Going from K&N Intake to Karb CSL Box with Alpha N Tune back to K&N

[karter16]

Is it just down the the ECU? Maybe a more powerful ECU, such as the MSV70 or MSS70, could handle not having MAP sensor data.

Interesting to read terra's posts on the subject:

Certainly the age of the DME is part of it (we're talking about a processor that doesn't even have the ability to perform floating point calculations). If you were using a modern ECU you could do all sorts of fancy things. I think though partly it's also down to how the ECU/intake/software combination was designed to work. The standard E46 M3 plenum has an intake diameter that is small enough to use with a MAF sensor. The MAF sensor is the most accurate approach which is why BMW used this. With the CSL intake the diameter of the intake is too large to use with a MAF sensor, hence the switch to a MAP sensor for that application.

The MSS70 on the Z4M is indeed a more powerful ECU, plus benefits from wide-band 02 sensors, however if you do a CSL intake conversion on the Z4M you're stuck with Alpha-N as BMW didn't make a version of the software to support the MAP sensor, even with the improved performance of the MSS70 and Wideband-o2's there are lots of Z4M owners who wish they could run the MAP sensor as well.

[Slideways]

There was a lot of misinformation years ago about the purpose of the MAP sensor and what it does and doesn't do. I think some of the early disassembly work found where the MAP sensor is used to support in the case of throttle potentiometer errors but missed (or didn't fully appreciate) the implications of how the MAP sensor is used to adjust RF (relative filling). This led to two misconceptions:

1: that the MAP sensor is only used as a back up when there is a WDK failure.
2: that the MAP sensor contribution is limited to 2.5%.

I think those misunderstandings have spread over time to the point that many people (quite reasonably) understand the MAP sensor to be less important in function than it actually is.

Is it just down the the ECU? Maybe a more powerful ECU, such as the MSV70 or MSS70, could handle not having MAP sensor data.

Interesting to read terra's posts on the subject:

MSS70 is much closer to the MSV70 used in the N52 cars. Has very little relation to the MSS60 and MSS65 in the M3 and M5. There really isn't much code to truly support a MAP sensor, it'd have to be fairly custom. That said, a well tuned alpha-N MSS70 would likely run better than a CSL MSS54HP. Largely thanks to the use of wide-band O2 sensors. And in fact, some euro N52 cars are alpha-N from the factory and you cannot distinguish them from their MAF counterparts - they run that well.

Not strictly true. The DME does have a pressure sensor on the board itself, and it does actually keep track of altitude. But as obioban alluded to, real data tends to work better than assumptions. Esepcially in our cases where our DMEs are running basically 30 year old processors and just can't process a truly accurate model in the same way modern DMEs can.

[karter16]

What I never get is why people go alpha n instead of doing what bmw did with the csl intake and give the computer the information it needs to do it's job.

Alpha n is designed as a get you home with failed maf sensor tune. Yes it can be made to work well in a specific set of altitude/fuel/temperature circumstances but without map or maf sensor the dme is half blind. At least on this forum people seem to speak the truth about the drivability issues.

There was a lot of misinformation years ago about the purpose of the MAP sensor and what it does and doesn't do. I think some of the early disassembly work found where the MAP sensor is used to support in the case of throttle potentiometer errors but missed (or didn't fully appreciate) the implications of how the MAP sensor is used to adjust RF (relative filling). This led to two misconceptions:

1: that the MAP sensor is only used as a back up when there is a WDK failure.
2: that the MAP sensor contribution is limited to 2.5%.

I think those misunderstandings have spread over time to the point that many people (quite reasonably) understand the MAP sensor to be less important in function than it actually is.

[Sajk]

What I never get is why people go alpha n instead of doing what bmw did with the csl intake and give the computer the information it needs to do it's job.

Alpha n is designed as a get you home with failed maf sensor tune. Yes it can be made to work well in a specific set of altitude/fuel/temperature circumstances but without map or maf sensor the dme is half blind. At least on this forum people seem to speak the truth about the drivability issues.

