike went down the track. Predictably, the g-force chart started high and steadily declined as the run progressed. But, late in the run when the airbox pressure started climbing, the bikes falling acceleration rate reversed, and started INCREASING.
If I remember correctly it took a .5 psi increase in airbox pressure to achieve this effect. I can't recall the exact mph where this took place either, but it I think it was around 150 mph. I'll try to find the info if you're interested.
An airbox can provide a slight supecharging effect but at the speeds capable of a fast NA Viper, 130'ish mph, it's probably not going to add much.
There was a g-force meter on the bike to measure acceleration as well as a pressure transducer mounted in the airbox to measure airbox pressure as the bike went down the track. Predictably, the g-force chart started high and steadily declined as the run progressed. But, late in the run when the airbox pressure started climbing, the bikes falling acceleration rate reversed, and started INCREASING.
If I remember correctly it took a .5 psi increase in airbox pressure to achieve this effect. I can't recall the exact mph where this took place either, but it I think it was around 150 mph. I'll try to find the info if you're interested.
An airbox can provide a slight supecharging effect but at the speeds capable of a fast NA Viper, 130'ish mph, it's probably not going to add much.
HouseofSpeed
Enthusiast
Despite all of our meanderings...the gravity switch is always on, and I have seen no more than 1 psi max off of any type of duct (NACA, Pro Stock style, etc). Ram air is a hook that sounds cool...in actuality its just a fresh/cool air intake...at least cooler than whats found at the end of an open element conical filter sucking up the fan wash. Hey, somebody sells that as an intake upgrade....how does that work??
Often times what we calculate in the static plane will change dramatically when the same variables come to play in a dynamic environment. A sealed box is better than an open element..but neither are big movers of the needle on the *** dyno.
Often times what we calculate in the static plane will change dramatically when the same variables come to play in a dynamic environment. A sealed box is better than an open element..but neither are big movers of the needle on the *** dyno.
jrkermode
Enthusiast
Several months ago I was working on an aero program with some local Viper owners headed for the Virginia City Hillclimb. Our research was rather extensive, including spending some time with Don Elder of Trackaero (professional aerodyanamicist / professor of aeronautical engineering) and Jeff of Daimler Chrylser (member of the GTSR aero team). I also have some personal aero experience having been involved in the development of the RX-7 IMSA GTO car.
No flame of anyone is intended, its just a long way of saying I know enough to be dangerous.
Ram Air: The objective is not to achieve some magical supercharging but simply to take full advantage of the frontal pressure acting on the car. An intake facing forward into undisturbed air is more apt to benefit from this pressure than one facing in some other direction. The gains are not huge, but are real.
Stock NACA duct: The stock duct is indeed too small to effectively flow an 8 liter engine's worth of air in race conditions. However, that's not why it doesn't "work". It's effectiveness is muted by its location on the car. The NACA duct is far enough back from the leading edge of the car that it is in a relatively low pressure area. Next time you see a GTSR, look at the vents on the hood of the car. They are located just behind where the NACA duct used to be (since the GTSR package eliminates the duct altogether).
Mike,
I'm not sure what experiences you had in your engineering and fluid dynamics courses that have you disbelieving in frontal pressure. However, I suggest you get Katz's book on race car aerodynamics. I have a zillion other books but find his the best single source. It's available from Amazon.com (make sure you select his race car aero book and not his light aircraft book). Perhaps Katz's presentation will make it more clear.
P.S. Vipers finished 2nd and 3rd at Virginia City, with one of them setting the fastest ever time for a naturally aspirated car. I say it was all aero, the drivers continue to assert that steering and braking had something to do with it!
No flame of anyone is intended, its just a long way of saying I know enough to be dangerous.
Ram Air: The objective is not to achieve some magical supercharging but simply to take full advantage of the frontal pressure acting on the car. An intake facing forward into undisturbed air is more apt to benefit from this pressure than one facing in some other direction. The gains are not huge, but are real.
Stock NACA duct: The stock duct is indeed too small to effectively flow an 8 liter engine's worth of air in race conditions. However, that's not why it doesn't "work". It's effectiveness is muted by its location on the car. The NACA duct is far enough back from the leading edge of the car that it is in a relatively low pressure area. Next time you see a GTSR, look at the vents on the hood of the car. They are located just behind where the NACA duct used to be (since the GTSR package eliminates the duct altogether).
Mike,
I'm not sure what experiences you had in your engineering and fluid dynamics courses that have you disbelieving in frontal pressure. However, I suggest you get Katz's book on race car aerodynamics. I have a zillion other books but find his the best single source. It's available from Amazon.com (make sure you select his race car aero book and not his light aircraft book). Perhaps Katz's presentation will make it more clear.
P.S. Vipers finished 2nd and 3rd at Virginia City, with one of them setting the fastest ever time for a naturally aspirated car. I say it was all aero, the drivers continue to assert that steering and braking had something to do with it!
Miles B
Enthusiast
Mike...
interesting reading. My aeronautical engineering courses are long forgotten distant memories.. mostly clouded by beer. I have often considered ram air. I have never come up with an answer I am happy with. I'm definitely not happy with vetteguru's explanation. Some of his "laws on gases" seem a bit confused... I can't put my finger on how, because I've forgotten too much. In the end, I prefer to turn to evidence.
There's lots of anecdotal stuff out there. For my money, I like to look at bikes. They have small engines compared to the duct size. Take the Yamaha R7. Saw some photos of that thing with its fairings off. HUGE ram air duct. That bike ain't no WS6 - it's a factory superbike.
But anecdotal doesn't really do it for me. Instead, have a search, and you should be able to find some results of a guy using a manometer on his hayabusa. Showed a definite pressure gain of (as Kyle said) around 1 psi, somewhere between 80 and 100mph (again - beer has dulled the details). Now, I'm not saying that's a huge amount, and it's the most important thing influencing the performance of my ride, but hey - I'll take a free 1 psi pressure gain in my intake. I wouldn't think the NACA duct has a chance of getting 1 psi. But importantly, it helps supply cold air.
vetteguru appears to be looking at some jet science for his comments on the mach 0.5 thing. I can't remember much of that either. I did, however, see a book the other day... on nitrous, turbo and supercharging bikes. Had a big section on ram air up front. Think I might buy it.
interesting reading. My aeronautical engineering courses are long forgotten distant memories.. mostly clouded by beer. I have often considered ram air. I have never come up with an answer I am happy with. I'm definitely not happy with vetteguru's explanation. Some of his "laws on gases" seem a bit confused... I can't put my finger on how, because I've forgotten too much. In the end, I prefer to turn to evidence.
There's lots of anecdotal stuff out there. For my money, I like to look at bikes. They have small engines compared to the duct size. Take the Yamaha R7. Saw some photos of that thing with its fairings off. HUGE ram air duct. That bike ain't no WS6 - it's a factory superbike.
But anecdotal doesn't really do it for me. Instead, have a search, and you should be able to find some results of a guy using a manometer on his hayabusa. Showed a definite pressure gain of (as Kyle said) around 1 psi, somewhere between 80 and 100mph (again - beer has dulled the details). Now, I'm not saying that's a huge amount, and it's the most important thing influencing the performance of my ride, but hey - I'll take a free 1 psi pressure gain in my intake. I wouldn't think the NACA duct has a chance of getting 1 psi. But importantly, it helps supply cold air.
vetteguru appears to be looking at some jet science for his comments on the mach 0.5 thing. I can't remember much of that either. I did, however, see a book the other day... on nitrous, turbo and supercharging bikes. Had a big section on ram air up front. Think I might buy it.
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