[rjahl]

Originally Posted by hassmaschine

Not too bad though - about 5% loss. That would theoretically translate into ~10hp if you could eliminate it entirely, but that's easier said than done..

I'd love to see data from someone who has modified their induction system with a new filter or hose. Before and after required mod to analyze.

We can pull something like 700-750 KGs of air per hour through the throttle body and that 180 degree turn at the bottom of the intake manifold, I'm surprised the drop is so little.

[CobraMarty]

So at low rpm there is more vacuum where there is low flow/velocity. At high rpm there is less vacuum where there is high flow/velocity.

I'm not so sure what this really means. Is the vacuum dropping because the air velocity is raising?

[rjahl]

Originally Posted by CobraMarty

So at low rpm there is more vacuum where there is low flow/velocity. At high rpm there is less vacuum where there is high flow/velocity.

I'm not so sure what this really means. Is the vacuum dropping because the air velocity is raising?

Sorry for the confusion, this is mapping manifold air pressure in millibar. 1,000 millibar being air pressure at sea level 14.7 PSI.

The 970 millibar data at high RPMs is a 30 millibar vacuum. About 0.4 PSI vacuum.

[hassmaschine]

Originally Posted by CobraMarty

So at low rpm there is more vacuum where there is low flow/velocity. At high rpm there is less vacuum where there is high flow/velocity.

I'm not so sure what this really means. Is the vacuum dropping because the air velocity is raising?

No, it has nothing to do with velocity really. Nominal atmospheric pressure (on Earth) is 1-bar / 100kpa / 1000mbar /14.7psi (with differences for elevation of course). The N52 normally opens the throttle all the way (except for special circumstances like overrun or idle), so theoretically the manifold pressure should always be 1bar.

When you start to see manifold pressure drop, that means that something is restricting air from entering the manifold and keeping pressure inside equal to atmospheric.

You'd see the same thing on a traditional throttle based engine, where the throttle itself is the "something" that restricts airflow - the more closed the throttle, the higher the vacuum / lower manifold pressure, the more open the throttle, the lower the vacuum / higher manifold pressure. Since the N52 nearly always opens the throttle to 100%, manifold pressure should always (theoretically) be equal to atmospheric.

All in all a 5% pumping loss near redline isn't bad but it does mean that there's some small potential to improve on it. The trick would be figuring out what is the source of the largest restriction (throttle? airbox? maf? the manifold itself?).

[CobraMarty]

Thanks, missed it, 1000mbar is 1 bar is 14.7psi at sea level is 0 gauge pressure/vacuum.

So up to 2000rpm there is no pressure drop/vacuum and no restriction.
Over 2000rpm there is a progressive drop in pressure, vacuum, and at 6500rpm there is a drop in pressure to 970mbar which is like 0.4psi vacuum.

I wonder what the N54 intake manifold on the N52, what this graph would look like?

[Terraphantm]

Originally Posted by hassmaschine

All in all a 5% pumping loss near redline isn't bad but it does mean that there's some small potential to improve on it. The trick would be figuring out what is the source of the largest restriction (throttle? airbox? maf? the manifold itself?).

Would be interesting to see how the N52 does with an S54 style (especially CSL) airbox.

I should try logging manifold pressures on my M3.

[3point6]

Hello forum members, since this thread it's been revived, I would like to hear from your experience with the euro air filter box, found mine at this forum and installed last weekend, it came with an almost new K&N filter, I must say that besides all the opinions about increased performance, I personally couldn't perceive much of a difference (already have installed BMW performance exhaust), understand that and not that I was expecting more hp, what I did noticed although was a little rougher idle when starting the engine first thing in the morning when compared with the original box/filter before, I don't have a warning light but based on the perceived smell, it seems like the mix is too rich maybe? I didn't cleaned the MAF sensor when swapped the air boxes to prevent (IMO) an unfortunate 'check engine' light, does anyone had this experience? should I need to clean that MAF sensor maybe? car has 86k miles and recently bought it so no idea on when was the last time the former owner changed spark plugs or did a tune up (?)
Any feedback will be greatly appreciate it, thanks

[anjuna]

Originally Posted by 3point6

K&N filter

Rip that POS out.
Install regular paper filter.
Clean MAF.
Problems solved.

