2nd Gen Non-Engine/Transmission Airbulldog Hood dyno numbers?

[PPettit]

Interesting subject! Since so many of you are capable of doing the math..... we should be able to get very accurate measures of horsepower at speed using a stopwatch and timing how long it takes to accelerate from, say, 60mph to 75mph. I am too lazy to look up the equations to do this but it would provide more scientific data than "seat of the pants". I wonder if my Edge Juice would do this for me. Hmmmm.



Phil

 

[Gary - K7GLD]

Interesting subject! Since so many of you are capable of doing the math..... we should be able to get very accurate measures of horsepower at speed using a stopwatch and timing how long it takes to accelerate from, say, 60mph to 75mph. I am too lazy to look up the equations to do this but it would provide more scientific data than "seat of the pants". I wonder if my Edge Juice would do this for me. Hmmmm.



Phil

ABSOLUTELY!



For some reason, I have great difficulty in placing much faith in someones else's butt - or the "seat of their pants"!



And in absence of supporting documentation, wild claims of vast HP increases with the class of hood scoops MOST of us would consider installing on our trucks is just so much... air... :-laf



Sure, cooler air WILL usually produce more HP than warmer air

More air volume and PSI will do the same - no engineering degrees needed here!



BUT, the scoop SIZE and placement needed for gains on the order being tossed around in this thread with reckless abandon and wild assumption (exactly how MUCH "vacuum" has anyone actually measured at their air cleaner at 70 MPH?) are likely FAR greater than any here would consider for use in daily driving - unless that driving is done at Indy or Daytona Beach!



The only way for actual measure of hood scoop performance gains is in a wind tunnel dyno combination - the NEXT best way would be under drag strip conditions, where any reduction in ET can be converted to HP - has anyone here DONE such a test, involving only the change/addition of a hood/scoop of the type under discussion here?



HEY - you can ridicule me and my "Armchair", and call me all the names you like :-{} - be as rude and crude as you want - but none of that does a BIT in regards to the thread issue as far as providing anything but guesses unless solid documentation is provided to back up any claims made.



Wanna buy a neat scooped hood for LOOKS? Great - lotsa good choices out there. IF you get a relatively small power increase up at freeway speeds GREAT, you got a bonus - but if you expect to get great looks AND 30-40 HP at the same time, well.....



NOW, does anyone HAVE any solid facts and documentation - or will we fall back on insults and name calling instead?

 

[BTowler]

Gary, did you also know that washing your wheels before a race is good for a few 10ths? :-laf

 

[Gary - K7GLD]

Gary, did you also know that washing your wheels before a race is good for a few 10ths? :-laf

HEY - that's old news - and the ricers swear their Fart cans and fuel line magnets give THEM a "seat of pants" gain, so that MUST be at least 30 HP, right? :-laf

 

[Air Bulldog]

Gary I appreciate your opposing opinion. This makes for a very lively conversation.

I have said the research that I have done was with a manometer a manometer is the only way you can get any kind of data whatsoever,as I said before at 70 miles an hour I got a half a pound of pressure between the Turbo and the top of the air filter that doesn't sound like much but you have to consider how much of this air is being consumed by the Turbo. If there was no air entering the hood there would've been 10 to 15 inches of vacuum or more at the same point of measurement. In 1993 when they came out with the new design Dodge the second Gen they showed a 94 Dodge in an wind tunnel. The air from the smoke wand was the closest to the truck surface right where I put my hood scoops I'm not sure how you can get a copy of this info commercial but I'm sure it's out there somewhere. When I designed this hood I had no plan to ever sell any of them. My main concern was function ability, anesthetics last. Before I come up with a design that I came up with,I was leaning towards a Cowl hood but I wanted positive air at a slower speed so that's why I built the hood the way I did.

 

[JasonCzerak]

HEY - that's old news - and the ricers swear their Fart cans and fuel line magnets give THEM a "seat of pants" gain, so that MUST be at least 30 HP, right? :-laf

If a ricer gained 30hp on a 100hp motor with a scoop then these diesels would get a good 300hp!

