PCV 101 for Forced Induction 80's

[Romer]

Ok guys. I have given everyone about as much rope as I am going to. You have expressed your opinion and you have given a counter.

Stay on topic, or I will have to get out of my chair and bitch slap someone . . . virtually of course

 

[turbocruiser]

Guys:
Address post 1. I am no expert. I can certainly give as much information/experience in turbo PCV applications as anyone here. We have something like what 10 turbo 80's on this list, maybe half again as many SC's. Call it 30 force inducted motors. I see more than that in a single month.

Bragging? Hardly. But I'm intimately familiar with how force induction PCV works, and know when opinions are eclipsing reality. PCV has been mandated since 1968, and I can't remember the last time I saw a turbo PCV line that wasn't pre turbo causing PCV vacuum under boost.

I've seen posts and forums about catch cans, turbo blade gunk, clogged intercoolers, lower HP. Don't see it doing a thing on the dyno. On an all out race car, I see and have built catch cans to make the combustion cleaner (as in the chamber, more air, less oil vapor), which allows more boost, more advance at the limit of a given motor. On the audis, that's over 26psi. At 15psi or under I don't see the need, at 8psi, it makes no sense to me.

I solved an issue that TRD didn't care/want/bother to address. AND Dan confirmed no harm/no foul from his TRD contacts on what I did. Don't let it upset you, you don't have to do it. I put up the issue, problem and solution as I saw it. Doesn't really matter to me if you choose to do it or not. It confirmed my suspicion on the seals, and solved the oil smell problem I was trying to address. Hope it helps someone (else?)

Want less stuff in a catch can, or going thru the crankcase? Change your oil more often with a good synthetic.

Want PCV vacuum under boost, do the 5 minute mod I described in post 1.

The rest is just good

I hope.

SJ

A pretty good post, Sumo, thanks, sincerely.

One observation / one opinion: Changing your oil more often with a good synthetic is not really going to give you less stuff in a catch can. Or perhaps more proper to say since I already change my oil with a good synthetic, changing my oil more often wont really help here. Just some knitpicking but to keep things accurate...

 

[cruiserdan]

Stay on topic, or I will have to get out of my chair and bitch slap someone . . . virtually of course

If you guys make him spill his Crown he is gonna get ugly...

 

[turbocruiser]

If you guys make him spill his Crown he is gonna get ugly...

If he was drinking his Crown he wouldn't care...

How's that on topic anyway?

Actually to get this on topic ... I'm wondering what others would suggest as an improvemetn to the 95 - 97 setup with a turbo as opposed to with a supercharger ... what I "want" is the best possible setup which would include twin catch cans. IOW what can be done to maintain the proper ventilation with say 8.5 psi and still catch whatever one wants using twin catch cans. Here's my setup which addresses the catch can consideration but does not deliberately upgrade any part of the PCV system. Thanks.

The turbo side,harder to see the routing if more pics are preferred I'll send em.



And then the PCV side, easier to see the routing.

 

[Waggoner5]

I solved an issue that TRD didn't care/want/bother to address. AND Dan confirmed no harm/no foul from his TRD contacts on what I did. Don't let it upset you, you don't have to do it. I put up the issue, problem and solution as I saw it. Doesn't really matter to me if you choose to do it or not. It confirmed my suspicion on the seals, and solved the oil smell problem I was trying to address. Hope it helps someone (else?)

SJ

I feel that Toyota/TRD didn't address this "problem" because they did not think it was a "problem". I am sure that over the years they have figured out what works and what doesn't and what needs to work and what doesn't. This thread was useful at first, but has turned into what most of your(SUMOTOY) threads do....I battle of wits so to speak. I think you have shown to be a pretty sharp guy on most of your posts, but somehow along the way you seem to piss off half of the readers of the thread. I think you have a great idea about the PCV, you just come across like your opinion is fact and not argueable. Like someone said "you want respect, you have to give respect".
Ken...you better wait 'till you get your present before the bitch slapping commences.

 

[Waggoner5]

If he was drinking his Crown he wouldn't care...

How's that on topic anyway?

Actually to get this on topic ... I'm wondering what others would suggest as an improvemetn to the 95 - 97 setup with a turbo as opposed to with a supercharger ... what I "want" is the best possible setup which would include twin catch cans. IOW what can be done to maintain the proper ventilation with say 8.5 psi and still catch whatever one wants using twin catch cans. Here's my setup which addresses the catch can consideration but does not deliberately upgrade any part of the PCV system. Thanks.

The turbo side,harder to see the routing if more pics are preferred I'll send em.



And then the PCV side, easier to see the routing.

TC, I have used pan/crankcase evac systems before on big turbo and supercharger motors (600+ci) and if I was looking for max ventilation, I would probably go that way, although I agree it is overkill on a street driven turbo/SC 1FZ. The PCV valve is fine for most applications, of course plumbed as this thread suggests, but to go the next step further, a pan evac system would be my next move. This would pull right from the heart of the beast so to speak, arguably freeing up horsepower.