[CobraMarty]

Let it learn. PI has more flow than stock with it's charcoal filter and paper filter. Give it some time. At first might have rough idle, stalling, CEL. Drive it for a week and then see.

Double check for hose connection leaks or slipped clamps.

[rick100]

Originally Posted by anjuna

Rip that POS out.
Install regular paper filter.
Clean MAF.
Problems solved.

running k & n filter on mine for over a year , zero problems , headers and all included

Also ran it in my others cars without any issue

[Bluewater328iT]

Originally Posted by 3point6

Hello forum members, since this thread it's been revived, I would like to hear from your experience with the euro air filter box, found mine at this forum and installed last weekend, it came with an almost new K&N filter, I must say that besides all the opinions about increased performance, I personally couldn't perceive much of a difference (already have installed BMW performance exhaust), understand that and not that I was expecting more hp, what I did noticed although was a little rougher idle when starting the engine first thing in the morning when compared with the original box/filter before, I don't have a warning light but based on the perceived smell, it seems like the mix is too rich maybe? I didn't cleaned the MAF sensor when swapped the air boxes to prevent (IMO) an unfortunate 'check engine' light, does anyone had this experience? should I need to clean that MAF sensor maybe? car has 86k miles and recently bought it so no idea on when was the last time the former owner changed spark plugs or did a tune up (?)
Any feedback will be greatly appreciate it, thanks

I'd say it's worth it just for the convenience of changing the filter from the top. Also, it uses a cone filter, so it is probably as efficient as any other intake and easier to install than CAIs that come with their own intake tube. Some members here did some tests on the filters and said the K&N Euro intake let more air through than the stock filter or the paper filter that comes with the Euro intake, but that difference is probably not perceptible.

I think it is a little noisier, pleasantly so, versus stock intake, and not as unpleasantly resonating as the AFE CAI, which I used and changed for this one. But the AFE has the highest claimed hp of any of them. Still, most any gain is probably at WOT, so you won't notice a big difference and you are paying more per hp for intake and exhaust mods versus adding the 330 three stage intake to a 325 or 328 that has a single stage intake.

Like others said, it takes a few days for the ECU to adapt to a new intake. Watch for CELs as it is easy to trigger one while working on the intake and MAF, but it is usually easy to fix by just redoing whatever you did wrong or fixing whatever the CEL might indicate.

[3point6]

Originally Posted by CobraMarty

Let it learn. PI has more flow than stock with it's charcoal filter and paper filter. Give it some time. At first might have rough idle, stalling, CEL. Drive it for a week and then see.
Double check for hose connection leaks or slipped clamps.

Thanks for the advise, I did checked the clamp and all seems to be installed properly, no signs of gaps neither a CEL so far..will drive it more and then see, so I assume the engine computer will adjust based on the new readings? Back in the day, you were required to 'tune' the mix..

[3point6]

Originally Posted by Bluewater328iT

I'd say it's worth it just for the convenience of changing the filter from the top. Also, it uses a cone filter, so it is probably as efficient as any other intake and easier to install than CAIs that come with their own intake tube. Some members here did some tests on the filters and said the K&N Euro intake let more air through than the stock filter or the paper filter that comes with the Euro intake, but that difference is probably not perceptible.

I think it is a little noisier, pleasantly so, versus stock intake, and not as unpleasantly resonating as the AFE CAI, which I used and changed for this one. But the AFE has the highest claimed hp of any of them. Still, most any gain is probably at WOT, so you won't notice a big difference and you are paying more per hp for intake and exhaust mods versus adding the 330 three stage intake to a 325 or 328 that has a single stage intake.

