posted 09-18-2003 07:39 PM                  

Enter Home Depot Speed Shop.

Now with the K&M Cone mounted right behind the front grill, with 85 degree ambient air temperature at 75 MPH, I have 87 degree air going into the filter. At a stop light, the temperature goes up to about 95 degrees, but comes back down very quickly to 87 degrees at 30 MPH. I figure that the seven feet of 3" duct presents the throttle body and additional (.1) degree F. due to engine and catalytic converter heat heating the aluminum duct. At 3000 RPM our 3.5 liter engine needs 185 CFM. The seven feet of duct present no real additional heat!

The cost was $5.88 for 3" diameter x 8' long Semi-Rigid Flexible Aluminum duct, and don't forget the cost of some duct tape. You can get that at Home Depot Speed Shop also! The main problem is routing the 3" duct under the front cross member which is under the radiator. I squeezed mine into an oval and reinforced it with duct tape. The nose of my 99 Prowler is about 4.5" above the street and the duct clears the street by 3.5". Also, I had to make the duct oval coming up between the battery tray and the right hand suspension.

I am now entering into the Beta test mode. Some problems that may be lurking are rain protection to the K&N filter and turbulence to air flow using ribbed duct. As this is just an experiment, I feel I can work around both of these issues. Clearance (3.5") is another issue that is of concern.

I will report on any other advantages and disadvantages as I test.

posted 09-20-2003 01:00 PM                  

I have done further testing with the CAI by Home Depot. Here are the results:

Last evening, Nancy and I went to dinner (I call it supper ) in the Prowler. The ambient was 91 degrees F. The inlet temperature to the K&N cone was right at 91 degrees when driving 70 MPH. We drove at this speed for about 20 minutes. The engine temperature as indicated by the Prowler gauge stayed at the half-way point (3 o'clock). So much for the K&N filter blocking air to the radiator.

Today I installed an additional temperature gauge to measure air temperature entering the throttle body. The ambient was 85 degrees F. I noticed that the air entering the throttle body was about 12 degrees above air temperature at the filter when driving at 60 MPH (98 degrees). I also noticed that under heavy acceleration the temperature came down to near the air filter temperature. This is a good thing! I suspect that as you have less flow through the seven feet of 3" aluminum duct while cruising at 60 MPH, the air has more time to be heated by engine heat (low amount of flow). The more throttle, the cooler the air is at the TB, to approach the filter temperature.

Soooo, IF you have your cone air filter (so-called Cold Air Induction) or the stock air filter where most folks have them (right side panel/right door jamb), you will be sucking air heated by the engine that will be 40 to 60 degrees above ambient. There is no chance that your air will be entering the throttle body lower than the temperature entering your air filter.

Some may say you will have a Venturi effect at the TB. I don't think so, since I am taking the air temperature entering the TB.

Further testing ongoing...

I must go now, as Tony Stewart and I are giving a seminar on CAI installation at my local Home Depot

Inlet temperature to the throttle body. (97.4)

posted 09-20-2003 08:50 PM                  

Very informative!!

My Paxton install also has the inlet to the throttle body moved to the drivers side panel. I went ahead and purchase TonyG's Cool side panels and added his Cold Air Snorkle to link the drivers side vent to Paxtons intake filter.

My boost always hits 10 with this modification where before it would be 10lbs of boost when cold but when the engine warmed up. My boost would decrease down to 7 to 8 lbs of boost.

Later...

posted 09-21-2003 11:51 AM                  

Great Idea and write up with photos.

posted 09-21-2003 01:04 PM                  

The answer is that if your XYZ cool air intake is located where I have seen them, (right side panel/door jam) it is sucking preheated engine air. Vented side panels do help.

posted 09-22-2003 12:31 AM                  

I removed mine and swear it is running stonger, chirping the tires more, and souding better. I read the suggestion on here to remove the rubber seal and think that it does make a difference. I was wondering if it really made a measurable diiference in the under the hood air temperature? An easy mod if so.

I have gears, an SSS muffler, MTD cold air intake, and Platimun +4 plugs. All of these have helped my performance I believe. I would be interested in Throttle body temperatures with a stock filter housing with a K&N filter, VS a MTD type cold air intake with stock side panels. Seems I read on here that a stock filter with a K&N out performed a MTD type intake? Possibly air temperature related? Does the stock filter position collect cooler air?

