Underhood Liner: How many of you still have it?
MBWorld Fanatic!
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From: Orange County, CA.
one car at a time
I'm speaking from experience, you speculate. Unless you've done this yourself and sampled before and after temps with liner and guard removed? In which case, could you answer for us if the temps dropped or increased in the engine bay once removing the vent guard and hood liner?
Sure when the car is sitting at a stop light you will see hot air escaping from the vent, but once at speed it will do the opposite.
I'll try to get to this test this week and will post IAT and engine bay temps later this week. And yes, I have done this before, but not with a Mercedes sedan, but rather race cars. Generally the best spots for venting are closer to the center of the hood or into the fender and out the back.
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2003 E55 estate
Pushing air out from the engine bay into a high pressure zone just will not work , as the car speed increases the air pressure increase to a higher level than that that is in the engine bay . Rather than pushing air out as the air pressure over the car increases with the speed of the car it will push air in rather than exhaus . Think about it guys , these vents feed mainly the air con inlets , if they exhausted air they would be fighting againt the pull of the fan that pulls air into the car . That's the main reason most cars pull air into the car from that location due to it being a high pressure location , if it pushed air out rather than in you car fresh air vents would suck rather than blow !!!
You can't re-right the law of physics !
Marc
You can't re-right the law of physics !
Marc
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From: Orange County, CA.
one car at a time
Pushing air out from the engine bay into a high pressure zone just will not work , as the car speed increases the air pressure increase to a higher level than that that is in the engine bay . Rather than pushing air out as the air pressure over the car increases with the speed of the car it will push air in rather than exhaus . Think about it guys , these vents feed mainly the air con inlets , if they exhausted air they would be fighting againt the pull of the fan that pulls air into the car . That's the main reason most cars pull air into the car from that location due to it being a high pressure location , if it pushed air out rather than in you car fresh air vents would suck rather than blow !!!
You can't re-right the law of physics !
Marc
You can't re-right the law of physics !
Marc
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2003 E55 estate
Worse case is if you have an exhaust leak before the catalytic converter , all you will do is fill your car with carbon monoxide and drift of nicely to sleep as you drive !
I think any increase in cooling at speed is due to the warm engine air being drawn into the interior of the car , you would notice an effect due to all air entering the car passes through the air con .
I think any increase in cooling at speed is due to the warm engine air being drawn into the interior of the car , you would notice an effect due to all air entering the car passes through the air con .
MBWorld Fanatic!
Joined: Oct 2009
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From: Queen Creek AZ
2004 E55 AMG
Totally get the argument here, but given when we DD our E55's, it's a start/stop affair anyway, so heat escapes. Morever to your point if the preasure zone is pulling air into the engine bay at speed, the outside air is still much cooler than the engine bay temp (140-160F), so their way you slice it, this cools the engine bay which is a good thing.
For the A/C part if you're worried about it, (which I'm not), run your A/C in recycle mode and you'll be fine. A/C runs cooler this way as well, as it's recycling the cooler inside cabin air rather than the hot outside air.
My $.02.
Alex
For the A/C part if you're worried about it, (which I'm not), run your A/C in recycle mode and you'll be fine. A/C runs cooler this way as well, as it's recycling the cooler inside cabin air rather than the hot outside air.
My $.02.
Alex
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From: Orange County, CA.
one car at a time
Totally get the argument here, but given when we DD our E55's, it's a start/stop affair anyway, so heat escapes. Morever to your point if the preasure zone is pulling air into the engine bay at speed, the outside air is still much cooler than the engine bay temp (140-160F), so their way you slice it, this cools the engine bay which is a good thing.
Alex
Alex
If you are concerned about engine temperature (and you should be since you live in the desert), you could always wrap or coat your headers and wrap your intake tubes.
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2003 E55 estate
My main concern would be that the area arond the air con inlet is the part with the lowest air pressure and air always takes the easy way out , into the car !! That's fine until you have a exhaust leak , carbon monoxide has no real smell and is pretty deadly . Tbh the best way to vent a engine bay is through side vents in the low pressure area behind the front wheel , under the car is also not the best place , even though it's low pressure do to Burnoullie's principle on ground effect , warm air being denser than cold would have only have negative effects on air flow under the car .
I think you guys are messing with things that could have serious implications , what are you going to do when the air pressure in the car increases with speed and blows out the rear window ?
I think you guys are messing with things that could have serious implications , what are you going to do when the air pressure in the car increases with speed and blows out the rear window ?