Like others said, it takes a few days for the ECU to adapt to a new intake. Watch for CELs as it is easy to trigger one while working on the intake and MAF, but it is usually easy to fix by just redoing whatever you did wrong or fixing whatever the CEL might indicate.

Appreciate your comments, on the CEL, I don't have any so far and one of the reasons I didn't attempted to clean that MAF was to avoid creating a new issue while trying to somehow improve the current condition of the car, I guess I'll give it some time to adapt and hopefully all will be fine, in fact I've noticed this morning that there's not that much of the rich gas mix smell, so maybe is starting to assimilate the extra air coming into the engine, will see, thanks

[Zajac1]

Euro box it's a great intake. Clean the maf sensor, tide up all clamps & clean filter with air pressure gun if you have a chance.
I got afe cone filter in my euro box similar to the one in link http://afepower.com/afe-power-85-100...-intake-system

To increase a little bit more power from the intake add scoops behind the grill and replace regular intake hose with silicone tube. Check some examples how the silicone tube looks like. First pic shows OEM plastic tube $ rest pics with silicone tube on.

[lab_rat]

Since you are fairly local, I'd like to see/hear the PE exhaust & intake combo on the 330i...it's just a matter of time before I get it all installed on mine!

[rjahl]

I've said this before, does anyone have any proof that these intake mods create more power?

More noise sure, if you are into that sort of thing but facts about power gains seem to be hard to find.

[justpete]

Originally Posted by rjahl

I've said this before, does anyone have any proof that these intake mods create more power?

More noise sure, if you are into that sort of thing but facts about power gains seem to be hard to find.

That's cuz they are.

[Terraphantm]

On most cars intake upgrades are mostly noise makers. I'd be surprised if an intake with no manifold change netted more than 3-5 hp on a good day.

Even on the S54 which has fairly aggressive cams and such for a stock car, something like the CSL airbox (which is about as good as running with no restriction) only gains around 10hp at the top end.

[3point6]

Originally Posted by Zajac1

Euro box it's a great intake. Clean the maf sensor, tide up all clamps & clean filter with air pressure gun if you have a chance.
I got afe cone filter in my euro box similar to the one in link http://afepower.com/afe-power-85-100...-intake-system
To increase a little bit more power from the intake add scoops behind the grill and replace regular intake hose with silicone tube. Check some examples how the silicone tube looks like. First pic shows OEM plastic tube $ rest pics with silicone tube on.

Thanks for the feedback, I'll clean the MAF although I must say that the 'funny smell' of rich gas mix seems to be fading away and the idle start to get closer to normal if there's such a thing, when I swapped the air box noticed that the stock intake hose have a bottom duct, sort of a hole at the lower portion, I assume it was some kind of drain maybe?, when I looked at those pictures you've sent, seems like the aftermarket silicone tube goes straight, is there any advantage of that?
So based on your avatar, you have a 3-series wagon with an updated front grill?, if so, can you share a picture? I remember seeing an updated version similar to the newer models, just curious if that's yours, thanks

[3point6]

Originally Posted by lab_rat

Since you are fairly local, I'd like to see/hear the PE exhaust & intake combo on the 330i...it's just a matter of time before I get it all installed on mine!

Sure, I've sourced both parts with little use from the original owners, I'll be pleased to share, work odd shifts but maybe if the weather cooperates in this area does sometime Sunday afternoon? If so, PM and we'll figure something out, thanks

[Taskmaster]

Originally Posted by rjahl

I've said this before, does anyone have any proof that these intake mods create more power?

More noise sure, if you are into that sort of thing but facts about power gains seem to be hard to find.

Yes, I do have dynos of a few different intakes.

[lab_rat]

Originally Posted by 3point6

Sure, I've sourced both parts with little use from the original owners, I'll be pleased to share, work odd shifts but maybe if the weather cooperates in this area does sometime Sunday afternoon? If so, PM and we'll figure something out, thanks

Sounds good. PM sent