Drivetrain Project "Low IAT"-Intake Manifold Cooling
#1
Project "Low IAT"-Intake Manifold Cooling
I've been kicking this project back and forth with DrPhil about how to lower the IATs that we have measured with a ScanGauge II.
We both agreed that if the manifold was exposed to some of the air coming through the grille, that would help to dissipate the heat that would normally soak into the manifold.
While aluminum is pretty good at dissipating heat, the intake manifold is pretty much getting cooked with the supercharger and water pump directly underneath it, and the upper radiator hose running right in front of it. Not to mention the heat transfer from the cylinder head.
I think DrPhil said it best with this statement,
"All the work we've done to cool the air intake with CAIs and fancy ICs is being undone at the manifold just before the air enters the cylinders."
I was looking at the top of the radiator shroud where the hood seal is, trying to see if there was a way to trim it to allow more air in to the front of the manifold. There is really no "nice" way to do it, so I decided to trim it all off...
...as you can see, the radiator hose runs right in front of the manifold, pretty much pre-heating the air coming through the grille.
While I did see quite an improvement in the IATs, as well as very quick recovery after getting off the boost, I had to do something about the hose placement/routing.
So I backed off the two clamps in the pic as well as the one at the radiator, and rotated the hose down away from the front of the manifold...
...the plexiglass(clear acrylic?) is experimental, but I needed to put something there to keep the hose from rubbing on the manifold. It was easy to cut and drill so I could fit it and rivet it to the shroud. The next piece will obviously not be riveted so I can get to the bleeder if I need to.
I have had no difference in coolant temp running the hose this way.
After all this, I am now seeing consistant single digit differences between ambient and IAT while cruising on the highway, sometimes as low as 5 degrees.
Another bonus is getting more air in from the front helps push the hot air out the back.
I realize this is not for everybody, so take it as you will.
Please disregard the rusted bolts on the DFIC diverter, they are NOT the ones that M7 supplies, and will be replaced.
EDIT:
The revised version...
EDIT: The revised version 2...
EDIT: The revised version 3...
We both agreed that if the manifold was exposed to some of the air coming through the grille, that would help to dissipate the heat that would normally soak into the manifold.
While aluminum is pretty good at dissipating heat, the intake manifold is pretty much getting cooked with the supercharger and water pump directly underneath it, and the upper radiator hose running right in front of it. Not to mention the heat transfer from the cylinder head.
I think DrPhil said it best with this statement,
"All the work we've done to cool the air intake with CAIs and fancy ICs is being undone at the manifold just before the air enters the cylinders."
I was looking at the top of the radiator shroud where the hood seal is, trying to see if there was a way to trim it to allow more air in to the front of the manifold. There is really no "nice" way to do it, so I decided to trim it all off...
...as you can see, the radiator hose runs right in front of the manifold, pretty much pre-heating the air coming through the grille.
While I did see quite an improvement in the IATs, as well as very quick recovery after getting off the boost, I had to do something about the hose placement/routing.
So I backed off the two clamps in the pic as well as the one at the radiator, and rotated the hose down away from the front of the manifold...
...the plexiglass(clear acrylic?) is experimental, but I needed to put something there to keep the hose from rubbing on the manifold. It was easy to cut and drill so I could fit it and rivet it to the shroud. The next piece will obviously not be riveted so I can get to the bleeder if I need to.
I have had no difference in coolant temp running the hose this way.
After all this, I am now seeing consistant single digit differences between ambient and IAT while cruising on the highway, sometimes as low as 5 degrees.
Another bonus is getting more air in from the front helps push the hot air out the back.
I realize this is not for everybody, so take it as you will.
Please disregard the rusted bolts on the DFIC diverter, they are NOT the ones that M7 supplies, and will be replaced.
EDIT:
The revised version...
EDIT: The revised version 2...
EDIT: The revised version 3...
Last edited by Partsman; 06-08-2007 at 04:45 PM.
#3
Thanks for sharing this with NAM, Partsman! Yes, it is somewhat extreme, but certainly in the spirit of experimenting, backed up bydata from your temperature probes and SG-II.
I am going to do this also, beginning with moving the radiator hose down, then getting some of that ample air coming in the grille to massage the manifold.
Props to you!
