Bosch 0280-155-710 offsets
#5
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Re: Bosch 0280-155-710 offsets
Let us know how this work out and what effects it has. Easier tuning, better idle, more stable BLM?
I'm curious about how these affect the operation and what I might expect to see from a troubleshooting perspective from incorrect offsets?
Rick
I'm curious about how these affect the operation and what I might expect to see from a troubleshooting perspective from incorrect offsets?
Rick
#6
Re: Bosch 0280-155-710 offsets
It's on a all stock engine that will not be datalogged. I will post the results after the tgo member lets me know.
I did have one recently I corrected the offsets and the blms were locked before to 120. After the change the went to 130 and I was able to tune. The odd the int always remained at 128 .
I did have one recently I corrected the offsets and the blms were locked before to 120. After the change the went to 130 and I was able to tune. The odd the int always remained at 128 .
#7
Re: Bosch 0280-155-710 offsets
Recommend unplugging the ECM and resetting it after the bin change. Probably want the ECM to forget everything it "learned" with the old offsets and start anew. End user should drive around for a while to log the new BLM's.
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#8
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Re: Bosch 0280-155-710 offsets
I plotted this data, fit a curve to it, and interpolated and extrapolated the numbers corresponding to the TPI table for pulse width voltage offset. I plugged in the numbers and let TunerPro find the closest matches, etc. Here's what I came up with:
(Edit: added RBob's zero voltage failsafe and also changed low voltage and high voltage to reflect OEM style mapping values):
GD
(Edit: added RBob's zero voltage failsafe and also changed low voltage and high voltage to reflect OEM style mapping values):
GD
Last edited by GeneralDisorder; 05-25-2017 at 10:28 PM.
#9
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Re: Bosch 0280-155-710 offsets
I was about to find out how well this works but just as I was about to start logging my cooling system gave out. So I'm a few days out testing these settings. Hopefully I didn't blow the head gaskets out of her or I'll be testing this a month from now after I swap in my spare 350.
GD
GD
#10
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Re: Bosch 0280-155-710 offsets
RBob.
#12
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Re: Bosch 0280-155-710 offsets
There was a thread about these new Bosch injectors a while back. I contacted FIC about their 22s and they told me they were the exact same as the Multecs. Id like to know if anyone has confirmed this or not because a recent trip to the dyno has resulted in my car running a bit lean on the top end
#13
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Re: Bosch 0280-155-710 offsets
Well I got my cooling system sorted last night.
The offsets seem to be working well. I did have to lower the injector constant to 22 lbs (these are "24's").
I have a feeling that if you use the factory offsets the injectors run ok-to-decent with the factory offsets and only changing the injector constant to 24. If you program the actual constants correct for the injectors they act like a 22lb injector (Witchunter says they flow 22).
So yeah..... more testing needed but that's my feeling right now.
GD
The offsets seem to be working well. I did have to lower the injector constant to 22 lbs (these are "24's").
I have a feeling that if you use the factory offsets the injectors run ok-to-decent with the factory offsets and only changing the injector constant to 24. If you program the actual constants correct for the injectors they act like a 22lb injector (Witchunter says they flow 22).
So yeah..... more testing needed but that's my feeling right now.
GD
#14
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Re: Bosch 0280-155-710 offsets
I edited the table and the above post to include RBob's fail-safe recommendation and also the low and high voltage numbers to better represent the OEM style mapping when voltages are way outside the normal ranges.
What role does the base pulse width play?
GD
What role does the base pulse width play?
GD
#16
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Re: Bosch 0280-155-710 offsets
So lowering the base pulse width would probably account for having to tell the ECU the injectors are a different size..... lower the BPW, and the ECM fires the injector for a longer interval (or more pulses)? - requiring a change to the injector size constant (smaller) to bring the system back into equilibrium. Anyone have the actual formula the ECM uses? I'm guessing that the BPW factor may have a greater effect at lower pulse width (idle, etc), than it does at higher pulse width? When I dropped this table and BPW of 0.50 into my system all my BLM's shot up and I had to tell the ECM the injectors were 22's not 24's. But that does jive with at least one source (Witchunter) that claims they are in fact 22.5's or so.
