Z4 MR NA Tune

[2fast_on4]

Hello all,

I am not a new member but I am not a frequent user of forums. I would like to share the result of almost 1,5 year of research. Being a big fan of NA cars, I wanted to tune my car taking down this path.
At February 2010 I ordered the Stage II NA tune from MK Motorsport (carbon fiber intake + mufflers + alpha N + headers). All the parts were exceptionaly good, quality wise. The problem was that the car delivered less HP than stock (325 vs 336 stock). After very long negotiations (July 2010) with MK and a really unacceptable after sales service we ended up with the car producing 331 HP (again lower than stock). On this point, I seriously considered taking legal action against the tuner. Then again, tuning my car was supposed to be fun and I would not like this process to end in a court.
Bottom line is that after another long six months and with the valuable help of my local mechanic, we managed to find a solution from another German programmer (I would rather not mention the company in public since it was a custom job). This resulted in 370 HP (with Alpha N programming) and a limiter of 8150 rpm. In total, the car has the following upgrades:
- MK Carbon air intake
- MK racing stepped headers
- MK mufflers
- Alpha N programming
- Bilstein PSS10
- 4.10 diff
- Racing Dynamics Short Shift
I am very happy with the cars' performance. It has not lost power low and it has gained a very nice pull high, that keeps growing even on the limiter (unfortunately I do not have a dyno graph available right now). The V max limiter is canceled and I have seen 280+km/h (on the speedometer) with the feeling that it could go even higher but had to let due to traffic. I post a short video taken with a cell phone and I hope that you will enjoy the sound.
My next mods will be:
- X pipe
- Racing catalytic converters (100 cells)
- CSL wheels with Michelin Pilot Cups
- Schrick Cams
- Brembo brakes (front and rear)

I know that most would think that I should have supercharged the car, got more power and saved myself the trouble of searching for the proper ECU tune, for just 30 HP. The problem is that I am a huge NA fan and I always respected the NA technology that the S54 motor has integrated. I did not like to change that character and since I love the speed at twisty roads and not the highway, this type of power is more difficult to explore but also more usable when you master it.

Greetings to all passionate Z4 drivers!

http://www.youtube.com/watch?v=3HJDLQLquOM

[Z4-VILLA]

first. lol

Welcome to the Post!

[krnnerdboy]

I'm all for n/a over boost if my cash supply was endless!

Goodluck on your endeavor

[RevsPlease]

Do you have pictures of all the goodies under the hood? Please share!

[2fast_on4]

Thanks for the welcome!

I will post some pics of the parts prior and after installation as soon as possible.

[ga41]

Για σου φίλε! Νομίζω φωτογραφίες επιβάλλονται! :P

That sounds like a great setup and the car sounds very nice indeed! You should post pictures ASAP!

[Beedub]

awesome car by the sounds of it.....

BTW a supercharger keeps the exact same stock power delivery... it simply moves up the graph.... thats what i love about the Ess kit... completely in keeping with the stock character... just feels like a v8 now :-)

[2fast_on4]

(Καλησπέρα στην Πάφο! Σπάνιο αυτοκίνητο για την Αθήνα, πόσο μάλλον για εκεί. Καλή επιλογή!)
Here are some pics of the carbon airbox and headers prior to installation. I will post some pics of these parts installed plus the mufflers later on.
The airbox has a panel filter inside.

[Z4-VILLA]

holy shit.

[ZStig]

nothing wrong with staying normally aspirated. I've heard you can get as high as 400rwhp on the s54

[VinnieAces]

wow that airbox looks insanely sexy, wonder if that alone actually increases HP unlike afe and gruppe

[ZStig]

no, alone it LOSES power, unless properly tuned

[ga41]

That looks GORGEOUS!

Installed pics and videos please!

Ευχαριστώ φίλε αλλά η δική σου επιλογή μετά από τις προσθήκες σου μάλλον καλύτερη είναι!

[esqu1re]

How did you measure 336 stock horsepower? Are not our cars around 280hp to the wheels? Did you use a calculation to reach 336? If so, did you then use the same calculation to reach 325 hp after all the mods were put on?

Just trying to understand. Thanks!

[2fast_on4]

Originally Posted by esqu1re

How did you measure 336 stock horsepower? Are not our cars around 280hp to the wheels? Did you use a calculation to reach 336? If so, did you then use the same calculation to reach 325 hp after all the mods were put on?

Just trying to understand. Thanks!

The HP mentioned are not wheel horse power, but HP on the engine crank. But I think that 280 whp on an s54 is a bit on the down side. Of course, these engines are known to have great variances on horse power amongst them (some owners are more lucky than others).

[2fast_on4]

Originally Posted by ga41

That looks GORGEOUS!

Installed pics and videos please!

Ευχαριστώ φίλε αλλά η δική σου επιλογή μετά από τις προσθήκες σου μάλλον καλύτερη είναι!

Ευχαριστώ πολύ! Είναι σημαντικό για εμένα γιατί τραβήχτηκα πολύ...

Pics and videos coming up as soon as I get the car cleaned and ready for the lens!

[2fast_on4]

Originally Posted by Roffle Waffle

no, alone it LOSES power, unless properly tuned

I totally agree. This installation works only with Alpha N programming (something that is extremely hard to achieve with the Z4's more clever ECU than the E46 M3), which cancels the use of the MAF sensor. In that way, you rob some of the ECU's cleverness in order to gain throttle response and proper use of the excess air available (that is a very rough description, but close to the result you get).
If even this reprograming is done but it is bad, you lose power again. My car is a tragic example of that when it lost around 15 HP from stock, due to bad ECU programing.
Unfortunately, in all modern cars, giving them the best (good airflow, exhaust flow or the best fuel) is not enough. You have to "convince" them or "teach" them also that they should perform relevantly!

[2fast_on4]

Originally Posted by Roffle Waffle

nothing wrong with staying normally aspirated. I've heard you can get as high as 400rwhp on the s54

I think that with the use of quite aggresive cams (not CSL's) and racing catalysts, plus a redline of about 8.500 RPM (a bit risky without crankshaft casing and valvetrain enhancement), 390 to 400 HP is probably achievable. And this is just about it for this motor in NA form. Of course, it will definitely be a screamer and that I like a lot...!

By now all our supercharged friends will be laughing over the silly EUR/HP ratio of these solutions, since the cost is several thousands (of any currency) for relatively marginal results. But the market needs some romantic guys!