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Old 01-14-2016, 03:52 PM   #1
breaksOFTEN
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Default Vacuum pump

Has anyone tried to mount a vacuum pump on their car? I was thinking a vacuum pump could assist in ring sealing, which would aid in blow by. Also utilizing an aos or a catch can to further optimize only clean air entering the intake tract.

I called moroso and they say space is a problem, plumbing would be hard, and getting the right pulley to drive the pump to correct speeds would be difficult, and they don't think their pumps would be able to overcome the positive crank case pressures created by the turbo and blow by. This didn't make a whole lot of sense to me because I think there is some positive crankcase pressure under high boost, but it's not like full boost pressure is making its way past the rings. Space is also not an issue if you mounted it where the AC pump is, so that would have to be a sacrifice but it's the only location I can see it ever fitting. Pulley size would take a little bit of math to pick the right size pulley so that's a bad reason for it not working.

I looked on yellow bullet forums and there's mixed reviews with the high boost guys over there. Some use a vacuum pump and swear by it, others say they were told it wouldn't help so they didn't bother.

I would have to think if you were after improving an issue with no drawbacks what could hurt. Well I guess losing your AC might be out of the question for some, but others might be more interested in the power gains, better ring seal, and less contaminants in their incoming air.

And yes I know a quality aos or catch can will filter out the oil but they won't seat the rings any better.

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Old 01-21-2016, 01:42 PM   #2
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Anyone?
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Old 01-21-2016, 06:30 PM   #3
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Often wondered if it would help. There are electric pumps that woud be much easier to install, and not require ac delete.

I know a guy that has a drag week car. 6 second over 200 mph. He runs a mechanical pump at the track, and has to pull the belt for street use. or the pump can pull oil from the crankcase and cause issues. Not sure that is an issue on all setups or not.
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Old 01-22-2016, 01:07 PM   #4
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Also with the electric pump you can run it PWM so it draws more vacuum at higher boost. I've talked and thought about this before just to much going on to actually make my own setup and cars on stock ecu in working on building a track only car with standalone it'll be a big project so I'll eventually try this on that most likely
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Old 01-25-2016, 05:07 PM   #5
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I've heard of the electric pumps, but getting it wired and programmed seems more difficult than a mechanical pump driven off the crank pulley.

As far as the vacuum pump pulling oil out of the oil pan/engine that would require a larger pulley to slow the pump down and not pull that much vacuum. We shouldn't need that much vacuum to promote better ring sealing and less blow by.

I know a buddy of mine reduced his blow by on his LS turbo GTO by installing a vacuum pump. His piston to wall clearance was loose or he had the rings gapped too loose. Either way the vacuum pump helped him out a lot.

I think I'll be reinstalled my Crawford AOS for the time being to help remove oil from getting into the intake tract. It's the FMIC version but with a fabbed bracket I should be able to mount it by the turbo to accommodate my TMIC.

I'm still interested in a full time vacuum pump to help the rings seal under boost.
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Old 01-25-2016, 05:18 PM   #6
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Electric is your best bet for street car do what works for you
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Old 01-30-2016, 12:37 AM   #7
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You mention stock ecu. Does that mean I would need to run something else to incorporate the electric vacuum pump.

And educate me, PWM?
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Old 01-30-2016, 01:24 AM   #8
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PWM = pulse width modulation. Basically controlling the pump via a duty cycle to increase speed as boost increases
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Old 02-19-2021, 04:15 PM   #9
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Used Toyota air pump, took out brushed motor and installed Milwaukee brushless motor from hand grinder unit. It draws 20 amps runs at 20k rpm stays cool after 4 hours of run time and pulls good amount of vacuum about 0.3 inHg.

Its loud as **** and tool didnt have any speed control, not going to run it just was a proof of concept i wanted to do for long time.

I think next step would be to find brushless 12v DC motor high rpm and external controller and have ecu control the rpm.

Last edited by Bariga; 02-19-2021 at 05:52 PM.
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Old 02-19-2021, 07:44 PM   #10
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Yep... I'll post more if it works
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Old 02-20-2021, 05:13 PM   #11
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Quote:
Originally Posted by Bariga View Post
pulls good amount of vacuum about 0.3 inHg.
Are you capping the crankcase system? Beware that could be problematic.