I am going to do this also, beginning with moving the radiator hose down, then getting some of that ample air coming in the grille to massage the manifold.
Props to you!
#4
Thanks for sharing this with NAM, Partsman! Yes, it is somewhat extreme, but certainly in the spirit of experimenting, backed up bydata from your temperature probes and SG-II.
I am going to do this also, beginning with moving the radiator hose down, then getting some of that ample air coming in the grille to massage the manifold.
Props to you!
I am going to do this also, beginning with moving the radiator hose down, then getting some of that ample air coming in the grille to massage the manifold.
Props to you!
The shroud is still in a rather "rough" state, I will be smoothing it out so that it looks factory.
Another thing I forgot to mention, is that I should have some kind of heat barrier in between the manifold and the SC outlet. It's pretty tight right there so that will require a little more thought. I wonder how thin you can get Aerogel...
#5
#7
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#8
Would it be possible to replace a section of the top rad hose to give it a different path? ie a hose with a different bend pattern? Or how about diverting off some of the air that comes through the front grill inlet to the airbox so that it flows over the inlet manifold?
I was also wondering if lagging that offending part of the top hose would help with heat radiation?
I was also wondering if lagging that offending part of the top hose would help with heat radiation?
#11
Partsman's mod reminds us to think air flow, always a good idea!
#12
Got it, Phil. Just early morning pondering. Maybe the cooling fins might work, given the additional airflow?
I seem to be going the opposite direction; after a 250 mile run yesterday, the underhood temps were extremely high. The outlet horn was too hot to touch!
I really need to get a Scangauge to monitor this stuff.
I seem to be going the opposite direction; after a 250 mile run yesterday, the underhood temps were extremely high. The outlet horn was too hot to touch!
I really need to get a Scangauge to monitor this stuff.
#13
Would it be possible to replace a section of the top rad hose to give it a different path? ie a hose with a different bend pattern? Or how about diverting off some of the air that comes through the front grill inlet to the airbox so that it flows over the inlet manifold?
I was also wondering if lagging that offending part of the top hose would help with heat radiation?
I was also wondering if lagging that offending part of the top hose would help with heat radiation?
Last edited by Partsman; 05-13-2007 at 05:59 PM.
#14
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An Aerogel sleeve to go around the coolant hose would be nice, and if not all the way around, draped over it for a sufficient length should work well. Nice work with the hose rotation!
I echo Dr. Phil's concerns regarding the significance of airflow. This is actually the reason why I have not yet cut-up or trimmed the shroud (as seen above). It seals against the top of the closed bonnet, and in doing so, while in forward motion, creates increased positive pressure forward the exchangers (A/C & radiator), funneling this ambient air through them, thus lowering the temp of coolant, and with that the oil. Air will take the path of least resistance, and if this (the shroud) is not in place, more air will go up and over these (exchangers), not through them...
Along these lines, when I removed my bonnet liner, I knew this would make for a slightly worse seal in this area (less pressure due to escape), and added a thin layer of weather stripping to account for this difference in thickness (not much). The APD (M7 product) shown at the bottom of a couple of the above photos works on the same premise, but for the lower section. This all said, I too will remove this shroud as well, but I will want to fabricate an APD-like contraption / diverter to aid in the channeling of ambient air through the radiator. The only reason I have not yet done this (should be easy) is that I'm looking to ditch my A/C system first, and I'm still doing my homework on this surgery...
I echo Dr. Phil's concerns regarding the significance of airflow. This is actually the reason why I have not yet cut-up or trimmed the shroud (as seen above). It seals against the top of the closed bonnet, and in doing so, while in forward motion, creates increased positive pressure forward the exchangers (A/C & radiator), funneling this ambient air through them, thus lowering the temp of coolant, and with that the oil. Air will take the path of least resistance, and if this (the shroud) is not in place, more air will go up and over these (exchangers), not through them...
Along these lines, when I removed my bonnet liner, I knew this would make for a slightly worse seal in this area (less pressure due to escape), and added a thin layer of weather stripping to account for this difference in thickness (not much). The APD (M7 product) shown at the bottom of a couple of the above photos works on the same premise, but for the lower section. This all said, I too will remove this shroud as well, but I will want to fabricate an APD-like contraption / diverter to aid in the channeling of ambient air through the radiator. The only reason I have not yet done this (should be easy) is that I'm looking to ditch my A/C system first, and I'm still doing my homework on this surgery...
