Bruce_K

So, Im currently worried about my Crankcase pressue. and I have an Elite Engineer Dual Valve Catch can. I've read it does it help crankcase pressure. but its not vented. I see the MightMouse Can has the filter to vent the pressure.

Do i need to make the switch? does it need to vented completely out the system? What are you guys experience?

robert miller

Yes if you have a turbo r a blower on the car I would go with the MMS catch can. I have had 3 others set up & sold those & got the MMS it does work on a blower set up for sure. The c7 is known for a weak front & rear seals in the car a NUMBER OF GUYS HAVE HAD LEAKING SEALS FROM THIS VERY PROBLEM.

David is great guy & has a great web site now to look at.. Robert

DTOM

The Mighty Mouse is vented and will help vent crank case pressure and avoid blowing out seals.

robert miller

I agree MMS catch can is the best set up for a blower car. Plus David is more then willing to help great vendor in here..Robert

BlueDevilZ51

I've heard good things about the MMS catch can. I also hear the Elite E2 catch can with the optional 2 hoses exiting the can for forced induction applications will help to vent crank case pressure.

Unreal

Mms is a very well engineered system. Vent is just a safety feature. The can itself is far superior to anything else on the market.

Fast6.3

Jaycajun

robert miller

I agree 110% on MMS

C7&7

Yea don't mess around with anything other than a MMS or a true breather like some of the shops manufacture and sell.

David@MMS

Just shipped a bunch of my kits to JDP 😉
Thanks for the support yall!

subieworx

I don't like the idea of running a VTA catch can system and in my experience over 15 years of racing have always found a proper closed system to work better. Drawing a vacuum on the crankcase along with increased ring seal is never a bad thing.

C7&7

subieworx

Sure, I'll bite. How do you "know".

C7&7

subieworx

I don't debate the piston situation.

How did you have the Elite can hooked up? You would not believe how many people I see run them incorrectly which will definitely cause the issue you had. While crankcase pressure would likely increase somewhat on a FI setup it won't be to the point where all of a sudden seals are blowing out. But if the can setup is hooked up in such a way that boost pressure is entering the crankcase (as I have seen frequently) it will blow the seals immediately.

C7&7

Oh man I recall calling them immediately to double check the shops installation and it was correct. This was December of 2014. Not saying a catch can is bad at all, I just think there has to be a way to get a vent to the atmosphere. Either always vented or some type of pressure relief. Especially in boosted applications. NA different story.

subieworx

It's not a different story though. I come from a FI background and have built many turbo street and race cars and hence always deal with crankcase vent issues. Properly installed the Elite can should not be a problem. If it immediately blew oil it wasn't hooked up correctly.

The most common thing I see is people route the vent of the can (exit) to the pipe just before the throttle body as it is done in a NA setup. On a NA setup this is fine, but on a FI setup it will pressurize the crankcase. I have also seen people put a check valve in that line to prevent pressure from getting to the crankcase from the FI intake duct. Fine, that will prevent pressure from getting in however it also prevents pressure from getting out. Both situations will blow seals.

I'm not saying the elite system is perfect and I don't really agree with their recommended installation, but can say as someone who has used that can multiple times and setup hundreds of proper crankcase venting systems that the can is not the problem.

David@MMS

this is why my 'wild' pcv systems are so popular and reliable. they are closed at all times possible and open in emergency to equalize any surges.

lots of good info here www.mightymousesolutions.com also check out the video page of the tests!

subieworx

I don't think it has to be like that though. One of the things I find interesting on the GM LS/T kits is how small the lines are. On any other turbo or NA engine I would run much larger lines to evacuate the can. On a subaru for example I run two 5/8" lines back to the turbo inlet and a 3/8" pcv line to the intake manifold. This is waaay more flow through than the standard for these cars which is 3/8" and theses engines are much larger. With proper line sizing it wouldn't be necessary to have a VTA valve that would need to open to allow for a spike of crankcase pressure as there would be enough reserve flow in the system.

As a means of example, the prototype system I made for my 700whp time trail Subaru back in 09 involved using three separator cans, two in parallel and one in series. The two primary cans drained back to the oil sump so as not to drain the sump of oil and the third was a pure catch can run after the two primaries. The two primaries had -12 outlets at top for evacuation of fresh air that went to the catch can at the end. That third can had a -16 outlet back to the turbo inlet to create the overall vacuum on the crankcase. I did not run a PCV system on this car as it was purely a race car that only saw three laps at a time before coming in for service. Point being, there was way more throughput for this comparatively tiny 2.5L engine than what I normally see on cans on these rather large engines.

I also feel that the return line should be setup to go to both the intake manifold and the intake before the throttle body. In this situation you have proper evacuation of the can in both situations of cruising and full throttle.

Thoughts?