FREE Air-Intake Mod: Full Details on Page 6 of this thread
- Thread starter exdos
- Start date
I appreciate the thoughts from all those who've tried this mod even if you think the mod does absolutely nothing.. 
Here's a datalog history of the air-intake and exhaust modding on my Z4MC. All the information is obtained directly from the car's ECU via the OBDII socket. The Airflow through the MAF (in Lbs/min) is a very useful way of assessing any improvements because an increase in airflow at any given RPM shows an increase in Volumetric Efficiency (and torque output).
When the car was completely OEM, the highest Airflow through the MAF I saw was around 31lbs/min but from a series of air-intake and exhaust mods, I've progressively seen an increase. Recently, after doing Pilchardthecat's Honeycomb MAF Screen mod with all my other mods, I've recorded as high as 36.22lbs/min.
Below are some sample datalogs at different stages. I've highlighted in red the highest Airflow through the MAF in each of the logs. In the case of the second graph, with gutted silencers and my own air-scoop, this showed no gains until I did the Eureka mod, thereafter it showed an increase in airflow through the MAF relative to OEM. The Eureka mod has remained in place on my intake ever since.
For those who think that improving performance by modifying the air-intake alone, without other engine mods is fantasy (and I know there are plenty that do :wink: ) I suggest that they should read the paper by L.J. Hamilton and J.E Lee of the US Naval Academy, Paper Number: 2008-01-3007 published by the Society of Automotive Engineers.
Here's a datalog history of the air-intake and exhaust modding on my Z4MC. All the information is obtained directly from the car's ECU via the OBDII socket. The Airflow through the MAF (in Lbs/min) is a very useful way of assessing any improvements because an increase in airflow at any given RPM shows an increase in Volumetric Efficiency (and torque output).
When the car was completely OEM, the highest Airflow through the MAF I saw was around 31lbs/min but from a series of air-intake and exhaust mods, I've progressively seen an increase. Recently, after doing Pilchardthecat's Honeycomb MAF Screen mod with all my other mods, I've recorded as high as 36.22lbs/min.
Below are some sample datalogs at different stages. I've highlighted in red the highest Airflow through the MAF in each of the logs. In the case of the second graph, with gutted silencers and my own air-scoop, this showed no gains until I did the Eureka mod, thereafter it showed an increase in airflow through the MAF relative to OEM. The Eureka mod has remained in place on my intake ever since.
For those who think that improving performance by modifying the air-intake alone, without other engine mods is fantasy (and I know there are plenty that do :wink: ) I suggest that they should read the paper by L.J. Hamilton and J.E Lee of the US Naval Academy, Paper Number: 2008-01-3007 published by the Society of Automotive Engineers.
One of many question is: does the eureka mod can produce some gain by itself on a oem car? From what i have measured so far with the same datalogger exdos uses, it appears not. But I have the US spec headers which are known to be more restrictive. I have also tried a k&n filter with no gain either. I have no doubt about exdos numbers above but still not sure if gains can be acheived on the intake side alone with the US spec setup. I will try and measure Pilchardthecat's mod soon and report for all north american fellows.
If you do a search for autospeed then go to the archive section you can find lots of information on modifying intakes and how to measure the results
I get this emailed to me every month, sometimes it's of no interest other times there are good articles, if your interested in automotive engineering and getting free or cheap upgrades its worth checking out
I get this emailed to me every month, sometimes it's of no interest other times there are good articles, if your interested in automotive engineering and getting free or cheap upgrades its worth checking out
Alex,
I've merged the data that you've sent me with my own data from when my Z4MC was OEM as shown in the graph below.
I've had to use the timeline of your data for both sets of data because I don't know how to merge 2 different sets of data in Excel using slightly different sampling rates on to the same timeline. My own sampling rate was marginally faster than yours. However, as the graph shows, the Intake Air temperature (IAT) at WOT for my run was 16 degsF lower than yours, so for the purposes of comparison, I think my using your timeline cancels out any differences for denser air that I was getting. I've highlighted the direct comparison of my run in 3rd gear with your run in 3rd gear in white, between 45-50secs. It would appear that my car in OEM state is a tad quicker (both in vehicle speed and time to increase Engine RPMs, as I'm sure we both expect from a Eurospec car, and the Airflow through the MAF is greater for my car too, presumably from the less restrictive Eurospec exhaust headers.
I think that our independent use of the DashDyno on two different cars of almost identical configuration confirm the accuracy of the method of OBDII data-logging and establish the OEM baseline of the data against which any improvement in performance can be assessed.
I've merged the data that you've sent me with my own data from when my Z4MC was OEM as shown in the graph below.
I've had to use the timeline of your data for both sets of data because I don't know how to merge 2 different sets of data in Excel using slightly different sampling rates on to the same timeline. My own sampling rate was marginally faster than yours. However, as the graph shows, the Intake Air temperature (IAT) at WOT for my run was 16 degsF lower than yours, so for the purposes of comparison, I think my using your timeline cancels out any differences for denser air that I was getting. I've highlighted the direct comparison of my run in 3rd gear with your run in 3rd gear in white, between 45-50secs. It would appear that my car in OEM state is a tad quicker (both in vehicle speed and time to increase Engine RPMs, as I'm sure we both expect from a Eurospec car, and the Airflow through the MAF is greater for my car too, presumably from the less restrictive Eurospec exhaust headers.
