Attn TDI newbs. Even if a K&N DIDNT destroy your MAF here is why they are worthles.

Attn TDI newbs. Even if a K&N DIDNT destroy your MAF here is why they are worthles.

The ECU takes 2 readings regarding airflow. The first is Mass air flow. It is based on this that the ECU can calculate how much fuel it can give to the motor and not smoke. The second reading is boost. The ECU measures and controls boost so a specific level of mass airflow can be obtained.

When one claims that a K&N helps to develop more power it can only mean one thing. some property of the K&N must cause more airflow and because of it more fuel is being injected.

Wait now and once again picture the intake system of a TDI. To pack more air in means you must be running more boost! If the turbo can maintain the specified level of boost it doesnt matter how much or how little restriction there is before the turbo.

So lets say that the K&N flows better and the turbo develops more boost. The ECU will see that and use the VNT to reduce the boost and put the airflow right back to where you were with the paper filter.

Cliffs: Unless you are unable to maintain the desired boost level with your current intake system a higher flow airfilter WILL NOT HELP YOU.

On a side note: There are only 2 ways to make a filter flow better, increase the amount of paper (or other filtering substance) or increase the diameter of the holes in the paper. Next time you replace your air filter compare the filters at autozone and find the one with the most paper. It will most likely flow the best while maintaining a proper level of filtration.

Wow.

I get what you're saying, but it's overly simplistic; i.e more air doesn't necessarily equal higher boost.

Haha, simplistic or not K&N is still a waste of money

K&N flows better and the turbo develops more boost. The ECU will see that and use the VNT to reduce the boost. final point.
Less restriction is less fuel, no more power at wheel but less fuel for same power.



Dieseleux

P.S.: very hard to see difference! but sound great!
P.P.S.: I'm not ok to use K&N.

dieseleux said:

K&N flows better and the turbo develops more boost. The ECU will see that and use the VNT to reduce the boost. final point.
Less restriction is less fuel, no more power at wheel but less fuel for same power.



Dieseleux

P.S.: very hard to see difference! but sound great!
P.P.S.: I'm not ok to use K&N.

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I never defended the K&N. My point was aimed more at the physics of the turbo (at least, as I understand them); higher restriction at the air-filter will cause a lower pressure to exist in the TIP, enhancing the conditions needed to created compressor stall, as the engine will still want the same levels of boost, but may not have the air necessary to create them. Search for the thread about the number of VNT failures at high altitudes.

Less restriction is not a bad thing at all.

otbBlaine said:

I never defended the K&N. My point was aimed more at the physics of the turbo (at least, as I understand them); higher restriction at the air-filter will cause a lower pressure to exist in the TIP, enhancing the conditions needed to created compressor stall, as the engine will still want the same levels of boost, but may not have the air necessary to create them. Search for the thread about the number of VNT failures at high altitudes.

Less restriction is not a bad thing at all.

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OK but is very very little input pressure change on turbo with K&N.
Effect is more in ear of driver and between!!!


Dieseleux

Not sure if any of you happened to read my earlier thread on this topic but here's a link to some interesting comparison testing - LINK

Thanks for doing that Ed and affirm what most have been saying

i myself think you should not rely on oil to do the filtering, which you are having to do to make up for lack of a quilityy filter element. you may as well go to a straight oil bath system....just my opinion

frank p said:

i myself think you should not rely on oil to do the filtering, which you are having to do to make up for lack of a quilityy filter element. you may as well go to a straight oil bath system....just my opinion

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Isn't that fairly close to the bong system?

For the sake of arguement you could say the K&N reduces the amount of vacuum in front of the turbo. This means the turbo doesn't have to work as hard to create that boost thus is does so more efficiently. The ECU will adjust the vanes to open them more and compensate resulting in less exhaust backpressure. Thus, a power gain could be had.

Do I think this would make a measureable difference? NO

I do run a K&N cone filter but only because I couldn't find a way to get the charge pipe around the air box. Initially I had plans of keeping the stock air box.

To the people who really hate upgraded intakes:
Have y’all had a chance to try out an intake system (not a drop in filter, or based on my friends experience, a CAI) on your cars?

