Evolution of intake air cooling in my car
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King of the Duct Tape
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From: PA
Evolution of intake air cooling in my car
Evolution of intake air cooling in my car
Disclaimer:
This is a long post. But I hope it generates intelligent discussion.
If you are offended by duct tape you MUST leave this thread now.
There. I warned you.
**note: 1st air intake mod was pettit tkt intake.
Section 1: IC duct fitment
It all started when I finally upgraded the stock IC to to the Pettit CC2 IC.
The duct didn't line up at all.
So a little wiggling and a lot of duct tape and a bit of aluminum screwed to the duct and that got it sealed up. Ghetto style yes, but also effective for now.
Section 2: IC fan
Then I installed a 7.5inch spal fan that flowed 440cfm. It worked, you could feel the flow through the duct but I realized I could fit something bigger.
Went to the 9inch hi-perf spal fan that flowed 740cfm. Needed some trimming but otherwise was an awesome fit. The 300 cfm made a huge difference, lots of flow thru the duct. The surface of the IC that is covered by the fan (like 80%) is always cool while the few corners not covered are a bit hotter.
**I've heard it mentioned that an IC fan will also increase the amount of hot air blown toward the engine. Since the air flowing from this fan is only heated by the IC it is guaranteed to be cooler than air flowing from rad fans which I've measured to be in excess of 70deg C (like 160F) and is likely actually cooling down the engine bay.**
Section 3: IC spray
See thread here:
IC spray how to
Section 4: IC Duct "Scoop"
Then i took a look at the duct out the nose of the car. Its, uh, small.
So in an effort to increase flow to the IC at speed and eliminate any rad heated air being sucked thru I extended it. In the process I cut the air guide and also
removed my foglights. It is just some aluminum attached to the bumper reinforcement and duct by sheet metal screws where possible, duct tape otherwise. Understand I'm stealing air from the rad but it hasn't been a problem, rad is SR ultimate.
Disclaimer:
This is a long post. But I hope it generates intelligent discussion.
If you are offended by duct tape you MUST leave this thread now.
There. I warned you.
**note: 1st air intake mod was pettit tkt intake.
Section 1: IC duct fitment
It all started when I finally upgraded the stock IC to to the Pettit CC2 IC.
The duct didn't line up at all.
So a little wiggling and a lot of duct tape and a bit of aluminum screwed to the duct and that got it sealed up. Ghetto style yes, but also effective for now.
Section 2: IC fan
Then I installed a 7.5inch spal fan that flowed 440cfm. It worked, you could feel the flow through the duct but I realized I could fit something bigger.
Went to the 9inch hi-perf spal fan that flowed 740cfm. Needed some trimming but otherwise was an awesome fit. The 300 cfm made a huge difference, lots of flow thru the duct. The surface of the IC that is covered by the fan (like 80%) is always cool while the few corners not covered are a bit hotter.
**I've heard it mentioned that an IC fan will also increase the amount of hot air blown toward the engine. Since the air flowing from this fan is only heated by the IC it is guaranteed to be cooler than air flowing from rad fans which I've measured to be in excess of 70deg C (like 160F) and is likely actually cooling down the engine bay.**
Section 3: IC spray
See thread here:
IC spray how to
Section 4: IC Duct "Scoop"
Then i took a look at the duct out the nose of the car. Its, uh, small.
So in an effort to increase flow to the IC at speed and eliminate any rad heated air being sucked thru I extended it. In the process I cut the air guide and also
removed my foglights. It is just some aluminum attached to the bumper reinforcement and duct by sheet metal screws where possible, duct tape otherwise. Understand I'm stealing air from the rad but it hasn't been a problem, rad is SR ultimate.
Last edited by airborne; Jun 13, 2003 at 11:27 AM.