I think that our independent use of the DashDyno on two different cars of almost identical configuration confirm the accuracy of the method of OBDII data-logging and establish the OEM baseline of the data against which any improvement in performance can be assessed.
Alex,
I've now used your data again, as shown in the graph below, but this time I've compared it to my Z4MC fitted with several mods: Ramcharger II, Eureka mod, Frontal scoops, K&N filter and gutted silencers. My data was recorded in February 2013 when the ambient temperature was 37 degsF. I've now got my intake system working at ambient temperature at WOT, whereas when it was OEM, the lowest IATs were always 10 degsF or more above ambient.
I've aligned the data so that the engine RPMs of our respective cars is as close as possible at the lowest part of my acceleration which is at the time of 41.837secs, where your engine RPM is 3635rpm and mine is 3647rpm. In this instance the sampling rate for my car was almost identical to yours. As the graph shows, with all my mods, my car accelerates quicker than it did when it was OEM, which is the whole point of the exercise of developing an improved air-intake system.
I've now used your data again, as shown in the graph below, but this time I've compared it to my Z4MC fitted with several mods: Ramcharger II, Eureka mod, Frontal scoops, K&N filter and gutted silencers. My data was recorded in February 2013 when the ambient temperature was 37 degsF. I've now got my intake system working at ambient temperature at WOT, whereas when it was OEM, the lowest IATs were always 10 degsF or more above ambient.
I've aligned the data so that the engine RPMs of our respective cars is as close as possible at the lowest part of my acceleration which is at the time of 41.837secs, where your engine RPM is 3635rpm and mine is 3647rpm. In this instance the sampling rate for my car was almost identical to yours. As the graph shows, with all my mods, my car accelerates quicker than it did when it was OEM, which is the whole point of the exercise of developing an improved air-intake system.
H2O said:Thanks John!
Wow, you now get to 90 mils/h a second faster than me with your mods. It is a hudge difference
It is a big difference and I notice it when driving. I've never used a stopwatch in determining whether a mod works or not, I just use the datalogger and look at what's recorded when I analyse it on my PC.. Whatever parameters I record from the ECU, I'm seeing the same order of gains when compared with data recorded when the car was OEM or with low levels of modding. In the graph above, the Airflow through the MAF shows the reason for the performance difference.
billy_beemer
Member
So someone had to ask, what were the conditions like when you did your MAF tests?
I've noticed they were on different days. It stands to reason a nice cold day would produce much better results through the MAF anyway. Really the logging needs to be performed back to back to get the best results?
It looks like you are getting better results when the intake temperature is lower and air would naturally be more dense........
I've noticed they were on different days. It stands to reason a nice cold day would produce much better results through the MAF anyway. Really the logging needs to be performed back to back to get the best results?
It looks like you are getting better results when the intake temperature is lower and air would naturally be more dense........
billy_beemer said:
Billy,
I have a considerable amount of data collected on all this stuff which has been collected over several years now, and obviously the weather conditions have varied quite a bit during that time and when data logging! Obviously, it would be ideal to always do back-to-back testing in the same conditions, and this has been possible when comparing the OEM MAF Screen with the Honeycomb MAF Screen, which I can swap over in just a few minutes at the side of the road. However, with things like swapping gutted silencers or fitting my Ramcharger mods, this is impossible because I need some garage time to do these jobs.
However, from recording the Ambient Air Temperature and Ambient Pressure at the time of the run, it's possible to calculate the difference in air density so that the results can be "standardised" if required. If I use my DashDyno in "Dyno" mode, it's necessary to include temperature, pressure and altitude in the configuration, so the results that it produces are ALWAYS standardised, thus the weather conditions have no influence on the dyne figures it produces, irrespective of whether its boiling hot or freezing cold, so your always comparing apples with apples.
In the graphs I've posted in this thread above, you can see the differences in temperature, and I wrote: "However, as the graph shows, the Intake Air temperature (IAT) at WOT for my run was 16 degsF lower than yours, so for the purposes of comparison, I think my using your timeline cancels out any differences for denser air that I was getting."
At long last, there's another Z4M owner who is also "into" this stuff, (H20), who is an engineer, and he is also using a DashDyno on his Z4M and we are presently exchanging data with each other. In time we'll be able to produce a very interesting record of exactly what happens to performance with various mods. I am sure that H20 will point out to me if there are any errors in my methods or results that I haven't yet spotted.
EDIT
As it happens, both H20 and I did some data logging yesterday, and by sheer coincidence our respective datalogs showed during 2nd and 3rd gear accelerations, the IATs were the same at 75 degsF, although we were datalogging on different continents! I have merged the data, and you can see the difference between an OEM US spec Z4MR and my Euro spec Z4MC which has several different air-intake and exhaust mods.
