[Joshboody]

If the DME targets a load, which is basically calculated from MAP, Temp, and RPM. why is there a reduction in boost with FBO car? I'm mainly referring to Clap versus other Cobb non-FBO. It's clear Clap's boost is lower, and the lower boost to reach load due to more volume of air (VE) makes sense. BUT, how does the DME know this if only the above calcs are used?

[Clap135]

Because full bolt on parts make the compressor work easier to provide the same volume of air. I think there is more involved in the calculation, this is a shot in the dark but I think the MAF loging parameteres are a big part of it as well. What that parameter does is calculates how much air, not psi is entering the engine, once the ecu knows that, it adjust boost up or down to hit targets.

[themyst]

Originally Posted by Clap135

Because full bolt on parts make the compressor work easier to provide the same volume of air. I think there is more involved in the calculation, this is a shot in the dark but I think the MAF loging parameteres are a big part of it as well. What that parameter does is calculates how much air, not psi is entering the engine, once the ecu knows that, it adjust boost up or down to hit targets.

if the car runs more efficiently, takes less boost to hit the load target, such is the case for those running stage 1 Cobb AP with full bolt-ons.

At the very least, people really need to invest in a FMIC. After long sustained runs or idling in the heat, that stock FMIC REALLY sucks something awful, hence why cars are pushing more boost to hit the load target.

[momstmg78]

Agreed

[andrew20195]

Originally Posted by Clap135

I think there is more involved in the calculation, this is a shot in the dark but I think the MAF loging parameteres are a big part of it as well. What that parameter does is calculates how much air, not psi is entering the engine, once the ecu knows that, it adjust boost up or down to hit targets.

I thought the n54 didn't have a MAF sensor. Or do you mean there is a calculated MAF value? How would that be different than a standard speed-density calculated value?

I'm really curious about tuning the n54, especially with Cobb ATR coming out before long, but with the info available now I'm having trouble reconciling how BMW does things compared to more conventional speed-density tuning theory.

[dzenno]

It has a maf on top of the intake manifold..

[Forcefed3]

Originally Posted by dzenno

It has a maf on top of the intake manifold..

Im pretty sure that is a MAP sensor.

[Joshboody]

there's a TMAP on the charge pipe and MAP on the the manifold. Can't think of how volume could be measured or calculated without a MAF.

My thought is that FBO's are running less IAT translating to lower boost.

[dzenno]

Maf is on the manifold lol tmap is on the charge pipe...I'll double check but I'm pretty sure that one is a maf...

[Clap135]

open one of you cobb logs, it calculates the grams of air the engine ingests. Cobb would be a better source.

[OpenFlash]

Originally Posted by dzenno

Maf is on the manifold lol tmap is on the charge pipe...I'll double check but I'm pretty sure that one is a maf...

Nope, it's a MAP sensor on top of the manifold.

[chancejat]

n54 : map
n55 : maf

[Clap135]

Hopefully cobb answers with how they generate these grams of air logs under the maf logging feature. We all know the n54 uses a map as primary basis and the n55 uses a maf

[Calvin@Vishnu]

Originally Posted by chancejat

n54 : map
n55 : maf

Or more specifically,

N54: MAP+TMAP
N55: MAP+TMAP+MAF

[Joshboody]

Originally Posted by Clap135

Hopefully cobb answers with how they generate these grams of air logs under the maf logging feature. We all know the n54 uses a map as primary basis and the n55 uses a maf

Probably coming from a table. Darn BT, I have to plug it into the car to look... i wish they would change that part of the software.