do you have to use an air filter on a turbo?
01-21-2004, 09:33 AM
#41
1.5 BAR
Join Date: Feb 2003
Posts: 763
Re:do you have to use an air filter on a turbo?
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.
That is exactly the arguement the whole time. You are starting to contradict yourself :P Sorry you were offended in the original post, but come on......give it up, we are all right in our own respects.
oh BTW......Boost spike was not out of the blue. Among other things, boost spike or boost creep CAN be caused by colder/dense air. I used this as an example to demonstrate to you how colder air is compressed more efficiently.
That is exactly the arguement the whole time. You are starting to contradict yourself :P Sorry you were offended in the original post, but come on......give it up, we are all right in our own respects.
oh BTW......Boost spike was not out of the blue. Among other things, boost spike or boost creep CAN be caused by colder/dense air. I used this as an example to demonstrate to you how colder air is compressed more efficiently.
01-21-2004, 10:22 AM
#42
1.0 BAR
Join Date: Nov 2003
Posts: 310
Re:do you have to use an air filter on a turbo?
I don't think that the increase in HP is created by a reduction in back pressure when talking about cooler intake charge...
but rather more air molecules per a given measurement of intake charge.
Cooler air is denser...You know, more rich with oxygen.
The compression of the intake charge makes the air heat up as well as the radiation from contacting the heated surfaces of the system.
Edit:...and concerning the change to a less restrictive exhaust system...An exhaust system that flows more freely will allow more heat to escape out the tailpipe creating a cooler overall system operating temperature (along with other advantages).
If you take in cooler air from the beginning, you going to get cooler air into the combustion chamber. It's that simple.
We all love driving on a cool day rather than a hot day...Same principle.
but rather more air molecules per a given measurement of intake charge.
Cooler air is denser...You know, more rich with oxygen.
The compression of the intake charge makes the air heat up as well as the radiation from contacting the heated surfaces of the system.
Edit:...and concerning the change to a less restrictive exhaust system...An exhaust system that flows more freely will allow more heat to escape out the tailpipe creating a cooler overall system operating temperature (along with other advantages).
If you take in cooler air from the beginning, you going to get cooler air into the combustion chamber. It's that simple.
We all love driving on a cool day rather than a hot day...Same principle.
01-21-2004, 01:22 PM
#43
3.0 BAR
Join Date: Jul 2003
Posts: 6,449
Re:do you have to use an air filter on a turbo?
Hackish,
The guy said "However, the advantage of this solution is a reduced compression work done by compressor." I dont know exactly what he is getting at but it has nothing to do with compressor efficiency. Looking at the formula:
Tout = Tin + Tin x [-1+(Pout/Pin)0.263]
efficiency
The efficiency of a compressor is always that and doesnt change based on the inlet temps. The only things that change in this equation are temperatures and pressures.
And furthermore back pressure deals only with restrictions on the exhaust side(after the exhaust turbine in the turbo) of an engine so this should be left out of a discussion on filters and locating them. Now if you are talking about the "suction pressure" that he touches on, that might change based on the ability of your filter to flow, but thats all in a filter choice and nothing to do with temperature. Denser air will actually have a harder time flowing through any filter because there are more molecules to pass through the fibers.
In the example you pointed out, the 1st guy isnt calculating this correctly and his numbers are off. Look at the example on the second page. His inlet temp of 70 degress is an outlet temp of 258 degrees, while at an inlet temp of 100 degrees the outlet temp is 298. Thats a 40 degree difference. And if you drop the boost levels to what most are on this site are at of 8 psi, the numbers change to 166 degree outlet @ 70 inlet and 202 outlet at 100 inlet. How many people here are running 19 psi? Not many, and the 4 hp increase (40 degree difference at 1 HP per 10 degree drop in temp as the unofficial standard) isn't going to matter much on a car tuned w/ the hack running as rich as most people probably do in the DIY world. And remember that I am not figuring in an INTERCOOLER at all in this equation. If you have a 70%(weak sauce) efficient intercooler, 166 degrees becomes 100 degrees inlet and 202 degrees becomes 130 degrees inlet narrowing the margin to just 30 degrees inlet difference and only 3 net HP. Not exactly HUGE...
turbocivic17m,
Yes you did offend me with your initial useless post. Its that kinda ---- that has turned Honda-Tech and other sites that I frequent to be overrun by ******** who dont know their head from their ******** and I was simply pointing out all along (never contradicting myself) that if you could relocate your filter, by all means do it, if its a problem or might get costly (paying a welder, buying extra tubing, etc) that the 3 proven horsepower that you will gain just isnt worth it.
If YOU are bound and determined to prove to me and the rest of this group that boost spike (or creep) is caused colder ambient temperatures, please do so, legitimately. By just saying that it is so does no one, especially yourself any justice. Why should anyone believe it, because you say so?
