[Bmw doubles]

Made the move and purchased a VTT Crankcase breather.

Read many articles about increasing boost puts more stress on the seals exposing oil leaks, increased blow by and increased pressures making internals work harder. Worst of all our N55's have the notorious whining caused by a blown VC diaphragm. We also have the even more infamous OFHG that leaks like plastic bag punched with holes.

The articles go own to mention that performance increases can be anywhere from 1-3% by lowering internal pressure to 0 or atmosphere or in some cases negative vacuum. I can't confirm that but i will say the engine revs noticeably better. The shifts between gears stays in a higher rpm and don't fall as fast. Similar to a down-pipe it carries a heavy gas smell. Maybe not as pungent as a decatted pipe but the gas/oil fumes are prevalent.

People state that there's poor hood clearance issues but i am not experiencing that. Fits perfectly on the valve cover and the hood closes without problems.

I'll see how this goes as a daily. Might switch back to a cap and use this mod for the track. However, if I ran 20+ psi daily I would keep it in to prevent the negative effects mentioned above.

A catch can that has a baffle for aeration could be the ultimate daily combo that covers fumes and provides lowered internal pressures for boosted cars.

The quality of the hardware is top notch minus the faded logo on the top of the filter. The filter itself is quality.

[BimmerHausPerformance]

NICE! Is there a one way check valve on it or is it wide open?

[Bmw doubles]

Originally Posted by BrowBMW

NICE! Is there a one way check valve on it or is it wide open?

There's a check valve that opens at <0.5 psi

So far it's been a heavy gas smell and this morning my garage smelled like a gas can. I had a long crank. Might be unrelated but we'll see. I have no codes.

I will say the car does feel peppier. There could be a performance gain*? :

My next move that is similar to reliving pressure is manual gearbox and transfer case fluid changes. Tons of good reviews on performing that maintenance item.

[ziekxq]

Do you smell the gas while driving or parking it somewhere outside and letting the car run with window down or driving while window down?

[Bmw doubles]

Originally Posted by ziekxq

Do you smell the gas while driving or parking it somewhere outside and letting the car run with window down or driving while window down?

It's track mod def not a daily. When you're driving is fine if you're out of stop for too long it's very strong. If you have this man and a downpipe you would need an oxygen mask to drive the car LOL. I am enjoying it because I feel like my engine is revving better

[ziekxq]

Originally Posted by Bmw doubles

It's track mod def not a daily. When you're driving is fine if you're out of stop for too long it's very strong. If you have this man and a downpipe you would need an oxygen mask to drive the car LOL. I am enjoying it because I feel like my engine is revving better

Lol I got the downpipe and it already smells bad during winter... Now smell coming from exhaust and front engine bay that would be too much... I wonder if this has any effect on how soon you should be replacing your cabin filter?

Maybe it's one of those mods to switch on days when you want to do spirited driving or going on a highway drive towards city and wanna enjoy the full power.

[Unspec]

Originally Posted by Bmw doubles

There's a check valve that opens at <0.5 psi

So far it's been a heavy gas smell and this morning my garage smelled like a gas can. I had a long crank. Might be unrelated but we'll see. I have no codes.

I will say the car does feel peppier. There could be a performance gain*? :

My next move that is similar to reliving pressure is manual gearbox and transfer case fluid changes. Tons of good reviews on performing that maintenance item.

Buy old downpipe. Chop cats out and slap it over the vent. Perfect!

[Bmw doubles]

Originally Posted by Unspec

Buy old downpipe. Chop cats out and slap it over the vent. Perfect!

I'm starting to question the real benefits of a decatted DP. I saw a YouTube video on a 600hp Supra (older model) where they tested between stock and aftermarket and only found a 10whp difference. I think maybe the benefit is not overheating your turbo. I'll find that video and post it up

[BimmerHausPerformance]

I have a catless dp and my wife only complains when we are stopped and the windows are down, I personally enjoy the smell, reminds me of what I'm driving. Maybe I'd like it even more with this vent lol.

I would imagine a catch can with a breather on it would stink just the same... For 100 bucks maybe a catch can would be a better way to spend the money and kill possibly two birds with one stone?

[Unspec]

Originally Posted by Bmw doubles

I'm starting to question the real benefits of a decatted DP. I saw a YouTube video on a 600hp Supra (older model) where they tested between stock and aftermarket and only found a 10whp difference. I think maybe the benefit is not overheating your turbo. I'll find that video and post it up

Modern high flow cats (and even OEM ones) are really well designed to optimize flow thanks to computer modeling. So it's not surprising.

Personally I'd never got cat less. The fumes from the high flow cats already make me a little nauseous, so I think if I went catless I'd actually PTFO

[BimmerHausPerformance]

WAIT, how is this different than the crank case breather hose that vents to your air intake? In fact that vent, since it's connected to your intake, would actually be SUCKING air out of the crank case.

Please someone smarter than me explain.

[ziekxq]

Originally Posted by BrowBMW

WAIT, how is this different than the crank case breather hose that vents to your air intake? In fact that vent, since it's connected to your intake, would actually be SUCKING air out of the crank case.

Please someone smarter than me explain.

Good question, I want to know this as well. Maybe it helps release extra pressure that the tiny pipe can't.

[ezaircon4jc]

Originally Posted by ziekxq

Good question, I want to know this as well. Maybe it helps release extra pressure that the tiny pipe can't.

I don't 3/4" is a tiny hose. In fact, most catch-can hoses are in the 1/2" to 5/16" range.

[ziekxq]

Originally Posted by ezaircon4jc

I don't 3/4" is a tiny hose. In fact, most catch-can hoses are in the 1/2" to 5/16" range.

I am just saying on upgraded turbos the extra pressure that is created needs more than just that pipe. I could be wrong though. I was just guessing there.

[$howtime456]

i have this with the BMS catch can. Mabey overkill but hey

[BimmerHausPerformance]

With a name like $howtime, is there such a thing as overkill? Lol

[ezaircon4jc]

Originally Posted by BrowBMW

With a name like $howtime, is there such a thing as overkill? Lol

[Bmw doubles]

Ok turns out it wasn't the VTT breather. I had an actual fuel leak coming from the low pressure side that connects to the hpfp. Surprised my car didn't lite on fire. Hello insurance money lol.

[Unspec]

Originally Posted by Bmw doubles

Ok turns out it wasn't the VTT breather. I had an actual fuel leak coming from the low pressure side that connects to the hpfp. Surprised my car didn't lite on fire. Hello insurance money lol.

...yikes that's spooky. Too early in the year for such drama. This is why I carry an extinguisher in my car lol

[BimmerHausPerformance]

Wow, you should fire the mechanic that installed that thing! :-)

[Bmw doubles]

Originally Posted by BrowBMW

Wow, you should fire the mechanic that installed that thing! :-)

😂 I guess I'm fired. I also wrenched the lp connecting side pretty hard. I suspect that's where it was leaking from. I'll know this weekend. Tearing it all down again is never fun.

[Bmw doubles]

Here's that video of catted vs not