RYU's "properly molested" NSX build thread

[jwmelvin]

[1] Since it is after the TB, if an air leak exists, it's essentially a vacuum leak and will cause the engine to idle higher among other things... It's essentially an unmetered air source post TB and post TPS.

[2] A catch can, as least the way I understand it, and obviously the nomenclature is debatable, releases vapors from the valve cover straight to the atmosphere via the breather filter post "catch can". As is also illustrated in post #96 on previous thread.

[3] the reason why I think I DO NOT need a PCV is because my setup will take the existing vent hose as is on an OEM or CTSC setup whereby the valve cover vent connects to the intake snout post TB but pre blower. This is essentially always in some vaccuum state or near 0 vaccuum.

[4]dumb question... does the stock PCV valve stop air from going into the valve cover or does it stop air from coming out of it?

1. The PCV system as designed includes a vacuum draw from the valve cover to the post-TB port.

2. Okay by me if we want to proceed with that definition. I'm not convinced, however, that it is universal. Many people describe a catch can in a closed system that does not vent outside the intake.

4. From what I read everywhere, they kind of do both. The flow reduces under vacuum and all back flow is prevented.

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[MENTION=20915]RYU[/MENTION] that schematic of PCV valves from Radium that you posted shows the behavior I am talking about.

 

[RYU]

@RYU that schematic of PCV valves from Radium that you posted shows the behavior I am talking about.

Jason, first of all, thanks for the debate. It's quite helpful.

There's one area of difference I see with Radium's diagram of the PCV operations vs. what I have in mind as well as what CTSC had in mind.

Taking a look at the photo below. Notice the hose on the front bank valve cover. It connects after the PCV and into the snout of the CTSC, keeping in mind this is post TB, but pre blower (i.e. never under boost). This is why i'm wondering if a PCV is even needed in this condition as, effectively the air behavior here is typically high vacuum or at atmospheric pressures.

 

[jwmelvin]

Taking a look at the photo below. Notice the hose on the front bank valve cover. It connects after the PCV and into the snout of the CTSC, keeping in mind this is post TB, but pre blower (i.e. never under boost). This is why i'm wondering if a PCV is even needed in this condition as, effectively the air behavior here is typically high vacuum or at atmospheric pressures.

In the OE system, the PCV valve (front valve cover in NA1, rear VC in NA2) gets vacuum from the post-TB connection, as in all N/A cars. The PCV valve is used to prevent back flow in the case of a backfire (is this a leftover from carburetor days?) and to regulate the flow out of the VC. Nothing changes about this when using it with a CTSC, so I'm not clear on why you would want to remove the PCV valve.

Note: in the tradition of the Prime old guard (aka the NA1/2 vs. pop-up vs. whatever-else police), please be clear about PCV versus PCV valve. The latter is only one component in a PCV system. PCVV?

 

[Mac Attack]

Regan,

I'm not sure if my flickr picture works or not for you. It's a pic of two of those Moroso A/O separators plumbed into the OEM PCV layout (with a new Honda PCV valve).

BTW, Dave's post #96 does refer to inserting SS mesh for the vapors to condense on. That what makes a catch can turn into an efficient separator. Most catch cans don't do this, as you're finding out.

I don't know why people use a simple vent. Do it properly and you'll have cleaner oil and better ring seal.

Also, the Moroso setup you posted a pic of uses a high-quality Italian ball valve for the drain. Works like a charm!

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In the OE system, the PCV valve (front valve cover in NA1, rear VC in NA2) gets vacuum from the post-TB connection, as in all N/A cars. The PCV valve is used to prevent back flow in the case of a backfire (is this a leftover from carburetor days?) and to regulate the flow out of the VC. Nothing changes about this when using it with a CTSC, so I'm not clear on why you would want to remove the PCV valve.

Backfires are still very real. In another vehicle, I actually have a rupture disc built into my intake manifold to prevent overpressurization from blowing it apart.

Another function of the PCV valve is to help slow down the release of crankcase vapors into the atmosphere once you shut off the engine. Granted, this is reaching a little bit, but it does effectively reduce the venting area to the air filter and then the atmosphere.

 

[jwmelvin]

[MENTION=20915]RYU[/MENTION] check out the forum post that I linked to in my post over here. It's a pretty interesting look at various separator designs. I don't agree with all of it but it's the best view inside I have found.

 

[RYU]

[MENTION=28830]jwmelvin[/MENTION] - will do!
[MENTION=12356]Mac Attack[/MENTION] - I did noticed your OEM routing. I was trying to understand why Honda decided to vent the front back post TB and the rear bank pre TB. Haven't had a chance to really think about it yet but my initial setup was to vent both valve covers into a T or Y intersection and into the A/O separator. The other end of the catch can behind the TB and into the CTSC snout. The original fitting in front of the TB for the rear bank will be capped.

