I recently took a good look at the upper part of my air intake in the engine bay. One issue that I have been having since I got back to sea level from lofty Mexico City is basically having too much air get rammed in and the vehicle jerking at stops and starts when I step on the accelerator. This caused me to look at a few different modifications. As a temporary fix, I set this up with some duct tape and basically turning a way the curved piece by the fusebox that is used to suck up air from the bullhorn intake on the front. This has succeeded and engine idle stays at 750 RPM, drives quite normally. However, I still wanted to get the use out of the bullhorn intake. High rpms I could live with, but wanted to avoid the jerking that I get at starts and stopss.

This is the first piece, which was the temporary fix. I covered up the hole on the intake used to suck up engine air (this was for Mexico) with some duct tape and turned the black piece away from the lower air intake.

 

A closer shot and then will see what I came up with.

 

Now in the photos above, no air filter , and it merely takes the air from where the OEM air system would take it right behind the headlight. By duct taping the one piece, I have been able to maintain a good idle at 750.

However, here is what I recently did. You will note below the black piece has been reattached in front of the fusebox to take the air from the bullhorn intake on the front of the bumper.

The silver y-piece that has been more or less the staple part of this upper intake system that I developed in late 2006 has been turned around. Now the air coming from the bullhorn intake has two paths. Either through the upper pipe toward the engine or toward the air filter, which is one of those Spectre pieces you can get at Autozone. I favored that because it is a bit longer than the Weapon-R I have and for the moment will be used.

The reason behind this idea is so that the suction of the engine takes up what air it needs (not what it doesn't need) and any excess air will run out the side. The air intake serves as a catcher in that case or like a bov (blow off valve). In addition, at start up the engine can take a bit of engine air from this location and not to have to worry about a high idle rpm caused by their being a gaping hole at that location as there was for a few years with that system in Mexico City (where a gaping hole at that altitude worked fine with the idle).

The end result, is just a slightly higher than normal idle rpm while in Drive, but not much, say 800 to 900, and no jerking at stops or at starts upon acceleration.

 

Here is the junction under the fusebox. I didn't need to use a clamp here as the gasket works quite well by itself.

 

Picture of the front of the air filter. This Spectre filter is a bit more restrictive than the Weapon-R, but that's okay, that's what I want at sea level for this kind of project.

 

A rear shot

 

The modification I may make to this piece to get the idle rpm down a bit more is removing the black plastic piece in the upper right corner, just to the right of the front of the fusebox and to the left of the headlight bulb apparatus. That piece actually is a curved PVC piece that allows the air from the bullhorn intake to go toward the intake in the engine bay. By removing it, it sill will have access to fresh air coming from the bullhorn intake, but not having it rammed down its throat like it is now.

 

We're not done.

There is one small modification that I have seen done on other vehicles, but rarely on the 1MZFE motor. And that is a crankshaft or crankcase filter. I haven't added the filter for now, but I have made a modification to the way crankcase ventilation works. Remember about a week ago when I discussed why the inner part of the air intake can get some oil residue, https://www.clublexus.com/forums/sho....php?p=3706014

So, what I have done for the moment is redirect the flow from both the front and rear crankcases with some vinyl tubing in the size shown below.

I haven't added the air filters yet, but to get an idea see the last photo of this page, http://www.cardomain.com/ride/649812/3 of this Toyota Sienna and you will get an idea. I will discuss a bit more as I go long to rehash what I did a week ago.

UPDATE: I recently removed the breather filters in part due to the humidity down here.

 

I actually found I had to use some smaller vinyl tubing for the PVC valve on the rear bank, so I cut a bit of this tubing off so that the larger tubing I showed in the previous tubing would fit.

 

Then I stuck the larger black vinyl tubing over the piece.

 

Then I take two clamps that were from the OEM connector between the PCV valve and the intake manifold and clamp down the hose on the PCV valve.

 

Then I placed the pcv valve back in its place and stretched the hose behind the engine block (it doesn't touch it though, I made sure of that).

 

Then I tied it down with a plastic tie at this point.

To give you another idea what this does. Any of the vapor or mist from the rear crankcase, instead of being burned in the combustion, will flow freely here. Some vehicles like to reroute this into the combustion cycle for emissions reasons, but other car makes (will show you an example) like to let it flow freely through a crankshaft or crankcase filter.

 

This is just such a filter (as was also shown in that example with the Sienna) from my cousin Carlos' VR6 Golf as you see in the upper right hand corner. The vehicle uses this filter stock, though we replaced it with a K&N filter later on. Using of one of these (or even the hose like I did), will help gain back some of the octane lost due to the oil vapor/mist mixing into the combustion cycle, making it burn cleaner. I have seen these widely used on vehicles at my track.

I eventually plan to, perhaps within the coming days, use two crankcase filters like this in place of the hoses. The hoses have the advantage that any mist/vapor is sprayed away from the engine compartment, but the disadvantage that the length of the hose causes excess pressure to buildup.

 

Here is a modification to my college roommate Michael's 2006 Z06 Corvette that I have shown previously. A local company called Revxtreme here in Bradenton made a kit that includes an air filter and a catch can. Catch can catches an liquid and the the air filter spills out the vapor. I considered this design as well and have been monitoring this Vette to see if any vapor or liquid has been going into the catch can. This vette is also using Castrol 0W30, but thus far no issues in the air intake nor the catch can.