Thank you for sharing your design and information with us. Heat under the hood is truly a big factor with the performance of the car. I think removing the rubber seal may be of some help? Thanks!

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Prowl-On...

posted 09-22-2003 07:33 AM                  

Some questions.....

1) Why don't you have the standard autometer tach? Did you do work to raise your RPM redline? You seem to have a 7,200 RPM cutoff arrow...

2) back to the CAI....Are you worried about the aluminum duct getting a rock chip sometime, and getting a hole in the duct?

3) Maybe a small screen placed in front of the cone filter would protect the filter element?

4) Would you recommend this mod to someone who drives in rain frequently?

posted 09-22-2003 09:11 AM                  

Doesn't the mod just make the front clearance match the back clearance? And by the way, that maximum velocity of 5000 ft per minute I think works out to 56.81 miles per hour. (I hope the air in my dryer vent isn't moving that fast!)

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posted 09-22-2003 02:43 PM                  

I like the way you think. One thing that would worry me with the "dryer vent ducting" is a piece of the aluminum foil coming loose and getting sucked into a cylinder. I recently had a mud-dobber nest get sucked into a cylinder on my outboard motor and it trashed it...$2,500 worth!

I can only imagine what a chunk of aluminum might do.

Also it seems everybody is focusing on the intake in the front of the car. Why not put it underneath in the rear somewhere. There are a lot of open spaces in the back that are not susceptible to water or debris ingestion like they are in the front. The ducting could be run in the channel between the body and frame.

posted 09-22-2003 07:47 PM                  

This is not rocket science. There is a lot of info on the Net of the benefits to taking unheated air, not preheated air, to your TB (Throttle Body). The Mustang guys seem to be posting lots of info.

It seems to me that there is too much emphasis on selling so-called "Cold Air Induction" to us and other marquee car enthusiasts when what they are really selling is a filter that MAY flow better but is still sucking preheated air. The stock air filter also does this even with a K&N element replacement. Claims are easy! Without actual testing RWHP on a dyno or at a track, these claims are just sales pitches.

I have read on the Net where Kenne Bell and other respected tuners show the benefits in HP from ducting ambient air to the TB. Apparently there is about 1% increase in HP for each 10 degrees reduction at the TB. Some claim more! What I have measured and reported several times before is that we are sucking anywhere from 40 to 70 degrees above ambient temperature. So, "Do the math, DW, do the math."

Black Tie 161...The tach is an Autometer that Jay Harris discovered available from JEGS. He posted info a couple of years ago. Please do a search for more info. The red line marker must have slipped. It has no function other than to impress your friends. As for rock rips, yes, I am concerned. Rain is of no concern. I have driven in the rain with it.

BeWare...Yes, this is only for testing; however, I do plan on driving to CTC and running it on the strip if I haven't ripped it open by a rock and cratered the engine. No trailer queen here!

Whealy...At 3000 RPM the duct is handling about 185 CFM. About the same as a Maytag!

ed monahan...Good idea of using gold aluminum foil. A great mod to the mod. I am using duct tape to protect the aluminum duct. Do you have gold tooth fillings? I have that cheap plastic stuff for fillings. I must be running with the wrong crowd!

Blue Bullet...I am not concerned about the duct coming apart other than rock penetration. As for running the duct toward the rear, there are areas where running the 3" duct would interfere with the tub cross member, just as going in front of the radiator. Good idea though. Take a look.

As for making this a permanent fixture/mod, I believe we could fab a duct out of 3" thin wall aluminum tubing with all the required bends, and where the duct needs to go under the front cross member have a 1"x10" transition tube made to cross there. Again, this is not brain surgery so it could be done. I believe the benefits are there at a very low cost.

posted 09-23-2003 06:53 AM                  

Also, several years ago this hot air was a concern of mine too and I wrapped both catalytic converters with some insulating wrap available for that specific purpose. Sorry, no scientific data, but I immediately noticed that when I opened the hood after the installation, there was an absence of that rush of hot air. I know this modification helps so you might consider adding this to your overall package. I used 25' of this insulating wrap on each converter.

I want you to measure this modification during CTC just for fun, so bring your instruments, Dr. Cool Air.