Thread Starter
King of the Duct Tape
Joined: Feb 2001
Posts: 1,177
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From: PA
Section 5: Intake
I started with a pettit intake. Basically 3 K&Ns and a heat shield. I really wish I had bought an M2
With a good ol radio shack temp sensor mounted right next to
the intakes I recorded an alarming increase in the temp there while at idle, about 10C in 30sec. This is with the rad fans running, without them running the increase in
temp is slower. At first I tried to help this situation by running a duct from my passenger side oil cooler area (touring car, no cooler there) up the space between
the frame and rad. This seemed to help but only at certain speeds. I'm guessing the air pressure created by the rad fans overwhelm the air pressure of the air coming in this way...or something...ioughno.
*brentis or damian have a good thread with a write up on this*
So I gave up and started creating my homemade airbox. Started by making a template out of
cardboard for the backpiece that would fit over intake hoses. Then cut this out of aluminum and duct taped the edges because that damn stuff is sharp! I must of lost at least 9.2 gallons of blood in the process. Then i put another piece on the headlight side, and taped it to this rear piece.
In an effort to help air flow up the space between frame and rad i put this in, anchored by a bolt and of course duct tape. Kind of like a scoop.
Even after this I measured an unacceptable increase in the temp around the intakes at idle.
So i covered the damn thing with another piece of aluminum, one screw lots of duct tape.
Its ugly as sin but it works damn well. No joke. Holds the temps down at idle (still an increase) and with moving at only 5mph the air around the intakes drops to ambient within like 10seconds. No lie. I observed this airtemp to be about 100F after letting the car
run while I went into Wawa. Drove slowly out of the parking lot and it was down to about 70F by the time I was out.
Bottom line: Intake temp as measured by PFC.
At idle it heatsoaks. Still. Even with the IC cold and the air temp around the intakes near ambient (say 70F, 20C) the pfc reads as high as 50C, 122F. But now
the temp comes down MUCH faster once I get moving. Much much much much faster. My opinion? The intake manifolds, the throttle body, and temp sensor itself all
heat up due to the hot rad air constantly blowing on them. And once you're moving this hot air is sucked out and more cool air is pulled in. With the intakes getting
cold air and the IC cold it allows for a dramatic drop in intake temps.
Also, I saw a thread about phenolic (sp?) spacers that suggested that these parts abosrb a lot of heat just from being in contact with the engine.
Also read posts from the "its a good idea to relocate the intake air temp sensor" club and believe that if the intake temp sensor is heat soaked, so is the air. I understand the logic behind the argument but not confident enough in it to consider moving the sensor.
I'm a wuss and would rather let the pfc think the intake air is hotter, thus adding extra fuel rather than it think the intake air is colder and removing fuel, perhaps catastrophically.
So yeah, what do y'all think?
I'm in the process of tracking down a stock red hood to do some 'custom' venting. I'd like a
mazdaspeed style vent but also a second one behind it over the UIM. Also probably one on either
side toward the rear like the m2 one, since the pass side one would be over the turbos, an
obvious hot spot. Also getting the 2 main fuse boxes by the driver side fender moved into
the car, driver side foot well. After which I'll vent that fender liner like I did the pass
one, possibly mounting a fan to pull hot air out. Got that idea from what some company did
to a guy's aston martin virage...
I started with a pettit intake. Basically 3 K&Ns and a heat shield. I really wish I had bought an M2
With a good ol radio shack temp sensor mounted right next tothe intakes I recorded an alarming increase in the temp there while at idle, about 10C in 30sec. This is with the rad fans running, without them running the increase in
temp is slower. At first I tried to help this situation by running a duct from my passenger side oil cooler area (touring car, no cooler there) up the space between
the frame and rad. This seemed to help but only at certain speeds. I'm guessing the air pressure created by the rad fans overwhelm the air pressure of the air coming in this way...or something...ioughno.
