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Are catch cans necessary with single turbo setups?

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Old Mar 27, 2011 | 10:08 PM
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Default Are catch cans necessary with single turbo setups?

I'm about to go with a pte6265 single turbo kit from boostlogic and I see that some of you run catch cans. Are they really necessary?
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Old Mar 27, 2011 | 11:17 PM
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i dont think so IMO, they look good if you do it right, if you have that much blow by then something is wrong
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Old Mar 28, 2011 | 08:03 AM
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how much boost are you planning on running?

i personally wouldn't bother running a catch can unless i'm running more than 16-18psi on a stock 9.0:1 GTE.

maybe i'd run a catch can on an NA-T setup and 10psi or so, but the engine compression is like 10.0:1
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Old Mar 28, 2011 | 08:27 AM
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my na-t has never had any blow by whatsoever at stock compression or with the TT gasket so im not so sure it has to do with compression, more health of the motor.
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Old Mar 28, 2011 | 04:25 PM
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I'm gonna be on the stock 550s for a bit so I'm guessing I can't run more than 14 psi of boost. I'll run without a can then.
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Old Mar 28, 2011 | 10:26 PM
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IDK. My motor has 197-202 compression and I think I have a little blow by. Its just part of the turbo setup. My subie had it too.
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Old Mar 29, 2011 | 05:05 AM
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Never ran catch can on mine 21 psi na-t i have no blow by.
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Old Mar 29, 2011 | 05:49 AM
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I was reading this yesterday. A catch can setup is only about $75 if you do go that route.

http://cjsupra.kendra.com/PCV-Can.html

On the other hand, Ive seen more JZ motors without catch can setups than ones with catch cans.
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Old Mar 29, 2011 | 09:21 AM
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The catch can's main purpose is to relieve Crank case pressure and IMO, has more to do with the amount of power that you're making versus what PSI you're running at. Someone could be running 20psi and only making 450rwhp which wouldn't require one and someone could be running 20 psi and making 600rwhp that might require one.

If you're up there in HP, then I say it's good to run.

Also, if you have a nice can, it enhances the look of the engine bay too...
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Old Mar 29, 2011 | 10:23 AM
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Originally Posted by Wicked SC
The catch can's main purpose is to relieve Crank case pressure and IMO, has more to do with the amount of power that you're making versus what PSI you're running at. Someone could be running 20psi and only making 450rwhp which wouldn't require one and someone could be running 20 psi and making 600rwhp that might require one.

If you're up there in HP, then I say it's good to run.

Also, if you have a nice can, it enhances the look of the engine bay too...
Well the higher the compression ratio, the more crankcase pressure you will have. So thus 20psi without a TT headgasket would more likely cause blowby then with a TT headgasket and a lower comp ratio.

My DSM started having blowby issues at 30psi. I had to install a spring on the dipstick to keep the damn thing in place. I'm not sure if the GTE or GE is known for popping dipsticks but I know in the DSM world this can cause a huge oil fire! If your running really high boost pressures, blowby and excess crankcase pressure is a concern. AN lines ran off the valve cover can remedy this and the catch can is literally just that, a place to catch the oil instead of blowing it everywhere.
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Old Mar 29, 2011 | 11:45 AM
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everyone has some form of blowby period.. pcv cannot keep the oily residue out of the intake tract which can promote detonation from the the residue ..for the majority of us with more then 75k on the clock , oil sealing rings etc dont quite seal like a factory fresh motor..next time you guys have some time , remove your upper intake plen wether it be na-t or gte and look in the lower runner ports i bet you will see traces of oil in there which is no good in the combustion chamber..
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Old Mar 29, 2011 | 02:18 PM
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You right ED when i pulled my intake manifold it had some oil in it lol, i guess this time i will install a catch can... thanks OP for this thread learn something new everyday...
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Old Mar 29, 2011 | 04:24 PM
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If you do end up routing your PCV to something, please dont leave it routed to an idle catch can in the engine bay. I used to make this same mistake back in the day. It's not really benefiting you in any way other then catching some oil that blows by.

Route it to something that pulls vacuum.

You want to either route it to the exhaust (past the o2 sensor) or to the intake pipe before the turbocharger. Either one will pull a considerable amount of vacuum on the lines, creating a scavenging effect. It works much more effectively this way and is extremely helpful once you really start making some power.

-Isaac

Edit: If you really want to use a catch can setup, route the valve covers to a baffled catchcan. Then route the baffled catchcan to either the exhaust or the intake pipe pre-turbo to create a scavenging effect on your crank case.

Last edited by slow4cyl; Mar 29, 2011 at 04:33 PM.
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Old Mar 29, 2011 | 06:35 PM
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Originally Posted by slow4cyl
If you do end up routing your PCV to something, please dont leave it routed to an idle catch can in the engine bay. I used to make this same mistake back in the day. It's not really benefiting you in any way other then catching some oil that blows by.

Route it to something that pulls vacuum.

You want to either route it to the exhaust (past the o2 sensor) or to the intake pipe before the turbocharger. Either one will pull a considerable amount of vacuum on the lines, creating a scavenging effect. It works much more effectively this way and is extremely helpful once you really start making some power.

-Isaac

Edit: If you really want to use a catch can setup, route the valve covers to a baffled catchcan. Then route the baffled catchcan to either the exhaust or the intake pipe pre-turbo to create a scavenging effect on your crank case.
well said

thats exactly how mine is done with one addition.. my can also has a breather filter to equalize the pressure draw.. i pull more vac at idle with my agressive cams then those who are not cammed
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Old Mar 29, 2011 | 07:32 PM
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i blew my front and rear main seals before when i had no oil catch can, now that i have one i haven't seen a blown seal yet.
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