Another forced induction vacuum question

[flatboy]

Good day 4 Runners peeps, So long story short I rear mount turbo'd my 2000 4-runner
http://www.toyota-4runner.org/3rd-gen-t4rs/148568-flatboys-rear-turbo-build.html

and 1 thing I have not worked through is my vacuum line routing. I believe I'm seeing some blow by, and oil entering my intake track, its not pump related as I redid that with a sump and better positioned my pump and such.

I drilled out my pcv valve and that and the other valve cover breather both run to atmosphere, but that's kinda where it ended.

Looking for opinions and guidance on what else need to be modified. Oil in the intake is taking some of the fun out of the turbo thing but I'm sure we can work through her.

thanks for any comments and recommendations.


Shayne

 

[alanflies]

I haven't read up on the rear mount turbo setups but I have run quite a few turbo setups on other vehicles in the past. In my experience you need to make sure that all your vacuum sources (except ones you want to reference boost like a rising rate fpr or a boost gauge) are not subject to boost, In other words make sure they are all tapped into the intake upstream of the turbo. This may present some unique challenges on a rear mount setup. You may have to set up a vacuum manifold of some type. You should also be running a vacuum supplied catch can of some sort to compensate for positive crankcase pressure caused by blow-by pushing oil into your intake. Most turbo setups will have some blow-by at higher boost levels but really it's a bad ring thing.

BTW, I have just read your turbo build thread, and I must say I'm very impressed...great work!

I can't help but wonder if the oil isn't coming through the turbo itself? maybe check the turbo outlet for oily film getting through the bearings. I've seen this quite a few times when for whatever reason the oil can't drain back to the pan.

 

[shootmymime]

so your getting some blow by causing more pressure in the oil pan side of the engine and its pushing oil up the pcv valve back into the intake. Right?


Have you installed a catch can? look into that.

 

[flatboy]

I haven't read up on the rear mount turbo setups but I have run quite a few turbo setups on other vehicles in the past. In my experience you need to make sure that all your vacuum sources (except ones you want to reference boost like a rising rate fpr or a boost gauge) are not subject to boost, In other words make sure they are all tapped into the intake upstream of the turbo. This may present some unique challenges on a rear mount setup. You may have to set up a vacuum manifold of some type. You should also be running a vacuum supplied catch can of some sort to compensate for positive crankcase pressure caused by blow-by pushing oil into your intake. Most turbo setups will have some blow-by at higher boost levels but really it's a bad ring thing.

BTW, I have just read your turbo build thread, and I must say I'm very impressed...great work!

I can't help but wonder if the oil isn't coming through the turbo itself? maybe check the turbo outlet for oily film getting through the bearings. I've seen this quite a few times when for whatever reason the oil can't drain back to the pan.

Thanks for the good words.
So I'm not totally sure what lines should go to pressure and or should be caped off, my fpr is boost referenced. I believe your right and that I need a vacuum catch can of some sort too.

I worked a bit on this last night and will follow with pics, let me what you think please and thanks.

 

[flatboy]

so your getting some blow by causing more pressure in the oil pan side of the engine and its pushing oil up the pcv valve back into the intake. Right?


Have you installed a catch can? look into that.

Right now my pcv valve is open to atmosphere, and I'm working on a catch can, hopefully will work itself out.

 

[flatboy]

So here is where I'm at with trying to get pressure out of the crankcase.

Catch can.
Side connections are in and top will run to the intake side of the turbo.

 

[flatboy]

So any thought on where this line should get plumbed into? This used to connect to the pcv. I've just had it capped the whole time.



here is the pcv valve which I drilled out(not sure if I should have) right now it just dumps to atmosphere but think it should run to the catch can?



this is the valve cover breather from the driver side, right now just dumps to atmosphere, but think it should run to the catch can?


Please whats you guys thought and opinions?

 

[shootmymime]

Catch can looks good.

just a question. dont you expect that intake to suck in tons of heat soaked air from the exhaust being right there?

can you monitor the air intake temps and the ambient air temps?