You pull 1-2" of vac on most setups, stock to big turbo respectively, tapping into the turbo inlet.

For reference a sealed 2-3 stage DS setup will only pull vacuum under low load/RPM. You really need 4 vac stages to have any vacuum under high load/RPM.
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Old 02-22-2021, 01:27 PM   #12
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Yes. It does help. I believe Flatirons has a very long video series on their findings of crankcase pressure, breathing, and vacuum.

The biggest problem is finding pump that will pull enough vacuum, and survive, and be electric, and not cost the GDP of a small country.

The best one that I found for that is a factory installed unit that came on ONLY the 1984 corvette. I found the price, and it was reasonable for what it is, but then finding the part has been problematic.
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Old 02-22-2021, 06:15 PM   #13
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Quote:
Originally Posted by Bariga View Post

Used Toyota air pump... Its loud as **** and tool didnt have any speed control...
Loud is right, but great suction! You could attach a hose to the top of your oil filler tube and vacuum the shop.
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Old 02-26-2021, 12:04 AM   #14
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Crankcase vacuum pump. Motor references MAP sensor 0-5v. MAP plumbed to crankcase, adjusts DC brushless motor speed relative to crankcase vacuum. Targeting 2-4"Hg. Controlled via arduino and ESC. Something I worked on for a while. Needed a bigger/higher Kv motor. Worked well on the bench when I changed the code to PID and massaged the settings. Just couldn't pull enough vacuum to make it work well enough for me. I use a similar dumbed down system on my car now along with a oil separator and exhaust scavenging. It works very well.
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Old 02-26-2021, 07:07 AM   #15
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Worked well on the bench when I changed the code to PID and massaged the settings. Just couldn't pull enough vacuum to make it work well enough for me.
Yeah we went down this road 10 years ago. Bench testing a static test rig is far easier than a dynamic condition. The vacuum pump needs to be huge, or several stages, as boost and blow-by increases with load/RPM. This is why it's so easy to pull 2" crankcase vacuum from the turbo inlet. Ample flow to create a vacuum, and it's relative to (increases with) boost pressure.
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Old 02-26-2021, 11:25 AM   #16
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Quote:
Originally Posted by KillerBMotorsport View Post
Yeah we went down this road 10 years ago. Bench testing a static test rig is far easier than a dynamic condition. The vacuum pump needs to be huge, or several stages, as boost and blow-by increases with load/RPM. This is why it's so easy to pull 2" crankcase vacuum from the turbo inlet. Ample flow to create a vacuum, and it's relative to (increases with) boost pressure.
Nick not sure if you aware but the pump can free flow air out of it w/o pump running. So if somehow there is more pressure on engine side it will still leak out.
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Old 02-26-2021, 01:06 PM   #17
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Nick not sure if you aware but the pump can free flow air out of it w/o pump running. So if somehow there is more pressure on engine side it will still leak out.
This is Chris, not Nick.

Most pumps will windmill if they are overwhelmed. depending on the type it may overspeed and allow for increased flow, it may not. Although, as soon as you're doing that, the crankcase is venting, not having vacuum drawn, i.e.; the crankcase pressure goes positive.
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Old 02-26-2021, 02:30 PM   #18
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Quote:
Originally Posted by KillerBMotorsport View Post
Yeah we went down this road 10 years ago. Bench testing a static test rig is far easier than a dynamic condition. The vacuum pump needs to be huge, or several stages, as boost and blow-by increases with load/RPM. This is why it's so easy to pull 2" crankcase vacuum from the turbo inlet. Ample flow to create a vacuum, and it's relative to (increases with) boost pressure.

I went back to the brushed motor, on/off and pulls loads of current, but its a fast motor. The DC brushless would work, I just ran out of time, needed to try bigger/higher Kv motors. Thought about reference to boost, RPM, TPS, ect.... In the end it makes the most sense to reference motor speed (desired vacuum) to the crankcase itself. Take out all the variables and target outcome based on the objective = x crankcase vacuum. Sure its always going to lag a bit due to processing speed vs input, but using PID and always targeting above 1"Hg guarantees constant out flow, and let the PID control the motor as it learns the crankcase pressure/vacuum profile.
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Old 02-26-2021, 06:32 PM   #19
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Quote:
Originally Posted by KillerBMotorsport View Post
This is Chris, not Nick.

