do you have to use an air filter on a turbo?
01-15-2004, 10:10 PM
#11
3.0 BAR
Join Date: Jul 2003
Posts: 6,449
Re:do you have to use an air filter on a turbo?
Filter def...worrying about finding a cold air spot for your turbo is NOT important...while the car is moving, underhood temps are not high, very close to ambient actually because air is circulating around actually. And the reason an intercooler is needed is not because the hot turbo heats up incoming air, its because air is compressed and compressing air makes it hotter, thus the need for an intercooler.
Ever heard of a cold air intercooler intake? nope, didnt think so :P
Ever heard of a cold air intercooler intake? nope, didnt think so :P
01-15-2004, 11:02 PM
#12
1.0 BAR
Join Date: Nov 2003
Posts: 310
Re:do you have to use an air filter on a turbo?
Originally Posted by xenocron
Filter def...worrying about finding a cold air spot for your turbo is NOT important...while the car is moving, underhood temps are not high, very close to ambient actually because air is circulating around actually. And the reason an intercooler is needed is not because the hot turbo heats up incoming air, its because air is compressed and compressing air makes it hotter, thus the need for an intercooler.
Ever heard of a cold air intercooler intake? nope, didnt think so :P
Ever heard of a cold air intercooler intake? nope, didnt think so :P
If your filter is located behind the radiator, a good amount of that hot air will enter the turbo as intake charge under boost (while driving/ moving).
Not only does air flow through the radiator while sitting still due to the radiator fan, but more importantly while driving- when boost is likely.
Although the reduction in intake temps might be small, it's still worth the trouble in the design of a maximum effort turbo system.
Why do you think that there are "true" cool air intakes that get air from outside the engine bay?
01-15-2004, 11:12 PM
#13
0.0 BAR
Join Date: Sep 2003
Posts: 0
Re:do you have to use an air filter on a turbo?
I'll keep it simple for you *******
Get a Filter. If you are lazy, slap it directly on the turbo, if you feel like putting some effort forth route the filter to a section of the bay that will get some colder air. Will it make a world of difference? probably not. will it make some difference? im sure it will give you enough of a difference to spend the $6 on piping and jbweld and just route it to get some colder air.
NOW WHERE CAN I GET A K&N FILTER FOR CHEAP?
Get a Filter. If you are lazy, slap it directly on the turbo, if you feel like putting some effort forth route the filter to a section of the bay that will get some colder air. Will it make a world of difference? probably not. will it make some difference? im sure it will give you enough of a difference to spend the $6 on piping and jbweld and just route it to get some colder air.
NOW WHERE CAN I GET A K&N FILTER FOR CHEAP?
01-15-2004, 11:27 PM
#15
0.0 BAR
Join Date: Sep 2003
Posts: 0
Re:do you have to use an air filter on a turbo?
Im a subtle kind of guy.
Honestly i think there is alot of misconception on the net about turbo. t3/t4 this...and this intercooler wont do the job...dsm's are no good...blah blah blah
Keep it to the point...it is advisable to get the damn filter out of the heat of the engine but com'on its not going to make or break the setup.
And i will have plenty of pics....big write up...the whole SHABANG!
back on topic....Use a filter.....get it breathing colder air if possible
Honestly i think there is alot of misconception on the net about turbo. t3/t4 this...and this intercooler wont do the job...dsm's are no good...blah blah blah
Keep it to the point...it is advisable to get the damn filter out of the heat of the engine but com'on its not going to make or break the setup.
And i will have plenty of pics....big write up...the whole SHABANG!
back on topic....Use a filter.....get it breathing colder air if possible
01-16-2004, 09:41 AM
#18
1.0 BAR
Join Date: Jan 2004
Posts: 255
Re:do you have to use an air filter on a turbo?
I don't know where some of you guys are pulling your advice from... Put a filter on - that's a no-brainer.
However the filter itself does add a fair bit of restriction. So you want an intake that has a fair volume of air after the filter. The reason behind this is that it gives you a bunch of air already filtered and ready for the engine to follow in transient load conditions. Read - faster spool more responsive on and off boost.
Now secondly, some people don't think letting cold air to the turbo makes a difference because of the intercooler? The cold air is more dense and therefore more efficient for the turbine to compress. More efficient on that side means less exhaust backpressure (less effort for the turbine to spin the compressor). Directly that means more power.
