[hun77777]

it's around 40~50F in seattle thesedays (except today is sorta nice and mid50Fish). I had to take my car to dealer recently and had to re-install OEM intake back and realized that it actually feels much better than DCI. Sure noise is gone and i miss it but it almost feels like it responds better at throttle. Am i the only one who feels this? I have two set of DCI and i do clean them up quite often so dirty filter is not the case here... i'm kinda curious of keeping the OEM intake and trying aftermarket filter replacement...

[cstavaru]

Keep the OEM and add a Mr.5-style duct and filter. Best of both worlds (cold air + flow).

[a32guy]

Butt dynos are terribly inaccurate. (even though i'd never put that dual cone intake crap on my car, lol)

[FotiosF90M5]

Ive always felt this way.

[joec500]

Dual Cones just look janky in the Engine Compartment IMO.... always stock for me....But the Dinan one is pretty but not worth the $$$ I would rather go to Vegas for a weekend

[bulldog_yyc]

whats with the hate for dual cones? that "crap" $100 DCI seems to have consistently outperformed the other options for people who are tuned

[hun77777]

by no mean, i meant to trun this about another intake war thread. i actually was pretty happy with DCI, hence purchase extra set so that i can clean it up more often. i like the noise part of it too

as someone mentioned, i don't know if it's my butt dyno being inaccurate or cold weather plays a part here. just wanted to share my experience and confirm...

[Ilma]

I have had to swap to stock airbox a few times for dealer visits and yes.....sometimes at lower rpms it seems to feel kind of better in a way.

But once I put DCI's back on, the top end really opens up more than the stock airbox, which kind of makes sense that any restriction in the stock box design is going to impede airflow at higher rpm.

The DCI's don't restrict airflow so that is where they improve performance.

However, at low rpms, I certainly feel that during stop and go traffic the engine bay temperature does rise and the stock airbox would be better in terms of cooler intake temps.

On a constant drive like open road where you are getting some good airflow through the engine bay , I think the DCI's feel just as good as stock in lower rpms and definitely outperform at higher rpms.

Seems to me the Mr 5/Dinan design is the best of both worlds.

[hun77777]

Originally Posted by Ilma

I have had to swap to stock airbox a few times for dealer visits and yes.....sometimes at lower rpms it seems to feel kind of better in a way.

But once I put DCI's back on, the top end really opens up more than the stock airbox, which kind of makes sense that any restriction in the stock box design is going to impede airflow at higher rpm.

The DCI's don't restrict airflow so that is where they improve performance.

However, at low rpms, I certainly feel that during stop and go traffic the engine bay temperature does rise and the stock airbox would be better in terms of cooler intake temps.

On a constant drive like open road where you are getting some good airflow through the engine bay , I think the DCI's feel just as good as stock in lower rpms and definitely outperform at higher rpms.

Seems to me the Mr 5/Dinan design is the best of both worlds.

this just explained my thought EXACTLY... as far as MR.5's intake goes, i would love to try but i'm sorta lazy and scared.

[dlbrooks18]

I like the stock airbox and with a drop in filter I noticed even better throttle response!

[alextremo]

I recently did a few baseline data logs completely stock, then repeated after adding DCI but before adding tune.

I'm sure this has been done before, but results were consistently slower FATS score (albeit a very small difference) and a consistently higher IAT of ~6 deg F in 3rd gear WOT pulls (ambient temps of 30 deg F, starting IATs were identical) with DCI.

I will be repeating the test with a higher boost tune installed to see if the increased flow characteristics outweigh the hot air ingested by the DCI.

Again, I'm sure this has been done - just testing with my car to see with my own eyes

[lpphreakx06]

I took off my DCI's. for a dealer visit and they havent been on since. I just feel a lost of power with the DCI's.

[mwahlert]

i assure you bmw spent millions of dollars developing the airbox for this engine. surely the car can perform better w/ open filters under high boost conditions, but under daily driving use, and low rpm situations - i too find that the stock airbox performs better.

helmholtz resonance has a lot to do with it.

[Jeff@TopGearSolutions]

Mr 5 has specifically come the conclusion that there is an advantage to the DCI over stock, more importantly in lower Waste Gate Duty cycles.

Thats good enough reason right there, it is marginally quicker over stock in comparison as well.

[gerardm]

Originally Posted by mwahlert

i assure you bmw spent millions of dollars developing the airbox for this engine. surely the car can perform better w/ open filters under high boost conditions, but under daily driving use, and low rpm situations - i too find that the stock airbox performs better.

helmholtz resonance has a lot to do with it.

yeh well ur car doesnt make cool noises

[GeorgiaTech335coupe]

I have been in turmoil over what is better as well. I think it depends on a lot of other factors as well, especially the climate you live. The hotter the climate, the worse DCI will perform. DCI will definitely lower WG %, so that in itself might be worth it. At the drags I believe the stock box kept my IATs about 10-15 lower than DCI. I think with tune only, its a close call. If you have FMIC or meth, DCI is probably the way to go. Having said all that, I still use DCI and am located in a very warm climate.

[hun77777]

yeah i actually do feel little rattle with oem intake box which was gone after v4 update...

[PKumarM3]

my first gear has gone to shit w/the DCI. i plan on going back to the oem airbox w/a drop in when the weather gets better.

[SleepyE90]

There are people who argue DCI's are the way to go, while others say there is no better than the OEM intake.
I beleive that if you replace the paper filter in the OEM intake with one by Macht Schnell, BMS, or K&N you should be fine. Adding an additional CAI like the Mr. 5 intake increases the amount of air being taken in.

The stock intake can be arguably the best and most efficient because it is completely sealed off from the rest of the engine bay and therefore the air that is inhaled by the motor is nearly the exact same temperature as it was before entering the car, and not hotter because of exposure to the engine bay. The cold air means that it is more dense and therefore you get more power.

Scoops also direct more air into the intake plenum so they are useful in every situation, whether stock intake or dci.

Just my $0.2

[cstavaru]

In Mr. 5 test of the 3 intakes, the average boost on Mr. 5 intake and stock intake was 14.0psi, while the average boost with DCI was 14.3psi. This shows something ! Add a good intercooler and with the stock or Mr.5 intake you can make the same power at 1psi less boost compared to DCI/no intercooler, which is really significant.

[hun77777]

Originally Posted by cstavaru

In Mr. 5 test of the 3 intakes, the average boost on Mr. 5 intake and stock intake was 14.0psi, while the average boost with DCI was 14.3psi. This shows something ! Add a good intercooler and with the stock or Mr.5 intake you can make the same power at 1psi less boost compared to DCI/no intercooler, which is really significant.

although i think that's more to do with IC than intake...

[2wheelsrbetter]

as far as butt dyno, i've noticed over the years when going back to stock, daily driving around town "feels" quicker. after doing this numerous times i've come to the conclusion that the car is quieter and i'm probably giving it slightly more throttle w/o realizing it. car seems more effortless...