To throw a spanner in the works, not doubting anything that has been said in here as I've ran carbon ram air intakes on previous cars with good results...but if the standard ram air intake was so good why would BMW fit open mouth style intake on the CSL to improve performance?
I know there is a feed from the front bumper and grills as per a normal M3 but from memory when I last looked at a CSL it only fed air to the front of the intake?
The only thing I can think of is that the standard ram air intake piping before the airbox can't flow enough? I'm guessing you have already checked this though John? Other option is they just did it for the glorious noise!
Something I've pondered for a while!
I know there is a feed from the front bumper and grills as per a normal M3 but from memory when I last looked at a CSL it only fed air to the front of the intake?
The only thing I can think of is that the standard ram air intake piping before the airbox can't flow enough? I'm guessing you have already checked this though John? Other option is they just did it for the glorious noise!
Something I've pondered for a while!
RedUn said:
I understand the advantage of the CSL airbox is the filter is much larger and therefore is less restrictive and that's the gain you get from it. Also, it was probably cheaper to run the CSL with Alpha-n than to make a larger MAF specific for the car.
In the fullness of time I'll give the game away of exactly what I've been up to with the intake system.
Engineering is all about trade-off to comply with standard and budget while keeping the marketing guys happy believing they had what they asked for!
Seriously I'm not a pure automotive engineer but I was involved as a test engineer in the integration of battery packs inside the Ford Think and Honda Insight at the biginning of the years 2000. We had a dyno in our lab and NEVER used it. Instead, we data logged everything as it was more convinient, more reliable, more repeatable and assessed real world conditions. I was then sent to asses the car's performance in one of the most reputable independant lab in the United State and guess what, no dyno session whatsoever. Only data logging assisted by radar and gps in real world conditions. Have you ever seen those videos of BMW engineers at the ring, they data log everything. F1 racing, always looking for more track time to data log. Why would all those people spend time and money to collect and analyse real world datas if it wasn't accurate? Obviously, an engineer that wouldn't take advantage of the OBDII and CAN Bus technology to assess real world phenomenon almost impossible to replicate in the lab would be considered a dynosaur.
A big to Exdos who has found and promote the way of modern engineering for the last few years.
Seriously I'm not a pure automotive engineer but I was involved as a test engineer in the integration of battery packs inside the Ford Think and Honda Insight at the biginning of the years 2000. We had a dyno in our lab and NEVER used it. Instead, we data logged everything as it was more convinient, more reliable, more repeatable and assessed real world conditions. I was then sent to asses the car's performance in one of the most reputable independant lab in the United State and guess what, no dyno session whatsoever. Only data logging assisted by radar and gps in real world conditions. Have you ever seen those videos of BMW engineers at the ring, they data log everything. F1 racing, always looking for more track time to data log. Why would all those people spend time and money to collect and analyse real world datas if it wasn't accurate? Obviously, an engineer that wouldn't take advantage of the OBDII and CAN Bus technology to assess real world phenomenon almost impossible to replicate in the lab would be considered a dynosaur.
A big
to Exdos who has found and promote the way of modern engineering for the last few years.*SNIPPPPPPP*exdos said:I said I would post the details of the "Eureka Air-Intake Mod" at the end of June, so here it is!
If you open your air-filter box, and look at the bottom of the box you will see a hole (9.8mm to be precise) in the rear corner, which is there for drainage of any water, which might find its way into the air-filter box. The mod is that you put a plug into that hole! It’s that SIMPLE! I've never previously seen anyone write up this mod before, so I'm claiming originating it!
Oh my god! So this is what netted you a whopping 370rwhp from your Z4MC??? Plugging a drain hole?
BWAHAHAHAHAAAA
Thanks for the comic relief. Was certainly worth the wait.
SweetRide said:
WRONG! VERY WRONG! I've never claimed that the gains I've achieved have been solely from plugging the drain hole in the air-filter box. In fact, I've made no claims from doing this mod alone.
The gains are achieved from a combination of gutting the silencers and several other air-intake mods, but unless you plug the drain hole, none of the mods can benefit from the increased ram pressure that CAN be achieved when the air-intake system is properly sealed. Try filling your bath when there's no plug in the drain hole and tell us how long it takes to fill and how much water it takes to do it, then put a plug in your bath and give us the time and quantity of water to do the same.
If *you* were to properly investigate the air-intake and exhaust systems *you* would see that there is a very significant gain to be had from gutting the silencers *IF* the drain hole in the OEM air-filter box is also plugged. Likewise there are further gains to be had from other modifications to the air-intake system, then again, your complete disbelief would prevent you from ever attempting to find out. Your loss.
exdos said:RedUn said:
I understand the advantage of the CSL airbox is the filter is much larger and therefore is less restrictive and that's the gain you get from it. Also, it was probably cheaper to run the CSL with Alpha-n than to make a larger MAF specific for the car.
In the fullness of time I'll give the game away of exactly what I've been up to with the intake system.
I've noticed that S54"s running hot cams (from race teams) take oput the MAF and run on some sort of Alpha N (somletimes with a piggy back ECU). >Is that a necessity?