Hey, I made an html document with images and everything! Can't I just upload that?

Cooling your intake charge!



Things you will need for the Throttle Body Bypass Mod:

8 and 10mm socket, flat tip screwdriver, 3/8” brass coupler, a good pair of pliers, shop rags



Other things used by me:

Duct tape, wire loom (2 sizes), TB and intake cleaner



Total time to do everything listed: about 30 minutes – if the car is cool.



Here is the coupler I used, purchased at Lowe’s for $1.93:

The purpose of this mod is to keep the air going into your engine as cool as possible. Unless you want to use a cooling method of some sort, the way to do this is to keep the air from getting heated, and/or retrieve air from a cooler area. One thing I did that dropped the intake air temperature by 5 degrees minimum (as registered by my OBDII scanner) is cover the second hole in the fender well with duct tape:

That’s a PDM Racing cold air intake - much like the Ganzflow but much cheaper. Notice the hole I covered would be “upwind” of the intake tube, which would draw hot air into the intake unless it’s covered, which is how I achieved the aforementioned drop in temperature. Lucky me… my silver car matches the color of duct tape :-) , although I hear that you can also buy a fender plug for an RS.



The mod we are talking about here stops your car from heating the intake charge on purpose. Why would it do this you might ask? Well, if it got REALLY cold out, your air/fuel mixture might freeze. I live in the south, so I will undo what was done by the factory. In the following pic, notice that the Air Intake Temperature sensor is located before the throttle body, which is why I will not be posting any observed drop in intake temperature as reported by this sensor:

Your first step will be to remove the intake box from your vehicle.
1: These are 10mm bolts.

2: 8mm hose clamps (or flat tip screwdriver).

3: IAT sensor.

4: TPS (throttle position sensor).

5: Hoses from intake manifold.



Slide the airbox back from the TB and out. Easy, no need to force anything, just make sure all hose clamps are loose enough to slide off.

Now is a good time to clean your airbox out!

Next, locate the coolant lines going through the throttle body. They are located down low on my car, and are held on by spring clamps:

Using your pliers, carefully pinch the clamp tabs and slide the clamps back. Now you’re ready to pull the hoses themselves off. They will be stuck on rather well, and you will need to break their seal. Use a flat tip screwdriver to carefully pry back at the edges, then pull the hose back.

Now, using that 3/8 inch brass coupler, put the hose ends together.


After I did this, I carefully pushed the assembled hoses under the throttle body. Also, now is the time to dry the coolant that dripped out during disassembly so it doesn’t burn off later and freak you out.

I noticed that the rubber hoses would now be sitting against various objects, and decided to cover that section with wire loom. You will need about 2 to 2.5 inches:
Position wherever it might rub a hole for a little extra protection.

Some people feel it necessary to plug the open coolant passage so dirt doesn’t get in. I feel that if you want to reattach the coolant lines later, all you would have to do is blow the passage out with compressed air, but FYI, a 5/16 inch fuel hose is the perfect size to create a loop, no need to use hose clamps as there will not be any pressure on this line.

It is here that you will want to take a look at the throttle body itself.

After 19k miles, mine was a bit dirty. I used a TB and Intake cleaner made by STP to clean it out.
All the black you see came out of my TB. I had been using a K&N filter, and I have heard that it may not filter as well as a high quality paper filter. After cleaning black oily gunk from my TB, I switched back to my factory filter.

Now is an excellent time to also insulate your AC line. This is done to keep your AC colder. Some people use an insulating pipe cover; I just used a larger length of wire loom cover. It won’t insulate as well, but it will a little, and I will worry less about it insulating too well and freezing my lines.

Now put it all back together! Don’t forget to connect everything, there are 2 sensors – IAT and TPS. If you don’t reconnect the TPS you will get a check engine light and it won’t rev… ask me how I know!



PS: Do you hate the way you can’t listen to your stereo with the door open b/c of the incessant binging? Take a Phillips screwdriver, remove this rubber cover, unplug the wiring harness located inside, and put the rubber cover back on!