[jpy1980]

You can definitely do it if you want to pay like $300-$500

Yea, the money wasn't too much of an issue, it was more about the illegality or safety? haha When I was in my 20s, I would've done this, but in my mid 40s, I think I'm good.

anyways, I just sold my CSL intake tonight to a fellow member here, so hopefully it will go to a good home where they will enjoy the awesome sound of induction. With the proceeds, I just ordered an eVenturi intake and now trying to figure out if I want to get rid of my Eisenmann sport exhaust. I spoke with Bimmerworld and they actually said that the El Diablo muffler is not that much louder than my Eisenmann Sport muffler. Blew my mind when he said that. Not sure what to do now.

[Nate047]

Haha it's funny. I actually found a friend of a friend's mother's cousin brother uncle.., who said he can help me get Smogged with the box on the car. I was tempted until he said to meet him in the ghetto behind a grocery store. That was the point where I was like, imma take this shit off. hahah

You can definitely do it if you want to pay like $300-$500

[dukeofchen]

Link to "that guy in Germany" please?

I didn't think you could use this in the E46; do you have a video of this sound pipe being installed on an E46?

Didn't think about the sound pipe they have! That might be a good addition... do you have a link?
To my point above, Z4M+Eventuri is a great setup.

I had a hell of a time tracking him down as the email / website on his videos is outdated. This is his own video of it on an M3, and I know maupineda has multiple comparison clips of different configurations of OE Karb / Eventuri / sound generator from his Z4M. From the sounds of it the Z4M folks really like it as an upgrade.

I got through to them at [email protected]. The actual guy's email is [email protected], but he replies faster via WhatsApp at +491621506030.

Sounds like the original maker Eden passed along the business to this Janno fellow, and he makes them to order. If y'all are interested might be worth asking for a discount on a batch order, that EUR/USD conversion rate isn't doing us any favors...

[siamkazi]

I dunno man, I'm here in SoCal as well (Corona) and now that summer is here, top down in the evening with the csl box is unmatched with stock exhaust i.e. no drone at all. I think the S54 Intake noise is peak BMW Motorsport outside of the S65.

[jpy1980]

Interesting comments in here. It's hard to explain to people who don't live here just how stupid CA smog rules are. It really just depends on personal preference whether you're willing or have the energy to get around that.

Haha it's funny. I actually found a friend of a friend's mother's cousin brother uncle.., who said he can help me get Smogged with the box on the car. I was tempted until he said to meet him in the ghetto behind a grocery store. That was the point where I was like, imma take this shit off. hahah

[EthanolTurbo]

The Karb OEM carbon MAF airbox + Eventuri is 90% of the sound with none of the CSL tune quirks. Wish I had gone that route, MAF drives better than Alpha N+MAP.

[Nate047]

Interesting comments in here. It's hard to explain to people who don't live here just how stupid CA smog rules are. It really just depends on personal preference whether you're willing or have the energy to get around that.

[jpy1980]

Does anyone know what is involved with installing a MAP tune on a pre LCI (2003-) car? Anyone who has gone from Alpha N to Map, is the install process easy to reverse?

[stephen]

After installing a CSL intake I can't imagine ever going back. It really cements the S54 as the centerpiece of the car. I do also really enjoy the dual personality of having a car with a loud intake and quiet exhaust. The car is only loud when going WOT.

[ugaexploder]

I don’t think there is anything really bad with the Alpha N tune. Hassan’s tune on my car was fine, fun and pulled hard. The Alpha N tune just has some quirks or “characteristics” that make it different from the MAP route. It’s perfectly fine for the lay “tuners” if there is ever a thing. I’m sure the MAP route would be better overall, but for ease of use, alpha N is fine. If you are in an area where you have to SMOG your car often, an alpha N tune would be the best route since all you have to do is uninstall the box, slap your old one back on and flash your OEM tune. Super easy.

that makes sense. i remember when i found out Hassan runs alpha-N, it really made me scratch my head because it seems like everyone bashes alpha-N versus MAP sensor route.

[jpy1980]

doesn't Hassan at HTE run alpha-N on his own car?

I don’t think there is anything really bad with the Alpha N tune. Hassan’s tune on my car was fine, fun and pulled hard. The Alpha N tune just has some quirks or “characteristics” that make it different from the MAP route. It’s perfectly fine for the lay “tuners” if there is ever a thing. I’m sure the MAP route would be better overall, but for ease of use, alpha N is fine. If you are in an area where you have to SMOG your car often, an alpha N tune would be the best route since all you have to do is uninstall the box, slap your old one back on and flash your OEM tune. Super easy.