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Engine Specific Info and Questions => IDI Engine => Topic started by: Gizmoman on April 22, 2014, 05:30:23 am
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Now that I have the turbo sorted (K-14 to Holset HE200) and am drawing in a bunch more air, my intake is louder than the engine :o
I built a new filter housing and am drawing air in through the right pillar
(https://lh3.googleusercontent.com/-KyX2niSGUtI/Uzc8pu_EllI/AAAAAAAADT8/nCbX3aYTBeg/w975-h731-no/DSC01028.JPG)
(https://lh4.googleusercontent.com/-84oF08j5zhE/Uzc8l6DMpZI/AAAAAAAADTQ/eVzpKouvnLU/w975-h731-no/DSC01034.JPG)
I've done some reading but don't have a clear idea of the best solution - hoping for something simple. My first thought would be to get some dryer vent hose, form it around the square intake and run it up the pillar a foot or so. It will be tough to get the hose to stay in place but I'll figure something out. Maybe if I put a few bends in it on the way, it will deaden the sound a bit. I could also drill some small holes in the end of the housing around the edge (outside the sealing surface of the filter itself). Possibly bringing the air in several places will cancel out the in-rush through the single port I have now.
Any suggestions appreciated.
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The turbo that moves the air well also makes a lot of noise. Mine is in a lexan box and it is still louder than the engine. The car sounds like it has a turbo though. Probably like the intake, longer tubes make lower frequency so you may not hear it as much? Good luck
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AIUI...
Generally, sound waves travel straight, so curved or serpentine ducting is effective if the inner surfaces are non-reflective (soft).
Heavy materials generally absorb sound better than thin or light, e.g.: metal castings vs. thermoformed plastic. Dynamat type wrap on all the thin surfaces can help absorb resonance.
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cant you try a OEM airbox?with the snorkel inside?
if nor maybe you can locate the intake on another side,farther from the cabin...
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FWIW I'd try something like Dynamat on the outside and this: Auralex 2SF22CHA 2 x 2 Wedge StudioFoam 2" Foam
lining both the inside of what you have existing + an extension from the intake port.
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are you wanting to go after whistle or resonance?
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The turbo that moves the air well also makes a lot of noise. Mine is in a lexan box and it is still louder than the engine. The car sounds like it has a turbo though. Probably like the intake, longer tubes make lower frequency so you may not hear it as much? Good luck
Thanks, While the whistle is fine (actually less than the K-14), its the drone of the intake itself that gets to you over time and I'd rather not hear that at all.
FWIW I'd try something like Dynamat on the outside and this: Auralex 2SF22CHA 2 x 2 Wedge StudioFoam 2" Foam
lining both the inside of what you have existing + an extension from the intake port.
AIUI...
Generally, sound waves travel straight, so curved or serpentine ducting is effective if the inner surfaces are non-reflective (soft).
Heavy materials generally absorb sound better than thin or light, e.g.: metal castings vs. thermoformed plastic. Dynamat type wrap on all the thin surfaces can help absorb resonance.
Both great ideas. I'll see what I can rig up in the limited space. Possibly a tall thin box with baffles all lined with foam (if I can get it in the pillar)
cant you try a OEM airbox?with the snorkel inside? if nor maybe you can locate the intake on another side,farther from the cabin...
I don't have the stock intake (never did) and I doubt it could flow enough air. The other side is filled with my WAIC.
Thanks for the feedback!!
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I suspect part of your problem is turbulence in the transition from the small hose to that tin drum and from the drum to the square inlet to the outside air. I suspect that you will need to smooth up these transitions to have any chance of quieting it down. Pointing the inlet forward instead of at your feet may be the most important step, however.
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I suspect part of your problem is turbulence in the transition from the small hose to that tin drum and from the drum to the square inlet to the outside air. I suspect that you will need to smooth up these transitions to have any chance of quieting it down. Pointing the inlet forward instead of at your feet may be the most important step, however.
Good point about the "tin drum" - that's about what it sounds like - a big bass drum on max reverb.
Hmm. . .I may have to spend the weekend making an entirely different intake - possibly rectangular with plenty of baffles. Wife's gonna love hearing that ;D
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Add a 1/4 wave dead end passage off your intake tube. Same diameter, departing at 90 degrees.
start around 26" the total length of your intake path will have a big effect as well. An experiment with dryer duct might get you in the ballpark pretty quick.
Wrinkle coating the inside of your can might also help break up the boom.
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I think turbogreasel has the right idea. It could also be a tube that goes to a chamber off the side.
Dunno about wrinkle coating. bed liner type material probably damps the heck out of vibration tho.