I have used the OEM setup, OEM setup with no snorkel, K&N, K&N with no snorkel, BMC/CDA, and the BMC/CDA with its own tube that I cut up to get air in the area behind the headlight.

My impressions:
Taking out the snorkel alone made the car feel less chocked up when taking off. Using the K&N with the snorkel felt like the OEM setup, and the K&N with no snorkel felt like the OEM with no snorkel.
Therefore, the K&N was not very impressive.
MAF wise… It did stop working with both setups. The first was with the OEM after owning it for 3 years, and then with the K&N not two months after putting in the filter.

I have been using the BMC/CDA for a little over a year and no MAF issues. I can honestly say that the car just feels happy when you get on it, even at lower RPM’s. It is hard to describe, but the time interval between punching it and actually going reduced. Smoke wise, with all my modifications I do not smoke.
Anyway, last weekend I took apart the air box, and cleaned out the filter. I used the old-fashioned bucket of soapy water, plenty of shaking and so on. I went through many buckets of nasty looking water, miscellaneous insects, and so on. Despite all this crap the air box portion on the clean side of the filter had no dust on the walls what so ever.
Oh yeah, the sound it makes is just incredible. For the purpose of the anal cops right near by, I am running it with the tube (that I have routed to the area behind the headlight, keyword area behind, so not the little hole the OEM setup gets air from) which seems to silence the intake noise somewhat.

If it matters… My friend uses a CAI on his VW, I let him take a spin with his car, but using the BMC, and now he wants to get a BMC lol

I would love to get a dyno with the stock setup and with the BMC. The dyno would be useful if it had something plotting down the boost/RPM, power, and smoke levels. However, I did toss out the stock air box and snorkel.
At the same time, I am quite confident that due to me not being at “god status” on here. That if the outcome was to favor the intake, almost everyone would give 50 excuses as to how the data is wrong. If it were to favor the OEM one then everyone would rejoice with “We told you so.”

Isn't that fairly close to the bong system?

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Yes! Do you suppose drug users debate this on their sites?

Actualy an oil bath system would provide nearly perfect intake air filtration.

On a final note, as a partial nod to the K&N, over oiling of the oil based systems is the single biggest detractor from their performance and the longevity of an upstream sensor. Allow me to repeat that, a filter that looks like it took a bath in tranny oil is not doing it's job; it's merely drizzling oil all over your intake system. Applying the right quantity of oil and waiting the specified time for any excess to run off as well as waiting for the correct quantity to tack up is also a culprit.

I'm not going to argue one way or the other for either type of system but poor maintenence practices with either type are going to cause all kinds of down stream problems.

thermopylaetech said:

Actualy an oil bath system would provide nearly perfect intake air filtration.

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Agreed but i dont think that MAF sensros like oil bath systems. Also, they dont take the g forces of being in a car well.

validius said:

Agreed but i dont think that MAF sensros like oil bath systems. Also, they dont take the g forces of being in a car well.

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I dunno, had one in a 1980 ALF Century series and we'd corner that truck all the time. The idea id to build the canister such that you'd have to invert it to get oil near the port for induction.

As for a MAF, as long as you oil trapped the system, it should work just fine. But we digress.

In all honesty I ended up with my K&N becasue it was a matter of I NEEDED a filter right then and there as no sooner did I exclaim out loud to not throw the old one away; it was liberlay soaked in dirty engine oil... DANG!

Knowing how to care for one is the key to using it the right way and unfortunatly while al ittle oil does a lot of work, a lot of oil should then thusly do yet more, right? Right?

I don't like those "cold air pipes" becasue honestly, I highly doubt the airbox on any turbodiesel is whats holding you back and once you start playing around with 'well the aluminum tubing is this size but the filter cone neck is this size, so if we just crank the clamp down it'll work..." nothing I ever like as I've seen them come off and even ran a few of my own over. And while every parts counter GT1 racer is always going to come back with pick up points and filter area and a myriad of other reasons why their super magna-widget filter will work better than my stock airbox, my responce is always the same; If you arn't operating at 9-10/10ths of design capability, your fractional incremental gains will have no effect becasue you are not analysing at the required resolution, or in other words, that 2hp just you go is washed away by your stock aerodynamics and/or those heavier than stock super bling-masta-flex chrome 22's.

