I just got done the install which is outlined in the following two documents from JMILLET:
Acoustic Horn
Acoustic Horn Install
My opinion: Awesome Trick!
I highly recommend this to anyone that has a stock airbox. First, the sound is not any louder during normal driving, but if you get on it, you can definetly hear a change in the engine pitch...like it can breath and wants to get up and go.
The engine feels a bit more responsive, but I think the best benefit is that the transmission seems to shift more smoothly. I know, I know, I didnt do anything to the tranny, so how could it feel better or smooth?
My observation is that if you wind the rpm's up to like 4500-5000 and shift, you dont really see them start to drop off right away. By the time you shift, the rpm's havent bogged down yet. I used to feel like the rpm's started to drop off as soon as you let up on the gas, but now not so much.
Anyway, thats my input...I like it!
So since we technically have a CAI stock, is there any real benefit to buying one from an aftermarket company instead of doing this? Other than not hacking up your stock airbox, I can't think of any.
I wouldnt call myself an expert on this, but you are right, we do have a CAI stock! If you take the box out, the front of the airbox has a shaft going down to the hole in the bumper where some z's have fog lights. It is getting air from the scoop in the bumper. Cutting the A Horn is very easy...took me a few minutes in total.
This isnt exactly hacking anything up, its just removing restriction on the airflow...def. saw a slight performance gain.
I'll talk a picture of what it looks like if you guys want!
anyone know if the 2000 M5 has these in the airboxes? I'd like to do this for my dad!
Here are some pics of my work!
You can totally see that the air is coming from down below the bumper..similar to how Dinan's CAI is.
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Nice job - thanks for the pics!
I saw the same article and did the same surgery. I was surprised to find that, when reinstalling the air box, that I was missing the two covers over the air duct that goes behind the headlight. Thus, I has a nice hot air intake. Parts on order....
Also, I dumped a disturbing about of small debris out of the airbox. I blew out the filter while I had it out, but it was pretty clean. It had foam on one side that prevents you from really bending it to release the dirt.
Glad to see someone noticed the air box ducting coming up from the bumper cover brake duct. This ducting coupled with the large front grill ducting adjacent to the headlight assemblies provides more than ample intake air for the MZ3 Coupe and Roadster.
If you want that last tiny increment of airflow then spend $60 for the ITG flat panel foam air filter. I know some folks contend the foam filter doesn't function as well as the stock pleated paper filter. I've been using the ITG foam filter for over 70,000 miles with no appearent engine damage. I clean it once a year with strong detergent and re-oil with ITG spray oil being particularly careful not to over oil the foam. The MAF sensor wire does not like to be coated with oil![]()
Jim Millet
2007 E86 Z4 M Coupe
I just took my car a few blocks to the cleaners and MAN! the car feels like it lost half its miles! Props to JMILLET!![]()
Hey, this even takes it a step farther...thanks again to nixoda from Roadfly!
http://www.mz3.net/articles/185.html
k, only tools you need are a 10mm ratchet, a standard and a phillips screw driver, a small hand saw for cutting the plastic, and a file! Easy Easy!
I wonder how much making that duct down to the fog light area will help? I see it just being a way for more dirt/leaves/water to get into the airbox...maybe not a good idea?
I don't think it is necassary on an M.
iwas thinking of making my own cai, will try this frist... sadly the car is up for the winter... will be one of the frist things next spring. thanks for the pics and link, it will help.
Like i said, its minimal if apparent at all for regular driving...when you get on the gas it just sounds like your engine is a shade louder...not different sound at all.
awesome tip.
i'll give it a shot this weekend (hopefully i'll have the time).
thanks!
-mike
I had the pleasure of driving scotts car right after his horn "surgery". You can definitely feel the responsiveness improve vs stock, and the sound differences were fairly minimal. If anything the engine sounds a bit "angrier" at WOT, and that's a good thing. I plan on doing mine this weekend.
call me a skeptic, but im not buying it. I will however try it for shits and giggles, but Im thinking that this hp gain stuff is all in the head. That being said, if i can fool myself into beliving it, its just as good as having it right?
Thanks for the great write-up and details... Looks like I'll give this a try this weekend...![]()
Billy, I didnt say anything about a HP gain. We all know CAI's claim power gains and they always dyno for less than advertised.
I did say the engine feels more alive and because of this the car revs more smoothly and in turn feels like it shifts more smoothly because you do not lose rpm's as quickly...in effect the engine braking is lessened in lower gears - maybe because the engine car breath better. I dont know, I'm not a mechanic or gear head. Thats just my personal observation. There is a noticable difference in the way the car reacts.
The car is fast to begin with and feeling a slight HP gain is probably impossible!
That being said, I am glad I did it and I would do it again given the chance!
well i completed this task over the weekend. with the instructions above it's a VERY easy procedure.
results and input: well i feel the throttle is more responsive. does it give power gains... i think it's all in my head, but i notice a slight increase. nothing down low, but merging onto the highway and what not it feels like it has more pep.
the sound is a little better. you really have to let it crank over 4k to hear a difference.
all in all, i'm glad i did it.
-mike
Yeah! I'd say I agree with that! Wonder if Ted did it yet?
scott, did you get any better mpg because of doing this? this is the first tank i went through after doing the modification. granted my method of getting average mpg is not that accurate and is as simple as dividing my total miles by the total gallons used to fill up.
strange enough, for the past 5 weeks i've been around 22.4 mpg... last night, i was at 24.5. i drove pretty much the same, if not a little harder (to try and notice any gains). i'm going to monitor this over the next few weeks and see what i can find. maybe it was just a one time freak occurance.
-mike
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