[Mike@N54Tuning.com]

Hey guys,

I saw this posted on another forum and thought many would find it interesting. Especially the idle testing. The testing was done in 70 degree weather and the overall tuning is a bit hot for the octane and lack of mods on the car, but the air intake temperature differences between the DCI and factory airbox are very interesting. Looking at the time spent in 3rd gear you can also see the DCI is also making more power. They say DCI gains at high boost levels of 17-18psi are upwards of 25rw compared to stock but on map 1 or map 2 type boost levels closer to 5-10rw from 5500rpm to redline.

So for this round of testing we used our 135i which happens to be 100% stock at the moment aside from the JB4 using 91 octane + NOS octane booster (~93 octane). I've been testing map 2 with a default CPS offset lately so kept that all the same between both tests.

The two sets of tests were performed within 20 minutes of each other under identical conditions. First I did a 40-110mph sprint (on a safe private road) to evaluate the intake temperature increases throughout the run. Secondly an 8 minute (limit of JB4 logs) driveway test simply logging the car with the hood down and AC on to monitor intake temperatures at rest.

According to "hot air" conspiracy theorists the dual cone intake should result in higher intake temperatures during the wide open throttle run, no power gains, and heat up dramatically sitting in the driveway soaking up all that engine heat. opcorn

First up: Stock intake system








Next up: BMS Dual Cone Intake







Results:

I hate to say it again but the results were exactly as expected. The DCI did not produce higher air intake temperatures at wide open throttle, did not heat soak more sitting at a standstill for 8 minutes, and all around felt faster. I should also add it's certainly possible modifying your OEM airbox with an extra filter might offer minimal gains over a dual cone intake assuming you don't mind up cutting up your factory airbox but don't expect much. We've tested this as well with no significant performance gain over a DCI in 40-120mph VBOX times. You have a lot of options for intakes but three+ years later the tried and true DCI is still the intake of choice for those of us who are serious about performance...

[Q4P]

Great info thanx

[///M3THOD]

Thank you for posting this... This is great information. I bet the results on a FBO car would far more exaggerated. I have known since I put a DCI on my vehicle that I was making more power, its nice to know that I there is really not much to the whole "hot air" nonsense.

[boom]

I remain unconvinced. When I tested the dci vs the stock box and stock filter the dci did worse. The mr. 5 intake is the only intake that I've seen an improvement from.

Dci vs stock:
http://www.e90post.com/forums/showthread.php?t=491005

Stock vs mr. 5:
http://www.e90post.com/forums/showthread.php?t=580412

[///M3THOD]

Originally Posted by boom

I remain unconvinced. When I tested the dci vs the stock box and stock filter the dci did worse. The mr. 5 intake is the only intake that I've seen an improvement from.

Dci vs stock:
http://www.e90post.com/forums/showthread.php?t=491005

Stock vs mr. 5:
http://www.e90post.com/forums/showthread.php?t=580412

I don't believe the intent of this post was to convince anyone.. just to share findings that seem to offer evidence contrary to the theory of what many people argue.

[dzenno]

Great data..I've decided to give mr.5's intake a shot on my car after running stock, UR CAI (similar to STETT) and a DCI...looking for a bit of a quiter operation and looks like, if you don't mind cutting up your stock airbox, that there's even possibly some tiny gains over DCI and stock box...as I said, I'm mostly doing it for the quietness factor

[Ilma]

I believe these results.

I have swapped between stock and DCI on several occasions and monitored intake temps.

During long idles, the stock box was of no advantage since the intercooler was heatsoaking due to lack of airflow - not air temperature. Cooler air is of no use unless it's flowing into the engine in significant volume to do something about the built up heat.

When your throttle is in a closed position there is just not enough airflow at any temperature that is going to put a dent in the heat buildup coming from the engine components.

I also found that at WOT the DCI's ran a few degrees hotter than the stock box, but aided upper rpm's considerably.

Of course, what none of these tests show is what happens during low rpm part throttle scenarios. I would bet that the stock box brings the intercooler temps down faster than DCI's do. So probably faster recovery from heatsoak temperatures......but at higher power levels I think the temps between the two are not that far off from each other.

[boom]

Originally Posted by ///M3THOD

I don't believe the intent of this post was to convince anyone.. just to share findings that seem to offer evidence contrary to the theory of what many people argue.

BMS does sell DCIs...

[tibra1]

Originally Posted by Ilma

Of course, what none of these tests show is what happens during low rpm part throttle scenarios. I would bet that the stock box brings the intercooler temps down faster than DCI's do. So probably faster recovery from heatsoak temperatures......but at higher power levels I think the temps between the two are not that far off from each other.

^This..if ur on a track or race setting DCI..but on the street w stop n go some form of a closed air intake is the better setup

[Jeff@TopGearSolutions]

Now we just need a CAI comparison

[Ilma]

Originally Posted by tibra1

^This..if ur on a track or race setting DCI..but on the street w stop n go some form of a closed air intake is the better setup

Wouldn't know.....I've never been to a racetrack.

