I was pondering my intake today for no other reason than that I could. Something occured to me in that moment. Under heavy or even wide open throttle acceleration, your engine needs a large supply of air. Its safe to say that stock and even aftermarket intakes cannot deliver on this. The reason being is because the air has to be metered and filtered.
Your engine gets adequate air to operate, but not the volume it needs to not only perform better but to improve effiency. The ECU simply adjusts for this by ajusting the a/f ratio. But what if there was a way to get a higher volume of air?
Well in thinking about this I wondered what the possiblity would be to add a tube of some sort to the intake system that would work under near WOT conditions only. Sort of like the SVT intake, but without the need for a dual stage intake.
A tube of somesort that would open up and just allow the air to flow in at whatever rate it could. Put a screen type filter on it so that any larger size debris would be stopped and place it a strategic area under the hood so that it would be able to suck air in freely but not necesserily be in an overly exposed area to debris.
Now, I can tell you that from the numerous oil analysis that I have done that your motor isnt going to suffer any accelerated wear unless you just stay constantly at WOT. A good oil (yeah, like Amsoil) will and should hold most airborne contaminants in suspension and then the filter could pull out some of that. Granted you had better be on top of your oil and filter maintenance but it wouldnt harm it. If you run a paper filter you are in even better shape because the one thing paper filters do do well is filter. Its just that it comes at a very heavy price in air flow and performance.
There are only two aftermarket filters I would run, both are foam filters and one obviously is Amsoil. Ive run K&N before but not by choice and I wont do so again. There are gaps in those filters that you could drive a motorhome through so you can imagine the dirt that can get through, and again Ive seen the oil analysis that supports that.
Okay, so the tube could even be actuated from the drivers seat. A motorized control that you actuated if you knew you were going to get in the throttle, were getting on a highway from an on ramp or other situations where you were going to use the throttle heavily. Then once you are up to speed or such just close off that part of the intake.
Here's what I think you would see from it. First a great deal of improvement in performance because you would be able to pull in the most air that your volumetric efficiency would allow. Second, better fuel economy because you would have the most air intake available when its needed most.
I believe you could even do this without metering the air. Dont ask me how I know this, let it suffice to say Ive played a little in seeing what I could get past the MAF. You might run a tad lean but that would depend on a few things, not the least of which is the wildly different timing setups between different Foci.
So what do you think? Sound like a doable thing? I know most are going to immediately jump at "Its unfiltered air, your going to ruin the motor". All I can say is do a few oil analysis on your cars and let me know what you find out. Id say that with a high quality oil filter (yep, Amsoil came to mind) you'd pull out a great deal of anything that you would ingest and I have to add I dont think its going to add up to that much, furthermore, what isnt picked up should be held in suspension by the oil if it is of good quality and in good shape.
If I could quickly rig something up, Id have to give this a try and track everything including oil analysis to see whats going on inside. I got a spare intake tube, however it is metal and I dont have any tools I could retrofit it with unless I put some type of 'Y' connector set up on the end of it. If that were the case I would just have to modify my current plastic intake so I could avoid the whole heat soaking issue.
____________________ My car is a synner! It uses Amsoil Synthetic Lubricants.
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it
In theory, it sounds like it could work, but I don't think that it would be truly effective unless you have VCT or some sort of variable valve system. A conventional engine cannot even take in the amount of air that the stock intake provides, as is evidenced by the success of VTEC, VCT, and other variable valve systems. A V.V.S. would help let more of that extra air come in as it keeps the valves open longer, but on a non VCT motor, I doubt that it would do much if anything...either way, I'm interested to hear the results.
____________________ Proud owner of a Black 2000 Focus ZX3...
you just suceeded in slowing down the air velocity and therby cut down on the amount of air your engine will take in under WOT. why do you think intake manifolds have runners? strap the maf to the TB and take a cruise if you dont believe me.
your observations on WOT are off kilter also. WOT at low rpm and WOT at high revs are different. at low RPM, your air intake needs are low. having a wide open intake will slow down air speed and cause performance losses. this is why the DSIM has long runners. at high RPM, intake needs are high and so is air volume. having a long runner chokes the engine a bit so the DSIM has short runners for that.
