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05 XT2.5
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Discussion Starter · #1 ·
Re: my earlier moan about the milltek I modded an old motorcycle baffle I had in the shed and fitted it into the tailpipe. It's too quiet now :shake: but I have the option to drill some extra holes through if I get bored. No drone and the sound on boost is a bit less Subaru but with an interesting whoosh on top that I'm digging at the moment.

I can hear trim rattles that I never knew I had which is a pain but you don't get owt for nowt I suppose.

As the baffle came from a Harley Davidson exhaust I suppose this thread will be moved to the US section.
 

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2005 forester sti 6 speed manual
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428 Posts
"off a harley davidson":icon_eek:was it sat next to your leather chaps:biggrin:
keep an eye on it as it'll be rusted away inside of a month if your not carefull:chair:
 

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05 XT2.5
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Discussion Starter · #3 ·
No bike from any manufacturer in the world is made to a higher standard than a 'modern' - and I use the word aware of it's irony - Harley. Not Honda, not anyone. I admit this was not always the case and I admit I ride in leather jeans. No chaps though - sorry to spoil your fantasy....
 

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2005 forester sti 6 speed manual
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428 Posts
must admit once erik got his hands on some harley stuff they sort of appealed to me :catfight:, but i'll stick to R1 power and my one peice leather romper suit.:icon_wink::tissue:
 

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1999 Forester S Turbo 5MT
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I spent ages experimenting with different baffle designs before I landed on something acceptable, I found the motorcycle silencers too restrictive. That whooshing sound at the top end is caused by too much restriction.

My silencer is basically a 4" SS reducer with 2.5" SS pipe that comes drilled with 3mm holes all over it, for this very purpose, that I cut, spread drilled/tapped so that it could be bolted on to the narrow end of the cone. The pipe is around 8" long and loosely wrapped with wadding. Overall, it is similar to the baffle in the link below although I polished the cone, which has a shallower angle than that one, so mine looks nice :biggrin:. For all the agro I went through experimenting along with the cost, this would be a better solution and just wrap it with some (glass) wadding. That's mine at the bottom.

I drilled a 4mm hole in the exhaust and then a corresponding 3.2mm hole in the baffle and tapped that to M4. The hardness of the SS means that although it's only 1.5mm thick there is enough to hold the baffle securely in place with one fastener. I used a SS hex dome head M4 screw cut so that only about <0.5mm protrudes inside the lip. I think those nut and bolt fittings look a bit crude, but that's just me.

I've tried different diameters and lengths of piping and hole sizes as well as tight/loose wrap and different types of absorber but in the end this works best for a balance of noise reduction while keeping the power. I have a ZeroSports 3" catless system with a 4" straight pipe on the end. The motorway drone is a major issue with me along with a nasty pulsing bass I had at around 1.5K that was really annoying and uncomfortable at urban speeds (30 in 4th or 36mph in 4th).

If I pull the baffle, it is quicker but really noisy inside and out, as well as probably annoying everyone else so I think this is a good compromise. Final result is not as loud as some of the other lunatics around here but definitely UEL header/Scooby sound. It's kind of amusing seeing the young lads (everyone below 30 is young to me) heads turn when they hear me coming and the odd look on their faces when it isn't the Impreza they expected, "this is not the WRX you are looking for":starwars: :lol:.

4" Universal Exhaust Silencer Db Killer Fits Jap Box Baffle Bung | eBay

 

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98 sf - gls manual
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x2

and all bikes are made equal
dont mater if your a road racer or a comuter, stick together and keep our transport safe and legislation free
:)

same goes for our subarus lol
 

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05 XT2.5
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Discussion Starter · #10 ·
Having read Bassmakers post above I revisited my baffle and made it less restrictive. When it as on the bike it didn't do enough so I had a restrictor welded in. It still sounded rubbish so I dumped the whole system and bought a nice 2 into 1. Anyway I removed the restrictor (just hit it harder - it'll go - piiiiiinnnnnggggg - duck!!!!!) and wrapped the baffle in some of that exhaust wrap that people put round headers and such.

There's no whooshing now - it's just damped the annoying sounds out. I'm happy. :biggrin:
 

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55 2.5 XTEN Auto
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6 Posts
Ive just had the last 2 sections (cat bak) replaced with a ss hand made job. I have noticed the whooooshin near the red line. Do i have any restriction problems. wouldnt like to think ive been robbed of BHP after spendin 400 dabs.

mike
 

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Discussion Starter · #12 ·
Hard to say. When mine was too restricted there was a really pronounced whoosh as soon as you even got a tiny bit of boost going. Sounded quite cool actually but it certainly runs better now. And sounds pretty much like a Subaru. You also find with new exhausts - specially stainless ones - that the sound changes when they get sooted up a bit.

Also I could hear the whoosh really loudly with the rear window down a little so it was from the exhaust rather than the regular turbo whoosh from the engine compartment.

Don't know if that helps.
 
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