 

[flatboy]

Catch can looks good.

just a question. dont you expect that intake to suck in tons of heat soaked air from the exhaust being right there?

can you monitor the air intake temps and the ambient air temps?

My air intake temps according to the scan gauge( I think reads from the maf?) typically run between 80F and 140F. Cruising on the highway is only around 110F.

 

[shootmymime]

My air intake temps according to the scan gauge( I think reads from the maf?) typically run between 80F and 140F. Cruising on the highway is only around 110F.

whew id still say thats pretty warm even coming from a turbo. but it also depends on the outside air temps. now reading the temps coming into the motor are generally 2-3 deg warmer than outside. but there is no real way to tell the temps in between the supercharger and the motor, thats there a lot of the air get heated up at.

That kinda sucks you have to run the catch can back into the intake way down under the truck next to the turbo. but its the only place to on a turbo vehicle like that.

 

[JayRolla]

Catch can looks good.

just a question. dont you expect that intake to suck in tons of heat soaked air from the exhaust being right there?

can you monitor the air intake temps and the ambient air temps?

Its turboed, its all heat soaked now. Once air pumps past that turbo its hot and the air sucking in dont really matter much anymore. But with rear turbos the long piping can actually cool the air enough not to have an intercooler. If he has issues, intercooler and or meth injection would be best. I have ran cold airs, short rams, and just filters off my turbo cars with intake temps all over and with good intercooler and e85 never saw power difference. Also the intake temp at the intake mani stayed the same with cold air or just air filter right on the manifold.

 

[alanflies]

So any thought on where this line should get plumbed into? This used to connect to the pcv. I've just had it capped the whole time.



here is the pcv valve which I drilled out(not sure if I should have) right now it just dumps to atmosphere but think it should run to the catch can?



this is the valve cover breather from the driver side, right now just dumps to atmosphere, but think it should run to the catch can?


Please whats you guys thought and opinions?

All this looks fantastic, I would think about a vacuum manifold mounted on the firewall, supplied by the adaptor you made for the turbo inlet. make it with several ports of varying sizes that you can cap or use at your discretion. you could even make one with a gauge on it, then you will be assured that everything that needs it is getting pure vacuum. Then, pcv hose, valve covers, and any others you suspect of oil deposits can go through the catch can, also put a one way check valve anywhere you definitely don't want to see boost pressure like brake booster, PCV valve, etc. etc. You will have to make sure, but I'm thinking most if not all of the ports on your throttle body and intake should be capped and re-routed to the manifold as they will all be referencing boost conditions. You can leave them where they are if you want, and it will work fine, just know that you will only have certain functions, like power breaks, when you are off throttle.
Here's what I'm referring to.
http://www.rx7club.com/attachments/...block-anyone-tried-them-0000bloxmanifold2.jpg
http://gogoautoshop.com/media/catal...3aeddaea940bbf9921ed537307b95/v/m/vm-zz_1.jpg

 

[alanflies]

Doohh! I just noticed you already got a vacuum manifold on your firewall in the last pic there...Yea, I'm slow....Also, If your still running the "D" shaped thin metal gasket in between your throttle body and plenum, switch it to the "O" shaped one used with the supercharger setups. That alone may net you a couple PSI!

Yea, so anyway, you got all the parts you need there, just supply the vacuum manifold with vac from the adaptor you made, then everything except boost reference goes there. cap all the throttle body and plenum ports except for the ones for RR FPR and Boost gauge, or anything else you want to see boost. Replace your pcv check and run it and your valve covers, and anything else you suspect of oil, through your catch can back to the vacuum manifold. Basically, your vacuum manifold replaces your throttle body and plenum as a vacuum source for all your vacuum operated ancillaries. Just be sure to cap everything off tight. boost likes to find weak spots to escape from. Lastly, although it looks great where it is, I would think about relocating your catch can back to the firewall, It will just make routing things much cleaner and simpler. Then, Voila, your happily boosting...

