Club G40 Forum

Technical => Engine and Transmission => Topic started by: Chris_J on February 24, 2012, 08:07:38 PM

Title: Boost Return Mod - But without the hoo-haa
Post by: Chris_J on February 24, 2012, 08:07:38 PM
Ok, so I've been one of those who was never a fan of hot, moist and dirty (ooo errr) crankcase vapour being the only means of lubrication for the charger, so I intend on carrying out the boost return mod at some stage.

However, I want to dampen the sound as much as possible and I don't really want to remove the charcoal canister and purge valve etc to achieve this. Main reason really is I want it mostly to remain as factory as possible.

So, my idea is this - what if I remove the short length of hose from the rocker cover to the charger return, blank the return and run a new hose away relatively discretely from the rocker cover an down towards the slam panel into a catch tank.

Does that sound reasonable? My only concern really is the release pressure from the charger having to expel into the catch tank. May make a mess? My hope is this will cause minimal modification, but also dampen the noise?

Chris.
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: Alex on February 24, 2012, 08:20:30 PM
Surely you'd be better off running the boost return hose and blanking the inlet for the oil breather hose. Then run the oil breather to the catch tank.
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: PeteG40 on February 24, 2012, 08:30:48 PM
plug breather hose at the bottom and run breather to a catch tank. (hidden)

Get a new (second hand) hose from rocker to charger.  cut the bottom ridge off  and put holes in the bottom of it.  Then make a blanking plate same size as where  it attaches to charger amd put it under the hose.

looks factory..... boost return
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: Chris_J on February 24, 2012, 08:54:02 PM
Hang on, but then where does the excess boost pressure go? I have become confused :P
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: PeteG40 on February 25, 2012, 08:28:26 AM
excess pressure goes out the holes in the bottom of the rocker to charger hose.
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: Chris_J on February 25, 2012, 09:48:04 AM
Ah yes, makes perfect sense!

Cheers
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: Justin14100 on February 25, 2012, 10:24:01 AM
The induction noise is still going to be largely increased too its just the dump valve noise that will be muffled slightly, you'd most likely still hear it.
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: AlexG40 on February 25, 2012, 11:01:51 PM
This is what you mean?

(http://farm5.static.flickr.com/4107/5172547976_124d19ed8d_z.jpg)
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: scotsjohn on February 26, 2012, 04:51:47 PM
Stop showing that under-bonnet shot Alex. It makes me feel inadequate.
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: AlexG40 on February 26, 2012, 06:24:23 PM
Quote from: scotsjohn on February 26, 2012, 04:51:47 PM
Stop showing that under-bonnet shot Alex. It makes me feel inadequate.

It doesn't make me feel any better seeing as though it isn't there anymore.
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: Chris_J on February 27, 2012, 09:51:55 AM
Looks stock to me, Alex! So did you do what Pete described?
Title: Re: Boost Return Mod - But without the hoo-haa
Post by: AlexG40 on February 27, 2012, 06:32:41 PM
I had a blank at the charger end of the return pipe from the cover. I blanked off the breather pipe where it goes into the return elbow. Then I put a new length of pipe about 1.5 inches in diameter in to the elbow right on the corner after the tb and ran it down the back of the engine about a foot. Then fitted catch tank as normal. You can still hear the return but it's quiet compared to all the others I've heard and it looks stock.