exhaust CCV bung location - where is best?

[cpalella]

Looking at this option for both my e36 and e30s52 swap. Installing AC in the e30s52 interferes with my current CCV setup.

I am looking for advice as to WHERE to place the bung along the exhaust system. close to headers? before 2-1 merge? after the 2-1 merge? at a bend? in a straight section? etc.
Basically, is there a sweet spot or a trick to choosing the location along the exhaust system?

Pictured is my setup for reference

Here is the merge off the OBD2 headers





And here is the mid section. Inlet on the left, outlet on the right, after muffler

[NY98M3]

I was told after an outside of a bend where it would pick up most of the vac.

[cpalella]

I was told after an outside of a bend where it would pick up most of the vac.

Like this? (either 2 spots?)

The gray trapezoids are the bungs and the black arcs are supposed to be tubing........ please excuse the crude diagram. MS word FTW

[NY98M3]

yes exactly

[iRodD]

Perfect

[cpalella]

yes exactly

Perfect

Great guys, thanks!!

[Matutino]

This set up is working great for me

[cpalella]

This set up is working great for me

You have a very nice build.

So you run 2 exhaust ccv bungs? and if I see correctly, you ave the check valves near the swaybar? which check valves did you use?

Also, OT, are those slip fit connections on your exhaust with band clamps? Also, do you have a shot of the engine bay showing your ccv layout from up top? (I'll search for your build thread )

[milKt]

Nice photo Matt.
Well sorted.


Ideal placement is after the turn so the flow is crashing into it,
but having MULTIPLE crankcase vents
ANYWHERE for mid-pauer turbo systems is "just right".

I have THREE (3) vents to a hobo catch can,
but it still sprays all over the place.

Keeps the engine bay shiny, free from...well, dirt I guess.

[cpalella]

Nice photo Matt.
Well sorted.


Ideal placement is after the turn so the flow is crashing into it,
but having MULTIPLE crankcase vents
ANYWHERE for mid-pauer turbo systems is "just right".

I have THREE (3) vents to a hobo catch can,
but it still sprays all over the place.

Keeps the engine bay shiny, free from...well, dirt I guess.

Yea that setup looks quite nice and adequate. I have a vented can now but don't like it because of oily spray and smell. I like shiny dirt free engine bays. And I also like pulling vacuum on the crankcase.

[Matutino]

You have a very nice build.

So you run 2 exhaust ccv bungs? and if I see correctly, you ave the check valves near the swaybar? which check valves did you use?

Also, OT, are those slip fit connections on your exhaust with band clamps? Also, do you have a shot of the engine bay showing your ccv layout from up top? (I'll search for your build thread )

That's correct, each line has it own check valve (from Napa).
It goes like this.
Valve cover to oil catch can, then to obdii pump (modified with Hobbs switch), comes out of the pump and splits into 2 lines, check valve and finally to exhaust using the vibrant e-vac fitting.

[cpalella]

That's correct, each line has it own check valve (from Napa).
It goes like this.
Valve cover to oil catch can, then to obdii pump (modified with Hobbs switch), comes out of the pump and splits into 2 lines, check valve and finally to exhaust using the vibrant e-vac fitting.

Damn. That's an impressive setup - not just the ccv but the whole engine bay. Very nicely packaged too. Thanks for the pictures.

Where did you buy that burger motorsport catch can? I tried to buy one but they don't sell directly to CA because of emissions regulations

[milKt]

Damn. That's an impressive setup - not just the ccv but the whole engine bay. Very nicely packaged too. Thanks for the pictures.

Where did you buy that burger motorsport catch can? I tried to buy one but they don't sell directly to CA because of emissions regulations

Dang,
MATT just threw a cherry and whipt topping on that CCV set-up
with a pauer vacuum pump.

That SUCKS, literally.

[chikinhed]

The exhaust evac might actually work if the pump output is higher than the exhaust back pressure. What pressure Hobbs switch did you go with?

Sent from my GTX3582R

[cpalella]

Dang,
MATT just threw a cherry and whipt topping on that CCV set-up
with a pauer vacuum pump.

That SUCKS, literally.

Yea, you're not kidding. I remember a thread a while back discussing ccv options with the obd2 air pump being one. Didn't know anyone did it, let alone in line with exhaust ccv.

I guess this is how you definitively kill positive crankcase pressure.

- - - Updated - - -

The exhaust evac might actually work if the pump output is higher than the exhaust back pressure. What pressure Hobbs switch did you go with?