#15
I just got back from a track day here in Albuquerque (a great MINI course: 1.6mi, 15 corners!)
I removed the shroud before heading out this AM but didn't have time to move the radiator hose (btw, much easier when warm rather than cold!). I need to fab an APD for above the radiator that holds the hose in place and separates the hose from the airflow.
wrt airflow, there didn't seem to be a problem with air being robbed from the radiator as engine water temps never exceeded 207F with an ambient of 80F. While lapping IATs were around 100-110F and airbox temps never more than +2F over ambient (I love my FAD!--maybe it's no longer just a fad...)
Q: what's under that protrusion at the back of the radiator shroud in the middle--I'm guessing a probe or sensor? Can we remove the protrusion?
Anyway, I had a great day as one of the multi-year local racers sat in the passenger seat and got 10seconds of my time (to 1'48"). I still have a long way to go, nut-behind-the-wheel wise, but the car went well.
btw, the M7 COs worked very well!
I removed the shroud before heading out this AM but didn't have time to move the radiator hose (btw, much easier when warm rather than cold!). I need to fab an APD for above the radiator that holds the hose in place and separates the hose from the airflow.
wrt airflow, there didn't seem to be a problem with air being robbed from the radiator as engine water temps never exceeded 207F with an ambient of 80F. While lapping IATs were around 100-110F and airbox temps never more than +2F over ambient (I love my FAD!--maybe it's no longer just a fad...)
Q: what's under that protrusion at the back of the radiator shroud in the middle--I'm guessing a probe or sensor? Can we remove the protrusion?
Anyway, I had a great day as one of the multi-year local racers sat in the passenger seat and got 10seconds of my time (to 1'48"). I still have a long way to go, nut-behind-the-wheel wise, but the car went well.
btw, the M7 COs worked very well!
Last edited by DrPhilGandini; 05-13-2007 at 01:35 PM.
#17
#18
An Aerogel sleeve to go around the coolant hose would be nice, and if not all the way around, draped over it for a sufficient length should work well. Nice work with the hose rotation!
I echo Dr. Phil's concerns regarding the significance of airflow. This is actually the reason why I have not yet cut-up or trimmed the shroud (as seen above). It seals against the top of the closed bonnet, and in doing so, while in forward motion, creates increased positive pressure forward the exchangers (A/C & radiator), funneling this ambient air through them, thus lowering the temp of coolant, and with that the oil. Air will take the path of least resistance, and if this (the shroud) is not in place, more air will go up and over these (exchangers), not through them...
Along these lines, when I removed my bonnet liner, I knew this would make for a slightly worse seal in this area (less pressure due to escape), and added a thin layer of weather stripping to account for this difference in thickness (not much). The APD (M7 product) shown at the bottom of a couple of the above photos works on the same premise, but for the lower section. This all said, I too will remove this shroud as well, but I will want to fabricate an APD-like contraption / diverter to aid in the channeling of ambient air through the radiator. The only reason I have not yet done this (should be easy) is that I'm looking to ditch my A/C system first, and I'm still doing my homework on this surgery...
I echo Dr. Phil's concerns regarding the significance of airflow. This is actually the reason why I have not yet cut-up or trimmed the shroud (as seen above). It seals against the top of the closed bonnet, and in doing so, while in forward motion, creates increased positive pressure forward the exchangers (A/C & radiator), funneling this ambient air through them, thus lowering the temp of coolant, and with that the oil. Air will take the path of least resistance, and if this (the shroud) is not in place, more air will go up and over these (exchangers), not through them...
Along these lines, when I removed my bonnet liner, I knew this would make for a slightly worse seal in this area (less pressure due to escape), and added a thin layer of weather stripping to account for this difference in thickness (not much). The APD (M7 product) shown at the bottom of a couple of the above photos works on the same premise, but for the lower section. This all said, I too will remove this shroud as well, but I will want to fabricate an APD-like contraption / diverter to aid in the channeling of ambient air through the radiator. The only reason I have not yet done this (should be easy) is that I'm looking to ditch my A/C system first, and I'm still doing my homework on this surgery...
I've also been thinking about removing the A/C.