GD
GD
#17
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Re: Bosch 0280-155-710 offsets
There was a thread about these new Bosch injectors a while back. I contacted FIC about their 22s and they told me they were the exact same as the Multecs. Id like to know if anyone has confirmed this or not because a recent trip to the dyno has resulted in my car running a bit lean on the top end
The offsets are important for driveability and lower speed operation. Along with being able to get a decent idle.
RBob.
#19
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Re: Bosch 0280-155-710 offsets
I've found it is worth the money to either buy new injectors or have your injectors tested for correct offset and small pulse width correction values. If it is a daily driver, the smooth idle and gas mileage increase, especially low speed city driving will soon pay for the cost. The numbers you get off the internet or with the "rebuilt" may or my not be close enough. It is very frustrating to try to get a good tune at small pulse widths without the correct numbers.
#20
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Re: Bosch 0280-155-710 offsets
I'm referring to the scalar's "Min IBPW" and "Default IBPW"
I assumed one of these are what the sheet from Southbay referred to as:
MINPW Minimum repeatable fuel pulsewidth at 39.15 psid: 0.521
Then there is a multiplier for 44.95 psi fuel pressure.
So I set this scalar to 0.50 (it was set to 1.60 in the factory 19lb PROM).
??
Thanks!
Rick
Last edited by GeneralDisorder; 05-26-2017 at 06:05 PM.
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Re: Bosch 0280-155-710 offsets
RBob.
#22
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Re: Bosch 0280-155-710 offsets
How do those scalars effect the fueling calculation? Does it just compare the results of the calculated pulse width and if lower than the minimum then it defaults to the minimum instead?
Or is it used in the calculation?
I'm just trying to learn how all this interacts. Do you have the fomula used in the code for calculating injector pulse width so I know what scalars and other variables are used - that I might be able to better tune for different injectors?
Where might I find a disassembled (and preferably commented!) $6E? I'm no stranger to assembly and I would love to help the community by sorting out this Bosch 3 injector situation once and for all. I'll find someone or some way to test the injector offsets myself if I have to. I have an injector flow bench and I'm not afraid of modifying it to get answers.
Thanks!
Or is it used in the calculation?
I'm just trying to learn how all this interacts. Do you have the fomula used in the code for calculating injector pulse width so I know what scalars and other variables are used - that I might be able to better tune for different injectors?
Where might I find a disassembled (and preferably commented!) $6E? I'm no stranger to assembly and I would love to help the community by sorting out this Bosch 3 injector situation once and for all. I'll find someone or some way to test the injector offsets myself if I have to. I have an injector flow bench and I'm not afraid of modifying it to get answers.
Thanks!
#23
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Re: Bosch 0280-155-710 offsets
Link in the Tuning Guide Book sticky under the '7165 ECM:
https://www.thirdgen.org/techbb2/sho...hreadid=293764
RBob.
https://www.thirdgen.org/techbb2/sho...hreadid=293764
RBob.
#24
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Re: Bosch 0280-155-710 offsets
Ok so I think I understand now:
The pulse width vs battery voltage table is going to affect lower speed operation much more than higher speed so in general if my BLM's are high at low throttle/low rpm then increasing this offset will add more fuel to bring them down but will not have much effect at higher cruise.
Injector size scalars are going to affect fueling everywhere.
So what effect does the Low Pulse Width offset vs. Base Pulse Width table have? I'm not seeing much difference by changing this table. I've zeroed it out and it doesn't seem to do anything really. Is it because I'm running Bosch EV6 injectors and they don't really need much, if anything, here?
GD
The pulse width vs battery voltage table is going to affect lower speed operation much more than higher speed so in general if my BLM's are high at low throttle/low rpm then increasing this offset will add more fuel to bring them down but will not have much effect at higher cruise.
Injector size scalars are going to affect fueling everywhere.
So what effect does the Low Pulse Width offset vs. Base Pulse Width table have? I'm not seeing much difference by changing this table. I've zeroed it out and it doesn't seem to do anything really. Is it because I'm running Bosch EV6 injectors and they don't really need much, if anything, here?
GD
#25
Senior Member
Re: Bosch 0280-155-710 offsets
And why have 2 scalars, "min...." and "default...."? Seems like one would contradict the other, but maybe they are used differently, in the code?
Just wondering, if you dont mind.