Constants

Discuss Bosch (Porsche, BMW, Volvo, etc) tuning topics here. Request definitions, discuss parameters, etc.

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ecuconnection
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Constants

Post by ecuconnection »

lower for bigger injectors
Last edited by ecuconnection on Fri Dec 10, 2010 5:33 pm, edited 1 time in total.
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revlimit
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Post by revlimit »

highlight the whole map, 8 values. Then using that "tool box" feature in tunerpro, keep lowering in 2 values increments until you reach desirable air fuel ratio. Disconnect the 02 sensor before you do anything, and see at what air fuel ratio car idles with stock injectors and 02 sensors unplugged, in my case it is at 12.5afr, warmed up.
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Post by nickmpower »

multiply by stock injector and divide by new injector is what i have heard
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Post by ecuconnection »

nickmpower wrote:multiply by stock injector and divide by new injector is what i have heard
Last edited by ecuconnection on Fri Dec 10, 2010 5:34 pm, edited 1 time in total.
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Post by ecuconnection »

ecuconnection wrote:
nickmpower wrote:multiply by stock injector and divide by new injector is what i have heard
Having a brain fart here

stocks are 19 and bigger injects are 42 . can you show me this equation in number format ?

Thanks
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Post by ecuconnection »

revlimit are the AFM constants allways 1x8
Last edited by ecuconnection on Fri Dec 10, 2010 5:34 pm, edited 1 time in total.
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revlimit
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Post by revlimit »

They are all 1x8 in 1.1 and 1.3 motronics. Motronic 1.0 did not even have that option.

You may not be able to get a tune for 42lb injectors, they are too big for stock air flow meter. You would have to get bigger AFM.
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Post by ecuconnection »

I tested this method and it does not work with motronic 1.7.2
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revlimit
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Post by revlimit »

m1.7.2 is the one ecu ending in 282 digits?

Then for injector adjustment there is a 3 byte map located near 4B80, header in dec is 58, and has values 128 128 128. Lower that to tune for bigger injectors.

there is another map to turn off lambda feedback control, header is 59 so it is RPM based and it is 6 bytes map, values are all 154, tune them all to 0 and ecu will ignore 02 sensor. Then you can tune, after you are done, return the values back to 154

there is one more map for lambda, near that one, with values 140, so ecu might use that one too.

I don't have time to update all the info. I am the only one working on this and everybody just wines
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Post by ecuconnection »

This is for DME 990 that is posted on tunerpro . sw 070
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Post by revlimit »

ecuconnection wrote:This is for DME 990 that is posted on tunerpro . sw 070
Then that is M1.7 and not M1.7.2. The M1.7.2 is the ecu with 282 ending digits.

Do you have comercialy tuned file for 990?
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Post by ecuconnection »

sorry yes its 1.7
Last edited by ecuconnection on Fri Dec 10, 2010 5:35 pm, edited 1 time in total.
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Post by revlimit »

do you know how to edit XDF?
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Post by ecuconnection »

yes very simple
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Post by revlimit »

same goes for 990 soft 070

lambda map 1x6 at 5CF2 and again at 5D3B

turn off lambda before adjusting for bigger injectors. AFR should be around 12.5:1 at idle.

injector constants 1x3 at 4E5B
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Post by ecuconnection »

revlimit wrote:same goes for 990 soft 070

lambda map 1x6 at 5CF2 and again at 5D3B

turn off lambda before adjusting for bigger injectors. AFR should be around 12.5:1 at idle.

injector constants 1x3 at 4E5B
I'm prity sure this is what I did but I will try again tomorrow .
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Post by ecuconnection »

I have found injection constants for motronic 1.7 and 1.7.2 .

They were nowhere near where you suggested revlimit
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Post by revlimit »

Ok then what is it?
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Post by ecuconnection »

1x13 at 4323h =128dec

ecu 990 sw 070

Tune all at same time
Last edited by ecuconnection on Fri Dec 10, 2010 5:36 pm, edited 1 time in total.
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Post by revlimit »

Yeah, that may be it, interesting. I wondered what that was, it is in "constant" part of the bin file.
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Post by ecuconnection »

The next problem is figuring out why WOT fuel map is not used
Last edited by ecuconnection on Fri Dec 10, 2010 5:37 pm, edited 1 time in total.
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Post by DmcL »

can tune for injectors to an extent with the AFM 1x8 but to properly tune for injector size u should tune the 1x3 injector constant map. not sure if that map is in the currently available 173 XDF's on the net and i dont know if its in other bin definitions...

at any rate i have it in my own 173 XDF and i originally tuned for injectors with the AFM 1x8 but found tuning the constants map worked alot better on my E30 with no O2 sensor from the factory, with O2 sensor there is some degree of correction the ECU can do for cold start, etc. doesnt correct without manual adjustment of CTS transfer map if the car has no O2 sensor fitted tho whereas adjusting constants seems to cover that issue.
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Post by revlimit »

DmcL wrote:can tune for injectors to an extent with the AFM 1x8 but to properly tune for injector size u should tune the 1x3 injector constant map. not sure if that map is in the currently available 173 XDF's on the net and i dont know if its in other bin definitions...

