[RallyRcrr]

COBB AP Economy Map for the 335i in development

I've attempted to research the availability of a economy tune for the 335i and have found very little reliable information on it online or in the forums, so I decided to call COBB and get the information directly. I just got off the phone with one of their techs, and have summarized what I was told below.

I thought everyone interested in an economy mode would appreciate knowing this.

Economy Map
Currently its under development. It is something a lot of owners have requested so it is being worked on. No date was given for its completion though. The biggest hurdle they want to overcome is the safety of the tune. Optimizing wastegate and timing operation is their biggest concern for long term use.

Valet Mode
After understanding why an economy map is not yet available, I asked if the valet mode is safe to use continuously. Why? Because if the economy map reliability is in question, I was curious to know if I should be concerned about the reliability with a valet map. I was assured that it is safe. The main method of controlling power output in this mode is the rev limiter limit of 4000 rpm. No other variables were altered except for very minor tweaks to timing. No details on what those tweaks are were given. Boost/wastegate operation remains as normal.

Why an Economy Map? The 335i is for raw power!!
For everyone that would ask why get a 335i if you didn't want all the power... Not all of us want the power all the time. Personally, I don't feel the urge to turn every stop light into a drag race and I don't need to prove how fast the 335i is to every street racer around. I commute to work. I take long distance trips. I'm just a regular guy whose BMW is not a full time race car. I do turn on the Stage 1 for the weekend drags, track days, and trips to the mountain roads.

Why not just keep you foot off the pedal?
Same reason why recovering alcoholics don't keep alcohol around. Its just too easy and too tempting to use on a regular basis.

[Jeff@TopGearSolutions]

Sounds good on paper. My buddy has the economy map on his subaru. He noticed absolutely no difference. It all comes down to your right foot. Your driving habits (bad habits, and unknown habits) can change your gas mileage up to 30%! Way more then the economy map will do.

[MSport35TT]

Originally Posted by RallyRcrr

COBB AP Economy Map for the 335i in development

Why not just keep you foot off the pedal?
Same reason why recovering alcoholics don't keep alcohol around. Its just too easy and too tempting to use on a regular basis.

Great Line...How about the turbo turn off like JB?

[RallyRcrr]

Jeff

Very true. Much of the results any of us will get is highly dependent on our real world habits. That doesn't negate that some of us wouldn't like to try to things to aid our efforts. I would never tell a fat person "why bother with that diet?" you're going to stay fat anyways.

Msport

Thanks, I only put that there to stop people from flaming this post. I only wanted to pass on information I thought might be useful. Relaying what Cobb said, just turning off the boost wasn't enough to guarantee long term reliability. The tech didn't expand on that answer though.

[Ænema]

You can use ATR to design an economy map. Run ~4psi of boost across the board, add a little timing and run a leaner AFR and be good to go. Of course, it's not going to make any power and you're going to be pushing it harder to get it to move...

[BMWM.D.]

Maybe I'm imagining this, but I was pretty damn sure the "valet" map deactivates the boost control system. I've only used it once, but it sure felt like there was no boost present. Didn't log it to verify, but it felt like a 318i at WOT.

[Jeff@TopGearSolutions]

Originally Posted by MSport35TT

Great Line...How about the turbo turn off like JB?

N/A Mode was first developed on the PRocede.

It was probably the best map cause it brought back that inline 6 sound that was missing from the N54.

Originally Posted by RallyRcrr

Jeff

Very true. Much of the results any of us will get is highly dependent on our real world habits. That doesn't negate that some of us wouldn't like to try to things to aid our efforts. I would never tell a fat person "why bother with that diet?" you're going to stay fat anyways.

Msport

Thanks, I only put that there to stop people from flaming this post. I only wanted to pass on information I thought might be useful. Relaying what Cobb said, just turning off the boost wasn't enough to guarantee long term reliability. The tech didn't expand on that answer though.

haha I hear ya.

[caliguy562]

Originally Posted by Jeff@TopGearSolutions

N/A Mode was first developed on the PRocede.

It was probably the best map cause it brought back that inline 6 sound that was missing from the N54.




haha I hear ya.

My car as been back to stock for months now and I forgot all about N/A map 3. With the wastegates completely open, the car was beyond loud.