 

[landtank]

I'm still curious if the PVC valve might be at fault here a little. It wasn't spec'd for a boost situation but ended up in one. Not that it matters with the SC but on a turbo build it might make a difference in how much boost does migrate into the engine.

Here is the info on how Toyota addresses PCV on their twin turbo setup. It looks to me that they only expect the blow by to exhaust through the vent line on it's own. I'm wondering if they use a larger hose in these applications?

 

[landtank]

What do you guys think about modifying the intake so there is a venturi on the PCV line so it will be under vacuum regardless if in boost of not?

 

[SUMOTOY]

What do you guys think about modifying the intake so there is a venturi on the PCV line so it will be under vacuum regardless if in boost of not?

Guys,
I'm here to share post 1 as it stands. I also know exactly why every turbo application uses PCV feed pre turbo. No one here has even gone that direction yet. I just went thru the exact reason while dealing with 'inadequate' (not no vacuum) pcv circuit on a turbo car I picked up in California a couple weeks ago.

Since I kept all the parts from what a previously uniformed mechanic "thought" was the answer, I can take some pics of the carnage.

One has to think of how a turbocharger system is designed, and exactly what happens with inadequate PCV vacuum on a turbo application under boost.

I'll buy the beer for first one that can put forth the answer and theory/application to what happened on a stock turbo audi when the PCV line preturbo (all else working as stock) was restricted. This has huge crossover correlation to you turbo boys.

Scott Justusson
FZJ 80 Supercharged and Sumotoy PCV mod

 

[Waggoner5]

Like adding a fitting that would give a scavenging effect?

 

[SUMOTOY]

Like adding a fitting that would give a scavenging effect?

I see a lot of difficulty in that. IME, you have a lot of differences in airflow based on throttle position and boost level. I see more problems as you change from vacuum to boost (why most turbo apps have 2 separate systems and 2 line sizes, 1 with a valve...)

I would think minimally, you would need to have a variable nozzle, or some other type of way to control that much variation.

There is a reason for a given line size AND for putting it pre turbo where much wider air demand doesn't change the inlet vacuum as dramatically.

SJ

 

[landtank]

Like adding a fitting that would give a scavenging effect?

Kind of. It would need to create a low pressure area in the air flow.

 

[SUMOTOY]

Kind of. It would need to create a low pressure area in the air flow.

Why not put a nozzle in the exhaust collector and not put vapor into the intake at all? That's what was going on back in the 60's and 70's?

Rick, why reinvent a well rolled wheel? Either catch can it like TC, or put PCV pre turbo like every other stock turbo application. Some have actually done both!

SJ

 

[landtank]

While you think this is funny, I'm not thrilled with having the stuff enter the compressor as well as it condensing in the Intercooler.

Having all that crap enter the intake post compressor and combusted in the engine would be just fine with me.

Just thinking out load here and you must realize by now I'm not always swayed by popular belief or design and don't have a problem working outside the box.

A modified SC'd truck would make the ideal test bed for such a project. You could alter the port that you capped off and get some good data on how much vacuum you were generating while still being able to drive the truck around. I just don't have one handy.

 

[SUMOTOY]

While you think this is funny, I'm not thrilled with having the stuff enter the compressor as well as it condensing in the Intercooler.

Having all that crap enter the intake post compressor and combusted in the engine would be just fine with me.

Just thinking out load here and you must realize by now I'm not always swayed by popular belief or design and don't have a problem working outside the box.

A modified SC'd truck would make the ideal test bed for such a project. You could alter the port that you capped off and get some good data on how much vacuum you were generating while still being able to drive the truck around. I just don't have one handy.

Rick
I am known for thinking outside the box, I have done a lot of innovative modifications for track, street and offroad (trucks and SCCA ProRally cars), and continue to daily in my shop (er, see post 1?). When I see PCV, I find it rather boring frankly, and may post that I find it amusing. Why? Because I've put turbo cars on the dyno and did the really simple comparos, and couldn't isolate PCV impact as a measure. I could barely isolate the 'known gain' of a cleaner combustion charge. Under 15psi, I sure couldn't see it. Maybe 80's are different, I don't think so, I only think 80's have different size PCV lines.

I read crappy turbo blades, condensed intercoolers, and crudded intakes, and think that has to add up to some big gains by deletion. I couldn't find any measurable gains, and barely found any with catch cans.

There are several audi tubos running obscene boost levels (triple what we are using) that run the stock *turbo* PCV.