 

[Gary - K7GLD]

DHofeldt sez:

Gary I appreciate your opposing opinion. This makes for a very lively conversation

ABSOLUTELY - especially as long as we deal with FACTS, go lightly on the guesses and assumptions, and leave INSULTS totally out of it! :-{}



And I want to make it perfectly clear that my own comments and opinions are directly related to facts - I have absolutely no reason to attack you personally, or your product - but I do have reason to question some of the rather extreme and (apparently) excessive assumptions and guesses that some offer here, and that are then ASSUMED and then repeated as absolute fact, when absolutely NO supporting documentation has been provided so far in this thread - here's an example:

If there was no air entering the hood there would've been 10 to 15 inches of vacuum or more at the same point of measurement.

Let's focus on that single statement for the moment, exactly HOW, and by what actual measurement have you arrived at that statement? How do you know for an absolute, proven FACT, know that at ANY engine or vehicle speed there IS indeed "10 to 15 inches of vacuum at the same point of measurement"?



Is that statement a GUESS, or the direct result of a test?



You see, I personally have difficulty in the assumption that with the many *square feet* of space and DIRECT high volume airflow available to the engine bay thru the area of the radiator, and various open areas surrounding the engine and below the engine bay, that a mere addition of a few *inches* provided by a small hood scoop(s) will somehow make a significant reversal in airflow directly into the engine intake, regardless of added ducting - but if you have test result clearly SHOWING that claimed vacuum does ordinarily exist, and that your, or similar hoods reverse that to the degree claimed in this thread, I sure would like to see that test info...



After all, the engine bay in our trucks is HARDLY an isolated or sealed off area, even BEFORE scoops are added!



I can easily accept the fact that there may be a 1/2 inch of water INCREASE in airflow/pressure at the scoop exit point, because past similar tests have shown the same result - but the notion that there is a HUGE (and 15 inches of vacuum IS huge!) vacuum at the engine bay air filter area of our trucks at ANY speed or RPM exceeds my ability to accept without supporting data.



I certainly agree that many of these scooped hoods LOOK neat - and that for most of them, SOME performance benefits might be provided - but without something other than some one's butt to back up claims and expectations as to 30-40 HP gains, sorry, I'm not convinced...



And sir, finally, I mean NO disrespect for you, or your product - I'm sure it is of excellent quality and you have reason to be quite proud of it - I only attempting to separate FACT from BS here ( regardless of how painful that is for a few here to accept! )- as I'm sure you agree and understand.

 

[Air Bulldog]

Gary

My hoods are not stand-alone systems I build an air box that completely seals to the underside of the hood where the air comes through from the outside. So you can see the air that is underneath and around the truck doesn't mean anything to my system only the air that is coming through the hood. The Manometer reads in vacuum and pressure. Tomorrow I will take my truck out on the interstate with a stock airbox and get you the vacuum reading at 70Miles per hour. I'm not trying to be argumentative and just trying to answer your questions.

 

[CHornsby]

I have no argument. Only thing I want is one of those hoods!

 

[Gary - K7GLD]

Gary

My hoods are not stand-alone systems I build an air box that completely seals to the underside of the hood where the air comes through from the outside. So you can see the air that is underneath and around the truck doesn't mean anything to my system only the air that is coming through the hood. The Manometer reads in vacuum and pressure. Tomorrow I will take my truck out on the interstate with a stock airbox and get you the vacuum reading at 70Miles per hour. I'm not trying to be argumentative and just trying to answer your questions.

AS I understand from your earlier statement regarding your design, the underside of your hood is sealed, and acts - as you described - as a plenum. In other words the whole underside forms the "duct" that collects the air taken in from the scoop.



And that's fine, no issue - and I fully agree you will probably see the 1/2 inch of vacuum INSIDE the plenum at 70 MPH - but the ISSUE is, WHAT will the measured PSI be in the immediate area SURROUNDING the air filter - not what it is inside the plenum/duct of the hood - unless the engine and/or the air cleaner is ALSO inside that plenum where the measurements are taken.



When you take your 70 MPH vacuum/psi measurement, be sure to take it at some underhood open point near the air cleaner - after all, THAT is what this particular issue element is about - it really doesn't much matter WHAT the plenum PSI is at ANY speed - it's what gets to the air cleaner and intake area that matters. All the "plenum" is, is a big reservoir/duct to contain trapped air and direct it where it is wanted.