 

[flatboy]

So here is where I'm at today, just about to go out for a test drive







Here I put a check valve, though not 100% sure there should be one(poked around the interweb and saw mixed opinions). I guess my thought is not pushing any pressure back into the catch can, like when driving hard then lifting off the gas and before my bov opens.? It is real light like under 1 psi

 

[gamefreakgc]

So here is where I'm at today, just about to go out for a test drive

Here I put a check valve, though not 100% sure there should be one(poked around the interweb and saw mixed opinions). I guess my thought is not pushing any pressure back into the catch can, like when driving hard then lifting off the gas and before my bov opens.? It is real light like under 1 psi

It's a good idea. On vehicles that come stock with Turbos, the PCV line is usually the only one that goes into the catch can and the PCV has a built-in check valve. Makes sense to have others the same way as long as it doesn't restrict anything.

 

[flatboy]

It's a good idea. On vehicles that come stock with Turbos, the PCV line is usually the only one that goes into the catch can and the PCV has a built-in check valve. Makes sense to have others the same way as long as it doesn't restrict anything.

Hmm good to know, maybe I'm on the right track - hopefully


I also ran this line to the catch can, its from the drivers side valve cover.

 

[gamefreakgc]

Hmm good to know, maybe I'm on the right track - hopefully


I also ran this line to the catch can, its from the drivers side valve cover.

Is that a meth injector I see? If yes, what kit are you using and what flow rates? Want to go this route with my supercharger, but probably won't need as much flow since I'll be running 7-9 psi (currently 7).

To comment on the vacuum line, it's probably better to route to the air intake. That's the hose that pulls fresh air from the air intake to the crankcase, while the PCV blows it out. By pulling it from the catch can it's not getting clean air.

Will it blow up your engine that way? No. Will it affect long-term oil deposits and such in your engine? Maybe, hard to say.

 

[flatboy]

Is that a meth injector I see? If yes, what kit are you using and what flow rates? Want to go this route with my supercharger, but probably won't need as much flow since I'll be running 7-9 psi (currently 7).

To comment on the vacuum line, it's probably better to route to the air intake. That's the hose that pulls fresh air from the air intake to the crankcase, while the PCV blows it out. By pulling it from the catch can it's not getting clean air.

Will it blow up your engine that way? No. Will it affect long-term oil deposits and such in your engine? Maybe, hard to say.

It is a Snow Performance meth kit, my 2nd one I've used. Been very happy infact the first one I bought in like 2007 and its still working. I cant remember flow rates but it comes with a few different sizes of nozzles and used voltage or boost to signal.

I didn't know that line was sucking in air.

 

[alanflies]

Is that a meth injector I see? If yes, what kit are you using and what flow rates? Want to go this route with my supercharger, but probably won't need as much flow since I'll be running 7-9 psi (currently 7).

To comment on the vacuum line, it's probably better to route to the air intake. That's the hose that pulls fresh air from the air intake to the crankcase, while the PCV blows it out. By pulling it from the catch can it's not getting clean air.

Will it blow up your engine that way? No. Will it affect long-term oil deposits and such in your engine? Maybe, hard to say.

This is true sort-of for a stock N/A engine, for a forced induction set up it's a good idea to pull a little extra vacuum on the crankcase for a better delta across the ring seal and it also helps with windage in the crankcase created by the pistons pushing on the positive pressure caused by blowby. positive crankcase pressure is the enemy in a forced induction rig. this is basically a passive setup. Short of running an external vacuum pump this is the best way of creating system vacuum in the crank case. with this setup you should be able to feel the vacuum at the dipstick hole.

Here's some good reading on it...
http://www.enginelabs.com/engine-te...how-external-vacuum-pumps-free-up-horsepower/

 

[angus]

It think on a stock engine with low levels of blow-by, I would have left the PCV system exactly like stock.

You could have just run the left valve cover vent to the turbo air filter inlet and left the PCV just like stock - unless there's a problem (or it's a motor known to have issues I never mess with PCV systems.

You do know that the PCV valve is a check valve right?