Just installed hot air intake

[randerson0248]

I installed a hot air intake. The 2 inch hose runs around the front of the engine and around the passenger (right) side to the catalytic converter.

I mounted the 2 inch tube about 1 1/2 - 2 inches away from the cat metal shield. It is outside the shield. I did not make a 2 inch hole in the shield for the intake hose to go into.

My intake temp is now about 12 - 14 degrees warmer after about 8 - 10 minutes of driving. I thought it would have a greater increase.

Should I make a 2 inch hole in the cat shield and have the air drawn from around the cat (from air inside the shield), instead of from the outside around the shield as I have it now? How much of a temp difference do you think that would make?

[Insightful Trekker]

Originally Posted by randerson0248

Should I make a 2 inch hole in the cat shield and have the air drawn from around the cat (from air inside the shield), instead of from the outside around the shield as I have it now? How much of a temp difference do you think that would make?

Not sure just how much "better" such would be. From ooold posts and modification variations max improvement seems to be with an IAT in the 120F ish. AND only in cooler weather when presumably the colder IAT inhibits the quality of fuel vaporization AND the ability to enter lean burn as easily.

HTH!

[JuiceMcGoose]

At least one other Insighter has run a tube to the inside of his cat shield and it ran too hot, something like 140 degrees at the air cleaner sensor. Most people cite 100 to 110 as the ideal intake temp.

I made a shield that wrapped around half of the stock unmodified cat shield from an old Civic air cleaner to a short 2" pellet stove exhaust tube to the stock intake tube flipped to the back side. It also ran too hot, around 138 degrees on a cold day here. I then cut a hole in the duct tape that covered the stock intake T that usually points down but now points up and that cooled the air enough to drive, usually in the 90 to 110 range this winter.

I am going to build a valve controlled by an old manual choke cable attached to that intake T and mounted under the dash to keep the temp where I want it. When I am finished I will post a thread with pics.

[joecvt]

If you are going to make it valve controlled, perhaps you could take a look at what I did awhile back for your inspiration

Automatic warm air intake (very long)

JoeCVT = Just your average CVT owner

[3-Wheeler]

Originally Posted by randerson0248

...My intake temp is now about 12 - 14 degrees warmer after about 8 - 10 minutes of driving. I thought it would have a greater increase....

Should I make a 2 inch hole in the cat shield and have the air drawn from around the cat (from air inside the shield), instead of from the outside around the shield as I have it now? How much of a temp difference do you think that would make?

Drawing the air from inside the CAT shield will make a huge difference.

In warmer temperatures, and driving once in a blue moon on the Interstate, my intake temperature was running over 180°F !!! And that was only at 65 mph.

Not that I intended to run it that hot, but it is indeed very effective if done carefully. Look at JoeCVT's nicely done pictures.

Now that spring has set in, it needs to be dialed back quite a bit.

Jim.

[JuiceMcGoose]

Originally Posted by joecvt

If you are going to make it valve controlled, perhaps you could take a look at what I did awhile back for your inspiration

Automatic warm air intake (very long)

JoeCVT = Just your average CVT owner

I saw your thread and used the idea of a CRX air cleaner I had sitting around, '87 instead of '84, to attach to the CAT. I wanted a manual control so I removed the stock valve and welded up the hole.

[randerson0248]

Joe,

I have read your mod. Good stuff. I wanted to start out simpler, and then if needed, improve later. Also, waiting to see if I can find used parts to keep the cost down.

Jim,

I don't think I want quite 180 degrees. But that is the information that I was looking for.

I have mine set up now where it can be adjusted from about 3 inches away to moved right up to the cat shield. Next weekend, I will probably drill a 2 inch hole in the shield and then I can adjust anywhere from the intake tube being right at the 2 inch opening to about 3 inches away. I'll see how that works.

After warm up, on the highway this weekend, with the outside air being 44 degrees, my intake air temp was 57 - 58. If sitting in traffic, it would go up slightly from that. I would like to try for an increase of 30 - 40 degrees above ambient air temp.

[JuiceMcGoose]

Randerson, have you blocked off the cold air intake at the T just before it goes into the air cleaner?

[randerson0248]

Juice,

Not sure about "blocked off". I removed the snorkel that is about 1 1/2 feet long that runs paralllel along the front of the engine. In its place I installed 2 28" long "emission hoses" that are made of paper and aluminum. This hose runs along the front of the engine and makes a 90 degree turn and then heads toward the cat.

The Molded rubber piece that has the T for the hose that goes downward (resonator ?) is still there. Not sure if that was your question.

[JuiceMcGoose]

You can disconnect the hose that drops down from that T, tape it off and the intake air should be considerably warmer.