https://www.youtube.com/watch?v=HAvxjSdQsXI
At 3:40 minutes…
3:40 until when? Somewhere between 3:40 and 42 minutes where you invited me to drop in last time? I've seen this video before. Who do you think "Yowie 08" is with the youtube comment 12 months ago?
I've pulled the pin at the 10 minute mark. I'm not going to re-watch a 56 minute video I've seen before on a vague tipoff that there might be evidence for your statement:
Using a Perrin or psr v2 silicone inlet (more affordable) should maintain the correct pressure differential in the inlet for the pcv returns, meaning less reliance on an aos/cc setup for a street driven car not running e85.
Turning now to the following statement:
So the avo style pipe is huge at the pcv return port: low pressure acting on that port.
Great. Please produce the evidence (anecdotal, testing, whatever) that engines with AVO pre-turbo pipes have high pressure sumps compared to engines with different pre-turbo pipes. Alternatively, admit that it is speculation. Speculation based on some science sure, but speculation.
Now I feel bad that this info might kill some business for companies that don’t offer the option of having the stock pcv return in the stock inlet position,
I'm sure they will be fine until some evidence comes to light.
...however I want to clarify that for a race style 3in one out arrangement aos/cc, its fine, because there will be enough vacuum in the inlet for crankcase scavenging, regardless.
I think you and I are starting to agree. I also think it doesn't matter exactly where "in the general neighborhood of stock position" the ported vacuum draws on the engine blow-by pressure - if that is more-or-less what you're saying.
Interesting stuff Re "straight-pipe = equal pressure" engineering fundamentals versus the convoluted path (elbows, narrow bits etc.) of a real pre-turbo pipe. There may very well be differences at different points on one pre-turbo pipe, or the spigot points on different pre-turbo pipes. It's all speculation until evidence comes to light that brand X pre-turbo pipes have high pressure sumps compared to engines with Brand Y pre-turbo pipes.
I genuinely enjoy a good speculation/debate about which design for an engine thing is materially better. The trouble is, we live in a world where testing is expensive and marketing is rampant. As a result car modification parts seem to fall into three categories:
(a) stuff that is proven to be beneficial that everyone just does (bigger dump pipes, bigger turbos etc.);
(b) stuff that is probably better by small percentages, popular with racing teams chasing the "one-percenters" but not good value for most road-car and track day enthusiasts; and
(c) stuff that is endlessly debated (divorced dump pipes vs bell-mouth dump pipes vs dump pipes with little MRT splitters welded into them) with no definitive evidence to hand to settle the matter.
[Years ago I saw some great commentary on golf equipment developments and marketing. There are "remarkable" changes (large titanium driver heads, carbon fibre shafts etc) and there are "unremarkable" changes ("this year's clubs hit 1.78321 metres further due to Racing Stripes (TM) Techology!").]
As consumers and indeed opinion-leaders on a car modification forum (particularly where new members seeking advice are concerned) I think we need to be clear in our own minds and in our communication:
(a) which mods are objectively, provably better;
(b) which are "better but probably not materially/measurably"; and
(c) which are "probably good but opinion-based and unproven"
I freely admit that a lot of tinkering I do with my car is in category (b) and/or (c). Especially if it is cheap to do and personally interesting. See the throttle body porting and airbox ribs removal. If you can find a post where I tell someone else those changes are essential I'll post you a packet of biscuits.
see why divers place cages over low pressure orifices for safety.
Good advice to cover one's orifice.