Crankcase breather/ Catch can / Evac system thread.
#22
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I just installed my set up today, it pulls vacuum even at Idle, it seems like I will have to re tune. My idle AFRs went from 14-15 to 16-17 but it still is idling smooth at those AFRs with 550s currently which is something Ive never been able to do with the 550s.
#23
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? Did your fuel map move to a different load cell at idle? I don't think vacuum on the case would lean it up.
How much vacuum change do you see with it connected vs disconnected?
Also how did you do your setup? Direct? Catch can in between? What size hose and fittings?
#24
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Catch can between, I have 2 3/8 hoses to my catch can and a 5/8 hose to the valve, kpa's are the same on my gauge and in ms. I have not had many issues with my catch can set up the way it was so the only thing I changed was the 5/8 hose to the catch can instead of a filter to VTA. It may have just been an ms fluke I will start the car again and see if I still have the same results.
#28
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Yes catless and you apparently need minimal backpressure and restriction for this to work. A cat or restrictive muffler could of course, hurt the flow.
That said, to make HP you have to flow air. Stand behind the tailpipe of a high hp car on the dyno and you will see what I mean- the air coming out of the exhaust is like a leaf blower.
#30
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I got everything together on my car tonight went and added fluids and the radiator pissed out all over the floor. I must have nicked it or something while it was out actually I think the electrician who fixed light ballast in my shop might have. Got to fix that before it’s ready now. It was a Godspeed, I just ordered a CXRacing for a replacement.
Bob
Bob
#32
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Ok so I installed a vacuum gauge on to my catch can to see if this thing really works, so far nothing idling or revving on the gauge. But I will be at Infineon raceway tomorrow for the miata challenge and I have the gauge temporarily mounted where you will be able to see it with the go pro camera I am borrowing.
#33
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Ok so I installed a vacuum gauge on to my catch can to see if this thing really works, so far nothing idling or revving on the gauge. But I will be at Infineon raceway tomorrow for the miata challenge and I have the gauge temporarily mounted where you will be able to see it with the go pro camera I am borrowing.
#35
Ok so I installed a vacuum gauge on to my catch can to see if this thing really works, so far nothing idling or revving on the gauge. But I will be at Infineon raceway tomorrow for the miata challenge and I have the gauge temporarily mounted where you will be able to see it with the go pro camera I am borrowing.
Keep in mind that you are measuring the net result of positive crankcase pressure and the exhaust-generated vacuum. If your gauge only reads vacuum, the needle will not move off of zero if the vacuum does not overcome the positive pressure.
#36
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My gauge will measure positive pressure. So the results are... It does work and with out pulling any oil. Yesterday at the miata challenge my car ran like total crap, I could not rev past 4k with out my rpm signal getting confused, so I was shifting at 4k in every gear. But I never saw any pressure build and once in boost I did see vacuum being pulled. Only 1-2in but I was also at quite low load since my car really doesn't open up until 4500 rpm.
#38
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Ive had a similar problem before and it was the CAS, so I showed my log to Sav, he said its something in the ignition so Ill start at the grounds and check the wiring, shouldn't be a big deal. It rained hard all day so putting down power was not really an option anyways, I still had fun.
#39
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Bob
#40
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Update first track day and the slash cut was sucking oil out of the catch can and out the tailpipe after left hand corners. Didn’t do that for any of the street driving I was doing prior.
http://www.youtube.com/watch?v=5hsQYiIHiq0
I’m thinking some sort of check valve in the return line and cap off the OEM PCV breather port.
Bob
http://www.youtube.com/watch?v=5hsQYiIHiq0
I’m thinking some sort of check valve in the return line and cap off the OEM PCV breather port.
Bob