do you have to use an air filter on a turbo?
01-20-2004, 03:52 PM
#32
1.5 BAR
Join Date: Feb 2003
Posts: 763
Re:do you have to use an air filter on a turbo?
Originally Posted by xenocron
Hackish, i have to say I really dont agree with you. The turbo heats up the air in two ways...one by contact as the air enters the compressor and two by compressing to X times(psi) smaller than it was before it entered. The compression of the air is the major factor in how hot the air is exiting the compressor. And air entering the turbo will never have anything to do with back pressure in the exhaust as you stated above.
Most intercoolers are designed to be close to 80-90% efficient which would get most of the air entering back to the ambient temp outside...turbo inlet temps are not going to play a big factor in that. Some yes, so if you can obviously put the filter where its going to get cool air.
But air under the hood is still very close to ambient already while the car is moving so its not going to make a huge difference. Its all about the intercooler.
Most intercoolers are designed to be close to 80-90% efficient which would get most of the air entering back to the ambient temp outside...turbo inlet temps are not going to play a big factor in that. Some yes, so if you can obviously put the filter where its going to get cool air.
But air under the hood is still very close to ambient already while the car is moving so its not going to make a huge difference. Its all about the intercooler.
01-20-2004, 08:08 PM
#33
3.0 BAR
Join Date: Jul 2003
Posts: 6,449
Re:do you have to use an air filter on a turbo?
Originally Posted by turbocivic17m
Originally Posted by xenocron
Hackish, i have to say I really dont agree with you. The turbo heats up the air in two ways...one by contact as the air enters the compressor and two by compressing to X times(psi) smaller than it was before it entered. The compression of the air is the major factor in how hot the air is exiting the compressor. And air entering the turbo will never have anything to do with back pressure in the exhaust as you stated above.
Most intercoolers are designed to be close to 80-90% efficient which would get most of the air entering back to the ambient temp outside...turbo inlet temps are not going to play a big factor in that. Some yes, so if you can obviously put the filter where its going to get cool air.
But air under the hood is still very close to ambient already while the car is moving so its not going to make a huge difference. Its all about the intercooler.
Most intercoolers are designed to be close to 80-90% efficient which would get most of the air entering back to the ambient temp outside...turbo inlet temps are not going to play a big factor in that. Some yes, so if you can obviously put the filter where its going to get cool air.
But air under the hood is still very close to ambient already while the car is moving so its not going to make a huge difference. Its all about the intercooler.
You stupid ---- I never said I was right and he was wrong...I merely offered my opinion, and until your *** guzzling *** can PROVE that I'm wrong I am certainly entitled to say what I wish.
I have SEEN dyno plots and datalogs in person that offer NO change in flow or HP on the dyno or off...so I will go with what I believe in...you can continue posting useless information and be an asshat.
01-20-2004, 10:26 PM
#35
1.5 BAR
Join Date: Feb 2003
Posts: 763
Re:do you have to use an air filter on a turbo?
Boy that was a well thought out post and helped everyone here immensely.
If that was a well thought out post then i fell sorry for you. Most of that was common sense. By the way, im not a " boy," I dont even know where you got that from
You stupid ---- I never said I was right and he was wrong...I merely offered my opinion, and until your *** guzzling *** can PROVE that I'm wrong I am certainly entitled to say what I wish.
I dont think that i need to prove you wrong myself. There is plenty of information out there that suggests dense air is compressed more efficiently. Have you ever heard of boost spike? Didnt think so.... It is a known fact that actuators can spike by as much as 3 or 4 pounds during the winter months. I dont need to waste my time arguing this or conducting an experiment for you......do it on your own time.
I have SEEN dyno plots and datalogs in person that offer NO change in flow or HP on the dyno or off...so I will go with what I believe in...you can continue posting useless information and be an asshat.
I would not expect a change in H.P, never sayed it would.
01-21-2004, 06:11 AM
#36
3.0 BAR
Join Date: Jul 2003
Posts: 6,449
Re:do you have to use an air filter on a turbo?
Explain to me then if there if there is no change in HP (and you arent detonating already) what would be the point in relocating the filter to a colder inlet area?
Even if you were detonating already it would do squat to relocate the filter.
And then, out of the blue you come up with this boost spike thing in colder weather. Please explain to me how that has ANYTHING to do with the Intercooler/Compressor/Charge Piping Temperature inlet. Boost spike is simply a problem with flow of exhaust gases or a malfunction of the wastegate.
And to help clarify, the use of the word "Boy" in the statement above was used as a filler. Its like saying "well," "you know," Maybe because I forgot to use the comma you got all confused. Oh wait, you are already confused. Go bother someone else who isnt trying to help the other members of this great site. This board is meant to offer opposing views on different subjects, and so misinformation doesnt ------, people back that up with facts.
Even if you were detonating already it would do squat to relocate the filter.
