[Terry @ BMS]

Hey guys,

Did a little intake testing to disprove the "hot air intake" myth. I had been planning to use video, etc, but figured a basic OBDII scan would better prove the point. Plus it was a lot easier to setup.

Test vehicle: 2008 BMW 135, JB3 1.1v, Code3 Intercooler, Riss ******* downpipes, 91 octane

Test: For each intake cruise for 5-10 min to stabilize IAT, and then a 40-100mph acceleration run monitoring air intake temperature. Each log includes ambient temperature as well as stabilized air intake temperature (~64 degrees F and ~77 degrees F respectively).

Result: As expected

PS. If your single filter looks like this (this one has ~20k miles), time to clean it with a K&N cleaning kit from Pep Boys!

[mmmotornutz]

So ICs do work, well we all knew that lol.

[mistermojorizin]

Terry, thanks for finding the time to do this. Question: for stock intake, is graph #2 same as graph #4? I'd be curious to see the timing advance at the end of the stock intake run. Thanks.

[e90AW335I]

Glad you did the testing but I still think you need to do this on your 335i w/o the intercooler. Good testing still!

[BuLoOoSki]

thanks for doing this study terry. finally this topic is settled now

[E92White]

so let me see if I got this right..the temps actually run cooler with an open intake ?

[Terry @ BMS]

Originally Posted by BuLoOoSki

thanks for doing this study terry. finally this topic is settled now

Like all good urban legends there will always be believers... "But isn't it just sucking up all that hot air in the engine bay???"

[Terry @ BMS]

Originally Posted by e90AW335i

Glad you did the testing but I still think you need to do this on your 335i w/o the intercooler. Good testing still!

Tested many times, same results with stock intercooler. Maybe someone else with IAT logging can do a verification test.

[Terry @ BMS]

Originally Posted by E92White

so let me see if I got this right..the temps actually run cooler with an open intake ?

Cooler or the same. You pickup ~30 degrees at the filter, but drop ~30 degrees by reducing the amount of work the turbo has to do to suck the air in. So it basically washes out.

[Terry @ BMS]

Originally Posted by mistermojorizin

Terry, thanks for finding the time to do this. Question: for stock intake, is graph #2 same as graph #4? I'd be curious to see the timing advance at the end of the stock intake run. Thanks.

The timing values will not be accurate as the JB3 is dynamically altering it on the backend. But they are somewhat consistent.

[gophaster]

Very interesting results. This should have been done on "myth busters". Next time I pop my hood to show someone my intake and they ask the inevitable question about sucking in the hot air I will just point them to this thread.

[yahoo]

Would scoops help on an open intake by dissipating the hot air under the hood, therefore reducing intake temps?

[Terry @ BMS]

Originally Posted by yahoo

Would scoops help on an open intake by dissipating the hot air under the hood, therefore reducing intake temps?

I don't think it would matter much.

[dcafs]

These tests confirm the principles of thermodynamics associated with turbo's.

To quote BMW's own technical paper..."The charge air is greatly heated when compressed in the turbocharger, making it necessary for the air to be cooled again in an intercooler". The charge air heated in the turbocharger by its component temperature and by compression is cooled in the intercooler by up to 80 C".

That's 176 F! and that's with BMW's own stock cold air intake.

[mwahlert]

the jb3 does not alter the iat reported to the ecu?

[Driver72]

Originally Posted by Terry @ BMS

Cooler or the same. You pickup ~30 degrees at the filter, but drop ~30 degrees by reducing the amount of work the turbo has to do to suck the air in. So it basically washes out.

So if I am reading this correctly:
It does then suck in all the hot air from the engine. I think I was the first to say upon seeing one of the very first open air intakes on Walked U's car that it would suck in too much hot air.
I posted this long ago, some believed it, some dismissed it.
But having a 30 degree increase at the intake seems to support that.

It appears the best of both worlds would be an open intake that has a great heat shield and/or "ram air" intake tubing that directs more cool air into the filter but the heat shield protects the intake from sucking in all the hot air from the engine (similiar to what the stock airbox does).
This way you wouldn't get the +30 degree increase at the intake but still get the benefits of more air in and possibly getting BETTER than 30 degree decreases from the turbos doing less work.