Now suppose you have a 60% efficient intercooler. Air on the intercooler side coming in at 200degrees is going to come out at 120 degrees. Hot under-hood air let's say from behind the rad it's not uncommon to have 20 degrees hotter. so intake of 40 degrees versus 20, what do you think that does to your charge density? Now the turbo has to work harder and instead of the air exiting at 200 degrees it's exiting at 250 degrees. Subtract your 60% and you've got 150 degree air going into the motor. Indirectly this means more power because of the charge density.
Now the air going in is 25% warmer. The ideal gas law also says it occupies more volume so every part of the flow is now less efficient from your pressure drop across the intercooler to getting past the valves into the cylinders.
I re-tuned a car with a decent sized FMIC and he'd gone from a cone on the turbo to a piped intake in the bumper. Across the board I had to add fuel. He told me that it pulled a lot better. No dyno results - hard to get in that situation but nevertheless it made a difference.
To suggest that it doesn't matter what temp the air going in is not to understand what's really going on in that system.
-Michael
However the filter itself does add a fair bit of restriction. So you want an intake that has a fair volume of air after the filter. The reason behind this is that it gives you a bunch of air already filtered and ready for the engine to follow in transient load conditions. Read - faster spool more responsive on and off boost.
Now secondly, some people don't think letting cold air to the turbo makes a difference because of the intercooler? The cold air is more dense and therefore more efficient for the turbine to compress. More efficient on that side means less exhaust backpressure (less effort for the turbine to spin the compressor). Directly that means more power.
Now suppose you have a 60% efficient intercooler. Air on the intercooler side coming in at 200degrees is going to come out at 120 degrees. Hot under-hood air let's say from behind the rad it's not uncommon to have 20 degrees hotter. so intake of 40 degrees versus 20, what do you think that does to your charge density? Now the turbo has to work harder and instead of the air exiting at 200 degrees it's exiting at 250 degrees. Subtract your 60% and you've got 150 degree air going into the motor. Indirectly this means more power because of the charge density.
Now the air going in is 25% warmer. The ideal gas law also says it occupies more volume so every part of the flow is now less efficient from your pressure drop across the intercooler to getting past the valves into the cylinders.
I re-tuned a car with a decent sized FMIC and he'd gone from a cone on the turbo to a piped intake in the bumper. Across the board I had to add fuel. He told me that it pulled a lot better. No dyno results - hard to get in that situation but nevertheless it made a difference.
To suggest that it doesn't matter what temp the air going in is not to understand what's really going on in that system.
-Michael
01-16-2004, 02:53 PM
#19
0.0 BAR
Join Date: Sep 2003
Posts: 0
Re:do you have to use an air filter on a turbo?
Dude, that was really long 
Anywho, i agree with you, but if you are making ~200whp moving the filter into a colder region isnt going to give you an extra 30whp or anything amazing. lets be real here it will help to get colder air but it wont make or break the setup.
Now for your question about using a CAI. Take the filter off the CAI and leave the pipe in. that will be one of the pipes you use on your IC piping. Take the filter and either put it directly on your compressor or route it out of the heat of the engine bay. You already know what difference it will make since...well this whole thread is about
Anywho, i agree with you, but if you are making ~200whp moving the filter into a colder region isnt going to give you an extra 30whp or anything amazing. lets be real here it will help to get colder air but it wont make or break the setup.
Now for your question about using a CAI. Take the filter off the CAI and leave the pipe in. that will be one of the pipes you use on your IC piping. Take the filter and either put it directly on your compressor or route it out of the heat of the engine bay. You already know what difference it will make since...well this whole thread is about
01-16-2004, 03:33 PM
#20
1.0 BAR
Join Date: Jan 2004
Posts: 255
Re:do you have to use an air filter on a turbo?
If you're making 200whp and drawing your air from behind a hot rad and you have proper tuning to take advantage of each setup it is possible that something like that would result in 20-30 more hp. Highly dependant on your setup.
-Michael
-Michael
Originally Posted by bigwig
Anywho, i agree with you, but if you are making ~200whp moving the filter into a colder region isnt going to give you an extra 30whp or anything amazing. lets be real here it will help to get colder air but it wont make or break the setup.
