How to modify Cobb E30 OTS for E40?

[Jeffman]

Hey there.
Anybody have any suggestions for modifying Cobb's E30 OTS map using ATR to make it more suitable for E40?
Thanks in advance!

[E90Company]

You have to increase the fuel scalar @BuraQ

[BuraQ]

Keep in mind I am not a pro tuner, I am still a beginer so anything I say is only based on my own experience, my opinion, and what I have done on my own car, which is subject to error and disaproval from others who may have more knowledge than I do

If the 3D scalar is available for your ROM in ATR then I can help, if not, sorry no can do.

Download the Cobb AccessTunerRace PDF help file http://accessecu.com/cobbtuningweb/s...lpFile_BMW.pdf

Scroll to the last page (22) on the PDF help file and you will see a Fuel Scalar table for ethonal content

Look for the colomn of "E%" you are trying to target. E40 mix so your "starting" scalar value will be 1.16

Now lets take a look at your stock scalar values. You want to pay attention to the "begining" and "ending" cell values.



On the N54 you have two(2) banks 1 & 2 tables. Both of these will need to be modified

Highlight the entire table (the green values), use the "+" to increase the values until the begining and end value cells reach 1.16 . DO this for both Banks 1 & 2



This is your "STARTER". Next is the "TUNING" of these scalars which more than likely will have to be raised depending on the power level you are pushing in which you will have to tune the table for LOW-TOP end healthy STFT performance (another topic)

Next is "calibrating" the values for "idle" and "regular" commute driving (another topic) so you dont get the SES light when crusiing and or have your car going limp mode on your cause it thinks your LPFP is going awol which will run you tooooooo lean

So it doesnt end here, there is a lot more that you have to follow up on which will take me pages to type and probably make pro-tuners really upset at me....lol

SO technically after you have done the "STARTER" above for both banks you need to run logs for HPFP(psi) STFT Banks 1 & 2 with the standard loging parameters. Make sure your advance timing is not more than 9° in the top end for starters also.

[BuraQ]

LMAO wtf, sorry bro I was working and trying to do this and ended up giving out more info than needed. Instead of using stock scalar just highlight the entire table (all the green values) in the Cobb OTS E30 map and raise them up until the begining cell and the ending cell values reach 1.16

However Cobb put their scalar on their E30 OTS map to around E36 based on the scalar table. So following the same example raise it a bit more to about E46 which is 1.192

[richpike]

First - damn good write-up @BuraQ.

Second - @Jeffman - kudos to wanting to do this yourself. If you decide it is too much effort, you might also consider going the eTune route for ~$250.

Below is my experience with PTF - they do great work, but there are others out there too.

http://www.bimmerboost.com/showthrea...nce-and-Review

Good luck!

-Rich

[135pats]

I've always found it a good bet to run the 3D scalar a touch "strong" in both banks. IE if you are targeting E40 as fuel, set a scalar for closer to E50. Gives you a bit of headroom without any observable negative effects.

[jyamona]

I've always found it a good bet to run the 3D scalar a touch "strong" in both banks. IE if you are targeting E40 as fuel, set a scalar for closer to E50. Gives you a bit of headroom without any observable negative effects.

+1, agreed. I don't think there really are any downsides to this approach, as long as neither of your pumps are tanking.

[Jeffman]

Hey, thanks to everyone who chimed in, especially @BuraQ! (Sorry for not replying sooner as I've been on vacation this week.) I had been modifying some 93 octane (E10) tunes with Wedge's help when my E85 station's pump broke and was SOL for a month. I am a happy PTF customer (I was one of the first group-buy guys for E10 when they went live) and I have an introductory PTF E40 map from them to try out, but it's not as "buttery smooth" as I would like it to be. I actually got pretty comfortable with Cobb ATR with Wedge's advice along with V8bait's fine notes in the download section on this forum. For some reason my 3D scalars really need to be jacked up to bring my peak STFTs down into the mid-20s with 93 octane....injectors?...fuel pump?...So now I'm planning to work on my own custom E40 map. Banks 1 and 2 3D scalars are first to be modded. I'd also like to get my max timings up towards 13.5 during WOT 3rd-4th shifting without flatlining (yes, I am an Alpina flashed 6AT) and I was able to tune out the flatlining by reducing some top-end load values. It's really been a lot of fun for me! Surprisingly my LPFP and HPFP seem to be holding up pretty well, still. Only 46K miles. Knock wood!
NB - still stock downpipes. I'm afraid the Feds will come after me if I put in kittyless DPs!

[jnat]

I thought E30 was 1.05 fuel scaler?

[jnat]

I see that I was wrong, minimum 1.09 for E25.