*brentis or damian have a good thread with a write up on this*
So I gave up and started creating my homemade airbox. Started by making a template out of
cardboard for the backpiece that would fit over intake hoses. Then cut this out of aluminum and duct taped the edges because that damn stuff is sharp! I must of lost at least 9.2 gallons of blood in the process. Then i put another piece on the headlight side, and taped it to this rear piece.
In an effort to help air flow up the space between frame and rad i put this in, anchored by a bolt and of course duct tape. Kind of like a scoop.
Even after this I measured an unacceptable increase in the temp around the intakes at idle.
So i covered the damn thing with another piece of aluminum, one screw lots of duct tape.
Its ugly as sin but it works damn well. No joke. Holds the temps down at idle (still an increase) and with moving at only 5mph the air around the intakes drops to ambient within like 10seconds. No lie. I observed this airtemp to be about 100F after letting the car
run while I went into Wawa. Drove slowly out of the parking lot and it was down to about 70F by the time I was out.
Bottom line: Intake temp as measured by PFC.
At idle it heatsoaks. Still. Even with the IC cold and the air temp around the intakes near ambient (say 70F, 20C) the pfc reads as high as 50C, 122F. But now
the temp comes down MUCH faster once I get moving. Much much much much faster. My opinion? The intake manifolds, the throttle body, and temp sensor itself all
heat up due to the hot rad air constantly blowing on them. And once you're moving this hot air is sucked out and more cool air is pulled in. With the intakes getting
cold air and the IC cold it allows for a dramatic drop in intake temps.
Also, I saw a thread about phenolic (sp?) spacers that suggested that these parts abosrb a lot of heat just from being in contact with the engine.
Also read posts from the "its a good idea to relocate the intake air temp sensor" club and believe that if the intake temp sensor is heat soaked, so is the air. I understand the logic behind the argument but not confident enough in it to consider moving the sensor.
I'm a wuss and would rather let the pfc think the intake air is hotter, thus adding extra fuel rather than it think the intake air is colder and removing fuel, perhaps catastrophically.
So yeah, what do y'all think?
I'm in the process of tracking down a stock red hood to do some 'custom' venting. I'd like a
mazdaspeed style vent but also a second one behind it over the UIM. Also probably one on either
side toward the rear like the m2 one, since the pass side one would be over the turbos, an
obvious hot spot. Also getting the 2 main fuse boxes by the driver side fender moved into
the car, driver side foot well. After which I'll vent that fender liner like I did the pass
one, possibly mounting a fan to pull hot air out. Got that idea from what some company did
to a guy's aston martin virage...
Senior Member
Joined: Dec 2002
Posts: 451
Likes: 0
From: Indianapolis, IN
Also read posts from the "its a good idea to relocate the intake air temp sensor" club and believe that if the intake temp sensor is heat soaked, so is the air. I understand the logic behind the argument but not confident enough in it to consider moving the sensor.
Thread Starter
King of the Duct Tape
Joined: Feb 2001
Posts: 1,177
Likes: 0
From: PA
BMike> understand your point, what I was more concerned about is the fuel correction for intake temps. as i understand it the pfc dumps in more fuel to cool the intake air, amount as set by the correction map.
i know i should de-ghetto by 50% at least with a box intake but i'd rather try stuff than spend $500 on an intake...
as for getting the IC duct to mate up to the IC...any suggestions? its a pita to un-duct tape and re-duct tape everytime I remove the IC
i know i should de-ghetto by 50% at least with a box intake but i'd rather try stuff than spend $500 on an intake...
as for getting the IC duct to mate up to the IC...any suggestions? its a pita to un-duct tape and re-duct tape everytime I remove the IC
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Senior Member
Joined: Dec 2002
Posts: 451
Likes: 0
From: Indianapolis, IN
Yeah unfortunately the duct isnt exactly the worlds greatest. I found with mine so far <i havent really finished putting it in> during test fitting that if you cram the duct in first, drop the IC in and wiggle everything around alot you can get it pretty close, I was planning on using some of that foam tape stuff on the duct to try and seal most of the major leaks and then trim it etc as necessary to get it just right. if you wiggle it hard enough though you can jam it up in to where the intercooler stays pretty still, and since im switching to a Greddy Elbow and custom turbo hump pipe i should be able to push it into the duct pretty good.
