[jcarlucci1]

Originally Posted by sflgator

Secondly, although there was a 9 degree drop in AIT with the Stett CAI, I still wonder if this temp drop is enough to make a real difference in power. I understand that temps too hot will make a piggyback pull back a bit, but I thought this CAI was supposed to be pulling in more ambient air from the outside (especially while driving fast like on the hwy and/or at WOT). It just seems like we should have seen more like a 15+ degree drop in AIT, especially since the outside temps during your testing were relatively cool (in the upper 60's - low 70's F). What would happen if these tests were done in a more tropical climate where the weather is typically in the 80's with high humidity?

Lastly, we've got to wonder now how the oem stock intake (with or without air scoops) perform in regards to AIT in comparison to the BMS DCI and Stett CAI?

Maybe I'm just playing devil's advocate here, but I think these questions still remain unanswered. Hey, if this Stett CAI (and I assume others companies would follow with more true CAI's for the N54 engine) really does make a significant improvement to the N54 engine, then I would absolutely consider this CAI for my 2010 335i Coupe I have on "pre-order." . Thanks again for ALL your efforts and sharing all this info with us!!!

Dont forget that this was done with a very efficient IC. For many of us that are using only tune/intake with a stock IC, there may ending up being a 20-30 degree difference in IAT. Thats a big difference; and makes me think I made the right choice going back to the stock airbox from a DCI. Would LOVE to see the results of airbox vs. dci on a car with stock IC

[Former_Boosted_IS]

Originally Posted by Zeph

Nice job! I did notice though that your idling results you got mixed up. The graphs show the DCI to actually be slightly cooler but your typed results underneath show the STETT to be slightly cooler (so basically about even considering the air outside). You were right about the DCI going up "faster" in the 1st 5 minutes, although very slightly.

So basically the STETT CAI might be slightly better with back to back WOT's like a serious track event of non-stop drag racing. Not sure if you can actually make much out of an 8 degree difference when up in the 115 degree range for hp/tq but it is interesting somewhat to know.

I agree, point here is clear... stock FMIC has to go regardless of what you do with any other mods

I was a bit sleepy from working on this for 3 days straight. UGH. The only real point was the difference at after around 10 minutes was nearly negligable, but more noticeable within the first 5 minutes of idle.

[Former_Boosted_IS]

Originally Posted by sflgator

First, let me just say THANK YOU, Former_Boosted_IS for all the time you spent on this testing and all your efforts in getting this unbiased data to all of us!!!

Secondly, although there was a 9 degree drop in AIT with the Stett CAI, I still wonder if this temp drop is enough to make a real difference in power. I understand that temps too hot will make a piggyback pull back a bit, but I thought this CAI was supposed to be pulling in more ambient air from the outside (especially while driving fast like on the hwy and/or at WOT). It just seems like we should have seen more like a 15+ degree drop in AIT, especially since the outside temps during your testing were relatively cool (in the upper 60's - low 70's F). What would happen if these tests were done in a more tropical climate where the weather is typically in the 80's with high humidity?

Lastly, we've got to wonder now how the oem stock intake (with or without air scoops) perform in regards to AIT in comparison to the BMS DCI and Stett CAI?

Maybe I'm just playing devil's advocate here, but I think these questions still remain unanswered. Hey, if this Stett CAI (and I assume others companies would follow with more true CAI's for the N54 engine) really does make a significant improvement to the N54 engine, then I would absolutely consider this CAI for my 2010 335i Coupe I have on "pre-order." . Thanks again for ALL your efforts and sharing all this info with us!!!

sflgator, this question had to be answered at some point. I know you have been a member on the forum for a long time and I really to appreciate your excitement about the testing.

Remember, the delta between the DCI and STETT Performance CAI should be almost identical regardless of what ambient temperatures you are in. Colder will still be colder. Also this is not measuring the temperature of the air that enters the intake as it hits the turbos, this is measuring the air temperature after it gets heated up by the turbos, sent through and cooled by the intercooler, then measured as it passes into the intake manifold. So the initial difference pre-turbo has to be 20-30 degrees for the STETT Performance CAI. The question has always been does cooler in always equal cooler out on an intercooled car.

Next, at highway speeds without hard throttle the intake is not pulling much air, it should be expected that they would perform similarly. At WOT is when the CAI should theoretically make the difference and my testing showed this is exactly where it resulted in colder AITs.

I cannot speak to the stock unit other than speculating. Air flow will likely be the main issue there.

Finally, what is the effect real world? Terry believes that if the STETT Performance CAI flows air as well as the DCIs, then the 9 degree AIT difference would result in 0.2 - 0.3 second faster traps in the 1/4 mile. We do know that the JB3 will pull boost if the engine is not getting enough air at high RPMs, so I logged these as well and they were identical on the DCI and STETT Performance CAI.

[Former_Boosted_IS]

Originally Posted by Zeph

Any difference in dyno or 1/4 mile trap speed between these 2 intakes? I think you just saved me a few hundred dollars realizing I don't need to waste money on a CAI or Injen, etc... BMS @ $99 is winning IMO

No, I think you read it backward. The DCIs tested hotter on the AITs.