Most pumps will windmill if they are overwhelmed. depending on the type it may overspeed and allow for increased flow, it may not. Although, as soon as you're doing that, the crankcase is venting, not having vacuum drawn, i.e.; the crankcase pressure goes positive.
Chris.

Stock system will use Manifold vacuum for crankcase, ones manifold pressure goes positive it shuts it and switches to turbo inlet (which most people change to bigger less restrictive and guess what it aint pulling any vacuum anymore.

Still dont see any negative sides to have air pump in place.

I think using Smog pump isnt ideal unit to use, its probably running at like 60% efficiency and it leaks air from under the fan.
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Old 02-27-2021, 09:59 AM   #20
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Quote:
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Chris.
Stock system will use Manifold vacuum for crankcase, ones manifold pressure goes positive it shuts it and switches to turbo inlet (which most people change to bigger less restrictive and guess what it aint pulling any vacuum anymore.
Are you saying vacuum ports in the exhaust don't work as advertised?

When you have enough flow through a tube, you create vacuum when that flow passes over a hole, regardless of if that flow has positive or negative pressure. I've put pressure sensors all over these engines and run a 3582 on a 4" open inlet tube that was about 4" long. Open, no filter. With a single port on the inlet it puled just over 2" of vacuum in the crankcase through our AOS. With a filter (large of course) the vacuum was unchanged.

The short of it is, the bigger the turbo, the more flow, and the more flow, the more vacuum potential. I've done this testing with stock VF, Garrett 3067, 3071, 3576, 3582, Stock engine EJ and FA, as well as built versions of both.

One of the things I've thought about trying, is adding a venturi to an inlet to further boost crankcase vacuum. If done right, it should boost vacuum even more without a downside. Never got around to it.
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Old 03-02-2021, 03:35 PM   #21
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Quote:
Originally Posted by KillerBMotorsport View Post
Are you saying vacuum ports in the exhaust don't work as advertised?

When you have enough flow through a tube, you create vacuum when that flow passes over a hole, regardless of if that flow has positive or negative pressure. I've put pressure sensors all over these engines and run a 3582 on a 4" open inlet tube that was about 4" long. Open, no filter. With a single port on the inlet it puled just over 2" of vacuum in the crankcase through our AOS. With a filter (large of course) the vacuum was unchanged.

The short of it is, the bigger the turbo, the more flow, and the more flow, the more vacuum potential. I've done this testing with stock VF, Garrett 3067, 3071, 3576, 3582, Stock engine EJ and FA, as well as built versions of both.

One of the things I've thought about trying, is adding a venturi to an inlet to further boost crankcase vacuum. If done right, it should boost vacuum even more without a downside. Never got around to it.

wait so you put this in intake ?
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Old 03-02-2021, 04:14 PM   #22
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wait so you put this in intake ?
...
I recall awhile back yamahaSHO installed a similar fitting into his KStech CAI tube to get some additional vacuum pull.
https://forums.nasioc.com/forums/sho...2#post46123122
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Old 03-02-2021, 05:47 PM   #23
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I recall awhile back yamahaSHO installed a similar fitting into his KStech CAI tube to get some additional vacuum pull.
https://forums.nasioc.com/forums/sho...2#post46123122
Interesting, but im not sure if i want to do that even with big IAG can i still get some cream that comes out from the vent hose over time.
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Old 03-02-2021, 08:35 PM   #24
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wait so you put this in intake ?
No. Not necessary in the intake.

In the exhaust it's beneficial since you have near constant positive pressure, but there are several different port styles that can be used. Even a straight tube will work at high flow rates. That style is meant to provide some level of vacuum at even low flow rates, but they don't flow as well at high flow rate, or very low gas flow rates.
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Old 03-04-2021, 01:38 PM   #25
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Originally Posted by KillerBMotorsport View Post
No. Not necessary in the intake.

In the exhaust it's beneficial since you have near constant positive pressure, but there are several different port styles that can be used. Even a straight tube will work at high flow rates. That style is meant to provide some level of vacuum at even low flow rates, but they don't flow as well at high flow rate, or very low gas flow rates.
I tried the exhausts solution it wasnt good, pulled no vacuum and at some point actually pushed air back
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