I'm jaded and I know it. I have not only tasted serious power and handling but I've sat down to whole meals of it. Ranting about how K&N's are killing MAF's doesn't solve the operator error issues anymore than poor care of a stock unit. All things being equal, I prefer my K&N becasue all I have to do is clean and re-oil and its like new again.

So yeah, oil bath systems for all... in fact put the sensor in the oil for maximum flow control!

It's appropriate to warn TDI owners of the risks of the K&N. I've had a hard time deciding when mine were oiled correctly (probably weren't) in other vehicles and am not going to risk it in my TDI.

Braga_Dub said:

At the same time, I am quite confident that due to me not being at “god status” on here. That if the outcome was to favor the intake, almost everyone would give 50 excuses as to how the data is wrong. If it were to favor the OEM one then everyone would rejoice with “We told you so.”

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LOL. I must say that last paragraph gave me a chuckle.

I ran a K&N for a year....took it out when it was dirty...never put it back in....ran stock paper media for the last 2 years now I'm putting a CAI on this weekend. Hydrolock be damned. I know I won't see gains but the less restriction on these motors the better. And the tube is shiney and I like shiney!!

validius said:

Agreed but i dont think that MAF sensros like oil bath systems. Also, they dont take the g forces of being in a car well.

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Oiled filters work fine on a Toyota. Then again.... we are not talking about Toyota here... instead the crappy Bosch MAF sensors that fail even if you look at it wrong.

If you look at the plain facts.... doesn't increase power, because the limitation is with the ECU.

The 20 hp claim is with a GM 5.7L engine. With gas engines, if more air is let in, then it will compensate with more fuel so the a/f does not lean out too much---therefore increasing power. Doesn't work on a diesel. In fact, there is excessive air stock to cover smoke (hence fuelling mods)

Theoretically it can decrease spool time. Theoretically, the R32 snorkel can decrease spool time.

....these days.... I have a Amsoil eA cone filter.

Braga, you mentioned that your BMC has an extension pipe behind the front headlight. Do you ever have a problem with rain entering the cold air intake? I run my BMC without the pluming because I worry about hydrolock. I like the increase in throttle response and think this new setup is superior to my OEM. Also, the test provided by Ed had a lot of facts but did not mention if the diesel motor was running, which creates a **** load of suction. This is a key since our systems create a swirling effect during combustion and the BMC (if circulating in the same direction) would increase this effect. Leo.

The pipes opening is behind the headlight, right next to the battery. It does not go down into the wheel well or anything.
I'm only doing this to silence the intake a bit.

Isn't the throttle response a night and day difference with and without the OEM intake?

I am curious as to what direction it swirls. If you take apart the intake you will see that there are like 4 or so small curved fins inside.

Heheh. Where is dieseldorf with the link to NE DD I with the big air filter shootout?

MCA

I know this thread is kind of old but I wanted to add my input. I have owned a TDI for about 2 months and this is also my 1st diesel car. I primarily play with gasoline engines and have applied a few things to my TDI as far as the intake system goes.

Personally, I don't see much point in replacing a stock filter with another brand filter in hopes of some type of performance gains. If your going to replace the filter or "upgrade" the filter then it would be best to remove the stock box and put a cone filter on the end of the MAS. Make sure that you get a dry filter and not one that is oiled. What affect does the oiled filter have on our cars? Well, it has been my experience over the past month that any type of dampness that finds its way into the MAS will cause it to act retarded for a short period of time. For example, loopy idle in the morning while its warming up. After enough air has been sucked through the MAS it will straighten back out and idle fine. This issue drove me to gut out my MAS tonight (At which point I figured out that if the sensor is damp the issue comes back). Perhaps the stock box will prevent the MAS from getting damp since its more closed in. To me this is a flaw and someone should find a work around.

As far as "why bother adding a less restrictive filter only to build the same amount of boost" question. Here is the main reason to do this. Less restriction = more efficient air going into the motor (This also means it will be easier to make more power at higher boost and higher rpms). Less restriction also means less stress on your turbo seals which means less oil in your intake system and a longer healthy life for your turbo. If VW really wanted oil, diesel and air in the chambers...i think they would have designed it that way.