Fact is, the whole underhood area of our trucks is essentially open to the atmosphere, and the ability to PHYSICALLY ISOLATE a relatively small area of the underhood, such as around the alternator, batteries OR the air cleaner is virtually physically impossible other than by use of an airtight enclosure that DOES isolate a selected area from what surrounds it. DOES your setup do that, enclose and isolate the air cleaner?



This means that IF the general area around the air cleaner is at 15 inches of vacuum at 70 mph, the whole engine bay will be at the same vacuum in relation to PSI OUTSIDE the engine bay - in which case the hood would cave in like tissue paper!



I have a vacuum pump and gauge here I can use to easily display what happens to a plain 1 gallon solvent can when you place 15 PSI of vacuum into it - it ain't pretty...



As I see it, we have *2* closely related issues to be resolved:



1. The airflow/PSI your hood will deliver to the underhood area near the air cleaner.



2, The claimed existence of a high vacuum area in that same air cleaner area at vehicle speeds of 70 MPH or so that your design overcomes.



I'll be interested in your results.



(EDIT)



By the way, I see by your member profile that you have a 98 truck - and IF the stock airbox on that model is like the one that came with my '02, ALL the airflow feeding that box comes ducted in from the inner fenderwell area - none from underhood. SO, without mods, how does air from your hood/scoop GET INTO the airbox - and how, using the stock air box in tomorrow's test, can you get a PSI measurement from the air cleaner area?



Just curious...

 

[Air Bulldog]

I measure that air between the top of the air filter and the turbo, in the hose that connects the turbo to the top of the airbox it's a half a pound of pressure there not a half inch of vacuum at 70

 

[MCummings]

Gary, Doug clearly stated he has a special airbox for his hood that completely seals off the hood to the airbox.



That squiggly rubber boot between the factory airbox, and the turbo is where he is taking the pressure/vacuum readings.



What is the range of the OE filter minder? I've heard many could suck it down easily into the red on a trip around the block with a "hot" truck, but of course, cruising at 70 doesn't pull it down any...



I can't wait to see the vacuum readings of a OE truck at 70mph. (in the squiggly hose)



I guess It may not be only Dougs hood, but Dougs hood/Airbox combo.



Gary, weren't you around when Doug was first offering these hoods? They were high priced, but I'd say worth it if you wanted a aftermarket hood.





Merrick

 

[Air Bulldog]

may be this will help

 

[Air Bulldog]

this time I hope

 

[PPettit]

I do not believe there is a negative pressure on the stock setup.

Having a completely stock air box on my '01 it has the little differential pressure gauge mounted on it (filter minder). I am not sure but I think this is referenced to the general air pressure under the hood. Not sure what, if any units this is calibrated in but I can not pull any reading on it until the filter is really dirty. I can run the Juice at 5x5 and do a hard run from 0 to above legal speeds and never get any reading on this thing. If it is actually referenced from one side of the filter to the other then this is all meaningless!



Pressure differences aside, I think the other important bit of information not being discussed here is the actual air temp coming into the turbo. If the hood scoop can feed the turbo with air that is measurably colder than stock, or the underhood "cold air intakes", then there is a performance advantage.

I believe somebody at the very beginning of this thread started out claiming this is what the hood scoop really was anyhow. This would be soooo much easier to quantify than the pressure readings.



Phil

 

[Gary - K7GLD]

this time I hope

Interesting setup - I assume you also block off the fenderwell boot to restrict air flow to only what comes from the hood?



Still leaves open the suggestion as to the likelihood of high vacuum at the airbox area at freeway speeds - I wonder if your manometer setup can be used/installed in that area for a test run to eliminate or verify what PSI or vacuum DOES exist there at speed?



At face value, unless the scoop setup DOES overcome unexpected vacuum issues at the intake, it wouldn't seem reasonable to expect radical power increases purely from a 1/2 lb improvement in PSI - hopefully, testing you might do will help answer that question as well.



And the final, more difficult question, is actual power improvement - sure would like to see some before/after dragstrip runs for time/HP comparisons.



Thanks for the picture and info.

 

[Gary - K7GLD]

I do not believe there is a negative pressure on the stock setup.

