stock air box over dual cone - high heat

[Ilma]

Originally Posted by PKumarM3

i ran a DIY dual cone intake on my 335i and also noticed the car would be a monster during the winter time, but a joke in the hot pollution car exhaust heat soaked summers of NJ.

I put the stock airbox on and the car pulls like a rocket 365 days of the year.

i bet a stock airbox and an aftermarket fmic would make for a fantastic combination.

So out of curiousity I put my stock air box back on today and replaced the DCI's.

So now I am basically running a low boost tune at 12 psi, stock air box, and an aftermarket intercooler.

Ambient temps were 79F.

Based on past datalogs of the DCI's, my observed intake temperature is usually about 25-30F higher than ambient.

With the stock box, it was 19F higher than ambient.

So looks like the cooler air dropped my intake temps almost 10 degrees.

This is completely consistent with the testing Former_Boosted did with a Stett CAI. He found his intake temps dropped around 9F over the DCI's.

Now a higher boost pressure level may result in a different outcome, but even with my high power map I only run 13.5 psi of boost.

So I am keeping the stock airbox on.

Seems the combination of cooler air via the stock box and the greater cooling capacity of an aftermarket intercooler works quite well together.

The engine is a little quieter with out all that intake noise, and feels a bit smoother too.

[Ilma]

Originally Posted by BahamaBart

Living in Florida I would lean more towards thermal efficiency than pressure drop. As you point out colder air = denser air = more power. There is also a greater daily driver advantage when it comes to dumping heat soak.

How muck bigger is the VK core over stock? The VK might be the right size for the boost I am running and I don't plan on swapping turbos. Like you the VK is appealing from an install perspective as well. Even though I have been known to do crazy as cutting in the past.

Here you go......... Guess which one is stock

[Ilma]

Originally Posted by Ilma

So out of curiousity I put my stock air box back on today and replaced the DCI's.

So now I am basically running a low boost tune at 12 psi, stock air box, and an aftermarket intercooler.

Ambient temps were 79F.

Based on past datalogs of the DCI's, my observed intake temperature is usually about 25-30F higher than ambient.

With the stock box, it was 19F higher than ambient.

So looks like the cooler air dropped my intake temps almost 10 degrees.

Just a follow up on this testing for those interested....

I found one of my datalogs with the DCI's on.

Weather Conditions were pretty close with ambients at 73F for the DCI's versus 79F with the stock box.

With DCI's the intake temperature measured at 96.6F showing a rise of 23F.

The stock box showed a better rise of 19F (even at a slightly higher ambient temperature).

But I was running 14 psi of boost with the DCI's versus 12psi with the stock box......so I would expect intake temps for the DCI test to be a little hotter due to the additional boost.

In any case, sorry I couldn't replicate the conditions exactly, but it seems that there is only about a 5F difference in intake temps between the stock box and the DCI's (23F rise vs 19F).

The DCI's do run a bit hotter, but the duty cycles on them are lower, so the turbos spin a bit easier.

Seat of the pants tells me that the stock airbox does feel subjectively torquier (not much though), but the DCI's give better throttle response and the turbos seem to ramp up faster with them. So to me the car feels more responsive with the DCI's. With the stock airbox, the pull is there, but it feels a little duller throughout.

Overall, I don't think a difference of 5F is going to have much impact on engine performance, but I do think it's better for the turbos not to have to compensate for the intake restriction that comes into play as you increase boost.

[BMW-driver]

Hi all,

i drive the stock airbox, the vk ic and the acschnitzer tune (385bhp/565nm, all at the crank, same as your Dinan stage ii i guess). When placed the vk ic, i did not feel any powergain. But, the big benefit with the vk is, that the car feels better above 6000 rpm and on the track, the car keeps the power. With the stock ic, there defenitly a loss of power after a few hard pulls, with the vk ic that problem was gone

[bryans2k]

There was already a recent post on e90post that vishnu posted showing how just a few degrees hotter had a major affect on timing.

So to say it has no negative affects is just silly.

[Ilma]

Originally Posted by bryans2k

There was already a recent post on e90post that vishnu posted showing how just a few degrees hotter had a major affect on timing.