Do I think having an open element filter is a good idea? Heck Yes! Do I like the idea of having a crappy MAS that bugs out with the slightest change? Nope! Hopefully I can find a MAS outta some other car that won't complain.

I am running a super low oiled K&N with a fully cheesed OEM airbox on bottom and fender side with no hood seal. I thought the advantage of the K&N is one purchase and just cleaning for the life too. working sweet for ~40000 miles so far...

The Fact is that K&N has bigger holes to let more air in. The bad part is that the K&N lets more dirt in. May not be a big deal on a Gasser, but in a Diesel it's a big deal due to our tighter clearances. In fact K&N does not meet Cummins' filtration standards. Moose

Quote....
So lets say that the K&N flows better and the turbo develops more boost. The ECU will see that and use the VNT to reduce the boost and put the airflow right back to where you were with the paper filter.

This is very true......and the same can be said about every piece of hardware modification you make on the car e.g....larger turbo's / larger ic's / larger nozzles etc....but it why after doing so you then have the car re-mapped........because basicly the fuel and air levels are out of the /maps/sensors = parameters of the information stored within the ecu and now needs changing re-calibrating.........or it will always be trying to pull back on timing and fueling .



P.s at best you will loose some power at worst you may have drivability /smoke issues.

Moose00 said:

The Fact is that K&N has bigger holes to let more air in. The bad part is that the K&N lets more dirt in. May not be a big deal on a Gasser, but in a Diesel it's a big deal due to our tighter clearances.

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Don't forget that 100,000rpm compressor wheel. Even a little dirt can cause some significant impact/abrasion damage to it which can reduce pumping efficiency and take it out of balance.

This was the junk wheel of a spare turbo I bought. Notice how the leading edges are dull and pitted.

guys, you all forget about a simple factor... its about reducing the temps of sucked in air.

the cooler the air is, the less the turbo as to work to get it, because cold air is more compressed. Thats why CAI and cool-flo give you hp gains. The temp is the fianal part of the calcuation.

k&N suck fat DICK

I use ITG

if VW had every bit improved tuners wouldnt have a job....

and then agian goverment restrictions can even effect a airbox. and piping. It all comes down to crash tests and manufactoring cost.

A airbox could effect the emissions too...

AND insurence companies do not like CAI because its a mod to make your car faster!!!

VW cant pump all the power out... they have to think about warranties... so they tune the cars down to be sure all the parts last as long... because the warranty work will come out of there pocket.

then if they make a 200 hp diesel? How would they convice you to buy there 2.0T? If they tune there 2.0T to 250 hp, who will buy there 3.2 liters r32?

this threat seems like a kid is trying to convice me of something.

Even Exedy puts 100 hp lower rating on thier clutch to make sure no warranties come in.

TDISwapMaster said:

guys, you all forget about a simple factor... its about reducing the temps of sucked in air.

the cooler the air is, the less the turbo as to work to get it, because cold air is more compressed. Thats why CAI and cool-flo give you hp gains. The temp is the fianal part of the calcuation.

k&N suck fat DICK

I use ITG

if VW had every bit improved tuners wouldnt have a job....

and then agian goverment restrictions can even effect a airbox. and piping. It all comes down to crash tests and manufactoring cost.

A airbox could effect the emissions too...

AND insurence companies do not like CAI because its a mod to make your car faster!!!

VW cant pump all the power out... they have to think about warranties... so they tune the cars down to be sure all the parts last as long... because the warranty work will come out of there pocket.

then if they make a 200 hp diesel? How would they convice you to buy there 2.0T? If they tune there 2.0T to 250 hp, who will buy there 3.2 liters r32?

this threat seems like a kid is trying to convice me of something.

Even Exedy puts 100 hp lower rating on thier clutch to make sure no warranties come in.

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Your forgetting the ridges inside the airbox to quite everything down. Im quite sure they keep the air from flowing nice and smooth.

just curious has anyone looked at the amsoil dry filters?
https://www.amsoil.com/storefront/eaa.aspx