In the past day or so I've read a bunch of the info re evap system removal and the statements that it helps low speed performance. I'm trying to understand why. I don't see anything in the function of the system that should have any direct effect on engine performance. It's just a vent system.
What am I missing re function of the system that causes low speed running issues? I apologize if this has been covered previously but although I found plenty of info on removal I haven't found an explanation of the system's operation that cause low RPM running in the first place.
I guess what I'm thinking - apparently incorrectly - is that if the evap system is working properly, there should be no impact on running. ?????
Well, prepare not to like this post.
Though I do think you sometimes see unintended consequences of emissions standards affecting operation at certain rpm, I also think most people make mountains out of molehills or just flat out fool themselves into thinking something has an affect (good or bad).
Confirmation bias is strong.
I yanked my evap system in my Jackal many years ago because it was huge with dual canisters in each side taking up room I wanted to use. The only result, other than cosmetic, was my garage sometimes smelled from the venting fuel tank.
So I tested it on my B11 and my MkI V7 by clamping off the purge line and I could not perceive any difference in cold starts, hot starts, or running. Maybe I'm just a dull tool when it comes to such subtle perception, but I agree it's usually just a boogeyman that gets blamed when it's not the problem. So much so now that I've installed a happy face sticker on the canister in the V7 to show how happy it is to be there holding vapors between rides.
But then again I feel the same way about signal spoofers. Ok, the spoofer CAN have an actual affect (I guess just like a flooded EVAP can theoretically have), but it's limited and let me explain.
Depending on what signal you're spoofing the ECU can often adjust fuel trim to eventually ignore the spoof (at least if you're still running a map that uses the O2 sensors for feedback).
More importantly a spoofer IS a dumb tool in that it ASSumes that the map is lean everywhere and therefore needs to be "richened up a bit" across the board. Thing is, the map isn't lean everywhere, it's pig rich in places, especially when accelerating, so you do risk running too rich, wasting fuel, and contaminating oil in a lot of use. I'm not predicting catastrophic failures or anything like that, just waste, inefficiency, and potential wear. All of which bother me more than adjusting to an l any small perceived imperfect running condition.
Again, maybe I'm just a dull tool, but for me, it's a well thought out remap or just leave it stock. Same with my EVAP or SAS or...
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