Terry Burger did some good testing of intake temps on a turbo BMW. Very interesting stuff.

http://www.n54tech.com/forums/showthread.php?t=2014

 

If I read this correctly - the heated air does not matter because of the intercooler - so it is better to have a CAI and a cone filter?

 

This is common sense... the second the air goes past the compressor it is going to heat up regardless.

 

^^ he's right....then from that point on it's all up to the efficiency of the intercooler to get those air temps down.

 

After coming back to this forum after a little bit of time... i can see the same things are still getting beaten to death lol. On top of that once you are moving air/vacuum being moved through the bay will drop temps significantly. By laser temp readout, my engine bay was reduced by almost 30degs after in motion by removing the scoop grill cover to make it straight through style.

 

So basically adding boost tubes, an intercooler, an intake, a downpipe, and a better exhaust help with temps or am I misreading this. If so, then my mods were worth it.

 

its the cai vs "hot air intake" on turbo cars dispute. Been going on for a long time now, some people choose to think 15degrees will make a difference going though a hot compressor... noooooooooooot

 

Here's the thing, though: After a hard drive, that engine bay is a helluva lot hotter than 15 degrees above ambient. You telling me that after an hour's drive on a 70 degree day, the air inside the engine bay is only 85 degrees? You're nuts if you think that.

I doubt that a true "CAI" can produce much more power than a hot-air intake, but let's be honest about what is actually going on.

 

Monitor you iat's, The whole point is that people are battling about how cai's on turbo cars make a difference... they dont. "15 degrees"
was internet sarcasm.

 

Magazine/advertisement suckers will believe anything. Im sure every one has read "Well i have exhaust so +15 and intake +12...." blah blah blah it is all gibberish. First if you actually learn what the components of the powertrain are, how they work then you will easily by using common sense be able to point out frauds. I bought an NM "CAI" because it gives me power? No, because it sounds damn cool! On a turbocharged vehicle the air is going to get as hot as the heat being transferred by the comp housing, period. That charge will then be cooled by the transfer of heat via intercooler. Charge temp reduction will vary by ambient temp, airflow(speed/wind) and charge velocity. The days of the tuners is over... obviously now any joker can $buy$ a vehicle and their will be companies with cai's/exhaust making claims of immense gain blah blah blah.

The game isnt the same anymore.

 

I mostly agree. Like I said, I doubt much gain is to be had with a true CAI versus an open filter in the engine bay.

Still, you gotta wonder why BMW engineers went through so much trouble to put a snorkel at the grill and a sealed airbox if it serves no purpose whatsoever.

 

Sound, also an airbox will keep the iat consistant vs. open filter which will vary iat depending on quite a few variables.

 

I believe the rule of thumb is 19 degrees delta F ~ 1 psi boost

for non-competitive uses I doubt anyone notices
not necessarily the case in competitive venues

 

this thread has been posted many times before. there is a great video of mighty car mods testing every kind of set up on a dyno and making no more power than stock.
suckers who wasted $200+ for more power are always gonna claim they made more on the butt dyno to justify it. intake is for sound only on these cars.

 

Just a couple of points.

1.) while some heat will be transferred to the intake air by the actual compressor housing metal, most of the intake air temp gain is due to the act of compressing the air.

If the act of compressing the air to 18 psi results in a 100f gain, the cooler air you start with, the lower maximum temp you will see, the lower the temp of the air that goes into the engine after it passes through the inter cooler.

2.) I've watched the video and their testing methodology leaves a bit to be desired. A fan is not a suitable replacement for actual moving vehicle airflow.

Just saying

 

if you watched the video you would see that they put the pud against the fan which would be better than real world driving. also the only set ups for the mini all invole the pod inside the engine bay, which made no gains. and again it was on a 10 year old skyline so the mini stock system would be much better than the skylines to start with.

 

I just save hundreds of dollars by reading this thread.

After some research on trying to figure out which power mods I wanted that will net the best gains for a turbo S, its like in the Musclecar world unless its ported heads, headers or any other true mechanical advantage it appears most of it is still snake oil!

 

I suppose I can accept the idea that the temperature difference is minimal, such that it has a negligible difference on performance.

The other factor besides the temperature of the air is the amount of air. It's certainly NM's contention that the open filter provides additional air flow relative to the OEM snorkel/airbox combo, though one wonders how much of that is a consequence of the cylindrical filter (vs. the panel filter in the OEM airbox) as opposed to the lack of an airbox.

 

So I am a sucker because I bought an intake an several other supporting mods and I am now make 37mpg consistently and am running a more powerful car than stock and yes I have the dyno to prove it. Got to pay to play.

 

Wouldn't a tune help with a bigger inter cooler and intake? Vs just bolting on. I'm pretty sure you'll find gains and depending on what dyno you use and how hot the day is

 

Which intake did you get? A slight bump in mileage is one reason I'm looking into an intake.

What other mods you got, Porthos?

 

I have a DOS coming in the mail. When it gets here I will take Data logs with my current Alta intake with AEM dryflow and the DOS.

 

I got an NM intake(becuase it is CARB), NM boost tubes, helix intercooler, riss racing catless downpipe, invidia q300 exhaust, Accessport with a custom OXSpeed tune, Alta SSk, twm weighted shift ****, I had a Os Giken clutch(long story about why I don't have it anymore), nm springs, koni yellow, hsport rear control arms, hsport rear swaybar, I am on stock crownspokes again but, I have a set of OZ alleggritas that I am getting rid of, a gtspec stb, bsh occ, pass side pcv block, jcw steering wheel, powerslot rotors, and ebc redstuff pads.

 

Wow, thanks for sharing. Some good stuff there. Interesting that you went for the NM for the CARB certification but have a catless DP. I like your style.

 

my car is similar to yours so i know what did and didn't work. i was talking about intakes not mods in general.