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i see high HP buils using stock airbox(the larger,square one), why do you think it may not flow enough?
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i see high HP buils using stock airbox(the larger,square one), why do you think it may not flow enough?
Interesting thought, maybe I should have kept the 1.6 exhaust as well ;)
Kidding aside, typically automotive engineers who design stuff like this don't design them for three times the capacity required - just a guess though.
I ran a quick calc (keep in mind, I am math challenged) and came up with 322 CFM for my engine at 3200 RPM @20 psi. In comparison, the 1.6 NA runs about 90.4 CFM@ 3200.
Granted the numbers are rough, but that's nearly a 256% increase in air volume over the stock engine.
A stock 2.1 gasser vanagon intake box (as you suggested) would be designed to flow approximately 119 CFM @ 3200 - still 170% less than required for my engine.
If anyone want's to take a stab how many CFM's I may be running at 20 PSI/3200 RPM, that would be very interesting. Turbo is an HE200, medium head porting and short 2-1/2" exhaust.
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A quick test using the factory air box and a sensitive vacuum gauge in the intake tract might answer your question. As long as you're seeing less than 15" water column you should be fine.
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A quick test using the factory air box and a sensitive vacuum gauge in the intake tract might answer your question. As long as you're seeing less than 15" water column you should be fine.
Interesting concept, although I don't have a stock box to try your suggestion.
If you wouldn't mind explaining (in layman's terms) how that 15"w.c. relates to my engine's ability to receive all the air it can, that would be sweet.
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A quick test using the factory air box and a sensitive vacuum gauge in the intake tract might answer your question. As long as you're seeing less than 15" water column you should be fine.
OK - got it
"First, the term Absolute Pressure means the pressure above a zero reference (a perfect vacuum). Ambient atmospheric pressure at sea level on a "standard day" is approximately 14.696 psi absolute (or 29.92 inches of mercury, "HG, explained below).
Manifold Absolute Pressure, then, is just what it says: The absolute pressure which exists in the inlet manifold, usually measured in the plenum (if one exists). The MAP in an engine which is not running is equal to atmospheric pressure. If, on a "standard day", an engine is idling at a measured manifold "vacuum" of 14 inches,, the MAP is actually 15.92 "HG (29.92 - 14 = 15.92)."
Quoted from here http://www.epi-eng.com/piston_engine_technology/volumetric_efficiency.htm (http://www.epi-eng.com/piston_engine_technology/volumetric_efficiency.htm) - bottom of page.
I also found this handy calculator and plugged in a few numbers. This calculator was developed for the Mitsubishi 3000GT VR4 and Dodge Stealth TT turbocharged cars. "Overall density ratios are usually less than 2.5 (that is boost pressure is less than 24 psi)."
(https://lh6.googleusercontent.com/-LLDZxx4rXKs/U1kC8mLwXPI/AAAAAAAADdE/RLh7q3_VpZk/w622-h111-no/VE_1.9.jpg)
The calculator is found here http://www.stealth316.com/2-air-fuel-flow.htm (http://www.stealth316.com/2-air-fuel-flow.htm)
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15" of water sounds like a lot, and that is half a psi, im not sure what would be an appropriate amount tho.
my only suggestion would be to try the stock air box from a vehicle that has at least 200hp stock, which shouldn't be hard to find by browsing through a junkyard
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15" of water sounds like a lot, and that is half a psi, im not sure what would be an appropriate amount tho.
my only suggestion would be to try the stock air box from a vehicle that has at least 200hp stock, which shouldn't be hard to find by browsing through a junkyard
Yeah, I though of doing that. I've been looking at various boxes online but they don't offer dimensions. The good part though is they are generally designed to be quiet.
Browsing through a junkyard with a tape measure and a few simple tools would be a smarter way to approach this.
I've been driving the van to work every day this week (several semi-steep grades at 65-70). The round trip is about 45 miles. Other than the low drone from the intake - this engine really goes!
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15" of water column is about 1" hg so it's pretty minimal. Although it's the max amount of "vacuum" you want to see in your intake tract. As a reference it would be a worth while test to do on your current system. Sometimes air filter box's are built to flow way more air than the factory rated airflow through an engine. The MK4 is a perfect example. The stock air box on an MK4 can flow a ridiculous amount of air to the point that only the highest hp builds run custom systems. It's virtually the same air box on a 90 hp ALH and a 280 hp VR6.
If you end up at a junk yard, see if you can find a filter minder off a diesel truck. A lot of the GM gas trucks and SUVS have them too. It can help you get the most out of your air intake system.
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I like the hoses....