Senior Member
Joined: Dec 2002
Posts: 451
Likes: 0
From: Indianapolis, IN
Theres about umpteen zillion kinds, you'd have to go look around to find exactly what you want, but something to the effect of this:
Foam Tape or just do a search for foam tape at homedepot's website, its basically foam with an adhesive back, if you get it squished down good or use thin closed cell stuff it should make a decent seal.
Foam Tape or just do a search for foam tape at homedepot's website, its basically foam with an adhesive back, if you get it squished down good or use thin closed cell stuff it should make a decent seal.
Senior Member
Joined: Apr 2001
Posts: 334
Likes: 0
From: Boston, MA, USA
I've also gone to some lengths to make sure that I am pulling cold air from the front of the car - modifying my PFS intake to pull from beside the radiator with a riveted aluminium duct, and sealing off the duct that goes to the intake.
But with the all the careful sealing of the airbox I'm not seeing a huge difference in temps.
Then I read another thread that suggested that the temp before the turbos doesn't matter all that much in the end - and the restrictiveness of the intake is almost more of a factor to temps at the UIM. So I wonder. I have not seen huge differences that I thought I would. I measured 140 degree ambient temps under the hood at one point, and thought for sure that the open areas I had in my (cut up) intake would cause issues. I know I'm pulling cold air now and the difference - not really much. It would probably be different without a turbo. And sure it may make a difference while not on boost, but where it matters most is at max boost, and there the turbos probably negate things a bit.
So all those single turbo phreaks that have an open filter right on the turbo - they probably don't have it that far wrong. The next time I tune I will pull off all the housings/ducts and see if that increases top end at all.
I DO have an 8" IC fan, and that does slow down heat soak quite a bit. I also have it set up so it will run after the car is off, and that prevents the under-hood temps from hitting 200 degrees after a hot-day run - which is also nice.
But with the all the careful sealing of the airbox I'm not seeing a huge difference in temps.
Then I read another thread that suggested that the temp before the turbos doesn't matter all that much in the end - and the restrictiveness of the intake is almost more of a factor to temps at the UIM. So I wonder. I have not seen huge differences that I thought I would. I measured 140 degree ambient temps under the hood at one point, and thought for sure that the open areas I had in my (cut up) intake would cause issues. I know I'm pulling cold air now and the difference - not really much. It would probably be different without a turbo. And sure it may make a difference while not on boost, but where it matters most is at max boost, and there the turbos probably negate things a bit.
So all those single turbo phreaks that have an open filter right on the turbo - they probably don't have it that far wrong. The next time I tune I will pull off all the housings/ducts and see if that increases top end at all.
I DO have an 8" IC fan, and that does slow down heat soak quite a bit. I also have it set up so it will run after the car is off, and that prevents the under-hood temps from hitting 200 degrees after a hot-day run - which is also nice.
Senior Member
Joined: Apr 2001
Posts: 334
Likes: 0
From: Boston, MA, USA
Oh - if you go to McMaster-carr you can order rubber weather stripping of various kinds.
I ordered three kinds
10 FT 1120A112 - Vinyl Protective Trim $1.06 FT today
With Sponge Rubber Seal 3/8" D
Bulb, Grips 1/16" Edge, Bulb
Locate 'B', Black
4 FT 12335A42 - Sponge Rubber Gasket $1.59 FT today
Slide-On, Self-Gripping, 7/16"
Dia Bulb (On Top)
4 FT 12335A41 - Sponge Rubber Gasket $1.59 FT today
Slide-On, Self-Gripping, 21/64"
Dia Bulb
One of these worked far better than the others, but for the life of me I can't remember which was which now.