[Former_Boosted_IS]

Originally Posted by ThorsHammer

I think there are just too many variables to be honest.

It really comes down to how many molecules of oxygen are present with each combustion. We know from chemistry that the colder the air, the more densely populated the molecules are per relative volume.

So my point is, which provides more volume/quantity of O2 molecules? On one hand, the air is colder (CAI). On the other, there is more air present (DCI).

Maybe...just maybe...they balance each other and that's why it's so hard to prove/disprove that one is better than the other?

I think that is unfair to say that hte DCI will have more air present. In this testing, we know the AITs are colder even post intercooler with the STETT CAI. The STETT kit uses a very large filter and may very easily provide more than enough surface area for these turbos. We do know that the JB3 will pull boost if the air flow was not sufficient on the high rpms and the boost in this testing was identical for the testing on both intakes.

[Former_Boosted_IS]

Originally Posted by jcarlucci1

Dont forget that this was done with a very efficient IC. For many of us that are using only tune/intake with a stock IC, there may ending up being a 20-30 degree difference in IAT. Thats a big difference; and makes me think I made the right choice going back to the stock airbox from a DCI. Would LOVE to see the results of airbox vs. dci on a car with stock IC

jcarlucci, I think you are right in your AIT estimate on the stock IC.

Remember, even if the stock intake provides colder air then the DCI, the flow increase in the DCI should more than over come any AIT advantage the stock intake has.

[**335i**]

nice feedback

[Soni]

another nice review!!

[JoeyFiasco]

Nice work on the review

[marconi118]

There is still one big point open:

Is the DCI or the CAI more restrictive to air flow?

Cold air is better, but if the CAI is more restrictive the turbos will have to work harder to acheive the same boost level. If the filter is restrictive the inlet side of the turbos wil be under slight vacuum...

So the last test that you could do should be to mesure the depression (vacuum) in the pipe going from the filter to the turbo with a boost gaugue that has both positive and negative scala.
I know this requires an hardware modification because there isn't any pressure sensor in this pipe.
One solution if you have the RR catchcan could be to diconnect the pipe going to the CC coming from the rear inlet turbo pipe (not the one that is comming from the cam cover) and connect it to this boost gaugue.

If the wacuum is bigger with the CAI, then maybe DCI brings more air even if warmer...

I know this is a lot of work but shoulb be tested to give a final advice on DCI CAI and stock intake

[Former_Boosted_IS]

Originally Posted by marconi118

There is still one big point open:

Is the DCI or the CAI more restrictive to air flow?

Cold air is better, but if the CAI is more restrictive the turbos will have to work harder to acheive the same boost level. If the filter is restrictive the inlet side of the turbos wil be under slight vacuum...

So the last test that you could do should be to mesure the depression (vacuum) in the pipe going from the filter to the turbo with a boost gaugue that has both positive and negative scala.
I know this requires an hardware modification because there isn't any pressure sensor in this pipe.
One solution if you have the RR catchcan could be to diconnect the pipe going to the CC coming from the rear inlet turbo pipe (not the one that is comming from the cam cover) and connect it to this boost gaugue.

If the wacuum is bigger with the CAI, then maybe DCI brings more air even if warmer...

I know this is a lot of work but shoulb be tested to give a final advice on DCI CAI and stock intake

There is still info on this because the JB3 will decrease boost if it is lacking airflow in the high rpms. It didn't drop boost at all there.

Second, if these turbos were working harder in my opinion there would not be a 9 degree deviation with an intercooler that is 80%-90% efficient. That alone flattens out a lot of the difference, but it still showed up in the testing.

[pearlwhites]

Originally Posted by Former_Boosted_IS

sflgator, this question had to be answered at some point. I know you have been a member on the forum for a long time and I really to appreciate your excitement about the testing.

Remember, the delta between the DCI and STETT Performance CAI should be almost identical regardless of what ambient temperatures you are in. Colder will still be colder. Also this is not measuring the temperature of the air that enters the intake as it hits the turbos, this is measuring the air temperature after it gets heated up by the turbos, sent through and cooled by the intercooler, then measured as it passes into the intake manifold. So the initial difference pre-turbo has to be 20-30 degrees for the STETT Performance CAI. The question has always been does cooler in always equal cooler out on an intercooled car.

Next, at highway speeds without hard throttle the intake is not pulling much air, it should be expected that they would perform similarly. At WOT is when the CAI should theoretically make the difference and my testing showed this is exactly where it resulted in colder AITs.

I cannot speak to the stock unit other than speculating. Air flow will likely be the main issue there.

Finally, what is the effect real world? Terry believes that if the STETT Performance CAI flows air as well as the DCIs, then the 9 degree AIT difference would result in 0.2 - 0.3 second faster traps in the 1/4 mile. We do know that the JB3 will pull boost if the engine is not getting enough air at high RPMs, so I logged these as well and they were identical on the DCI and STETT Performance CAI.

