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- San Antonio, Texas
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- '15 CX-5 Miata AWD
Yea I decided against VTA for now, once I'm boosted If I need to I'll add a check valve with a breather to the can.
What have you done to your CX-5 today?
- Thread starter Kayger12
- Start date
That's not true with a Skyactiv G engine because of the variable valve timing and the way it used to reduce the effect of the throttle plate. Much of the throttling of the engine is achieved with the VVT. Also contributing, the PCV valve is a variable valve that controls the flow of crankcase gasses by only opening in proportion to the amount of vacuum in the intake manifold.
That's not true either in a Skyactiv G engine. It looks like the brilliant engineers at Mazda have thought this through and are a step or two ahead of the armchair prognosticators.
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- San Antonio, Texas
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- '15 CX-5 Miata AWD
bulls***, it's completely true and you can monitor it withOBD2 hardwareand software that reads the correct PIDS. You seriously need to get off the "armchair" as you call it and actually look/monitor instead of assuming and speculating where others have actually tested. Speculation is fine when there is no alternative.
Lowest vacuum is at WOT, just before it might go positive. For me sine I've been monitoring these pids (about 2 -3 days now), I've seen .4 max of positive pressure is at high rpm/wot red line region and the PCV is most open at low vacuum.. that's exactly why I get that wot powerloss *sometimes* at a redline shift, because that's the most active period of oil vapor/blow by going into the intake mani and lowering my octane/afr. Since you are discounting his statement, I guess you believe that the PCV is most active when the engine is at low RPM because that's surely the best time to induce "waste" back into the system. Do you actually drive your car? Or do you just comment on how sweet the motor and handling are in the same manner; i.e no experience lol. I guess some people like to live vicariously.
Lowest vacuum is at WOT, just before it might go positive. For me sine I've been monitoring these pids (about 2 -3 days now), I've seen .4 max of positive pressure is at high rpm/wot red line region and the PCV is most open at low vacuum.. that's exactly why I get that wot powerloss *sometimes* at a redline shift, because that's the most active period of oil vapor/blow by going into the intake mani and lowering my octane/afr. Since you are discounting his statement, I guess you believe that the PCV is most active when the engine is at low RPM because that's surely the best time to induce "waste" back into the system. Do you actually drive your car? Or do you just comment on how sweet the motor and handling are in the same manner; i.e no experience lol. I guess some people like to live vicariously.
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Mike, are you saying that they intentionally keep the high vaccuum in the intake throughout the rpm and load range??? Choking the engine at wot by magically keeping the throttle semi-closed? That's the only way to create the vacuum in the intake, by the way. And PCV system really depends on the intake vacuum.
No, this is not how it's done. This is not throttle -less BMW - style system. VVT does not substitute throttling in this case.
I'm not prognosticating anything either. I admire the engineering that went into SkyActiv technology as much as the next guy. But there are certain things that that are legislated, either by the government, or the law of physics.
No, this is not how it's done. This is not throttle -less BMW - style system. VVT does not substitute throttling in this case.
I'm not prognosticating anything either. I admire the engineering that went into SkyActiv technology as much as the next guy. But there are certain things that that are legislated, either by the government, or the law of physics.
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- San Antonio, Texas
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- '15 CX-5 Miata AWD
I'll even give you benefit of doubt and call that a confusion between "low vacuum" being Closer to zero, and hi vacuum being away from zero left on the number line, Also the naming of the gauge is misleading as it is called a "boost/vacuum" gauge in the software and lists low/hi instead of hi/low
this one if form a few hours ago, same batch of fuel lower temp ,lower pressure, lower density altitude.. so I got a higher lambda, same boost, lower vacuum and more timing. FWIW on the first one I did bounce the limiter because that was the first log I did with those pids.
this one if form a few hours ago, same batch of fuel lower temp ,lower pressure, lower density altitude.. so I got a higher lambda, same boost, lower vacuum and more timing. FWIW on the first one I did bounce the limiter because that was the first log I did with those pids.
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- San Antonio, Texas
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- '15 CX-5 Miata AWD
TO be honest, I would like to see what kind of numbers others are getting, just to compare results based on fuel used, temp etc.. if anyone is interested. With the correct software (I.e "Torque", basic version free for Android) It's also useful for viewing CEL's, and "Pending" faults which do not show up on the cluster, however are stored in the ECU as a prediction to a possibly negative event.. It's has other datalogging features as well.