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From: Las Vegas, NV
1000Hp Diesel Trucks, 2019 E63s
My main concern would be that the area arond the air con inlet is the part with the lowest air pressure and air always takes the easy way out , into the car !! That's fine until you have a exhaust leak , carbon monoxide has no real smell and is pretty deadly . Tbh the best way to vent a engine bay is through side vents in the low pressure area behind the front wheel , under the car is also not the best place , even though it's low pressure do to Burnoullie's principle on ground effect , warm air being denser than cold would have only have negative effects on air flow under the car .
I think you guys are messing with things that could have serious implications , what are you going to do when the air pressure in the car increases with speed and blows out the rear window ?
I think you guys are messing with things that could have serious implications , what are you going to do when the air pressure in the car increases with speed and blows out the rear window ?
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MBWorld Fanatic!
Joined: Oct 2009
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From: Queen Creek AZ
2004 E55 AMG
Yeah good points peeps but I think between this mod now blowing out windows and me dieing from carbon monoxide poising because of this minor modification, I do believe we're taking this to the extreme.
I mean c'mon, it's not like we're curing cancer here or solving for peace in the Middle East.
I will let you know though if my windows blow out because of this mod OK? :P
On a serious note, drove 50 miles to work today, and with the A/C blowing a bit (I'm alive yay!) and the radio playing I didn't hear any additional cabin/engine noise.
Under full throttle though, it sounds awesome!
So very happy I did this.
Alex
I mean c'mon, it's not like we're curing cancer here or solving for peace in the Middle East.
I will let you know though if my windows blow out because of this mod OK? :P
On a serious note, drove 50 miles to work today, and with the A/C blowing a bit (I'm alive yay!) and the radio playing I didn't hear any additional cabin/engine noise.
Under full throttle though, it sounds awesome!
So very happy I did this.
Alex
Last edited by alextaylor29; Sep 17, 2012 at 03:38 PM.
MBWorld Fanatic!
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From: Queen Creek AZ
2004 E55 AMG
This thread and the turns it's taking reminds me of the TTM Group Buy Scoops we did a few months back. Towards the end, people were throwing down airflow dynamics, physics, the curvature of the earth, with graphs, charts, molecular flow...etc...and how the scoops don't do anything.
I'm in sales of course I understood none of this.
The way I saw it, the scoops slammed more air into the engine which equals goodness.
This mod (which costs you nothing), allows heat to escape from the engine (even a few degrees in heat reduction should be welcome) so this is good as well.
Since you're all smarter than I am, I think this could be another case of, "Overthinking" something just a bit.
Not throwing any stones here I promise...and remember you can always put the stuff back if you want to.
Alex
I'm in sales of course I understood none of this.
The way I saw it, the scoops slammed more air into the engine which equals goodness.
This mod (which costs you nothing), allows heat to escape from the engine (even a few degrees in heat reduction should be welcome) so this is good as well.
Since you're all smarter than I am, I think this could be another case of, "Overthinking" something just a bit.
Not throwing any stones here I promise...and remember you can always put the stuff back if you want to.
Alex
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2003 E55 estate
Hehe , as I said blowing the back window out was to illustrate a point , and if you guys are happy venting your engine heat through the interior of your car good luck
Just hope you never get an exhaust or manifold leak when you guys have your family in your car .
Don't want to fall out with any body , but the area you are opening up to let engine heat into is sealed for a reason , to create a air proof bulk head between the fresh air in let and the cabin for safety reasons .
Marc
Just hope you never get an exhaust or manifold leak when you guys have your family in your car .
Don't want to fall out with any body , but the area you are opening up to let engine heat into is sealed for a reason , to create a air proof bulk head between the fresh air in let and the cabin for safety reasons .
Marc
MBWorld Fanatic!
Joined: Oct 2009
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From: Queen Creek AZ
2004 E55 AMG
Hehe , as I said blowing the back window out was to illustrate a point , and if you guys are happy venting your engine heat through the interior of your car good luck
Just hope you never get an exhaust or manifold leak when you guys have your family in your car .
Don't want to fall out with any body , but the area you are opening up to let engine heat into is sealed for a reason , to create a air proof bulk head between the fresh air in let and the cabin for safety reasons .
Marc
Just hope you never get an exhaust or manifold leak when you guys have your family in your car .
Don't want to fall out with any body , but the area you are opening up to let engine heat into is sealed for a reason , to create a air proof bulk head between the fresh air in let and the cabin for safety reasons .
