Homefry RS2 Setup boost?

[Rusty]

Connection is on the underside of the IM and does get pressurised when under boost, check valve ensures this part of the system is only open to the breather under vacuum, it's almost clever!

[newsh]

Ok John, I'm following what your saying, but what confuses me is how does boost get to the sump vent side of the valve in the first place anyway?

It only happens when the One Way Valve gets stuck open. In this diagram its called the check valve.

[s2_bo]

Fair comment Bo.. You'd think so wouldn't you but there must be some pressure build up, not a lot but the only escape is via that 12mm tube round to the MAF hose..

The one way valve fits in between the 2 different size pies round the back of the IM, it looks just like the pipe reduces in size, the valve is hidden in there.

This could be the problem with Steve's car as the boost test pressurises both sides of this valve equally so the valve does not actually get tested.. Next time we'll disconnect the PCV system so it does.

Ok John, I'm following what your saying, but what confuses me is how does boost get to the sump vent side of the valve in the first place anyway?
Am i completely missing something here?

I thought the system connected to vents at the sump and the cam cover and then again at the maf hose.
Is there another connection somewhere else? As all the above never see any pressure anyway.

Sorry to hijack this thread. Just trying to clear this up in my head more then anything else..

Andy when i first fitted the tank i think something was wrong, mainly with the venting. thats why it now vets out to the wing, no more fumes in the engine bay.


Good luck Steve

[stevieyid]

How about the DV Steve?

The DV has been changed a few times with various different items.

[newsh]

How about the DV Steve?

[Rusty]

Ah, was that why you pressurized your catch tank Bo?

[newsh]

John are you sure that thats correct? The Maf hose is pre turbo so any boost going in there will just vanish.
It could only build up pressure if there was no free exit to atmosphere. I.e. if it was only routed to the sump and cam cover for example. Then both would pressurized.

Also, the famous one way valve, where does it plumb in? I binned mine so many years ago, cant even remember what it looks like.




Steve, have you tried a diffrent maf or wgfv? Sorry if you have already stated that in this thread...

Fair comment Bo.. You'd think so wouldn't you but there must be some pressure build up, not a lot but the only escape is via that 12mm tube round to the MAF hose..

The one way valve fits in between the 2 different size pies round the back of the IM, it looks just like the pipe reduces in size, the valve is hidden in there.

This could be the problem with Steve's car as the boost test pressurises both sides of this valve equally so the valve does not actually get tested.. Next time we'll disconnect the PCV system so it does.

[stevieyid]

Not tried a different MAF yet although i will give my brothers one a go at some point. The wgfv is brand new and i have changed it with another from my brothers but no difference

[s2_bo]

Good one Steve and nice explanation Rusty ( BTW I'm less grumpy today for some reason

The pipe that the one-way-valve goes to is vented into the MAF hose so if it does fail its basically sending boost back to the MAF, it will put the seals under a bit of pressure (I've had the Cam cover seal fail due to this) but it wont build up a load of pressure.

Off on work for a few days now Steve will be back Sunday at some point.

John are you sure that thats correct? The Maf hose is pre turbo so any boost going in there will just vanish.
It could only build up pressure if there was no free exit to atmosphere. I.e. if it was only routed to the sump and cam cover for example. Then both would pressurized.

Also, the famous one way valve, where does it plumb in? I binned mine so many years ago, cant even remember what it looks like.




Steve, have you tried a diffrent maf or wgfv? Sorry if you have already stated that in this thread...

[stevieyid]

Took the car out today and put it in third gear gave it WOT from about 30mph up to red line. It boost to about 1.3 bar then back to 1 bar around 5k rpm but then started to increase again to 1.3 bar until 7k rpm! Does this make the diagnosis of the problem any better?

[newsh]

Good one Steve and nice explanation Rusty ( BTW I'm less grumpy today for some reason

The pipe that the one-way-valve goes to is vented into the MAF hose so if it does fail its basically sending boost back to the MAF, it will put the seals under a bit of pressure (I've had the Cam cover seal fail due to this) but it wont build up a load of pressure.

Off on work for a few days now Steve will be back Sunday at some point.

[Rusty]

My mistake Bo, assumption is the mother of all f ups and all that...

Removal of all the knackered old breather system can only be a good thing if done correctly.

[Rusty]

Thinking about it i would be better with one of your catch tank kits

Sure would, give me a shout, still for sale.

[stevieyid]

If i put, let's say 1bar of pressure to the maf hose. How long should the pressure hold?
Longer than 15sek.

Bad injector o-rings makes the screeching sound? Got to look in to that.

Here is the thread about the injector rings causing a whistling noise under boost:

http://www.s2forum.com/forum/showthread.php?t=37241&highlight=squeeling

Could explain my slightly low boost and also the noise im getting. So changing the injector O Riungs is my next mission

[quattro20v]

I forgot to write that, i had soapy water when i tested. About everywhere else but the injectors.

Thanks for the tip.

Btw. a flametrap of 7A