at any rate i have it in my own 173 XDF and i originally tuned for injectors with the AFM 1x8 but found tuning the constants map worked alot better on my E30 with no O2 sensor from the factory, with O2 sensor there is some degree of correction the ECU can do for cold start, etc. doesnt correct without manual adjustment of CTS transfer map if the car has no O2 sensor fitted tho whereas adjusting constants seems to cover that issue.
I discovered the 3 value injector constant, first I tought it was barometric correction but then using emulator I see that ecu jumps from first 128 to last 128, so it has to be a control constant for injection. 1x8 AFM map for adjusting for bigger injections I saw that in miller tunes. so DmCL what settings do you use and what size injectors you have now?
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Post by DmcL »

i had 19lb single pintle injectors in for a while and had the volvo MAF conversion and AFM 1x8 tuned along with a tweaked CTS transfer map and a moderate ignition/fuelling tune via wideband/road tuning.

currently have stock AFM back in, new tune with injectors adjusted via constants but with the constants left ever so slightly higher than they should be by calculation, did that deliberately tho and im running between about 12.3-12.8 right across the WOT maps, normal AFR's at part throttle. running E36 4 pintle 323i/325i 0280150415's, smaller than the 19lb singles (calculates out to around 15.5lb at 3 bar pressure, seem to have no trouble supplying enough fuel tho). feels better and slightly better MPG also, at WOT with the new tune and these injectors the car feels like its pulling harder up top and about the same in the mid range compared to the MAF/19lb singles, plan to put the MAF back in and re-adjust the 1x8 on this latest tune and injectors and see how much more i can get from the engine in its current state, maybe make a larger, custom MAF housing/TB elbow since i have a 64mm TB.

miller might not have known about the constants map when they started tuning and peicing MAF conversions together..
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Post by revlimit »

Miller is total scam they don't know much, they only reason why it motivated me to make XDF files for BMW is miller's arrogant customer service.
The 4 pittle injectors deliver finer mist of fuel so power will improve, so whats your injector constant now? at 130? or higher?
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Post by DmcL »

injector constants are set at 120 with the 0280150415's tho by calculation it should be 118 if memmory serves but i deliberately kept it a little higher so i wouldnt have to scale the part throttle fuel maps much.

this is the equation i use to calculate change in constants according to injector size:
Tuning for Injector Flow

We haven’t said that much about injector flow up to this point, but it is equally important to having your engine run correctly. Injector flow is the “obvious” thing that most people change when installing different injectors. Most older systems account for injector flow with a “fuel constant” (it is called many different things in different systems such as… ) – when you change the size of injectors, you multiply the fuel constant by the difference in flow between your old injectors and your new injectors. For example:

1. Fuel constant = 16.4
2. You have 24lb/hr stock injectors
3. You install 32lb/hr stock injectors
4. 24 (old) / 32 (new) = .75
5. New fuel constant = old fuel constant * change in injector size = 16.4 * .75 = 12.3

Keep in mind, this is just a guideline to get you close. You can use the injector size / injector constant to make sweeping, global changes to fueling if your tune is off everywhere. You *should* be able to get a tune very close to where it was before an injector change by changing nothing more than battery tables and an injector size / injector constant.
obviously in our case the fuel constant = 128 as standard. also handy because u can calculate change to constants that are already set for different injectors, if i wanted to work out change from my current constant of 120 for 19lb injectors id just stats with 120 as the fuel constant in the above equation.

full article can be found here:
http://support.moates.net/2010/02/10/th ... tor-model/
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Post by Pacman »

Injector size is only one value that determine the final amount of fuel delivery.
Injector opening time and Battery voltage correction is two other very important values that all ECUs must deal with, and with that in mind all files must contain this information also. The search must go on.

By mappning a lot of different aftermarket EMS one get a sense of all the small things that already is integrated 15-20 years earlier in OEM systems.
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Post by xbyte »

I have the 0261200950 ecu which is 100% the same software as the 0261200990 discussed in this thread.

Im about to install 440cc (42LB) injectors, and the standard injectors seems to be 170cc.

Do i have to adjust every fuel map to match 440cc injectors , or are there anywhere to set it as a constant ? i got a bit confused about everything that is written over here as everyone seems to have different meanings about this constant.
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Post by DmcL »

just following on from this discussion ill put everyones curiosities to rest about tuning for larger injectors.

initially i tried tuning constants map but that had inconsistant results and only allowed a certain amount to be leaned out. i tried adjusting the 1x8 AFM map but this was prior to discovering how the AFM maps work and now knowing how they work DO NOT mess with the AFM maps (there are 3 in total for M1.1/1.3) as they are all calculated together by the ecu and changing anything without plotting a graph in excel or similar will seriously mess up the airflow curve (thats what i call it anyway, may not be proper terminology).

so how do we adjust for larger injectors then? simplez... drop fuelling in part throttle, full throttle, idle and cranking maps. use a wideband and an emulator to first lean out idle fuelling then apply the difference (say -20 from stock values for example) to all relevant fuel maps and fine tune from there. i had much success doing it this way.. much better than tuning constants or messing with AFM maps. i sucessfully tuned for 5-6 different sets of injectors on a stock M20B25 ranging from just a hair larger than stock up to some large-ish 30lb/hr volvo turbo injectors and even on the 30lb-ers the engine ran as good if not better than stock with no problems whatsoever. based on my experience tuning for larger injectors this way i believe injectors as large as 42lb or more could also be made to work perfectly. i wont have confirmation on this till i pick up some huge injectors for my turbo build but i cannot forsee any issues arising tbh.
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Post by tunesss »

a
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Post by aboutton »

100% true
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Re: Constants

Post by woodtime »

Is the conclusion about constants in MOTRONIC 1.3 still unchanged now?
Should I change the fuel maps without changing the constants?
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