[brusk]

Originally Posted by Ænema

You can use ATR to design an economy map. Run ~4psi of boost across the board, add a little timing and run a leaner AFR and be good to go. Of course, it's not going to make any power and you're going to be pushing it harder to get it to move...

This is probably the best start. I toyed around with one for awhile for long distance trips. I set up a non linear map where the throttle didn't hardly move until the last 75% or so. This helped by about 2 MPG just taking the the sensitivity out of the pedal. Then I adjusted the timing and the AFR's for a small RPM window that would be used for cruising only. This was in the hopes that if you needed to floor it due to seeing some dbag on the highway you could still have fun and get your gas mileage. Enough patience and playing with ATR you could have whatever setup you want.

[M5Rlz]

I already get 20-25 on stage 1 aggressive I'm not going to do much better even stock. If you are able to realize you don't need power all the time you should also be able to adjust your own throttle response

[ihc95]

Running an N54 in N/A mode causes some weird adaptation issues and is not the best thing to do for the car.

[mump]

I had eco mode in my evo x from cobb. I used it once for approx 1/8 of my trip. All it did was cut boost to nothing - literally 0 psi, maybe 1 - a giant drop from 26 psi. I got out on the autobahn and it went 0-100 in about three days. I tried to pass a car and was pissed. I swear it traded the engine in for 2 squirrels. I pulled into the first rest stop, switched maps and decided I would be my own eco mode.

[gunmetalcoupe]

I had the stupid eco map on my Subaru STI and it was a massive waste of time. Aggressive timing to the point where you had to worry about holding the gas down to the floor to pass a car, plus a lack of power that forced you to floor it every time you needed to pass someone, and in the end it made no perceptible difference in fuel economy.
What needs to happen is someone has to enable lean burn on these cars. That'd make a huge difference in fuel economy (while also miserably failing emissions).
Here is the post I made on COBB Forums about it:



Hi, its my first time on this forum but I'm a second time AP user; I had it on my '05 Subaru STI and liked it so much that I got it for my '08 BMW 335XI. From a Mechanical engineer employed in engine research: COBB makes a great product: please keep it up!

As you know, the N54 engine is unique in its usage of a hollow cone piezo electric fuel injector. BMW elected to do that for two reasons; the piezo technology allows extremely rapid injector actuation (and therefore the ability to run multiple injection pulses per event), and the hollow spray cone provides a more uniform fuel distribution in the combustion chamber.
The original intent was to enable a lean burn strategy where the bulk of the fuel charge is injected early on after the intake valve closed, creating a very lean, evenly distributed mixture which is essentially non ignitable (too lean). A second, much shorter injection pulse just before the ignition event then creates a localized rich region around the spark plug that can be ignited, and its ignition then allows the rest of the bulk charge to combust.
With strategies like this lambdas as lean as 2 and beyond can be ignited: Much past maximum flame temperature, so with less combustion heat, losses are reduced and since the amount of power produced is also low the engine can be run with minimal throttling, reducing throttling losses. This is the most efficient way possible for running a conventional gasoline engine.

Audi called their take on this strategy TSFI: "Turbo Stratified Fuel Injection" (Stratified = lean). Except it is not: Lean combustion generates Nitrogen Oxides which are traditionally removed by your 3-way catalytic converter by oxidizing excess hydrocarbons. When the mixture is too lean, there are no hydrocarbons to oxidize the NOx and therefore emissions exceed federally mandated levels. Audi TSFI engines actually run Lambda 1. I *THINK* they, and BMW, run (or at least used to run) lean in Europe where NOx is not as tightly regulated by I don't know that for sure. I have seen illustrations for the Ford Ecoboost 4 cylinder that suggest it also runs a similar strategy, but again I know here in the US this is not true.

What I am really interested in is the ability to run a map on my car where the engine runs a stratified charge strategy for lean cruise. The hardware and controls are already there; it is even possible that Euro spec 335s did or still do have those strategies in the ECU. Have you guys ever looked into it? This would be the definition of having your cake and eating it too; with power enrichment the engine would go open loop and make full power as soon as you are on the gas, but if we can run it stratified for cruising the highway fuel economy improvements could be substantial!

Cheers!

[Ænema]

That's potentially a hellluva lot of DME logic to reprogram just to pick up some economy. Especially when it's use/demand is limited.

