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

[edgerat]

I just bought my truck and it came with an Airbulldog hood on it. I particularly dont like the looks of it on the truck but thats just me. The truck with the mods in my sig pulls HARD all over the place and is generally a handful to drive with the comp box on I put the stock hood back on the truck and an AFE stage 2 intake and I swear to you the truck doesnt have as much bite as it did with the bulldog hood on it. So, has anyone dyno'd their truck before and after the installation of the bulldog hood and ONLY the bulldog hood? I think I am going to go back up to DDP this week and re-dyno the truck with the AFE on it and see if I pull a bigger number or if the airbulldog hood actually gave me an advantage. if it did then I am going to put the fugly pete's dragon looking thing back on it :-laf

 

[JGK]

Can't answer your question, but the hood is really only going to shine when you're blowing down the road ramming air into the scoops. Can't easily duplicate that on a dyno unless you can pound air into the scoops at 30 or 40 mph minimum. That's just my semi-educated opinion, however.



-Jay



P. S. I really want that hood, but I can't use it as designed unless I go back to my stock airbox, or build a box around my megacannon. Always something...

 

[BTowler]

This has always been one of my biggest pet peeves, ram air! It is nothing more than a cold air induction, you can't drive our trucks fast enough to force enough air in the scoop to create an increase in pressure. I wish I still had the article, but an extensive test showed the only vehicle that exhibited any increase was a motorcycle that had scoops almost as big as most automotive "ram air" scoops, which was filling a 900cc engine, and the increase did not come on till over 80 mph! Remember, our trucks are 360 cubic inches of displacement, spinning at approximately 2000 rpm at 70 mph, do the math (oh yeah, don't forget the increase in volume from the turbo), then figure the total area of that scoop... think you are forcing air into the engine? It can give performance gains as a cold air intake, but don't be mislead into believing you are forcing more air into the engine than it is actually drawing on its own.

 

[edgerat]

BT that answers my question for the most part

 

[Joseph Donnelly]

You won't get more air pressure; the turbo dies that. However, the air will be denser and cooler so more air molecules will be a part of the boost pressure. PV=nRT. I got around 50-100 deg. egt reduction with the SRT10 hood on my 2004, using a home made scoop inside the hood to direct the air from the scoop to the aFe filter area. The dyno won't show the benefit because the truck is not moving. Raising the hood at the dyno will partially simulate the effect, however, if the engine compartment is hot.

 

[Air Bulldog]

My name is Doug Hofeldt I was a manufacturer and designer for air bulldog hoods I had to get out of that business because of health reasons but I did find out a lot of information about airflow and pressures to the air box from my hood. A man that bought one of my hoods had a heating and air-conditioning business and after he bought my hood he wanted to do a little research on it. He got electronic manometer, And did some testing, and call me back with the results he was astounded at how well the hood worked. Later he gave me the electronic manometer and I did some testing of my own. At 70 miles an hour on the interstate with no headwind or going up hills I could measure a half a pound of pressure between top of the airbox and the Turbo, this electronic manometer wasn't much over a hundred bucks but it was very accurate. Lawrence Boldon of Diesel Dynamics had one of my hoods on one of his project trucks he claimed that 70 miles an hour the hood was worth 35 to 40 horse I'm not sure how he come up with those figures but with his knowledge I'm sure it was well based. I don't sell my hoods anymore and I'm not trying to market them I'm just sharing information with you that I have found about my ram air system. I know that this system works and works well but on a dyno you just can't simulate the road conditions that ram air works in. Data is very hard to come by when it comes to ram air. I have a 2000 Trans Am it is a WS-6 which is a ram air car General Motors claims that it's worth 15 horse this system on the Pontiac is not sealed is very restrictive but yet they claim 15 horse. The nice thing about ram air when she put it on there's no more cost it just works. If you have one of my hoods and you don't like it every month I get people calling me asking for one of these hoods, just put it on the classifieds here and I'm sure someone will take it off your hands.

 

[TJSHOTROD]

DH can you post a pic of the hoods you use to sell? I am hoping it is not the one I was wanting.