All my results were drawn from stop and go city traffic.

Like I stated - sitting at idle in traffic, the stock box is no better at cooling your intercooler. You just don't have enough airflow going.

You will see much more of a temperature improvement by upgrading your stock intercooler than by using your stock airbox.

Airflow volume and intercooler heat transfer capacity seem to have a lot more influence on IAT's than anything else besides meth.

[cwn23]

Even though the logs show little difference, I am still an advocate of a true CAI period

[tibra1]

Originally Posted by cwn23

Even though the logs show little difference, I am still an advocate of a true CAI period

A CAI is outta of the question for those who live in high rain environments..buddy of mine hydrolocked his engine running a CAI..went thru some flooded roads..game over

[thebigragu99]

Told you Jeff the dci is better then the restrictive box

[Ilma]

Originally Posted by thebigragu99

Told you Jeff the dci is better then the restrictive box

Better at providing more unrestricted airflow at higher rpms - definitely.

But as many advocate, and I have to agree - the colder the incoming air the better.

It's just that at WOT and idle scenarios, there doesn't seem to be as much of a difference as you would think considering how hot the engine bay gets.

During normal cruise situations the DCI's ran 18-20F above ambient consistently.
The stock box ran 10-15F above ambient.

Those observations are pretty consistent with testing that Formerboosted did some time ago comparing a Stett CAI against DCI's. He found a delta of about 8-10 degrees between the two.

Part throttle could be a different story.

[Jeff@TopGearSolutions]

Originally Posted by thebigragu99

Told you Jeff the dci is better then the restrictive box

Not sure when I said a DCI wasnt better then stock? Please find that quote?

http://www.e90post.com/forums/showpo...postcount=2474

Originally Posted by Jeff@topgearsolutions

Wouldnt hurt to have an intake. The stock box is very restrictive at high boost which in turn causes elevated wastegate duty cycles. It would behoove anyone looking at stage 2 to have some intake, preferably one which breathes cooler air.

[themyst]

So much banter over 3 whp. The DCI has a benefit over stock, end of story. For a $100, it's one of the best mods you can do for the money.

[Joshboody]

restriction to stock intake is the opening at the front of the actual airbox. Someone modify the airbox itself and offer new wider tube with air ducts. you could have a core exchange and potentially charge $500 each. No issues with water or routing. Put me down for 1.

[Mike@N54Tuning.com]

Originally Posted by ///M3THOD

I don't believe the intent of this post was to convince anyone.. just to share findings that seem to offer evidence contrary to the theory of what many people argue.

+1 you can never have enough data!

For what its worth BMS was saying that their favorite intake aside from the DCI is the Dinan style (and Mr5) and that in their testing it performed the same or slightly better, but not well enough to justify the $500+ retail price tag vs their $95 DCI. They also said the AFE, Injen, etc, are all less efficient and more expensive versions of the DCI.

Mike

[vasillalov]

This is so funny! Of course the DCI will make more POWAH than stock airbox. It has crap filters which have bigger holes and allow more air than the OEM paper filter!

Noone is denying that OEM airbox does not suit FBO car IF you don't change out the stock paper filter. Tell you what: put a less restrictive filter in the stock airbox (K&N or similar), smooth out the airbox and do a Mr.5 mod on it. Then compare the results.

This is just junk...

[BMWsky]

Originally Posted by tibra1

A CAI is outta of the question for those who live in high rain environments..buddy of mine hydrolocked his engine running a CAI..went thru some flooded roads..game over

I've seen you make this statement a lot. I live in NY like you (upstate) where rainfall is no stranger, no issues with my CAI. Freak accidents can happen, and I won't make broad based, sweeping generalizations based on "a guy I know..."

Many of us run CAI's and choose not to drive through flooded roads. During the last flood (the one that was here 2 weeks ago), I was driving on the highway and came upon a section of road underwater. I had no idea how deep it was...I decided to take an alternate route. It's amazing what common sense can do for an opinion.

[tibra1]

Originally Posted by BMWsky

I've seen you make this statement a lot. I live in NY like you (upstate) where rainfall is no stranger, no issues with my CAI. Freak accidents can happen, and I won't make broad based, sweeping generalizations based on "a guy I know..."

Many of us run CAI's and choose not to drive through flooded roads. During the last flood (the one that was here 2 weeks ago), I was driving on the highway and came upon a section of road underwater. I had no idea how deep it was...I decided to take an alternate route. It's amazing what common sense can do for an opinion.

I dont think anyone "chooses" to drive thru flooded roads..if that was the case we would never see instances of ANY cars getting caught in flood water..yet it happens ALL the time..so this statement makes no sense.

I have personally had vendors who sell CAIs and when i was shoppingg for an intake, could have easily made a sale on me..instead they advised me of this same thing..guess there are still some with integrity out there..

Im not going to beat a dead horse here..its common sense..if you want to run a CAI in a climate that has seen 12 inches of rain the last 3 months..then have at it//