Thanks for the writeup! This is the type of thread I'd like to read daily on the 335 portion of the forum. Is there any chance you could be pursuaded to run the same test with the stock airbox? You should be able to tell if the JB3 is pulling boost due to lack of air flow and we would have one more measurement to help us make informed decisions.

[Former_Boosted_IS]

Originally Posted by pearlwhites

Thanks for the writeup! This is the type of thread I'd like to read daily on the 335 portion of the forum. Is there any chance you could be pursuaded to run the same test with the stock airbox? You should be able to tell if the JB3 is pulling boost due to lack of air flow and we would have one more measurement to help us make informed decisions.

Let me think about it. I am always trying to move forward with my car and in my opinion the stock box is so restrictive that it is not an option. I said I wouldn't do this for a CAI too though. LOL

[SennaZ]

Very nice study/review - thanks for the great info!

Just to echo everyone else, it would be important to test the stock system to really see if these CAI's are really worth the money. If we look at what BMW has done with the M-series, the new Dinan CAI will probably produce the best of all worlds, but unfortunately at a high $-to-performance gain.

If you do test out the stock system, just for laughs try it with the lid off.

[Riss Racing]

Great review! The dual cone system did well on Nicks dyno.

[Klepper1]

Originally Posted by Former_Boosted_IS

There is still info on this because the JB3 will decrease boost if it is lacking airflow in the high rpms. It didn't drop boost at all there.

Second, if these turbos were working harder in my opinion there would not be a 9 degree deviation with an intercooler that is 80%-90% efficient. That alone flattens out a lot of the difference, but it still showed up in the testing.

Former_Boosted_IS is 100% correct here in my opinion. The JB3 is hitting boost targets, which means it is getting all the air it needs. Now, it may have to work hard to get that air in due to restrictions, but that will all show up in the AIT (the extra 'work' the turbos did will have heated up the air). The amount of oxygen in the air is also shown with this. The volume of oxygen is dependant on the volume of air (fixed because JB3 is hitting the boost target), and temperature - colder temp means more oxygen.

Monitoring AIT is the best way to take that all into consideration.

Great job Former_Boosted_IS!!

The last piece of the puzzle would be to test the stock box. If the JB3 hits it's boost targets with the stock box, and AIT's are cooler than DCI, then that answers the last question!

[Former_Boosted_IS]

Ok, I have done FATs style testing on the 2nd run in the data log (first on the charts). This is for 2nd through 3rd gear because I could verify 100% throttle on both runs in this section.

DCI FATs style time = 7.69 seconds
STETT CAI FATs style time = 7.47 seconds

That makes the STETT CAI 0.22 seconds faster through the 2nd to 3rd gear pull.

This then means the STETT CAI produced 8 degrees colder AITs in that run and the car was 0.22 seconds faster from 2nd through 3rd gear.

[jpsimon]

Did you do the pulls on the same exact piece of road? .22 seconds is pretty big

[Former_Boosted_IS]

Originally Posted by jpsimon

Did you do the pulls on the same exact piece of road? .22 seconds is pretty big

Identical. If you look at the AIT graphs, you can see where I stop the car to turn around so I can go over the exact same run again.

I am just offering the data jpsimon that some requested.

[jpsimon]

I know, and i appreciate it. I was just curious because .22 is a pretty big margin, i wasn't expecting that

[Zeph]

Originally Posted by jpsimon

I know, and i appreciate it. I was just curious because .22 is a pretty big margin, i wasn't expecting that

It "could" be a little extra torque and mid-range like people have seen with other intakes (such as Injen) but as far as peak who knows. As long as we are shifting at 6k rpm's I don't know if peak is gonna matter anyway. That is why I hope a GT35R will raise HP all the way past 6700 RPM's

[sflgator]

Originally Posted by Former_Boosted_IS

sflgator, this question had to be answered at some point. I know you have been a member on the forum for a long time and I really to appreciate your excitement about the testing.

Remember, the delta between the DCI and STETT Performance CAI should be almost identical regardless of what ambient temperatures you are in. Colder will still be colder. Also this is not measuring the temperature of the air that enters the intake as it hits the turbos, this is measuring the air temperature after it gets heated up by the turbos, sent through and cooled by the intercooler, then measured as it passes into the intake manifold. So the initial difference pre-turbo has to be 20-30 degrees for the STETT Performance CAI. The question has always been does cooler in always equal cooler out on an intercooled car.

Next, at highway speeds without hard throttle the intake is not pulling much air, it should be expected that they would perform similarly. At WOT is when the CAI should theoretically make the difference and my testing showed this is exactly where it resulted in colder AITs.

I cannot speak to the stock unit other than speculating. Air flow will likely be the main issue there.

Finally, what is the effect real world? Terry believes that if the STETT Performance CAI flows air as well as the DCIs, then the 9 degree AIT difference would result in 0.2 - 0.3 second faster traps in the 1/4 mile. We do know that the JB3 will pull boost if the engine is not getting enough air at high RPMs, so I logged these as well and they were identical on the DCI and STETT Performance CAI.

Oh, ok. Sounds great! The Stett CAI may just be on the agenda for my 2010 335i then. How is the install? It seems a bit more complicated and time consuming than a DCI...is that the case?