 

[Air Bulldog]

I tried but it said my files are to big

 

[Air Bulldog]

How is this

 

[Bob Wagner]

Doug I still have the files that you sent me and I will post pictures tomorrow.



Good to see you back on TDR

 

[Air Bulldog]

Thanks Bob

 

[TJSHOTROD]

Thanks for the pic it is not the one I was wanting but looks good.

 

[Bob Wagner]

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[Bob Wagner]

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[Bob Wagner]

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[JasonCzerak]

http://turbodieselregister.com/forums/showthread.php?t=104648&highlight=Bulldog+ram+air+hood

 

[Gary - K7GLD]

I did some testing of my own. At 70 miles an hour on the interstate with no headwind or going up hills I could measure a half a pound of pressure between top of the airbox and the Turbo, this electronic manometer wasn't much over a hundred bucks but it was very accurate. Lawrence Boldon of Diesel Dynamics had one of my hoods on one of his project trucks he claimed that 70 miles an hour the hood was worth 35 to 40 horse I'm not sure how he come up with those figures

Yeah, I'm not sure where the guy came up with his numbers either - your 1/2 LB PSI increase sounds about right - but ANYONE thinking a 1/2 lb PSI intake increase at a normal cruising speed will magically deliver a 35-40 HP increase needs to be institutionalized - they're totally out of their skulls and ignorant of automotive physics - as well as REALITY! :-laf :-laf :-laf



Perhaps about 5 HP would be LOTS closer to the truth...

 

[MCummings]

Yeah, I'm not sure where the guy came up with his numbers either - your 1/2 LB PSI increase sounds about right - but ANYONE thinking a 1/2 lb PSI intake increase at a normal cruising speed will magically deliver a 35-40 HP increase needs to be institutionalized - they're totally out of their skulls and ignorant of automotive physics - as well as REALITY! :-laf :-laf :-laf



Perhaps about 5 HP would be LOTS closer to the truth...

Gary, there is one part of information we are failing to ask.



Sure there is now . 5 PSI of air pressure in the cold air ducting between the air filter and turbo.



Now we need to ask another question. What was the amount of vacuum before the addition of "ram-air"?



Going from 10" of vacuum to . 5PSI Positive pressure might be good for 35HP.





Merrick

 

[BTowler]

Lawrence Boldon of Diesel Dynamics had one of my hoods on one of his project trucks he claimed that 70 miles an hour the hood was worth 35 to 40 horse I'm not sure how he come up with those figures but with his knowledge I'm sure it was well based.

I would challenge that statement in a heart beat! How is he measuring real world figures? Does he have a dyno that simulates the wind resistance at 70mph? Once again, do the math, there is no way that you are ramming more air in than the engine is pumping on it's own. Any benefit is strictly cold air induction, which is good, but not for the figures I have heard many companies claim.



On edit: M Cummings, your post showed up immediately after I posted this. If you do the math, at 2000 rpm the engine is drawing in 1200000 cubic inches of air per minute. Figure the raim air scoop size and tell me if you are forcing that much air into the engine.

 

[HeberRam]

Right On!

Gary, there is one part of information we are failing to ask.



Sure there is now . 5 PSI of air pressure in the cold air ducting between the air filter and turbo.



Now we need to ask another question. What was the amount of vacuum before the addition of "ram-air"?



Going from 10" of vacuum to . 5PSI Positive pressure might be good for 35HP.





Merrick

Merrick, you are right on. Doug's design provided positive pressure where normally you would have a vacuum situation, which increased turbo spool and lowered EGT's. I had one his hoods on my second gen. and you definitely could feel a seat of pants power gain at 70 MPH and over. Lawrence Bolton a pioneer of Diesel Performance used to say if you can feel the power increase by a modification made to your engine by the seat of your pants (at that time 500 Hp truck) it would take more than 30hp actual gain to feel it. The higher the horse power truck was prior to the modification, the higher the HP modification would be in order to feel it. He has Dynoed thousands of times during his R&D of products and is the bases of his experience in making the statement.



Gary, I take exception to your remarks about Lawrence Bolton, and again your ignorance of diesel performance. Isn't it about time you quit TDR again? Hopefully this time you will stay gone... . :-laf :-laf