What's wrong with this setup?

 

[jwmelvin]

I was trying to understand why Honda decided to vent the front back post TB and the rear bank pre TB. Haven't had a chance to really think about it yet but my initial setup was to vent both valve covers into a T or Y intersection and into the A/O separator. The other end of the catch can behind the TB and into the CTSC snout. The original fitting in front of the TB for the rear bank will be capped.

What's wrong with this setup?

Honda set it up that way because the pre-TB line is fresh air into the crankcase and the post-TB line is suction out of the crankcase. That's what so many of these setups are missing and why they will not clean the oil properly. Your proposed setup, like so many, lacks the path for fresh air to enter the crankcase. Simply adding a tap to the other valve cover would preserve that but it would eliminate the circulating flow that Honda designed.

 

[RYU]

I see, says the blind man

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If I understand correctly, in Mac Attack's setup the front A/O separator would fill up much quicker than the rear bank?

 

[jwmelvin]

If I understand correctly, in Mac Attack's setup the front A/O separator would fill up much quicker than the rear bank?

I'd be interested to know. There is a lot more time of flow through the PCVV line but in conditions of positive crankcase pressure, the flow through that line is reduced due to the forward resistance of the PCVV. (I use that designation for the two lines because I can't remember if Dave has an NA1/2 engine.)

 

[RYU]

I texted a good friend of mine who basically is the wizard tuner of my car and my tuning mentor . This was his comment. He use to own an NSX many moons ago.

Either way will work. By routing pre and post throttle body, that is basically a PCV system. The pcv valve should be used to control the amount of vacuum drawn in and the catch can is just inline to separate the oil spray. This is the way i did it on my car. Kept the stock Pcv and inserted a air compressor filter/catch can.
Venting both valve covers to atmosphere is fine also, but there are benefits to having s vacuum on the crankcase. On a turbo or sc motor, you have to make sure the pcv valve seals against any positive pressure. Or you will pressurize your crankcase and force more oil out.

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It's never a bad idea to get a 2nd opinion I guess.

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I just received the Steeda A/O separator can. I'm not sure I like it. I think it's going back.............

 

[jwmelvin]

I texted a good friend of mine who basically is the wizard tuner of my car and my tuning mentor . This was his comment. He use to own an NSX many moons ago. . . . It's never a bad idea to get a 2nd opinion I guess.

Nice! Thanks for asking him and reporting back. I don't think that there's much concern about pressurizing the crankcase with the CTSC setup since the tap is preblower.

I just received the Steeda A/O separator can. I'm not sure I like it. I think it's going back.............

Thanks for reporting. What's the next one to try?

 

[jones83]

The group I would look at over the evo or sti crowd is the GTR group. The R35 aftermarket is what has better engineered setups. Pricier than moroso or jegs, but they are engineered very well and give a much better idea of how you want it set up. Used ones pop up from time to time in the forums on gtrheritage. AAM Competition makes a really nice one that I like and have seen good results with.

As far as the difference between a catch can and an air/oil separator; "the ABSOLUTE distinguishing characteristic is if they return separated oil to the crankcase. One that does is an air/oil separator. One that does not is referred to as a catch can, even if it is baffled, removes the pcv valve, and is hooked to vacuum only."

In the order of who needs one the most; E85 turbo> Pump Gas Turbo > NA

 

[jwmelvin]

I like that distinction between separators and catch cans. Thank you.

The AAM design looks pretty straightforward. It uses a horizontal entry into wire wool and an exit above that, with the two separated by a baffle.
http://aamcompetition.com/i-13464348-aam-competition-gt-r-oil-catch-can-system.html
I'm not convinced it's fundamentally any better than another design. It's set up with dual entry and dual exit ports for the twin turbos (and twin vents?) of the GT-R. But who knows if they are eliminating the fresh-air inlet to the crankcase like many people seem to do? I see no reason that flow path is significantly better than any of the other designs.

So far, I think the RX looks like the best design:
http://www.rxspeedworks.com/product/catch-can-kits/
I like how the flow goes through a lot of the wire wool and how there is a fairly long path from there to the exit.

The closer I look at the Elite, the more I like it too, especially for the price. The entry is straight into the wire wool but the flow has to both reverse direction and also run through an annular gap to the exit. For the money, I haven't seen a better design yet. This post gives some good pictures:
http://socalviper.com/message-board/index.php?topic=1165.msg10379#msg10379

 

[jones83]

I don't want someone to reinvent the wheel. I just want them to take a formula that is proven to work and overengineer it so that I have less to worry about. Billet, baffling and wool, cylindrical design to seperate the air, and proven. I have seen this work on more than one R35. One ran e98, e85, and 93 on occasion. His was street driven and tracked with the design plumbing fresh air back into the crankcase. All worked perfectly and he constantly checks it every 2k or so due to the excessive output from e85. Keep in mind the R35s run more boost than 99.5% on this site would dream of adding to their NSX.