Sent from my GTX3582R

I was thinking the same thing.

Matutino - do you mind sharing your ccv vacuum/pressure readings with this setup at various rpm? (I would have to assume you tested the system, and it works)

[Matutino]

I have been running the system for a while now with great success.
The exhaust back pressure is actually helping the set up as it always pulls vacuum thanks to the e-vac fitting so the pump is never "fighting" the exhaust back pressure.
The purpose of the pump is to shine when back pressure is actually not enough to pull vacuum.
If you remove the pump you will always have vacuum pulling more or less(if the e-vac fitting is installed correctly), I know many forum members have had great success and others not so much.
The Hobbs switch Im currently running is set at 7 PSI, I have another one that triggers at 2 PSI but never used it yet as I see 7 PSI almost instantly.

I tested the pump and saw a max of 6 PSI if I recall correctly after fixing some issues. I have a vide with a renamed engineer helping me when I first installed it and he endorse the system, check it out...


Also, I used this harness to provide power to the pump

[bry195]

the SAP just works. I probably have 3 years on mine with 0 issues. not to say the venturi wont work but it has to be played with. the venturi converts velocity into vacuum but there are windows of efficiency. turbulence, venturi placement, velocity, and orifice size all have to be in alignment and what I found is idle is very different than boosting.

the fitting venturi is not very forgiving. for example you have a semi barreling down the road at 75mph. if you pull a motorcycle within 3 feet of the bumper you get pulled along. iff the semi is doing 40 then you need to be 1 foot from the bumper. at 20 you need a bike half the size.

the idea is to create this drafting zone over the orifice in the pipe that leads to the vacuum line.

if you have ever drafted a semi (please dont do this) you will notice that at different speeds you get a buffeting side to side at certain points and depending on where you are at in the draft side winds of moderate velocity affect you less but as the low pressure zone moves side winds effect you more.

this isnt to discourage the venturi fitting. it works but its not as easy as it might appear. some guys get lucky and it works right away. some guys never got it to work and some guys know how it works.

I setup a test rig and controlled the area where velocity increases plus or minus 10mm. the orifice that pulls the max vacuum had a sweet spot about 2mm wide. I could be 5mm off but I would pull half the vacuum for a fixed velocity through the venturi. after finding the sweet spot I would take vacuum measurements based on halfing or doubling velocity and the relationship between exhaust velocity and vacuum had a very small window for linear increase/decrease in vacuum. on the low end it would drop off rapidly and the high end resulted in very little vacuum increase.

just be prepared to be lucky or spend some time with it. if you are dedicated you will get something.

[Butters Stoch]

Surprised no one has mentioned the stock Mustang Cobra pump .

[cpalella]

Surprised no one has mentioned the stock Mustang Cobra pump .

I'm aware of it.

- - - Updated - - -

the SAP just works. I probably have 3 years on mine with 0 issues. not to say the venturi wont work but it has to be played with. the venturi converts velocity into vacuum but there are windows of efficiency. turbulence, venturi placement, velocity, and orifice size all have to be in alignment and what I found is idle is very different than boosting.

the fitting venturi is not very forgiving. for example you have a semi barreling down the road at 75mph. if you pull a motorcycle within 3 feet of the bumper you get pulled along. iff the semi is doing 40 then you need to be 1 foot from the bumper. at 20 you need a bike half the size.

the idea is to create this drafting zone over the orifice in the pipe that leads to the vacuum line.

if you have ever drafted a semi (please dont do this) you will notice that at different speeds you get a buffeting side to side at certain points and depending on where you are at in the draft side winds of moderate velocity affect you less but as the low pressure zone moves side winds effect you more.

this isnt to discourage the venturi fitting. it works but its not as easy as it might appear. some guys get lucky and it works right away. some guys never got it to work and some guys know how it works.

I setup a test rig and controlled the area where velocity increases plus or minus 10mm. the orifice that pulls the max vacuum had a sweet spot about 2mm wide. I could be 5mm off but I would pull half the vacuum for a fixed velocity through the venturi. after finding the sweet spot I would take vacuum measurements based on halfing or doubling velocity and the relationship between exhaust velocity and vacuum had a very small window for linear increase/decrease in vacuum. on the low end it would drop off rapidly and the high end resulted in very little vacuum increase.

just be prepared to be lucky or spend some time with it. if you are dedicated you will get something.