$8 Shipped Adapter plugs into the obd2 port on the left side of the dashboard https://www.ebay.com (commissions earned)
Torque (or Pro) Google Play Store, here is the web address for information http://torque-bhp.com/
$8 Shipped Adapter plugs into the obd2 port on the left side of the dashboard https://www.ebay.com (commissions earned)
Torque (or Pro) Google Play Store, here is the web address for information http://torque-bhp.com/
No. Vacuum at WOT is relatively low regardless of Skyactiv vs. old school engines. But there is still vacuum, particularly as the air in the intake is accelerating. Air has mass. As it accelerates into the engine it causes a small vacuum even when the throttle plate is wide open. This effect is more pronounced in lower gears because the air mass is accelerating faster.
The part I was taking issue with was your statement that the blowby gasses try to force themselves out of the crankcase at WOT. The crankcase is also vented to the area under the valve cover which is vented to the air intake before the throttle plate. At wide open throttle there is a venturi effect at the outlet of this vent tube into the intake manifold that creates a vacuum greater than that in the intake manifold and this actively draws crankcase gases into the intake at WOT.
I used the word "almost", and you have to agree that the highest rate of evacuation takes place when the vacuum is at its highest. No venturi effect would produce over 15mm of vacuum that is observable in the intake at idle, unless the air in the intake goes supersonic. And only the air pressure differential causes the movement of gases in our case.
Are you sure this is not the fresh air intake for PCV system? In any case, the blow-by has to find its way through there, meaning the vaccuum in the intake is negligible. So we agree on that. So PCV system at wot is not a ventilation system anymore, as it becomes evacuation system, with no fresh air dilution. I hope we're on the same page here.
So some people have valid concerns about the blow-by going through the intake, even "washing" the open throttle, leaving minute deposits of oil in the process. Chris is concerned about losing octane rating, for instance. I'm more afraid of intake deposits, not just on the valves, but on the plate, tubes, walls, etc. I just don't want it there. So, however effective, the stock oil separator can't objectively be 100% efficient. Proposed addition of the catch can will help with further reduction of oil/water mix in the gas being evacuated, at minimum cost, with no harm done. If it catches next to nothing, so be it, let's praise Mazda's engineers. But if it does catch some, I know what I will be doing. I have the experience....
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- San Antonio, Texas
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- '15 CX-5 Miata AWD
Hey what would you guys recommend for a thread sealant for use with threads sealing against oil? Going to use some on an oil p gauge thread, a block off bolt, and n adapter for and oil feed line. What have you 'all used on other similar applications?
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- San Antonio, Texas
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- '15 CX-5 Miata AWD
Picked up some permakotex thread sealant based off feedback for the oil P gauge, oil feed line bung, and block off bolt for the oil sandwich plate. I will be changing the oil and installing the new pan next week
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- San Antonio, Texas
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- '15 CX-5 Miata AWD
It shouldn't; this stuff is specifically for this type of application(sealant vs locker) and is rated up to 400f.
Put in my oem Mazda all weather floor mats that I got dealer to throw in for free, took 2 weeks for dealer to get them in stock, but they were free so I won't complain. Also received my cargo net and put that in. No more groceries sliding around.
Now I need to buy the cargo cover
Now I need to buy the cargo cover
Curious to know (and if you don't mind the ask) - how much did it cost for the CQ? There are a few places locally that do it here and I toy w/the idea of doing it. Thx.
karlmagnum
Member
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- CX-5
Just removed the factory roof rack and changed the wiper blades.
mini roadtrip (300 miles return)
beautiful sunny day, highway runs parallel to the foothills 50 miles west, big azz rocky mountains a little taller and further away, both with bright white snow sparkling
dry roads, little traffic
great day for a drive with the tunes cranked up
We'll be together with a roof rack over our heads;
(ok, ok, so it's really : We'll be together with a roof right over our heads)
beautiful sunny day, highway runs parallel to the foothills 50 miles west, big azz rocky mountains a little taller and further away, both with bright white snow sparkling
dry roads, little traffic
great day for a drive with the tunes cranked up
We'll be together with a roof rack over our heads;
(ok, ok, so it's really : We'll be together with a roof right over our heads)