The guy said "However, the advantage of this solution is a reduced compression work done by compressor." I dont know exactly what he is getting at but it has nothing to do with compressor efficiency. Looking at the formula:
Tout = Tin + Tin x [-1+(Pout/Pin)0.263]
efficiency
The efficiency of a compressor is always that and doesnt change based on the inlet temps. The only things that change in this equation are temperatures and pressures.
And furthermore back pressure deals only with restrictions on the exhaust side(after the exhaust turbine in the turbo) of an engine so this should be left out of a discussion on filters and locating them. Now if you are talking about the "suction pressure" that he touches on, that might change based on the ability of your filter to flow, but thats all in a filter choice and nothing to do with temperature. Denser air will actually have a harder time flowing through any filter because there are more molecules to pass through the fibers.
In the example you pointed out, the 1st guy isnt calculating this correctly and his numbers are off. Look at the example on the second page. His inlet temp of 70 degress is an outlet temp of 258 degrees, while at an inlet temp of 100 degrees the outlet temp is 298. Thats a 40 degree difference. And if you drop the boost levels to what most are on this site are at of 8 psi, the numbers change to 166 degree outlet @ 70 inlet and 202 outlet at 100 inlet. How many people here are running 19 psi? Not many, and the 4 hp increase (40 degree difference at 1 HP per 10 degree drop in temp as the unofficial standard) isn't going to matter much on a car tuned w/ the hack running as rich as most people probably do in the DIY world. And remember that I am not figuring in an INTERCOOLER at all in this equation. If you have a 70%(weak sauce) efficient intercooler, 166 degrees becomes 100 degrees inlet and 202 degrees becomes 130 degrees inlet narrowing the margin to just 30 degrees inlet difference and only 3 net HP. Not exactly HUGE...
turbocivic17m,
Yes you did offend me with your initial useless post. Its that kinda ---- that has turned Honda-Tech and other sites that I frequent to be overrun by ******** who dont know their head from their ******** and I was simply pointing out all along (never contradicting myself) that if you could relocate your filter, by all means do it, if its a problem or might get costly (paying a welder, buying extra tubing, etc) that the 3 proven horsepower that you will gain just isnt worth it.
If YOU are bound and determined to prove to me and the rest of this group that boost spike (or creep) is caused colder ambient temperatures, please do so, legitimately. By just saying that it is so does no one, especially yourself any justice. Why should anyone believe it, because you say so?
01-21-2004, 02:13 PM
#44
1.0 BAR
Join Date: Nov 2003
Posts: 310
Re:do you have to use an air filter on a turbo?
A 30 or 40 degree reduction in intake charge temps is a notable difference.
...and intake temp reduction is not only about HP, but also about detonation and overall system reliability. A reduction of this amount can make all the difference in the world to someone who needs it.
Potentialy, you could at that point raise your boost level safely creating more HP.
...and intake temp reduction is not only about HP, but also about detonation and overall system reliability. A reduction of this amount can make all the difference in the world to someone who needs it.
Potentialy, you could at that point raise your boost level safely creating more HP.
01-21-2004, 02:31 PM
#45
1.0 BAR
Join Date: Jul 2003
Posts: 361
Re:do you have to use an air filter on a turbo?
i noticed this post has 43 replies and i thought, "why does it take that much to tell someone to use a filter" then I noticed this has become a debate over whether a turbo car benefits from a cold air intake, should we start a new post? :P
01-21-2004, 04:06 PM
#47
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 stretch-d
A 30 or 40 degree reduction in intake charge temps is a notable difference.
...and intake temp reduction is not only about HP, but also about detonation and overall system reliability. A reduction of this amount can make all the difference in the world to someone who needs it.
Potentialy, you could at that point raise your boost level safely creating more HP.
...and intake temp reduction is not only about HP, but also about detonation and overall system reliability. A reduction of this amount can make all the difference in the world to someone who needs it.
Potentialy, you could at that point raise your boost level safely creating more HP.
01-21-2004, 05:04 PM
#49
1.5 BAR
Join Date: Feb 2003
Posts: 763
Re:do you have to use an air filter on a turbo?
If YOU are bound and determined to prove to me and the rest of this group that boost spike (or creep) is caused colder ambient temperatures, please do so, legitimately. By just saying that it is so does no one, especially yourself any justice. Why should anyone believe it, because you say so?
As I stated before, Boost creep/ spike CAN be caused by cooler air. There is a handfull of other explenations out there for this phenomina as well. YES, Forced induction engines will boost faster when they are sucking in cold, dense air. Sometimes boost even rises so fast that you can spike into overboost range. It's not unusual to see your boost respond differently with different air temps. It's a fact.....dont know what else to tell ya :P
As I stated before, Boost creep/ spike CAN be caused by cooler air. There is a handfull of other explenations out there for this phenomina as well. YES, Forced induction engines will boost faster when they are sucking in cold, dense air. Sometimes boost even rises so fast that you can spike into overboost range. It's not unusual to see your boost respond differently with different air temps. It's a fact.....dont know what else to tell ya :P
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