TunerPro User Forum

So, I've been tuning cars professionally for about 10 years now. My personal car is a 95 M3 with a Holset HX35 compressor mated to a machined .82 ar Garrett turbine housing, Ford MAF and 42# injectors. I've been researching for almost a year, studying maps in tunerpro and WinOLS. I have a basic understanding of how it all works.

There's a lot of misinformation out there and non-functioning maps. Is there a verified turbo bin that exists that I can study?

Also, the xdfs that I have just have a check box to disable o2 feedback, is there a threshold map, and if I disable the o2 to tune then enable o2 feedback, will the o2 target the new values?

Last, when scaling for larger injectors, load has to be scaled as well, obviously necessary but in my head I have the idea that the increased maf values from positive pressure would put the ECM back up into higher load axis. Am I way off?

Sorry if these are basic questions it's hard to find definitive answers. I appreciate any input. Thanks!

Sorry but you are way off. You need to rescale every table, constant that references load by the injector constant. There are like 30 some. If this is not done you will have a lot of problems. This was posted elsewhere.

NickG
9-30-2008, 07:40 PM

With a naturally aspirated motor and stock calibration, the load value will range anywhere from 8-10ms at WOT. Ironically that also maxes out the injector duty cycle for the stock injectors (not by coincidence either).

Now, let's keep the same injector size, so the injector constant (K) remains unchanged. But, let's add some boost, say 50% more airflow worth. This means the calculated load should now be 12-15ms.

But wait a second....the load variable can only read up to 12.75ms. Oh no, what do we do?

Simple, we increase the injector size (since we need larger injectors anyway to fuel the extra airflow), and change the injector constant (K) a corresponding amount. Now our new, modified load variable is back into a useable range and not maxed out.

Of course, changing the K value also means you HAVE to change all of the load references in the cal by the corresponding percentage. If you don't, things won't run properly.

You can Pm me for more info.

I've read that before, I understand that and have mimicked the motions in the software, I've yet to try it on my car beasue its not done yet. My question was poorly articulated.

I have two bins, which look like FI bins. The injectors are scaled as well as the load. In the part throttle maps and WOT ignition maps the middle to right side of the load axis is increased beyond the original values, I assumed this was done to increase resolution while in boost while keeping the cell data close to the original values, where other, what I assume are FI maps have a load scaling across the board with much larger cell values than a stock bin.

Like I said before, this is me sifting through all the bullshit. Im not even sure if I'm still getting what I'm trying to ask across clearly.

So you have to make sure all load axis for all the constants and any reference tables. You don't need to rescale the load axis for any of the fuel or ignition tables. Plus you can't go past 12.75m.s. of load so you can't rescale them to like 15m.s. . You could change the axis to get more resolution out of boost or in boos, but not necessary. If you use a scanner you will be in boost between 2.0-2.5m.s.of load. Where a stock car this would be light cruising area. The injector constant and the maf curve will dictate the engine load in m.s. Also unless you read the hex and changed the break points for load and rpm, they will most likely be wrong. If I sent you my xdf It will Auto scale the Rpm and load break points so they will always be correct when viewing in tuner pro.

If you start out with a turbo bin everything will be rescaled in the background. You will have to input a maf curve and then shift the whole curve to get the load to read correctly. Then just adjust the fuel tables. The fuel tables will not change your load reading. So if your maf curve and load scaling is correct and you switch injectors you can just adjust all fuel tables by the percentage change in injector size, and this will get you close. If the injectors are alot larger, will have to adjust the battery voltage offset for the injectors. What maf are you using? You can send me the two bins and I can make sure they are rescaled.

I appreciate your response. I know a lot of people across all the forums just want everything laid out for them in simple terms. I'm not looking for that. And if I do ask for information, I just want you to know that I've spent countless hours researching and studying, trying to understand how the system works. I've been tuning mainstream systems with user interfaces and support for 10 years. I could easily just go that route but I really want to learn this. I don't want to let it beat me, cave in and go buy a megasquirt after all this time spent. I'm on a constant quest for knowledge.

That being said, what you just said is a new part of the puzzle. From what I gathered if you scale injectors, say, 40% you have to find all instances of load and scale them a corresponding amount. My understanding, which is most likely wrong, open winOLS find all the maps that contain D5 and scale the axis 40%, working backwards from the final value of the axis.

I'm using a Ford slot maf at the moment just to see if I can get it worked out before I buy a HPX maf. From what I've read a 3" tube should be able to support over 300hp which is what I'm aiming for until I figure it out. I'm also using 42# injectors.