The DME already uses a "spool mode" that advances timing and runs 1:1 lambda, exactly how/if the injector pulses are arranged differently in spool mode i don't know. If you want to you can take this further and run a leaner AFR(as long as you keep loads low i assume this wouldn't cause harm.)

[AltecBX]

Adjusting your own throttle response is your best weapon for MPG.
Remember turbo cars are more efficient.
If I go TPS 50% on 4psi of boost for 15 seconds from 0 mph I get lets say 1/2 mile till it stops.
If I go TPS 50% on 0psi of boost for 15 seconds from 0 mph I get lets say 3/8 mile till it stops.

See the extra efficiency of the air through the turbo gets your car further with the same amount of throttle (gas feed to engine) gaining you more mpg. You turn off boost and then you force (feed more gas) to the car to move the same distance than not introducing some boost into the turbo.
Timing is another story. By using ATR or playing with timing then you'll be able to retard or advance timing. That's where you'll see better or worst gas milage with the same amount of TPS input. This will also increase or decrease power depending on how fast (rpm) your engine is moving and increase amount of spark, fuel, air is mixing.
Also weight is another factor in saving mpg. Have a empty trunk whenever possible. And maybe loose some weight, lol.

[Jeff@TopGearSolutions]

Originally Posted by AltecBX

Adjusting your own throttle response is your best weapon for MPG.
Remember turbo cars are more efficient.
If I go TPS 50% on 4psi of boost for 15 seconds from 0 mph I get lets say 1/2 mile till it stops.
If I go TPS 50% on 0psi of boost for 15 seconds from 0 mph I get lets say 3/8 mile till it stops.

See the extra efficiency of the air through the turbo gets your car further with the same amount of throttle (gas feed to engine) gaining you more mpg. You turn off boost and then you force (feed more gas) to the car to move the same distance than not introducing some boost into the turbo.
Timing is another story. By using ATR or playing with timing then you'll be able to retard or advance timing. That's where you'll see better or worst gas milage with the same amount of TPS input. This will also increase or decrease power depending on how fast (rpm) your engine is moving and increase amount of spark, fuel, air is mixing.
Also weight is another factor in saving mpg. Have a empty trunk whenever possible. And maybe loose some weight, lol.

Best way to save gas is to stay out of boost, period.

A car in 0 Vacuum may use (arbitrarily) "1700" units of fuel @ 2000 RPM. At the same RPM it would require over 40% (2500+ units) more fuel for 4 PSI of boost at the same RPM.

More Air requires more fuel, which makes more power, plain and simple. If you reduce the amount of power you are making to maintain speed you reduce the amount of fuel used and by no accident there is less air in the engine. Improving efficiency can be done by timing or cam profile changes (where applicable).

The name of the game is definitely to stay out of boost.

For those with manual transmission, stay in gear longer when braking. By going into neutral for a stop light you force the car into idle which runs the injectors to keep the engine running. If you stay in gear until the last second you reduce the amount of time your injectors are firing. As your engine decelerates while in gear it does not need to use the injectors to stay running.

[AltecBX]

Originally Posted by Jeff@TopGearSolutions

Best way to save gas is to stay out of boost, period.

A car in 0 Vacuum may use (arbitrarily) "1700" units of fuel @ 2000 RPM. At the same RPM it would require over 40% (2500+ units) more fuel for 4 PSI of boost at the same RPM.

More Air requires more fuel, which makes more power, plain and simple. If you reduce the amount of power you are making to maintain speed you reduce the amount of fuel used and by no accident there is less air in the engine. Improving efficiency can be done by timing or cam profile changes (where applicable).

The name of the game is definitely to stay out of boost.

For those with manual transmission, stay in gear longer when braking. By going into neutral for a stop light you force the car into idle which runs the injectors to keep the engine running. If you stay in gear until the last second you reduce the amount of time your injectors are firing. As your engine decelerates while in gear it does not need to use the injectors to stay running.

+1
Yes the more TPS, the more air so hence the more fuel for the correct mixture.
But a turbo charged car delivers on demand power rather than the constant consumption of fuel for motivation.

[X.X.I.V]

You can run the procede in any map you want and toggle on the transport mode. the rpm will limit to 4500
It will scare the out of you the first time you hit it at full throttle.