Last edited by Partsman; 05-13-2007 at 06:16 PM.
#20
I just got back from a track day here in Albuquerque (a great MINI course: 1.6mi, 15 corners!)
I removed the shroud before heading out this AM but didn't have time to move the radiator hose (btw, much easier when warm rather than cold!). I need to fab an APD for above the radiator that holds the hose in place and separates the hose from the airflow.
wrt airflow, there didn't seem to be a problem with air being robbed from the radiator as engine water temps never exceeded 207F with an ambient of 80F. While lapping IATs were around 100-110F and airbox temps never more than +2F over ambient (I love my FAD!--maybe it's no longer just a fad...)
I removed the shroud before heading out this AM but didn't have time to move the radiator hose (btw, much easier when warm rather than cold!). I need to fab an APD for above the radiator that holds the hose in place and separates the hose from the airflow.
wrt airflow, there didn't seem to be a problem with air being robbed from the radiator as engine water temps never exceeded 207F with an ambient of 80F. While lapping IATs were around 100-110F and airbox temps never more than +2F over ambient (I love my FAD!--maybe it's no longer just a fad...)
Originally Posted by DrPhilGandini
Q: what's under that protrusion at the back of the radiator shroud in the middle--I'm guessing a probe or sensor? Can we remove the protrusion?
btw, the M7 COs worked very well!
btw, the M7 COs worked very well!
#21
The plexiglass sheet is from Home Depot, thay have all different sizes and thickness. I'm going to replace it with some sheet aluminum this week.
#22
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Tony, I haven't shown an increase in coolant temp at all, but maybe "splitting" the grille will work, basically a flat piece behind one of the slats that extends toward the radiator. I'm sure it will provide you with the flow you want for the radiator, while having some go up to the manifold.
I've also been thinking about removing the A/C.
I've also been thinking about removing the A/C.
The only thing keeping me from removing the A/C is that I hear that I will or might get fogging issues in the Winter w/o it. I'm having a hard time getting a solid answer on this, and if true, what's the work-around. That's 23 lbs gone (and off the front!) that I don't need, and allows for better flow through the radiator...
Keep up the great work, I really appreciate it!
#23
[quote=TonyB;1521031]An Aerogel sleeve to go around the coolant hose would be nice, and if not all the way around, draped over it for a sufficient length should work well. Nice work with the hose rotation!
quote]
That's basically what I did, Partially wrapped the hose in thermotec barrier ("C" shaped barrier between the intake and the hose and zip tied the hose in place so there was some space betweent he hose and the intake for air flow. Also did not the self adhesive type Like alot of us have used in the intake box but The kind with the highly reflective barrier).
quote]
That's basically what I did, Partially wrapped the hose in thermotec barrier ("C" shaped barrier between the intake and the hose and zip tied the hose in place so there was some space betweent he hose and the intake for air flow. Also did not the self adhesive type Like alot of us have used in the intake box but The kind with the highly reflective barrier).
#24
Good to hear (coolant temp not going up). I'm pretty confident that this seal point is for this reason though; and might not truly reveal itself until harsher conditions (much higher ambient temps & track-like abuse) are experienced. Extending a lip forward (JB Weld on aluminum should work well) from the top of the radiator, and on the sides should help capture the oncoming air, and drive it through. The OEM grille has slats angled upward, and I would think that something like M7's will better allow for a more direct shot at the intake manifold...
The only thing keeping me from removing the A/C is that I hear that I will or might get fogging issues in the Winter w/o it. I'm having a hard time getting a solid answer on this, and if true, what's the work-around. That's 23 lbs gone (and off the front!) that I don't need, and allows for better flow through the radiator...
Keep up the great work, I really appreciate it!
The only thing keeping me from removing the A/C is that I hear that I will or might get fogging issues in the Winter w/o it. I'm having a hard time getting a solid answer on this, and if true, what's the work-around. That's 23 lbs gone (and off the front!) that I don't need, and allows for better flow through the radiator...
Keep up the great work, I really appreciate it!
I'll keep you posted on the coolant temps if summer ever gets here.
An aluminum lip sounds like a good idea as long as it's not too big.
You get winter there?
23 lbs is a pretty good amount of weight off the front, not to mention a more exposed radiator.
#25
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Thanks for again for the thread!