[Terry @ BMS]

Hey guys,

It's been around three years (!) since we did our first intake air temperature testing which showed open element intakes do not result in higher air intake temperatures or "heat soak" as many assumed they would. But back then when we did the original testing the car had a larger intercooler which many felt skewed the results and the testing was done with an OBDII tool which was a little difficult to read. We also omitted the critical "stuck in traffic" test.

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.

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...

[evilstib]

Great thread. I have a BMS DCI and I'm glad I bought it!

[Bash]

Just curious what the ambient temps were..

[335iMspizzle]

Originally Posted by dzenno

Would've been nice to see mr.5 intake results in there as well but good data in any case, thanks

He's saying there isn't significant gain over DCI, but I guess there is some, just for some it's not worth it to cut the stock box for.

[bmwfan19]

thanks Terry for sharing this

[Ocean]

How much power do the DCI add over stock airbox? I saw some graphs on that once but can't remember where.

[enrita]

great test. what was the outside temp?

[cstavaru]

So a vendor does a test showing that it's own product does not suck.

I felt the difference on my own, no need for vendor's own tests to make me believe. I bought an Injen intake to replace my stock airbox and after 3 days I was looking for ways to do the Mr.5 modification.

[infinity]

Thank you for sharing this experience

[drfrink24]

Looks like ignition advance recovered to a higher amount post shift with the DCI as well.. is this consistent, or just a fluke captured in the logs?

[Terry @ BMS]

Originally Posted by enrita

great test. what was the outside temp?

70-72 degrees.

[Terry @ BMS]

Originally Posted by drfrink24

Looks like ignition advance recovered to a higher amount post shift with the DCI as well.. is this consistent, or just a fluke captured in the logs?

I'm testing some "too hot for my mods" settings and cylinder1 advance has not been overly consistent from run to run. There should be some reduction in advance due to the increased intake flow there but nothing significant.

[Terry @ BMS]

Originally Posted by 335iMspizzle

He's saying there isn't significant gain over DCI, but I guess there is some, just for some it's not worth it to cut the stock box for.

I don't have the exact data handy but we did a series of 40-120mph runs and one or two of the runs gave identical times to the DCI and one or two were a tenth of a second quicker. Overall we decided the gains were not significant and consistent enough over the $95 DCI to justify offering a $500+ Dinan style intake (which was what we were evaluating at the time). Mr5 is just a home made version of the Dinan. I like the concept of it and would encourage anyone who doesn't want a DCI to go that route. It's much better than wasting your money on an AFE, Injen, etc, which are essentially less efficient versions of the $95 DCI, as so many do.

[Terry @ BMS]

Originally Posted by Ocean

How much power do the DCI add over stock airbox? I saw some graphs on that once but can't remember where.

It all depends on the boost levels and engine RPM. I've posted charts before showing 25whp gains at high RPM at 17-18psi boost levels. But for the typically map 1 or map 2 driver the gains are around 5-10whp from 5500rpm to redline. We have a few dyno charts at lower boost levels but most of those are from before the JB4. So I hope to hit up the dyno this week or next to do some more stock vs. DCI comparison testing on a 100% stock car for the website.

[infinity]

will be interesting to see how go it with the JB4, though I doubt that the records vary.

[335iMspizzle]

Originally Posted by Terry @ BMS

I don't have the exact data handy but we did a series of 40-120mph runs and one or two of the runs gave identical times to the DCI and one or two were a tenth of a second quicker. Overall we decided the gains were not significant and consistent enough over the $95 DCI to justify offering a $500+ Dinan style intake (which was what we were evaluating at the time). Mr5 is just a home made version of the Dinan. I like the concept of it and would encourage anyone who doesn't want a DCI to go that route. It's much better than wasting your money on an AFE, Injen, etc, which are essentially less efficient versions of the $95 DCI, as so many do.

Yeah fukk that I already sold mine and made profit, it just didn't feel right having a $650 intake. I want to make the Mr.5 one

[chi335xi]

Love the dirty DCIs! That alone should put the conspiracies to rest.

[5soko]

Nice info Terry!! love these tests.

[Irishace]

Thanks for the test, I look forward to seeing this on myth busters

[dfjaws]

I love my DCI. I love the sound. I love how simple it is. I love the price compared to other stuff out there.

I'm not cutting up my intake. I'd like to keep the option to go back to completely stock at any time.

Maybe I could make 2 more hp with a Mr. 5. Maybe I could go 60-130 .2 seconds quicker. In my opinion though, it's not worth cutting up my stock air box.

(Not to take away from Mr. 5. I have a lot of respect for people who take initiative to do their own thing and succeed.)

[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

[Terry @ BMS]

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

There is always room for dissenting opinions.

Just keep in mind there are a lot of variables at play. Just doing a cursory look at your first post there it appears there is a good deal of run to run variance, and that the DCI and stock airbox eventually trapped within 1/2mph of each other in the end. IAT deltas look similar and you are using a load based tune.

Using a load based tune the DME will simply raise boost to compensate for increased compressor outlet temperatures and reduce it to compensate for reduced outlet temperatures, so unless you are operating at the edge of efficiency it's harder to spot a net performance gain.

Like I said I like the Dinan/Mr5 concept and if someone wants to go that route I have nothing negative to say about it. But for maximum performance we've found the DCI to operate at the same level for a lot less effort and cost.

[SportyGuy28]

Nice post I've been wanting to get the DCI but is it worth it being stock? What kind of gains should be expected? Also, some people say engine responsiveness improves a bit and others say the opposite... any input on this? Sorry for the noob questions. I just might order DCI this weekend, for 95$ seems like a pretty good deal.

[Terry @ BMS]

Originally Posted by SportyGuy28

Nice post I've been wanting to get the DCI but is it worth it being stock? What kind of gains should be expected? Also, some people say engine responsiveness improves a bit and others say the opposite... any input on this? Sorry for the noob questions. I just might order DCI this weekend, for 95$ seems like a pretty good deal.

Power gains are minimal stock but it sounds and looks good. There is no significant change to response either way at lower boost levels. I personally think people get caught up with the sounds, their opinion on hot air, and "feel" response is improved or degraded depending on their particular viewpoints. The flow differences do not become significant enough to "feel" until higher RPM and higher boost levels.

[bmwfan19]

Originally Posted by chi335xi

Love the dirty DCIs! That alone should put the conspiracies to rest.

can be cleaned with KN kit