I'm not a fan of the RX and don't care much for the ease of which that internal design could get clogged. The second one seems ok, but I want dual inlets and a drain.

 

[jwmelvin]

All good, we all get to decide how to spend our money. I think you point out a potential issue with the RX. From what I read about people's experiences, it didn't seem to show up in use but forums on the interwebs are far from complete or even accurate information.

I find the AAM overpriced for what it is. Elite offers a model that would seem to meet your desires for $230. http://www.eliteengineeringusa.com/elite-engineering-e2-x-catch-can/

I find the CFD pictures amusing. My brother has a PhD in CFD and a very successful career in race car aerodynamics, and has taught me to trust few things less.

 

[jones83]

No offense but your brother's PhD in CFD has no bearing on whether the CFD of the AAM is accurate. I have seen real world testing with it working in high hp boosted conditions. I added the picture because you sounded like you weren't certain how it was working internally.

There is an R35 tax added on the AAM. No doubt, but it is not much I surmise. Put one in your hand and you will see it is well machined. Price is always subjective, but quality cost when it comes to machining. Especially in America.

I'm just mudding up Ryu's thread so this my last post. Sorry.

 

[Mac Attack]

It is difficult to design the system that not only provides significant enough differential pressure to circulate crankcase vapors during normal driving for cleaner oil and reduced emissions, but then to provide a true suction pressure in the crankcase during high engine loads that maintain ring sealing while keeping the intake clean of contaminants. It seems like 99% of the aftermarket setups do neither of those. Admittedly, I doubt there is any recovered HP in my engine due to my setup, but I made a conscious decision not to vent the crankcase to the atmosphere.

* We have tight-tolerance engines with normal-tension rings. A powerful vacuum pump on the crankcase will most likely not yield any additional engine power. The quoted values for other engines that do benefit from this are an apples/oranges comparison.

* For ultimate performance, just vent the crankcase vapors to the atmosphere through an air/oil separator to keep your engine compartment clean.

* If you care about the environment, you can try to retain the OEM setup for your N/A vehicle, or your OEM FI'd vehicle. One that was normally N/A but converted to FI will require a bit more thinking. If you have problems with blowby and are concerned about detonation issues, then add air/oil separator(s) before routing back to the intake.

* If you are concerned with water vapor in your crankcase due to E85 or methanol injection, you have bigger problems to worry about and a magical air/oil separator is a Band-Aid.



I've evaluated all of these separators before making my decision based on an effectiveness/$ ratio. Everyone has their own needs that may sway them to one product over another. Unless there is a consistent oil carryover test performed on each of these to clearly distinguish their flow/filtration capability, we are once again bench racing. I have not yet seen a design that I would consider clearly superior than all the others. Like every engineering project, there is no perfect design - only compromises to fit specific design/cost goals.

One important aspect to these I have not seen mentioned much is the need to keep the lines going to these separators as hot as possible, and the cans as cool as possible to aid condensation. That's one reason why you see OEMs insulate the rubber lines. How many companies/enthusiasts do this?! After I set up my system(s) I've insulated all of my vent lines penetrating the top of the engine.

Furthermore, it is very difficult to maintain all of the design goals from an OEM PCV system. Some cars, like Supras, have problems with high crankcase pressures blowing out their main seals. Obviously, they need a better venting/extraction system since they are also losing power. If you tune the engine correctly, you also shouldn't be concerned with E85 or methanol. Like I said earlier, most tune overly rich which leads to a slow engine death instead of a catastrophic one. I don't use an intercooler due to lack of space - only methanol injection. But, I also can log my combustion cylinder pressures and know exactly what is going on. No need to be overly rich. No problem washing down my cylinder walls or reducing the effectiveness of my engine oil. No problem with recirculating contaminants back into the intake. Not much in my separator reservoirs when I was breaking in the engine. Even FI'd, I popped off lines and vented to the engine compartment so I could observe any significant vapor flow coming out of them while driving enthusiastically.

To each their own. One method or product is not "the best" out there. I was just showing what I did and went overboard since I was learning back then. YMMV.

Dave

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It seems the last few pages of this thread could be moved to the catch-can thread!

Sorry Regan!

 

[jwmelvin]

For ultimate performance, just vent the crankcase vapors to the atmosphere through an air/oil separator to keep your engine compartment clean.

I'm trying to understand why this would be better performance than maintaining a path to the intake, which will never be above atmospheric pressure?

One important aspect to these I have not seen mentioned much is the need to keep the lines going to these separators as hot as possible, and the cans as cool as possible to aid condensation. That's one reason why you see OEMs insulate the rubber lines. How many companies/enthusiasts do this?! After I set up my system(s) I've insulated all of my vent lines penetrating the top of the engine.