Thanks for the detailed analysis. Very cool. I'll try my luck with it since I've had the parts sitting around forever. On the e30s52 it's not as crucial since it's NA. I just want to pull a little vacuum and avoid the smell. On the SCed e36 however, I'll see if I can pull enough vacuum (or at all) with the venturi fitting, and if not I still have my SAP in a parts box somewhere that I could rig up as well with the hobbs switch like matutino to supplement the venturi fitting.

- - - Updated - - -

I also found this article from motoIQ a while back. It's an excellent dissemination of CCV options for N/A cars (and good info on the topic in general)

http://www.motoiq.com/MagazineArticl...A-Edition.aspx

- - - Updated - - -

And I think I just found the original source of the article from sr20-forum. There's a forced induction edition as well here:

http://www.sr20-forum.com/informatio...d-edition.html

[bry195]

I'm aware of it. - - - Updated - - - Thanks for the detailed analysis. Very cool. I'll try my luck with it since I've had the parts sitting around forever. On the e30s52 it's not as crucial since it's NA. I just want to pull a little vacuum and avoid the smell. On the SCed e36 however, I'll see if I can pull enough vacuum (or .....on-fully-explained-turbocharged-edition.html"]http://www.sr20-forum.com/information-library/44727-crank-case-ventilation-fully-explained-turbocharged-edition.html[/URL]

glad to participate. sounds like your head is in the right place. I think the mustang pump was what I originally read about and I believe its a vane style pump. so when I had the idea that I needed to pull 30" of mercury (cuz allot is better than a little) I went to something that could pull a deep vacuum and flowed reasonably well. A 2hp DC diaphragm pump.!!!! when I would turn the pump on this noisy old 2.8 would go almost dead quiet. it scared the shite out of me. something was going to go wrong for sure. then the venturi's followed but I had to know what the motor was designed for. the oem ccv will not allow you to pull more than 10" of water column before it closes the check valve but I still like more. more in the form of flow. one of my customers was designing an elevator that used 4 shop vac motors to lift the elevator in a tube. like a bank tube. it worked and bingo it clicked. the SAP is a shop vac with no vanes. so im off to save the world with SAP's and discover guys were doing pretty similar things already. another discovery I made too late. Gotta learn how to use google better. Anyways, Im sure we all have done the same it just seems to be a pattern with me.

good luck, now Im off to invent a fishing pole you can keep in your pocket!

[Haifisch M3]

what is the advantage of pulling so much vacuum vs just venting to atmosphere?

[bry195]

they say you get horsepower from pulling a vacuum but I didnt notice anything. Venting did not control my oil smoke problem. a small low flow vacuum didnt either.

[cpalella]

glad to participate. sounds like your head is in the right place. I think the mustang pump was what I originally read about and I believe its a vane style pump. so when I had the idea that I needed to pull 30" of mercury (cuz allot is better than a little) I went to something that could pull a deep vacuum and flowed reasonably well. A 2hp DC diaphragm pump.!!!! when I would turn the pump on this noisy old 2.8 would go almost dead quiet. it scared the shite out of me. something was going to go wrong for sure. then the venturi's followed but I had to know what the motor was designed for. the oem ccv will not allow you to pull more than 10" of water column before it closes the check valve but I still like more. more in the form of flow. one of my customers was designing an elevator that used 4 shop vac motors to lift the elevator in a tube. like a bank tube. it worked and bingo it clicked. the SAP is a shop vac with no vanes. so im off to save the world with SAP's and discover guys were doing pretty similar things already. another discovery I made too late. Gotta learn how to use google better. Anyways, Im sure we all have done the same it just seems to be a pattern with me.

good luck, now Im off to invent a fishing pole you can keep in your pocket!

Interesting experience and information you've gathered here. Thanks for sharing. I think I've got my work cut out for me.

Good luck on that fishing pole

[TVega]

This set up is working great for me

That's just how I did mine. Works great.

[milKt]

what is the advantage of pulling so much vacuum vs just venting to atmosphere?

I've never heard of horsepower gains from our cars
as a result of pulling MORE vacuum.


The reason this trend started a few years back was to minimize oil pressure blowing through the oil feed/return lines
gathering in the charge pipes and down pipes/exhaust of quite a few members.
This was partly the result of inadequate crankcase venting.


"Sincere" boost builds up severe crankcase pressure and it can affect the system negatively.
I have three vent lines coming off my crankcase.
Two (2) off the pan
and one (1) off the valve cover.
They work very well,
even with my oil drain line attached to my oil drain PLUG location.

No issues to date.


Though there MAY be hp difference documented amoung other hot rod platforms
I doubt we've shown any data among our hot rodley's