FREE Air-Intake Mod: Full Details on Page 6 of this thread

[jimmybell]

It makes sense really - it's a pressure based system, and by putting a hole in it - there will be little-to-no pressure. Simples!

[hydra]

This is the cheapest mod I seen after painting brake calipers

Cheap as in cost wise not sense. No offence intended !

[billy_beemer]

So of the people who tried it, what did you think?

[mmm-five]

So of the people who tried it, what did you think?

To be honest, I can't feel any difference - even at speeds above 100mph.

I'm not saying it's not working as it may simply be my terrible 'butt dyno' or possibly the varying temps/weathers that I've been driving it in making any comparison difficult. Even before the mod, my weekly average MPG could vary between 25mpg and 32mpg depending on what the roads were like that week (just look at the erratic nature of my MPG on my Fuelly link).

I really need to do the 'before' data logging again - as I've corrupted the original files - to see what the 'max' air flow is, as that should show the rise even if I can't feel it.

I'm not going to remove it, and will probably do the MAF grill mod too at some point - but I'm also investigating getting a CF version of the OEM airbox made (for more noise), and possibly adding an e46 M3 style 'snorkel' to ram more air in (or Exdos' RamAir v3).

[billy_beemer]

I see the theory... it would almost be like adding 'boost'

So are there any proven results? I could try it with dynolicious at some point. What about combining it with the infamous RPI scoop?

[exdos]

I see the theory... it would almost be like adding 'boost'

So are there any proven results? I could try it with dynolicious at some point. What about combining it with the infamous RPI scoop?

I've posted quite a lot of information from datalogging my Z4MC over the past 12months with a number of different mods to the air-intake system and from gutting the silencers: collectively they have enhanced the performance of my car significantly.

The "eureka mod" in this thread is the foundation mod of all the other mods, because without it, I found it impossible to increase the ram pressure, no matter what I did, because the hole in the aiIr-filter box just acts as a drain. I'd already done an air intake mod and gutted the silencers on my Z4MC, and neither of these two mods showed any gains, (I'd previously done similar mods to my Z3MC with good gains), which left me puzzled as to why the mods weren't working. It was only when I closely examined the air-intake system that I discovered the hole, and after I plugged it, datalogging showed the sort of gains from my other mods that I was expecting to see at the outset.

If your Dynolicious has the ability to monitor the airflow through the MAF, then I suggest that doing before and after recordings of the MAF, will show if you see any difference.

I've recently removed my own version of an intake scoop, and I intend to datalog the car again, to see what effect that has. I think that the simplest and most effective mods will be the Eureka mod combined with Pilchardthecat's Honeycomb MAF Screen mod.

[billy_beemer]

Dynolicious is the iPhone app you set, drive around and it logs your 0-60, 0-100, quarter mile and gives a predcited at the wheels power figure.

It gave me a 0-60 time of 4.72s and an at the wheels Peak Horsepower of 282hp.

The reviews from people who use the app at 'run what you brung' style events are positive and people seem to believe its fairly accurate.

I could certainly go out and do a run, pop back, make the mod and re-try. (clearly I'd be doing this on my friends private run way)

I have the Supersprint X-Pipe and Race Mufflers installed so more air could result in good things although the standard manifold (that's headers to people in the United States of Americaland) could be a bit restrictive

[ga41]

Have you noticed much of an improvement with the X-pipe/mufflers combo billy_beemer?

[billy_beemer]

Differences with the x-pipe and mufflers (80mm race version):

- Smoother, much smoother
- Sounds a lot better
- Lots more of that (not quite popping but more bur-bang) noise you get when you lift off the throttle
- A tiny bit boomy around 2,000rpm but doesn't drone as such which I was worried about
- TVR driving mates even said it sounded pretty nice!
- Still not overly loud.

Hang on, have I just hi-jacked this thread? Back to the topic, I don't think it's added any performance to the vehicle but apparently if I do the manifold it would but that's a lot more cash. Perhaps worth trying out this airbox tweak

[ga41]

Hmm... i was asking more along the lines of power gains. I want some more power damnit. (Have yet to do Exdo's intake mod. Not much car-time lately, not even time to bleed brakes....)

[Simon_P]

I have tried this mod for the last month at various speeds and revs on all roads covering 300 odd miles. As yet my seat of the pants dyno and highly tuned ears have so far not noticed any difference. Thanks to exodus for letting me in on his secret

[exdos]

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 ) 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.

[H2O]

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.

[exdos]

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.

Alex,

I'll put your data onto a graph with my own data so we can compare a US and Euro spec Z4M.

[alfamale]

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