Great point and approach. I saw one design that circulated engine coolant through the separator, which seems contrary to what is desired. Another person put the catch can in the path of entering cool air, which seemed good but tough and unlikely to be worth the trouble in an NSX.

Not much in my separator reservoirs when I was breaking in the engine. Even FI'd, I popped off lines and vented to the engine compartment so I could observe any significant vapor flow coming out of them while driving enthusiastically.

This kind of suggests that there is no need for a catch can at all, assuming proper tuning. I'm still planning to add one but I appreciate your experience and input.

It seems the last few pages of this thread could be moved to the catch-can thread!

He kind of asked for it. I appreciate everyone's willingness to entertain and respond to my questions and thoughts. I have learned a ton and have you all to thank for it. Regan has been somewhat of a guiding light for me so perhaps it's fitting that his thread gave birth to this discussion. Or maybe I'm the only one why finds it useful and interesting; if so, sorry about that.

 

[Mac Attack]

I'm trying to understand why this would be better performance than maintaining a path to the intake, which will never be above atmospheric pressure?

Two reasons:
1) I doubt our cars would gain much HP from drawing a slight vacuum in the crankcase.
2) No worries if your air/oil separator is filtering out all potential contaminants that may introduce detonation. They're just vented to your engine compartment!

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This kind of suggests that there is no need for a catch can at all, assuming proper tuning. I'm still planning to add one but I appreciate your experience and input.

You have to ask yourself if it is worth the hassle and expense to do so. If you install and route a proper system for collecting crankcase byproducts, then you will collect "something." Is that "something" sizable enough in volume per operating hour or "bad enough" to do something about it? On my particular engine and the manner I use it (no short trips in cold weather) I know it is not. Others may vary.

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He kind of asked for it. I appreciate everyone's willingness to entertain and respond to my questions and thoughts. I have learned a ton and have you all to thank for it. Regan has been somewhat of a guiding light for me so perhaps it's fitting that his thread gave birth to this discussion. Or maybe I'm the only one why finds it useful and interesting; if so, sorry about that.

I think this is a great discussion with a lot of neat products mentioned and linked to. I think the catch can thread would be significantly improved by moving or copying a lot of the discussion over there!

Dave

 

[RYU]

Hi Guys,

I've been busy at work but would love to get into this later today or this wknd! Great conversations. Thank you for the input and sharing of knowledge.

I have no problem moving this thread to the catch can thread (I originally rebumped that thread from the dead) but happy to host the conversation here as well.

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I did notice quite a bit of activity there btw. I haven't had a chance to update myself on it yet either.

At the end of the day, I want a solution that's simple and easy to service. I've accepted that I need to spend a few hundred dollars for a proper setup (thanks to you guys lol)

 

[Ponyboy]

The group I would look at over the evo or sti crowd is the GTR group. The R35 aftermarket is what has better engineered setups. Pricier than moroso or jegs, but they are engineered very well and give a much better idea of how you want it set up. Used ones pop up from time to time in the forums on gtrheritage. AAM Competition makes a really nice one that I like and have seen good results with.

Great point. I didn't think of the GTR crowd previously. That AAM looks very well made and an effective design. :thumbup:

 

[RYU]

Reading thru this I still can't decide

on on a side note... I was busy driving around a 650S Spider at Sears Point last weekend. It was easy to forget my measly catch can issues when behind the wheel of one of those

 

[RYU]

As it turns out, I was able to fit in another track day this year. A friend invited us to Spring Mountain Motorsports Ranch. This is easily my favorite motorsports park thus far. It's like a Pebble Beach country club for car guys. Very cool place.

I ran with my street tires on this go around. Temps were pretty cold (high 30s in the AM with a high of 66F). Not sure if my DOT R-Comps would have come up to temp fast enough. The Continental ExtremeContact DW's were pretty fun. I'm running 215/265 and it was loose in a very predictable way. I also adjusted my front sway settings to full soft (from full stiff in the past 3 or so track days). The car is finally starting to feel more neutral. The massive understeer is gone. It's just got a slight understeer which is very manageable and even preferred. Though i'm not sure if the understeer was impactacted by the 215 Continentals vs. my usual 235 RC1s. Good times! This might be my last event for the year but it seems another track day might come up on Dec.

We ran the old long config. I really like this config. Good mix of fast and technical sections.

This place is very cool.

Also had a long chat with Shinoo from Sector 111. He's now promoting this home grown, LS3 E-Rod powered, Ariel inspired, street legal track car. Look for it. It's impressive and probably loads of fun.

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p.s. Videos to come...

 

[illwillem]

Videos!

 

[RYU]

Videos!

OK! Here's the unedited version. Pardon the first half where I'm taking forever to put on my gloves. Following a slower McLaren on the first half too.

https://youtu.be/9F1qSCSaKuo