GB
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I like the hoses....
GB
Yeah GB, everyone who looks at the engine likes em as well ;D. I tell em they're wrapped with 20 dollar bills and painted blue ;D
Thanks for the input fellas. I removed the can today and wrapped it in rattle trap. Then I got a 4" diameter bit of expanding aluminum dryer duct and formed it over the intake of the can and up the rear pillar. I but a few bends in it and its a very rough surface. I'll report tomorrow if the ride to work is a bit quieter.
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I can make a custom silicone flex duct with cuffs on each end 1' thru 5' i.d.
I make these for aircraft heating and cooling systems
send me a email for a pic you may load, helping you helps others
GB
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i wasnt refering to stock vanagon airbox,my mistake.
was talking the golf ones.
seen many people running tdi engines on mk2 shells with above 200hp using OEM airboxes(to avoid problem with police),i am running a vnt2052 at 1.5bar with passat airbox(just removed the snorkel as it was smaller diameter) and -not as a good example because its a gas engine- i run stock airbox with my golf g60 and i am hitting above 180hp.
stock golf limited was 210hp from factory and used same box.(equal to late TD ones,just different locations on exit holes).
how can we check if airbox is becoming a problem?
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i wasnt refering to stock vanagon airbox,my mistake.
was talking the golf ones.
seen many people running tdi engines on mk2 shells with above 200hp using OEM airboxes(to avoid problem with police),i am running a vnt2052 at 1.5bar with passat airbox(just removed the snorkel as it was smaller diameter) and -not as a good example because its a gas engine- i run stock airbox with my golf g60 and i am hitting above 180hp.
stock golf limited was 210hp from factory and used same box.(equal to late TD ones,just different locations on exit holes).
how can we check if airbox is becoming a problem?
Agreed, there are probably plenty of air boxes I could use that wouldn't hurt the airflow and if what I did to mine didn't do much (very likely), it's time to go browsing.
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i see high HP buils using stock airbox(the larger,square one), why do you think it may not flow enough?
Interesting thought, maybe I should have kept the 1.6 exhaust as well ;)
Kidding aside, typically automotive engineers who design stuff like this don't design them for three times the capacity required - just a guess though.
I ran a quick calc (keep in mind, I am math challenged) and came up with 322 CFM for my engine at 3200 RPM @20 psi. In comparison, the 1.6 NA runs about 90.4 CFM@ 3200.
Granted the numbers are rough, but that's nearly a 256% increase in air volume over the stock engine.
A stock 2.1 gasser vanagon intake box (as you suggested) would be designed to flow approximately 119 CFM @ 3200 - still 170% less than required for my engine.
If anyone want's to take a stab how many CFM's I may be running at 20 PSI/3200 RPM, that would be very interesting. Turbo is an HE200, medium head porting and short 2-1/2" exhaust.
I might be wrong, but have you overestimated the extra air gained by 20 psi?
If n/a air is at 14.7psi, and true pressure is atmos + reading, ie 34.7psi, I make that 90.4 x 34.7/14.7, or 213cfm...
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i see high HP buils using stock airbox(the larger,square one), why do you think it may not flow enough?
Interesting thought, maybe I should have kept the 1.6 exhaust as well ;)
Kidding aside, typically automotive engineers who design stuff like this don't design them for three times the capacity required - just a guess though.
I ran a quick calc (keep in mind, I am math challenged) and came up with 322 CFM for my engine at 3200 RPM @20 psi. In comparison, the 1.6 NA runs about 90.4 CFM@ 3200.
Granted the numbers are rough, but that's nearly a 256% increase in air volume over the stock engine.
A stock 2.1 gasser vanagon intake box (as you suggested) would be designed to flow approximately 119 CFM @ 3200 - still 170% less than required for my engine.
If anyone want's to take a stab how many CFM's I may be running at 20 PSI/3200 RPM, that would be very interesting. Turbo is an HE200, medium head porting and short 2-1/2" exhaust.
I might be wrong, but have you overestimated the extra air gained by 20 psi?
If n/a air is at 14.7psi, and true pressure is atmos + reading, ie 34.7psi, I make that 90.4 x 34.7/14.7, or 213cfm...
Am I wrong? extremely good chance of that
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What I did, with the 4" wrinkly drier duct and rattle trap on the can seems to have brought things under control.
Now all I can hear is the cabinet doors rattling ;D
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If you get the total tube length exactly wrong, not only is it loud, it's also self amplifying.
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What I did, with the 4" wrinkly drier duct and rattle trap on the can seems to have brought things under control.