Just imagine the decrease in temps at the turbos if the turbos not only didn't have to work as hard sucking the air in, but that air wasn't 30 degrees hotter like it is in open filter setups, but rather 30 or more degrees cooler from a heat shielded true CAI.

[Driver72]

Terry what do you suppose the temp increase would be at the intake on those open intakes when the engine is really hot.
You saw a 30 degree increase after doing a 40-100 mph run on an engine that was run for 5-10 minutes just cruising. So the engine was relatively "cool".

You should try it too after doing 2 consecutive 40-100 mph runs, then log on the 3rd run.
The temp increase at the intake would probably be +50 degrees or more on a hot engine.

[Terry @ BMS]

Originally Posted by mwahlert

the jb3 does not alter the iat reported to the ecu?

No, just taps it.

[Terry @ BMS]

Originally Posted by Driver72

So if I am reading this correctly:
It does then suck in all the hot air from the engine. I think I was the first to say upon seeing one of the very first open air intakes on Walked U's car that it would suck in too much hot air.
I posted this long ago, some believed it, some dismissed it.
But having a 30 degree increase at the intake seems to support that.

It appears the best of both worlds would be an open intake that has a great heat shield and/or "ram air" intake tubing that directs more cool air into the filter but the heat shield protects the intake from sucking in all the hot air from the engine (similiar to what the stock airbox does).
This way you wouldn't get the +30 degree increase at the intake but still get the benefits of more air in and possibly getting BETTER than 30 degree decreases from the turbos doing less work.

Just imagine the decrease in temps at the turbos if the turbos not only didn't have to work as hard sucking the air in, but that air wasn't 30 degrees hotter like it is in open filter setups, but rather 30 or more degrees cooler from a heat shielded true CAI.

I've done testing with heat shields and the IAT reduction was pretty minimal, and by ducting the air you start to bring back the restriction. The bottom line is at this point I think the normal dual cone (or BMS single) is the best intake for all around performance at higher boost levels. At stock boost levels, the factory intake is adequate. But open intake will not cost you power.

[Terry @ BMS]

Originally Posted by Driver72

Terry what do you suppose the temp increase would be at the intake on those open intakes when the engine is really hot.
You saw a 30 degree increase after doing a 40-100 mph run on an engine that was run for 5-10 minutes just cruising. So the engine was relatively "cool".

You should try it too after doing 2 consecutive 40-100 mph runs, then log on the 3rd run.
The temp increase at the intake would probably be +50 degrees or more on a hot engine.

The engine was up to temperature, I drove for around 20-30min before cruising off boost for 5-10 min to stabilize IAT. If it was not up to temperature IAT would be at ambient, rather than 10 degrees above.

[Driver72]

Originally Posted by Terry @ BMS

I've done testing with heat shields and the IAT reduction was pretty minimal, and by ducting the air you start to bring back the restriction. The bottom line is at this point I think the normal dual cone (or BMS single) is the best intake for all around performance at higher boost levels. At stock boost levels, the factory intake is adequate. But open intake will not cost you power.

Fair enough.

[mwahlert]

Originally Posted by Terry @ BMS

The timing values will not be accurate as the JB3 is dynamically altering it on the backend. But they are somewhat consistent.

it would be very neat if you could incorporate actual timing display in your upcoming boost/iat gauge!

[Terry @ BMS]

Just to revive an old thread from the dead. A few have emailed asking if we'll make a cold air box for the filters. The short answer is no. We tested many designs and found zero benefit as measured in 40-120 vbox runs. The better sealing boxes actually hurt performance compared to no box, and the top shields, etc, all resulted in the same performance run after run. So save your time and money.

[GENEaTALS]

Originally Posted by Terry @ BMS

Just to revive an old thread from the dead. A few have emailed asking if we'll make a cold air box for the filters. The short answer is no. We tested many designs and found zero benefit as measured in 40-120 vbox runs. The better sealing boxes actually hurt performance compared to no box, and the top shields, etc, all results in the same performance run after run. So save your time and money.

I was just looking at this thread last night as well...I think all the q's recently are due to shiv showing his closed box prototype....

[E92White]

LoL..I was about to shoot an email and ask the same thing..Shiv seems to think it benefit..