So to say it has no negative affects is just silly.

What is even sillier is you thinking you are quoting factual information.

Shiv's conclusion was the EXACT OPPOSITE of what you are claiming. The effects on timing are not from high temps, but from engine knock.

His timing curves were almost identical at 90F as they were at 160F.

And this testing also happened at an Intake temperature of 160F......which is some 70F higher than what I was testing at.

Here is that link and the conclusion from it:

http://www.e90post.com/forums/showthread.php?t=408699

"So assuming that you are holding other variables reasonable constant (oil temp, coolant temp, etc,.) any additional amount of ignition retard is coming courtesy of the knock/knock sensor activity."

"Holding all other things equal, the effects of IAT increases are huge. But not on ignition timing. But on Boost target. And not in the direction that you would want (in a tuned car). In fact, peak boost target INCREASES from only 7psi to 9.5psi. Which is why that tunes that don't offer isolated boost control see so much boost target fluctuation depending on IAT.

So let me make this easy for you.......

What he said was, As intake temps went higher - so did boost. And Ignition timing changes are due to knock activity and that the DME did not have an automatic amount of retard built in as intake temps rise.

Now you can argue that at an intake temp of 160F you are going to get more knock...and I would agree, but Shiv superimposed the timing curves and there was hardly any difference between. Maybe 1.5 degrees at most

Now realize that my testing showed a 5F difference between the stock CAI system and the DCI's at intake temps of less than 100F.

Sorry....just don't see your point being valid here. No huge difference in heat impact.

But you really should retract your statement as that is not what Shiv said.

[jeremyc74]

Originally Posted by Ilma

What he said was, As intake temps went higher - so did boost. And Ignition timing changes are due to knock activity and that the DME did not have an automatic amount of retard built in as intake temps rise.
.

If you really think this car doesn't retard intake timing based on IAT, you're completely stupid. Seriously. IT HAS TO.

[Dmacc]

Stock Airbox w/ dropin filter FTW

[Ilma]

Originally Posted by jeremyc74

If you really think this car doesn't retard intake timing based on IAT, you're completely stupid. Seriously. IT HAS TO.

Why....because you think it's common sense and by calling me stupid it makes you right? Common sense thinking used to view the world as flat.

Did you stop to consider that combustion chamber temperatures are what makes the engine knock? And they are upwards over 1,000 degrees.

Sure hotter intake air contributes but it's a matter of relativity. Do you seriously think that five degrees difference on intake temp is going to make any kind of a significant dent in the temperature of a combustion chamber explosion?

Man you are so grumpy and angry

[jeremyc74]

Originally Posted by Ilma

Do you seriously think that five degrees difference on intake temp is going to make any kind of a significant dent in the temperature of a combustion chamber explosion?

Man you are so grumpy and angry

Hell yes I do, and so does anyone else who's ever tuned an ECU.

Have you ever even looked at an timing map? There are three factors. Throttle, RPM, and IAT.

[Ilma]

Originally Posted by jeremyc74

Hell yes I do, and so does anyone else who's ever tuned an ECU.

Have you ever even looked at an timing map? There are three factors. Throttle, RPM, and IAT.

Guess shiv has never tuned an ecu then.

[bryans2k]

My statement still holds true regardless of how you get to the conclusion. You increase IAT and timing will be affected. It doesn't matter if it's a compound problem.

Like stated above in every ecu tune I've seen there is always a timing adjustment table/map for IAT, coolant temp and knock, etc.

The plain and simple fact is if IAT increases there are negative side affects on how your car runs PERIOD. The details of how it gets there matters NOT unless you plan on re-programming the ecu to work differently and even then performance will always prefer colder IAT's versus hotter IAT's.

So you are increasing air flow and decreasing stress on the turbo BUT at what cost? If you want to IMPROVE your air intake system than do it with consideration of IAT.

Bryan

[Ilma]

Originally Posted by bryans2k

My statement still holds true regardless of how you get to the conclusion. You increase IAT and timing will be affected. It doesn't matter if it's a compound problem.

Like stated above in every ecu tune I've seen there is always a timing adjustment table/map for IAT, coolant temp and knock, etc.