Marc
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2003 E55 estate
If I had my way I would also make most of the manufactures of rear defusers change the name of the products they make , so that rather than calling them defusers they have to call them 'carbon fibre style enhancers , and front splitters ' cosmetic spoiler enhancers '
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Audi A4
I'd be happy to post a video with data since you think you know what you are talking about...Hood venting has been done for years, but the key is to vent in a low pressure zone, not a high pressure zone.
Sure when the car is sitting at a stop light you will see hot air escaping from the vent, but once at speed it will do the opposite.
I'll try to get to this test this week and will post IAT and engine bay temps later this week. And yes, I have done this before, but not with a Mercedes sedan, but rather race cars. Generally the best spots for venting are closer to the center of the hood or into the fender and out the back.
Sure when the car is sitting at a stop light you will see hot air escaping from the vent, but once at speed it will do the opposite.
I'll try to get to this test this week and will post IAT and engine bay temps later this week. And yes, I have done this before, but not with a Mercedes sedan, but rather race cars. Generally the best spots for venting are closer to the center of the hood or into the fender and out the back.
Exactly.....I removed my insulation and plastic shield a few weeks ago in the Florida summer heat, and with headers!! I took some measurements before/after with an infrared thermometer. Before, my engine compartment was cooking, everything was 150-160F under there, including the surge tanks. When opening the hood after a drive, a wall of extreme heat would blast you in the face. After, The temps dropped from 10-20F. The surge tanks now run from 120-140. Removing these 2 things allows hot air to escape the engine compartment now.
Allow me to clarify: you don't need to do this test anymore, you race car driving guy you. Someone has already done it. His tests, coupled with my personal experience, as well as the testimony of others who have done it here leads me to believe its a mod with more pros then cons-- as of yet I still don't see a major con.I'd like to further clarify in regards to Marc.l's post-- don't let his delusional "cooling your car with interior" theory fool you. The vent guard/hood liner has nothing to do with the air con inlet. I've had it off for a long time. AC is still ice cold. And my rear window is still intact. And my engine stays cooler and cools off quicker. See above quoted test. You guys are really just making a mountain out of a molehill.
If I fail to respond to anymore physics lessons from you two, it just means the carbon monoxide in my car has killed me (ah, the major con I was looking for!)
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2003 E55 estate
Lol , nothing delusional about the laws of physics , but by removing the trim you ate opening the engine bay to the air inlet for the air con . Simple as . That's fine until you have an exhaust leak . The hot air is certainly not exiting by the bonnet vents once you are on the move , but being drawn through the car .
and that's fine , until you get an exhaust leak .
This is my view , no disrespect to you at all
and that's fine , until you get an exhaust leak .
This is my view , no disrespect to you at all
MBWorld Fanatic!
Joined: Oct 2009
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From: Queen Creek AZ
2004 E55 AMG
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Joined: Apr 2008
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2003 E55 estate
How the air con in let works
http://imageshack.us/photo/my-images...ep17234555.jpg
What is now happening
http://imageshack.us/photo/my-images...ep17234608.jpg
So if you would like to show me how the heat is escaping at a stand still I'm all ears
http://imageshack.us/photo/my-images...ep17234555.jpg
What is now happening
http://imageshack.us/photo/my-images...ep17234608.jpg
So if you would like to show me how the heat is escaping at a stand still I'm all ears
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2003 E55 estate
And here is a picture of the cabin air intake with the carbon filter removed , you can just see the fan that draws in when the car is at a stand still . If you look at your carbon filter you will notice that the air intake is on the under side , that's to stop uncontroled air at speed entering the car .
So when you are at a stand still and the fan is drawing in air with the seal removed where do you think it's drawing air in from ?
http://imageshack.us/photo/my-images...ep13145423.jpg
So when you are at a stand still and the fan is drawing in air with the seal removed where do you think it's drawing air in from ?
http://imageshack.us/photo/my-images...ep13145423.jpg
MBWorld Fanatic!
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From: Orange County, CA.
one car at a time
So Greasemonkey here clearly has no clue what he's talking about and doesn't know how to use an infrared thermometer.
It seems the sarcasm in my previous post escaped you, cij911. Allow me to clarify: you don't need to do this test anymore, you race car driving guy you. Someone has already done it. His tests, coupled with my personal experience, as well as the testimony of others who have done it here leads me to believe its a mod with more pros then cons-- as of yet I still don't see a major con.
I'd like to further clarify in regards to Marc.l's post-- don't let his delusional "cooling your car with interior" theory fool you. The vent guard/hood liner has nothing to do with the air con inlet. I've had it off for a long time. AC is still ice cold. And my rear window is still intact. And my engine stays cooler and cools off quicker. See above quoted test. You guys are really just making a mountain out of a molehill.
