Reduce Subaru induction noise

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mshaw1980
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Reduce Subaru induction noise

Post by mshaw1980 »

Hello

So nearly at a point where my van is ready to drive, hurrah, however I have noticed the induction noise is quite annoying, almost like a hum or whine coming from passenger side rear intake vent.

I have a standard Subaru air filter box so thought it would be fairly quiet but it's not. Anyone got any suggestions what to do? Most of the van is sound deadened as I have put loads on it but as said induction noise is a bit annoying.

Thanks
1987 VW T25: Subaru EJ20 using RJES parts (If it was meant to go fast it wouldn't be brick shaped!)

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Titus A Duxass
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Re: Reduce Subaru induction noise

Post by Titus A Duxass »

Use the oval sound deadening oval duct that VW developed.
It's not the cheapest solution but it does work.
VW T3 GTi Camper 2,0l

mshaw1980
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Re: Reduce Subaru induction noise

Post by mshaw1980 »

Titus A Duxass wrote:Use the oval sound deadening oval duct that VW developed.
It's not the cheapest solution but it does work.
.

Do you mean this?

http://www.brickwerks.co.uk/air-intake-hose-t3-rear-pi" onclick="window.open(this.href);return false;
1987 VW T25: Subaru EJ20 using RJES parts (If it was meant to go fast it wouldn't be brick shaped!)

multisi
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Re: Reduce Subaru induction noise

Post by multisi »

Try a universal cone type filter, I have a Subaru air box on the 3.3 that I modified and that links into the vw intake hose and snorkel on the left side, that was there already being that the van was a late diesel originally. The petrol version wont fit cos its handed to fit in the right side. I don't have any annoying sound from either set up.
1992 red lle 2.2 subaru 1990 rhd caravelle 2.2 subaru 1986 california import vanagon

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Titus A Duxass
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Re: Reduce Subaru induction noise

Post by Titus A Duxass »

Yes, that's the one.
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adie89
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Re: Reduce Subaru induction noise

Post by adie89 »

I’ve also used th diesel filter housing to significantly reduce induction noise, my dog hated it using a cone filter straight into the engine bay. It had only meant to be a temporary job to get th3 conversion finished in time. I got a welder to move the air box intake so I could flip the housing 180. However when I did my cfm research and found the numbers are similar for 1.6D to 2.5petrol I missed an important factor, the petrol revs higher and subsequently it gets strangled above 3,5 to 4k rpm. The theory was there, the air box outlet was only 10mm dia smaller than the Subaru air box but with an unfortunately restrictive snorkel hose (it was a tired original one). It’s noticeably worse on power without the snorkel attached. I lost the Subaru air box and pipe in a house move.
Image
The intake is now at the opposite end and points Behind the light cluster on the right side
Another welder fabricator made me an ally induction pipe with the crankcase breather and fuel vapour line feeds. Sorry I don’t have a picture handy.
I do have another air box and a box full of various intake bits so I’ll have a tinker once the bodywork is done, it passes MOT with the filter and drives ok so it’s a low priority to bits falling off/buggered.
I’m only continuing with this because I have the bits, I would have just used a K&N Apollo type jobby connected to a snorkel and wrapped the whole thing in foam to further deaden noise.

That reminds me I’m sure I saw a thread where someone used the tar like roof flashing sheets as a cheap dynamat inside the rear quarter to reduce the resonance on the very long sheet panel. A few Db here and there add up eventually.
Greta: 85’ LHD 2.5L Subaru 14in Syncro
http://forum.club8090.co.uk/viewtopic.php?t=165773

multisi
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Re: Reduce Subaru induction noise

Post by multisi »

Nobody suggested using the diesel air filter housing .
1992 red lle 2.2 subaru 1990 rhd caravelle 2.2 subaru 1986 california import vanagon

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Cobra88
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Re: Reduce Subaru induction noise

Post by Cobra88 »

Stick a WBX back in mate :lol:
____________________________________________
84 CaravelleGL 1.9 DG WBX Bronze Beige Metallic auto

mshaw1980
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Re: Reduce Subaru induction noise

Post by mshaw1980 »

WBX spun a big end an hour after buying the van in Devon ( home is the isle of man) so you can understand if I think it's crap. Subaru nearly double the power and more reliable.
1987 VW T25: Subaru EJ20 using RJES parts (If it was meant to go fast it wouldn't be brick shaped!)

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Woodyyellow
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Re: Reduce Subaru induction noise

Post by Woodyyellow »

Hi Mark
Just been rereading this again and was thinking if it is possible to collect the air down the rear air duct using a snorkel. I think VW only ever made one for the os, so it would need some fabrication but would take the actual intake point up to the top of the rear pillar and away from the engine bay. Not sure if the noise would be more tolerable from that area. Need some research doing.
John
1987 1.9 WBX DG Hi-Top. Soon to be Subaru ej20

I'm an old guy but I still learn new stuff!

adie89
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Re: Reduce Subaru induction noise

Post by adie89 »

Woodyyellow wrote:Hi Mark
Just been rereading this again and was thinking if it is possible to collect the air down the rear air duct using a snorkel. I think VW only ever made one for the os, so it would need some fabrication but would take the actual intake point up to the top of the rear pillar and away from the engine bay. Not sure if the noise would be more tolerable from that area. Need some research doing.
John

Diesel was left side, petrol was right side. The actual structure and mounting clips both sides is identical. Key bit being that the inlet faces rearwards so it doesn’t suck in water in the rain, and it does, a lot. Found out the hard way.
Greta: 85’ LHD 2.5L Subaru 14in Syncro
http://forum.club8090.co.uk/viewtopic.php?t=165773

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