I really don't want to start with a turbo bin. I know why certain things have to be done, I just really want to understand how... Unless that involves using IDA or something. That is completely out of my realm of understanding. Then I'd have to find a verified bin somewhere.

Omniscient,
The stock BMW 3" MAF is good to 350whp, the 3.5" is good to 500whp. No resistor was used just stock wiring to MAF, all the adjustment was made in fuel maps. Evil's xdf is a very good xdf.

HI Brian Shor. Looked at the turbo tune you sent me and it has all the load references re scaled by the injector constant.

Is that the 506 xdf you posted about?

I don`t think they posted it up to the downloads yet.

Do you happen to have or know where I can find some material to study? Bins, literature, whatever?

PM me your email

Evilm3,
In the xdf I had put together over 1/2 a decade ago for the 413 I never created a parameter for readily scaling the injector size, I just went through all the fuel tables and made the adjustments to get the desired AFRs. It would have been easier to just rescale injectors but it didn't happen that way.

Hey, Brian. Do you happen to have any material I can study? Anything helps, even just a verified FI bin that I can compare to other bins. I downloaded the zip file floating around the forums that has some FI files in it but theyve all been altered and some of the data doesn't make sense.

I'm not trying to beg for handouts, I have spent the least year searching high and low for information but a lot of it is misinformation by people like me, trying to learn and vague cynicism by other professionals.

I emailed evilm3 but haven't heard anything back.

Can anyone send me that 506 xdf?

I'll get the XDF posted to the site. Sorry for the delay, evilm3666.

It's there, now, at the end of the definition list under BMW.

Awesome thank you both!

Omniscient,
Please remember that most of us on forum are not able to be on everyday so give evilm3 a few days to respond.
In terms of literature for tuning the bosch dme I can't say I have come across anything formal, it has just been info from post on various forums.

I've tried downloading the new 506 xdf, the link seems to be broken.

There's a missing "/" between BMWBMW in the link. I emailed the correct link to myself so I could right click and download in case anyone else has tried.

I spent some time and did a data comparison in WINOLS between a stock 506 and the turbo BIN I have and found somewhere around 45 instances where the load has been scaled. Appears to be scaled for 60lb injectors.

I wonder if the right direction now, would be to add these tables to a XDF in a specific area for scaling injectors?

I've narrowed it down to 33 necessary maps and a handful that were modified but not necessary, rev limiter, idle speeds, etc. A lot of the maps were already defined in various XDFs but some I can't find any information as to what they control.

Omniscent,
Seeing your last post I am wondering if you are using Evilm3's 506 xdf. Evil's xdf has the parameters laid out and there should be little doubt as to what they represent, so tuning your car should now be a breeze.
Eons ago when I had created my xdf for the 413, it was only fuel and ignition maps and the rpm and load references were calculated guesses (going from right to left). Evil's xdf has the rpm and load references extracted from the bin so you know the actual rpm and/or load point you are at.
Is it that you are trying to tune your car, or is it that you are trying to learn to write xdf?

I've had my car running for a week now off the map that evilm3 sent me. The map he sent me is scaled for 60lb injectors, I'm using 42lb. So I increased all the fuel maps by 1.42%, 60/42=1.42, I want to adjust the MAF table but I'm not sure what the idle AFR should be with the O2 sensor unplugged, I think I read somewhere that it's 12.5:1, does anyone know if this is true? If so I think if I increase the MAF table to reach 12.5:1 it'll get my load reading into the ball park of what I need.

AFR @ idle and cruise 14.7
If you are running a tune calibrated for the same maf you are using
Then you should not adjust the maf curve. This will change the load reading. Just adjust all the fuel tables until the AFR is correct.
Adjusting the fuel tables does not change the load.

Omniscent,
Why do you have the O2 sensor unplugged? Feedback from the O2 allows the ECU to make a smoother transition from PT to WOT.

Brian is correct. Just turn the o2 off when tuning then turn it back on when finished.

I am using o2 feedback, I had it disabled to tune, a stock file and car with the o2 disabled will idle around 12.5-13afr. The car was running lean and I was out of adjustment in the fuel tables since I'm using 42lb injectors on a file scaled for 60lb and the MAF was reading low, keeping the car in closed loop under part throttle boost. I increased the MAF table 8% and it brought everything back into a usable range and gave me headroom in the fuel tables, gave the factory open loop idle AFR and brought the load up enough to go into open loop under part throttle boost.

Could just be the the placement of the Ford MAF but for $20 it's great, it's just about maxed out at 15psi, had a multimeter hooked up and was getting about 4.6v at peak torque.