If I fail to respond to anymore physics lessons from you two, it just means the carbon monoxide in my car has killed me (ah, the major con I was looking for!)
It seems the sarcasm in my previous post escaped you, cij911.
Allow me to clarify: you don't need to do this test anymore, you race car driving guy you. Someone has already done it. His tests, coupled with my personal experience, as well as the testimony of others who have done it here leads me to believe its a mod with more pros then cons-- as of yet I still don't see a major con.I'd like to further clarify in regards to Marc.l's post-- don't let his delusional "cooling your car with interior" theory fool you. The vent guard/hood liner has nothing to do with the air con inlet. I've had it off for a long time. AC is still ice cold. And my rear window is still intact. And my engine stays cooler and cools off quicker. See above quoted test. You guys are really just making a mountain out of a molehill.
If I fail to respond to anymore physics lessons from you two, it just means the carbon monoxide in my car has killed me (ah, the major con I was looking for!)
You clearly have never worked on your car (my guess any car), because if you did you would know the cabin air intake is on the passenger side firewall behind a cabin filter. Marc was trying to tell you that if you have a bad exhaust leak and you did this "mod" you would run the risk of the exhaust fumes entering the cabin. I doubt you have the brain cells to be affected, but for most it would be a concern.
I don't care if you want to play internet games. I was trying to help. Sorry if you want to believe, keep drinking the kool aid.
Last edited by cij911; Sep 17, 2012 at 07:15 PM.
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From: Orbiting the planet
This place is a joke.
I understand your "high pressure" theory, but the diagrams are assuming the engine compartment is completely sealed all around, and on the bottom...What makes you think this high pressure air isn't pushing it's way into the cabin intake, through the open vent directly above it, as well as pushing the hot engine air downward underneath the car, through the now open hood vents? Maybe your theory is backwards, and only when stopped at idle the cabin intake MAY be mixing some engine compartment air with outside air, but once cruising your "high pressure" air is entering the cabin filter and pushing the hot engine air downward and out the bottom of the car?
The only thing that has been PROVEN to be true here is that my underhood temps have dropped... Everything else is theory and conjecture
Why not show some actual data or tests for your theories?
You guys aren't engineers are you? Because every day I fix things that were designed by engineers, the SBC braking system is a perfect example
Last edited by E55Greasemonkey; Sep 17, 2012 at 08:22 PM.
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2003 E55 estate
It's all down to real world physics , the sort that make hot air rise and high pressure move to low pressure areas if you guys have found away round the basic laws in all ears
What I will do is put a smoke generating tablet in the engine bay so you can see where the heat is exiting the car
I did not in my little scribbles include where the air under the car exits . it was mainly to show how the air con inlet uses the high pressure zone to draw in air rather than exhaust .
So what you guys are saying is the hot air is pulled into the bottom of the car ? I suggest you look up Venturi effect and passing air over a tube , it's the way most air paint guns work , the air coming into what was once the sealed area for the air con air take will cause a similar effect .
I am not arguing that the temps have dropped , but rather the reason why , and the reason being that you are now drawing the hot air into the car via the carbon filter inlet that feed the air con . If you guys are cool with venting your engine through the cabin good look to you
if you guys have found away round the basic laws in all ears What I will do is put a smoke generating tablet in the engine bay so you can see where the heat is exiting the car
I did not in my little scribbles include where the air under the car exits . it was mainly to show how the air con inlet uses the high pressure zone to draw in air rather than exhaust .
So what you guys are saying is the hot air is pulled into the bottom of the car ? I suggest you look up Venturi effect and passing air over a tube , it's the way most air paint guns work , the air coming into what was once the sealed area for the air con air take will cause a similar effect .
I am not arguing that the temps have dropped , but rather the reason why , and the reason being that you are now drawing the hot air into the car via the carbon filter inlet that feed the air con . If you guys are cool with venting your engine through the cabin good look to you
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From: Orbiting the planet
This place is a joke.
Sounds like a simple temp probe inserted into the cabin air intake/filter area before and after the underhood shield installed would prove this theory? That would be an easy test, a couple screws and the shield comes in/out.
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2003 E55 estate
That's a good idea, I think on the air con unit in the car there is a way to show air take temps , will have a look in the morning .
Don't want you guys to think I'm against any thing that lowers temps .
Don't want you guys to think I'm against any thing that lowers temps .
