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Catch can advice

Posted: Tue Aug 12, 2014 12:45 pm
by jjmartin349571
Hi folks,

I want to run a catch can on Laura's Audi as it's apparently an upgrade which can help prolong the life of a turbo engine. I know little about catch cans other than cheap ones are hollow and for them to be effective you want some gauze/screen inside of them to cause the oil vapours to condense. I seem to recall somebody mentioning that you can push wire wool inside of the cheapo ones though and this produces the same effect as the more expensive ones - is this true? Or am I going to have to stump up for some proper kit :?

Cheers,
Josh

Posted: Tue Aug 12, 2014 1:01 pm
by Thebusofwoe
All i can tell ya chap is i ran a cheap one with alot of wire wool stuffed into it. I ran that on my 200sx s13 1.8t. And it did ok. But i wish i had brought a proper one with the proper condensing baffles. :D

Posted: Tue Aug 12, 2014 1:05 pm
by bennyboy
I've run an empty one for years. Yes, in an ideal world it would have some gauze, but it's not the be all and end all - look at where the hoses attach too, offset is best, so that the oil has chance to 'hit' the insides of the tank.
You'd be surprised how much they catch.
Oh and use proper vac hose of course, they are a vacuum system so conventional hose will collapse eventually.

Posted: Tue Aug 12, 2014 1:28 pm
by Drax
theres the stupid expensive baffled mishimoto ones, or most other basic cheap ones as far as I can see.

only new one ive seen are these
http://www.ebay.com/itm/ADD-W1-Blue-Baf ... 18&vxp=mtr
no idea if "universal" ones are any good or b0ll0cks :? but they seem reasonably cheap for (supposedly) baffled

Posted: Tue Aug 12, 2014 1:47 pm
by Thebusofwoe
The one i got for my Nissan when i had it was advertised as baffled, but it wasn't :evil:

Posted: Tue Aug 12, 2014 1:50 pm
by NafemanNathan
This is inside the Mishimoto one...

Image

It's expense, because it's well made, but the principle is simple. All that's needed is a divide purely so the vapours aren't instantly drawn back out of the catch tank into the inlet manifold. A baffle plate could do this, like this...

Image

But if you added a gauze roughly where it says "BAFFLE DIVIDER" from the side wall to the baffle plate and retain it somehow, that would be even better. Just obviously don't have your baffle plate too low that the bottom of it would get submerged in oil and cause a vacuum.

Posted: Tue Aug 12, 2014 2:17 pm
by Drax
hmmm it seems if someone like Tramroad bought a load of cheapo ones then used his quick super mega awesome welding skills to put in little baffle plates and then resold them, we'd have cheaper baffled oil catch cans, plus he'd make a nice little side bit of cash....... maybe? :oops:

or not as easy as that... :?

Posted: Tue Aug 12, 2014 2:31 pm
by NafemanNathan
Yeah, quite easy... Although probably not worth the effort ;)

You could just cut a piece of stainless/aluminium plate a fraction wider than the ID of the catch can, cut it full length, but then cut a big notch out of it from the bottom (so that it has two legs). Then flex the plate so that it drops down inside the catch can. When you let go the legs will sit on the bottom so that it doesn't drop, and the sides should jam up against the ID (That's why you cut it a fraction wider). Just make sure you cut the crotch of the notch high enough or know where it is, so that the oil that collects on the inside never reaches it.

... If that make sense. You obviously need a catch can with a removable lid ;-)

Posted: Tue Aug 12, 2014 3:17 pm
by Drax
NafemanNathan wrote:Yeah, quite easy... Although probably not worth the effort ;)

You could just cut a piece of stainless/aluminium plate a fraction wider than the ID of the catch can, cut it full length, but then cut a big notch out of it from the bottom (so that it has two legs). Then flex the plate so that it drops down inside the catch can. When you let go the legs will sit on the bottom so that it doesn't drop, and the sides should jam up against the ID (That's why you cut it a fraction wider). Just make sure you cut the crotch of the notch high enough or know where it is, so that the oil that collects on the inside never reaches it.

... If that make sense. You obviously need a catch can with a removable lid ;-)
sounds quite easy... if you have the plate alloy, cutting tools etc. ;) ill look into getting that done by a mate, thanks Nath 8-)

Posted: Tue Aug 12, 2014 3:21 pm
by NafemanNathan
Tin snip and/or hacksaw would suffice, and I'm sure you could scrounge some material from somewhere/something ;)