The plain and simple fact is if IAT increases there are negative side affects on how your car runs PERIOD. The details of how it gets there matters NOT unless you plan on re-programming the ecu to work differently and even then performance will always prefer colder IAT's versus hotter IAT's.

So you are increasing air flow and decreasing stress on the turbo BUT at what cost? If you want to IMPROVE your air intake system than do it with consideration of IAT.

Bryan

Listen.....I am not disagreeing with your statement in theory.

But I think it is a matter of what degree of temp change before timing gets pulled.

Honestly, I don't know.

But I checked a couple of my datalogs and I almost always get about 10 degrees of advance by 6000 rpm no matter whether it's winter or summer.

Specifically at an intake temp of 84F I saw 9.8 actual degrees of advance and on another log taken during colder weather, the intake temp hit 68F at the same rpm and guess what the timing advance was?

9.8 degrees BTDC.

So on my engine, I can see a 16F change in intake temps and no change in timing.

Then there is Shiv's post where he electronically fooled the DME to think intake temps were 160F and he concluded that timing was virtually identical as when intake temps were 70-90F.

I'm not saying timing tables don't consider intake temps as I am no expert here.

But based on what I am seeing on my own datalogs, I kinda agree with Shiv's conclusions.

I think combustion chamber temperatures which induce engine knock have more of an influence on timing values within a given timing map.

But I could be wrong.

So why don't some of you guys start posting some measurements and links to backup your comments instead of me doing all the work.

[bryans2k]

Usually it's extremes where you see those kind of temps like Berk tracking the car but in hot weather im sure it's more common. I need to do some logging.

[Ilma]

Originally Posted by bryans2k

Usually it's extremes where you see those kind of temps like Berk tracking the car but in hot weather im sure it's more common. I need to do some logging.

If I recall that thread correctly, wasn't he talking about coolant temps?

I don't think he had any logs of timing.....just intake and coolant.

[bryans2k]

nah, he had IAT too. I thought I posted it earlier in the thread?

They peaked at 183F. Much higher than Vishnu's simulation.

So with everything stated up to this point they would be in that red zone at that point.

[Ilma]

Originally Posted by bryans2k

nah, he had IAT too. I thought I posted it earlier in the thread?

They peaked at 183F. Much higher than Vishnu's simulation.

So with everything stated up to this point they would be in that red zone at that point.

That's what I said.....they measured intake temp and coolant temp.

They Didn't have any timing measurements so you can't see what's happening with timing.

But I would bet that his combustion chamber temps would have been hot enough to induce some timing retard, given how heatsoaked the rest of the engine was.

183F for IAT is very high but not unexpected for someone running a race course with surface temps approaching 120-130F ambients.

Even on a stock car, you can hit 150F on IAT during a sustained multiple gear run. But that's just a short run that wouldn't heatsoak the oil and coolant temps like Berk's car was doing.

He would have limped because of overheating due to excessive coolant temps. His coolant hit a peak of 242F and he would be seeing a yellow warning indicator on the dash when coolant temps hit 248F and the engine shuts itself down at 264F.


htthttp://www.e90post.com/forums/sho...p?t=406402p://

[esscolab]

Just wondered if anyone has ever rigged their aircon to the air intake? Sure I will get blasted for this...

[Ilma]

Originally Posted by esscolab

Just wondered if anyone has ever rigged their aircon to the air intake? Sure I will get blasted for this...

Lol....you are not the first one to mention this.

But I think it was suggested running your heater is a good way to help remove some heat from the cooling system.

Might be a tad bit toasty in 90 degree weather though!

[JHOOPS2]

Originally Posted by maxnix

Ford has a patent where they use the AC to cool a liquid that has an IC in it. Good for maybe one 1/4 mile pass before it goes over ambient.

Yep. And it works fantastically! Most see an average of about a 40F drop in IAT temps down stream of their blower or turbo. Which is some cases actually drops the temps 10-20F degrees below ambient. It just needs to be routed into your AC system. The gains over the cost of running your AC all of the time more than make up any drag caused by the AC system.

http://www.killerchiller.com/

-Jeff