The look, however is very nice.
I ordered three kinds
10 FT 1120A112 - Vinyl Protective Trim $1.06 FT today
With Sponge Rubber Seal 3/8" D
Bulb, Grips 1/16" Edge, Bulb
Locate 'B', Black
4 FT 12335A42 - Sponge Rubber Gasket $1.59 FT today
Slide-On, Self-Gripping, 7/16"
Dia Bulb (On Top)
4 FT 12335A41 - Sponge Rubber Gasket $1.59 FT today
Slide-On, Self-Gripping, 21/64"
Dia Bulb
One of these worked far better than the others, but for the life of me I can't remember which was which now.
The look, however is very nice.
2/4 wheel cornering fiend
Joined: Nov 2002
Posts: 3,090
Likes: 3
From: Pasadena, CA
Re: Evolution of intake air cooling in my car
Originally posted by airborne
Section 2: IC fan
Then I installed a 7.5inch spal fan that flowed 440cfm. It worked, you could feel the flow through the duct but I realized I could fit something bigger.
Section 2: IC fan
Then I installed a 7.5inch spal fan that flowed 440cfm. It worked, you could feel the flow through the duct but I realized I could fit something bigger.
Went to the 9inch hi-perf spal fan that flowed 740cfm.
Thread Starter
King of the Duct Tape
Joined: Feb 2001
Posts: 1,177
Likes: 0
From: PA
that 9inch (make sure you're looking at the high perf 740cfm one) fan rocks. when i just had it laying on the car and turned it on to test it the damn thing jumped around it had so much torque. great power for size.
i'm actually hoping for good results from venting the other wheel well and possibly using a fan.
article was in sport car international, the guy wanted sick power out of the aston martin without exterior mods so no vented hood. they vented hot air out the wheel well with a fan that switched on at 95F. guarantee our underhood temps are like twice that.
btw, the aston made over 1100lb/ft of tq with a turbo's 7l v8.
i'm actually hoping for good results from venting the other wheel well and possibly using a fan.
article was in sport car international, the guy wanted sick power out of the aston martin without exterior mods so no vented hood. they vented hot air out the wheel well with a fan that switched on at 95F. guarantee our underhood temps are like twice that.
btw, the aston made over 1100lb/ft of tq with a turbo's 7l v8.
Senior Member
Joined: Apr 2001
Posts: 334
Likes: 0
From: Boston, MA, USA
One question on the 9" fan. What does it sound like when it is on - from outside the car? Is it loud? Is it a high or low pitched noise? - that is - a whooshing noise like the stock radiator fans, or a high-strung hairdryer noise?
But hey, he warned ya. And if it works? Well, I wouldn't complain.
Thread Starter
King of the Duct Tape
Joined: Feb 2001
Posts: 1,177
Likes: 0
From: PA
fan is from
http://www.jaycorptech.com/shop/shopexd.asp?id=9
who were very cool. they didn't get it shipped out when they said they would so they shipped it priority at no extra charge. btw, absolutely perfect fit for pettit cool charge 2 IC
http://www.jaycorptech.com/shop/shopexd.asp?id=9
who were very cool. they didn't get it shipped out when they said they would so they shipped it priority at no extra charge. btw, absolutely perfect fit for pettit cool charge 2 IC
Glug Glug Glug Burp
Joined: Jan 2002
Posts: 3,819
Likes: 0
From: Scott AFB, IL
Originally posted by airborne
fan is from
http://www.jaycorptech.com/shop/shopexd.asp?id=9
who were very cool. they didn't get it shipped out when they said they would so they shipped it priority at no extra charge. btw, absolutely perfect fit for pettit cool charge 2 IC
fan is from
http://www.jaycorptech.com/shop/shopexd.asp?id=9
who were very cool. they didn't get it shipped out when they said they would so they shipped it priority at no extra charge. btw, absolutely perfect fit for pettit cool charge 2 IC
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