And then, out of the blue you come up with this boost spike thing in colder weather. Please explain to me how that has ANYTHING to do with the Intercooler/Compressor/Charge Piping Temperature inlet. Boost spike is simply a problem with flow of exhaust gases or a malfunction of the wastegate.
And to help clarify, the use of the word "Boy" in the statement above was used as a filler. Its like saying "well," "you know," Maybe because I forgot to use the comma you got all confused. Oh wait, you are already confused. Go bother someone else who isnt trying to help the other members of this great site. This board is meant to offer opposing views on different subjects, and so misinformation doesnt ------, people back that up with facts.
01-21-2004, 07:28 AM
#37
1.0 BAR
Join Date: Jan 2004
Posts: 255
Re:do you have to use an air filter on a turbo?
I will dig up some of the datalogs I have of intake and underhood temps. turbocivic17m is sharing the extent of his intelligent argument for it but I think we can all agree that lower intake temps mean more power and safety. If you looked at a dyno plot before and after a relocation and that relocation did result in lower intake temps then the fault lies in the tuner - it's probably running leaner and needs more fuel and advance.
The physics say that the turbo will be more efficient. We all know that a more efficiently running turbo means less backpressure and lower intake temps. If that doesn't result in more power then you'd better call up Corky Bell and tell him he's full of ----.
-Michael
The physics say that the turbo will be more efficient. We all know that a more efficiently running turbo means less backpressure and lower intake temps. If that doesn't result in more power then you'd better call up Corky Bell and tell him he's full of ----.
-Michael
01-21-2004, 08:03 AM
#38
3.0 BAR
Join Date: Jul 2003
Posts: 6,449
Re:do you have to use an air filter on a turbo?
Because I like to be sure of what I know and what i am saying, I went out and found proof of my original recommendation, that its all about the intercooler and that while relocating the air intake will help, the focus should be on cooling down the air coming out of the compressor.
And hackish, i do agree that a colder inlet temp will produce more power...i wanted to prove that this dope has no idea what he is talking about.
Try these links for a good read.
http://www.eng-tips.com/gpviewthread...lev2/6/lev3/35
http://www.gnttype.org/techarea/turbo/turboflow.html
And hackish, i do agree that a colder inlet temp will produce more power...i wanted to prove that this dope has no idea what he is talking about.
Try these links for a good read.
http://www.eng-tips.com/gpviewthread...lev2/6/lev3/35
http://www.gnttype.org/techarea/turbo/turboflow.html
01-21-2004, 09:19 AM
#40
1.0 BAR
Join Date: Jan 2004
Posts: 255
Re:do you have to use an air filter on a turbo?
While there is no doubt effective intercooling is necessary the article does point out a few things:
"For example, with a 1.80 pressure ratio and 70% V/E, when the inlet temp is dropped by 40 deg the discharge temp is lowered by 49.583 deg, a change of 123.956%"
He's even talking about the best case situation - consider 70%-75% is peak efficiency for many turbos.
Relocating the air filter is far more cost effective than upgrading the intercooler. Theory agrees with what they're saying but it's the practical situation - ingesting cooler air rather than trying to cool the pre-turbo air that provides a cheap solution.
The last dude touches on my point: "However, the advantage of this solution is a reduced compression work done by compressor."
It is in my opinion largely that a reduction in backpressure that will give gains here.
As an example, With my freightliner intercooler in the 323 I was cooling the charge temps to within 5 degrees of ambient. Yet it just wasn't making any more power. I replaced the exhaust system from a restrictive POS the DSPO put on and it made so much more power I had to rework my entire fuel map.
The original question was whether or not the guy could make more power taking in cooler air. Some said no, no more power because the intercooler cools the charge. I said and continue to say yes, even if your intercooler cools it all to ambient it means less exhaust restriction from the turbo having an easier job of compressing the cooler inlet air.
-Michael
"For example, with a 1.80 pressure ratio and 70% V/E, when the inlet temp is dropped by 40 deg the discharge temp is lowered by 49.583 deg, a change of 123.956%"
He's even talking about the best case situation - consider 70%-75% is peak efficiency for many turbos.
Relocating the air filter is far more cost effective than upgrading the intercooler. Theory agrees with what they're saying but it's the practical situation - ingesting cooler air rather than trying to cool the pre-turbo air that provides a cheap solution.
The last dude touches on my point: "However, the advantage of this solution is a reduced compression work done by compressor."
It is in my opinion largely that a reduction in backpressure that will give gains here.
As an example, With my freightliner intercooler in the 323 I was cooling the charge temps to within 5 degrees of ambient. Yet it just wasn't making any more power. I replaced the exhaust system from a restrictive POS the DSPO put on and it made so much more power I had to rework my entire fuel map.
The original question was whether or not the guy could make more power taking in cooler air. Some said no, no more power because the intercooler cools the charge. I said and continue to say yes, even if your intercooler cools it all to ambient it means less exhaust restriction from the turbo having an easier job of compressing the cooler inlet air.
-Michael
