| Author | Message | ||
     Torquehd |
I know some of you Badwebbers are educated on the finer points of vehicle design theory. I'm thinking of designing a new cold air intake for my '07 duramax that feeds directly from the outside of the vehicle (think cutting a hole in the body panels). I'm trying to figure out the best place, from a theoretical standpoint, to draw air from. It should be at a point where the air pressure is high when the vehicle is moving, right? But anywhere along the lines or sides of the hood or fender will be low pressure, because the air is moving fast like in a venturi or airfoil?? Any insight? I've wondered the same thing for motorcycle design. isn't that why jon britten put the intake right in the middle of the front of the vehicle (the "apex" of the "raindrop"? man i need to go to school and learn this stuff for real) | ||
| Mr_grumpy |
Ram scoop & shaker hood conversion maybe? Question is why? it should already have a cold air intake point. I'd be looking to pick up somewhere in front of or next to the radiator. | ||
| Akbuell |
The NASCAR guys all use the juncture of the end of the hood/base of the windshield. High(er) pressure when moving, and tends to discourage solid bits from coming in. And given the number of years they have been doing this, and the amount of money and time they spend in a wind tunnel, probably a good place to start. | ||
| Torquehd |
for function and looks. been wanting to play around with fiberglass or carbon again. and see if "ram air" would do anything for fuel efficiency. | ||
| Hughlysses |
The early Oldsmobile 442's used to have two massive scoops under the bumper. These fed ~4 inch flex ducts that tied directly into the air cleaner. These parts were a pretty cool/cheap retrofit for other cars of the time.  You could rig up something like that. I wonder if they're available as reproduction parts? | ||
| Torquehd |
oh, now that's cool. if nothing else, it looks like horsepower in the making. except for the accordian hose that adds turbulence to the airflow... that probably defeats anything that the scoops would gain. | ||
| Akbuell |
One more thing, to expand on Grumpy's question about Why? Engines that are tuned for torque won't really gain much, if anything, from ram air induction. Nothing wrong with fabbing fun aero devices that also work. | ||
| Hootowl |
I think he wants cool air, not ram air. You don't want to try to suck air from low pressure areas. Hard to tell where those might be unless you designed the car, or have access to the wind tunnel data. Generally, the cowl is a good place to get fresh cool air. | ||
| Natexlh1000 |
Most modern cars inhale from the empty space in the fender. It may be a good idea to actually measure the intake temp with a thermocouple. I'll wager it's pretty much the same as the outside ambient temp except in heavy traffic. | ||
| Hootowl |
here's a cowl induction hood for a 2007 chevy truck. http://www.summitracing.com/search/product-line/go odmark-steel-cowl-induction-hoods/year/2007?SortBy =Default&SortOrder=Default | ||
| Torquehd |
The XBRR used that ridiculously huge dual intake tube setup that stretched out of the airbox up into the fairing. it looks ridiculous, but i wonder how much difference a similar setup would make on an 1125, the intake duct on which is surprisingly narrow and runs inbetween the hot frame and the hot valve cover iirc. there are a lot of ugly "ram air" airbox covers for the XB, but they do seem like they'd be better at drawing in cool air than the factory setup. especially if you closed off the lower portion of the airbox so the air had to come in through the "ram air" port. | ||
| Buelliedan |
cold air for a diesel is not necessarily a good thing. I have found that my powerstroke makes more power when the incoming air is about 95-100 degrees. Diesels and gas engines are very different in this respect. | ||
| Strokizator |
If your turbocharged rig is equipped with a wastegate then the net results will be the same whether you start at 0 psi (1 atmosphere) or slightly above or below. I think an aftercooler would get better results (I'm not familiar with the Duramax intake system and you may already have one). | ||
| Gregtonn |
In the end it would probably be cheaper to buy a kit from somebody like AirAid. They've already done the research you're asking about and run the kit on a dyno. G | ||
| Azxb9r |
Keep in mind that under boost that duramax is the worlds most powerfull shop vac. The intake needs to be someplace that it is not going to suck up water while driving in the rain or splashing through puddles. One other consideration is the integrity of your filter media. GM has had issues with some aftermarket air filters getting sucked into the turbo and ruining the vanes. | ||
| Torquehd |
haha... funny you should mention that. the previous duramax I owned had been severely neglected. I bought it just prior to moving across country. The aftermarket air filter was so clogged it was unserviceable (unwashable). I couldn't get a replacement in time, so I cut up a t-shirt and hose-clamped it over the intake. It held fine from NC all the way to Montana. Then I heard a "chunk", felt a little bump, and my turbo started wining loudly. The T-shirt was gone, along with half the impeller wheel. I wasn't able to fix it til I got to Washington. Had to drop the transmission to replace the turbo. And as you can imagine, the engine started consuming oil after that. That's a mistake I won't make again. |