Rick, it's not that testing out of the box stuff isn't good, it's that I have looked at it already. And found things like proper shrouding of the IC and release airflow makes high measurable gains than PCV present or not. I suspect and have read the reason is, that proper crankcase ventilation causing pistons to operate in a vacuum, more than offsets the inpurity losses of a closed loop PCV system.

The only issue I see with PCV, is proper vacuum under boosted conditions being important to a closed or open loop PCV system. And the most critical on a turbocharged application.

Before you think outside the box, you have to explore what's already in it. Like Rick, why does just about every turbo car (I'd say all, but don't need to, millions of them is fine) have PCV feed upstream of the turbo?

There is an in the box reason for it. Start there, then I'd probably be more willing to think outside the box. You might have to excuse me for jumping ahead and asking why? What's the gain? 'Crap' in the intake tract? I see no correlation between that and performance on the dyno.

I look at a redesign of PCV out of the box thinking as time spent better elsewhere on a boosted motor. Make sure the engine is under vacuum under boost, especially in my case, is plenty of out of the box thinking on the subject.

YOMV

Scott Justusson
94 FZJ 80 with Sumotoy PCV mod

 

[landtank]

As it is right now we have to periodically clean the throttle body to help keep the engine running correctly. I've read countless posts on the web of people dumping condensed oil out of their intercoolers.

For me it's never about performance gains. I honestly could care less how it impacts a Dyno run. I leave dyno runs stats to the dick swingers.

I personally think if a mod like this was able to route all the gases post compressor and post throttle body the system would be a cleaner, healthier one and less maintenance would be required.

The catch can looks good but that adds to the maintenance of the truck and I'd prefer a solution that didn't do that. And does this solution capture 100% of the oil?

I realize that I have a different take on things, like designing a replacement MAF when everyone else was perfectly happy with the stock one. I was told that I was wasting my time and would end up destroying engines. That didn't happen and I'm very pleased with the results.

This idea could possibly go nowhere as so many do. But I enjoy the journey just the same.

 

[SUMOTOY]

As it is right now we have to periodically clean the throttle body to help keep the engine running correctly. I've read countless posts on the web of people dumping condensed oil out of their intercoolers.

For me it's never about performance gains. I honestly could care less how it impacts a Dyno run. I leave dyno runs stats to the dick swingers.

I personally think if a mod like this was able to route all the gases post compressor and post throttle body the system would be a cleaner, healthier one and less maintenance would be required.

The catch can looks good but that adds to the maintenance of the truck and I'd prefer a solution that didn't do that. And does this solution capture 100% of the oil?

I realize that I have a different take on things, like designing a replacement MAF when everyone else was perfectly happy with the stock one. I was told that I was wasting my time and would end up destroying engines. That didn't happen and I'm very pleased with the results.

This idea could possibly go nowhere as so many do. But I enjoy the journey just the same.

Rick, again, think inside the box first. WHY is PCV routed so that it's vacuum all the time (not dead air zone, not post compressor)? The reason is REALLY obvious to turbo theory and application (insert free beer)

I like designing a lot of things, and have a pretty good resume and reputation of doing so, including on this list. I read countless posts of folks dumping oil out of intercoolers too, tho not if the PCV is designed correctly. Y*O*MV, but turbocharger application on this list has a really low 'n'.

As it stands, post 1 is a good mod to the SC truck, in theory and application. I hope you now understand and agree. Whatever you decide to do with *your* pcv mod, I only urge you to consider how important proper PCV vacuum is to a turbo motor.

I've seen a lot of creative PCV systems over the years. My only benchmark is that I only look that it is designed to operate to accepted theory or practice. TC wants to empty a catch can, his choice to do so (whatever I may have posted regarding the reasoning). I choose to stay closed loop, and say that TRD design for the aftermarket SC install, does not allow vacuum under boost.

Best of luck whatever you decide is 'better'. I'm glad my post 1 got you thinking about it anyhow. I chuckle at the length of posts following, given my apple knife and channel lock mod in the parking lot of my local discount auto parts store.

SJ

 

[landtank]

for the most part Scott I have no idea what you just said. The reference to free beer and all those acronyms left me puzzled to the point where I can't fill in the blanks.

If you've got some insight as to how to properly set up a PVC system on a turbo I'd be all ears. But if this is to just taunt me and others then I don't see a point in posting it.

 

[Romer]

I think what they are saying is talk to others as equals. You are not doing that. You started off great and simple, but then . . . . .

No one likes to be talked down to and when people start asking you lots of questions you talk down to them and tell them how much experience and how smart you are and don't discuss their question as an equal.

 

[turbocruiser]

I think what they are saying is talk to others as equals. You are not doing that. You started off great and simple, but then . . . . .

No one likes to be talked down to and when people start asking you lots of questions you talk down to them and tell them how much experience and how smart you are and don't discuss their question as an equal.

Ahhaa! Words of Wisdom! You Stated That So Much Better Than I!!! Thanks Ken.