Now all I can hear is the cabinet doors rattling ;D
I'd be interested in some pictures next time you have it out :)
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Ha - Im big on taking lots of pics while I work, except for this time - go figure.
When I fabbed the can up, I just got lucky when I made the intake which ended up having the same perimeter measurements as the ID of 4" flex duct (12.57"). I used the 4" aluminum drier ducting from Home Depot (found in the ducting isle). Mashed it into an oval and bent it to look like a flattened 2' long candy cane.
I formed one end to fit onto the intake and stuffed it up the pillar. You can see the top end of the candy cane if you look down into the pillar through the vent.
Then I installed the back half of the can. It was tough but after I got the can in and worked the formed the flex-duct end onto the intake (which is pointing straight up), I used that aluminum ducting tape (not the fabric duct tape) to hold in in place. I also added some tape to the inside where the flex slips over the intake just to make sure it never comes off.
Heres a shot of the intake - it's ponting like this when mounted and aligned to shoot straight over and up to the vertical pillar - in other words, a slight jog is required in the flex before it goes vertical.
(https://lh4.googleusercontent.com/-zmvhCCmuIVE/Uzc8qf_e_HI/AAAAAAAADUE/R6ll4RTx8n4/w959-h719-no/DSC01027.JPG)
As suggested, the sound has to smack against the first bend at the top (the "J" of the candy cane shape), hit all the "ruffles of the ducting, hit the jog in the bottom, then finally enter the can.
Sorry, but chances of ever taking it out are slim. Hopefully my explanation combined with your imagination, you can visualize the outcome.
I wish I had Db readings from before and after (have an app on my phone) but I don't have that either :(
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So the dryer hose is your actual intake hose, post filter correct?
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So the dryer hose is your actual intake hose, post filter correct?
Considering the direction of air-flow, I'd call it pre-filter
Here's a shot of the intake HARD piping from the filter to the turbo inlet
(https://lh6.googleusercontent.com/-isS2xKb6w50/U0nfhAaXzyI/AAAAAAAADYE/RIfqZqAEcOc/w959-h719-no/DSC01056.JPG)
Here's a shot down the RH pillar through the vent. You can make out the dryer vent tube inside the collum
(https://lh6.googleusercontent.com/-db9IgSoTMxs/U1xLE0WFYUI/AAAAAAAADeQ/kuRuwhlrC7Y/w959-h719-no/DSC01091.JPG)
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That makes more sense. Thanks Jim.
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I can make this for you with smooth cuffs
http://www.aircraftspruce.com/catalog/appages/sceet.php?clickkey=5261
advise your i.d. and length
3' i.d. is 3.50 per inch
http://www.beechtalk.com/forums/viewtopic.php?f=37&t=90998&view=unread#unread
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(http://i218.photobucket.com/albums/cc281/d-schnutz/skeet.jpg)
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85 % of my work is aircraft gaskets , hoses and ducts
I support 465 different models of aircraft, I do the silicone automotive for ***s and giggles
The ducati coolant hoses allows me to get a new model to tool for every two years..
If you want the best quality, let me know
My silicone ticco hoses kits sell very well, and are shown above..
GB
Name three people that were shot in the back of the head
1. President Lincoln
2.President Kennedy
3.The Guy sitting in front of Pee-Wee at the adult theatre
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I can make this for you with smooth cuffs
http://www.aircraftspruce.com/catalog/appages/sceet.php?clickkey=5261
advise your i.d. and length
3' i.d. is 3.50 per inch
http://www.beechtalk.com/forums/viewtopic.php?f=37&t=90998&view=unread#unread
Thanks for the offer, The aluminum drier vent pipe is working just dandy and I think the rough ID helps quiet things a bit.
(http://i218.photobucket.com/albums/cc281/d-schnutz/skeet.jpg)
I don't get it. However, I've shot skeet, sometimes even two, but never three. Oh, and I believe that guy's been caught shooting something as well (sorry)
Gee-Bee, ironically, I was posting this at the same time
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Its spelled Sceet
Its a 2 ply silicone with one wire fiberglass reinforcement..
Used in heater and intake air applications..
GB
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Its spelled Sceet
Its a 2 ply silicone with one wire fiberglass reinforcement..
Used in heater and intake air applications..
GB
Thanks for the explanation and good to know what you can do. I design separation machinery for the recycling industry and I'll file this info in my head for a possible solution of some sort.
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Name three people that were shot in the back of the head
1. President Lincoln
2.President Kennedy
3.The Guy sitting in front of Pee-Wee at the adult theatre
hahaha, thats one of my favorite jokes
and skeet was something dave chappelle used to say frequently, its meaning is perverse