Having a completely stock air box on my '01 it has the little differential pressure gauge mounted on it (filter minder). I am not sure but I think this is referenced to the general air pressure under the hood. Not sure what, if any units this is calibrated in but I can not pull any reading on it until the filter is really dirty. I can run the Juice at 5x5 and do a hard run from 0 to above legal speeds and never get any reading on this thing. If it is actually referenced from one side of the filter to the other then this is all meaningless!



Pressure differences aside, I think the other important bit of information not being discussed here is the actual air temp coming into the turbo. If the hood scoop can feed the turbo with air that is measurably colder than stock, or the underhood "cold air intakes", then there is a performance advantage.

I believe somebody at the very beginning of this thread started out claiming this is what the hood scoop really was anyhow. This would be soooo much easier to quantify than the pressure readings.



Phil

Phil, a couple of us did a few test runs a year or so back with remote temp sensors at various points under the hood, including the air filter area - that was done to prove or refute the often claimed high underhood temps vs outside ambient in normal operation, and the "benefits" of drawing in cooler outside air. I have a thread on this board resulting from those tests.



Those test runs displayed a consistent difference of only 10 degrees maximum in the worse case scenario - towing, A/C on, etc. , and often, only 5 degrees between underhood and ambient outside air at any speed above about 30 MPH - the underhood area, at least for our Dodges, is actually pretty cool once the truck is in motion. Stopped, and at speeds lower than 30 MPH, things get hotter - but few guys buy aftermarket "cool air" setups for speeds under 30 MPH anyway.



And yeah, we got lots of "hate mail" on that one too - no one likes to see long held assumptions and personal opinions challenged or myths busted...



For some, ignorance is bliss - for others, it's Sacred - for my part, I like to test stuff out to see what the truth is, then make my choices from an informed and educated standpoint rather than rumors or heresay...

 

[Gary - K7GLD]

I've sent this by PM to DHofeldt - but figured it might be appropriate to share with the rest of the group to clear the air a bit and cool tempers:



===



I just want to say how much I appreciate your patience and courtesy in responding to my own personal comments and observations concerning your hood/scoop as well as others in general.



I also want to personally apologize to you for the more vocal and abusive participation of some members my comments have generated in the thread - I've run into them before - same folks, same abusive attitudes and behavior.



I'm sure you have pretty well determined my motivation and goals in obtaining accurate info on performance claims where scoops and other ducting of outside air to the engine is concerned - this is not my first TDR exchange on this subject, and I *have* made a number of test runs of my own regarding related statements and claims made in this subject.



I obviously have NO first hand knowledge or exposure to your specific product and design - which looks like a very good one by the way - but HAVE had enough exposure to engine operation regarding intake air PSI and temperatures to arrive at what I feel is a decent layman's understanding and conclusion as to what will work, and what won't - as well as a general yardstick of what a given effort will logically produce in the way of results.



THUS, my continued belief that the single, simple increase in intake PSI to the turbo of about 1/2 PSI or column inch - even with the typical 5-10 degree improvement in air temp - is not nearly sufficient for the claimed 30-40 HP gain that has been offered in the thread under discussion - at least unless/until other related but so far unforeseen side benefits surface to account for so high a power gain.



I mean you or your product NO personal derogatory intent - and have both appreciated your own willingness to cordially discuss the finer points of it's construction, and may well be interested in one myself if you choose to resume production of them - I'm interested in a hood/scoop setup based purely upon appearance - and have no doubt that yours WILL provide some level of improved performance as well - it only remains to be seen how much that typically is in real life installations.



You have my best wishes for your future, as well as that of your product.



Respectfully



Gary

 

[HeberRam]

I've sent this by PM to DHofeldt - but figured it might be appropriate to share with the rest of the group to clear the air a bit and cool tempers:



===





I also want to personally apologize to you for the more vocal and abusive participation of some members my comments have generated in the thread - I've run into them before - same folks, same abusive attitudes and behavior.







Gary

Again look into the mirror... . :-laf :-laf :-laf

 

[Air Bulldog]

Thanks Gary

I didn't get a chance to do the testing today. It is cold here and I have not been feeling well. Once I get it I will post it for everyone.