Construction

Before you start, your engine bay should look something like this:

Excuse the poor picture quality.  This is an ST165 engine pictured, however the ST185 is very similar.

In order to mount a straight intake, you must move the battery.  You can either choose to move it to the trunk, or "swap" places with the factory air box.  Although it is possible to mount in the engine bay, you must consider that you will not have very much room to work, and is an inconvenience to say the least.  That said, I chose to keep the battery in the engine bay.

The first step is to remove the battery, which will free up a bunch of extra space.  Then, begin to remove the factory air intake piping and box.  Once everything is out, put it somewhere safe just in case you decide to go back to the stock set up, or if you want to sell your car.

Gather all of your parts together, make sure you know how they are going to fit together.  Unassembled, you should line them up like the picture below.  The turbo on the left is given as a reference to where you are going to fit the intake.

Turbo --> Transition Hose --> 3" Aluminum Pipe --> Silicon Coupler --> AFM --> Adaptor Plate

You will mount the air filter on the adaptor plate.  Assembled, it should look like this:

Now, install the unit, piece by piece, and leave the air filter until last.  Once you have everything fitting properly, install the air filter without clamping it quite yet, since you will be removing it a few times yet.  I have been told that the wires leading to the AFM do not always reach the AFM with the straight intake.  If this is true for you, you will have to extend these wires by soldering in a new length of wire for each and every wire.  On my car, I did not have to do this, however, I did have to move a few other parts that attached to the AFM wires.  Just a warning of caution that not all cars are the same.

Now you must deal with your battery.  I would suggest that if you choose to wire it to the rear, that you do this before installing the intake.  This is just in case it takes longer than expected forcing you to be without your car for a while.  If you are going to install it in the engine bay, read on.

My battery is an AC Delco "Professional", which is slightly smaller than the OEM Toyota battery.  I would recommend you use something at least this small in size, or possibly smaller to be successful. I have since mounted a sealed Opima battery in the hatch, to create more space to work in the engine bay.

Test fit the battery in a position similar to the way you see mine mounted below.  You may have to use a little imagination here.  It is extremely important that you test to see if you hood will close with the battery in place, before you have it finished.  In order to allow enough space for my hood to shut (with the hood insulation in place), I had to remove a protector plate which was directly below where the factory air box sits.

As you can see, there is just barely enough room for this battery to fit in place.  Here is a close up so you can see just how close it sits, even with a small battery.

You can see  that I used the factory battery mounting brace to hold the battery in place.  In order to allow it to mount to the factory bolt which holds the hood stopper, you must use a hammer to bend it to fit.  The ground wire was just barely long enough for me to mount it to an existing bolt hole at the headlights.  Holding the other side of the brace down is a thick wire, which extends down and wraps around a metal piece below.  Although this may not be the optimal solution, it will definitely hold strong until you can fabricate a custom brace that is able to hold down the battery.  My solution was good enough for track officials, and did the trick for me.

Attach your 1/2" hose to the two nipples from the two pipes where the original hoses came from.  One is the PCV hose and the other allows the car to idle properly.

Now, why do you see all this ugly shiny stuff on my upper radiator hose and my intercooler?  Well, with the new intake, you are going to be sucking in a lot of hot engine air.  The ECU will see these high intake temperatures, and attempt to save the engine by severely retarding the ignition timing.  Therefore, you must do your best to keep that intake air as cold as possible.  I did several things to help fight this battle.  First off, I went to Home Depot and got some plumbing insulation on a roll, for about ten dollars.  I started by wrapping the radiator hose because it gets very hot, and was in direct contact with the aluminum pipe.  This helped a little bit, but I still suffered from the problem.  In retrospect, I would now go and buy some exhaust wrap, even though it is more expensive.

The next step was to insulate the intercooler.  I used the same insulation, which again helped out as well as helping out against the effects of heat soak.  I was still not satisfied.

You should now have something like this (insulation not shown):

I think the next step is probably the most important, and helped the most.  I went to Canadian Tire, and purchased some generic flexible air intake hose.  I believe it was in a 2" diameter, but I can't be sure.  It must be small though, in order to fit.  Basically, I ran the hose from a hole in the front bumper all the way up to the air filter.  There is just enough room.  Here is a picture of where it is mounted up front.

And on the intake side, you must first remove the factory plastic piping (which is a PITA), in order to feed the new hose through to the filter.  In the picture below, I have taped it to the filter.  I have since removed the tape because of the custom air box I built.

The last part is to build a custom air box to enclose your air filter, and protect it from the hot air in the engine bay.  To do this, start with cardboard and slowly develop a template of how your air box should look.  I would recommend that you take your time to ensure the air box properly fits in the limited space, because it is going to be harder to work with metal.  Insulate the metal once you are done, to help block the heat from entering.  Since the air box can become an entire project on its own, I would strongly suggest you read Dennis Heath's write up.

You shouldn't expect huge HP gains from this mod, however it will allow you to increase your boost pressure effectively when you are ready to.

Once you finish your air box, you should have something like the pictures below.  Let me know what you think of the write up!

Finished Pictures