Fuel Rail High Pressure Sensor Upgrade

[Erich]

Originally Posted by SSinstaller Yeah, but my fuel system is on steroids LOL.. I can not target my FP like that. I tried running a 2050psi valve and still spike high enough to get the cut even targeting OEM fuel pressures.. I see 2000psi running the OEM RV and targeting ~1900psi... I guess I'm stuck waiting for a port injection solution...

Must be those injectors. Pull them off the car and send them to me and I will test to verify.

[06Speed6]

Fail

[phate]

lol, few hundred references. fuck.

[Dano]

no shit...I'd say its time for a dedicated piggyback for the fuel sensor...no?

or is there not enough voltage to scale it and you're right back to the SB limitations?

[superskaterxes]

Originally Posted by Dano no shit...I'd say its time for a dedicated piggyback for the fuel sensor...no? or is there not enough voltage to scale it and you're right back to the SB limitations?

how old r you? dont u remember the famous DJCKT?!?!?!

[Dano]

Originally Posted by superskaterxes how old r you? dont u remember the famous DJCKT?!?!?!

yessssss I absolutely do!!!! those things were poised to sell like hotcakes...then cobb up and started back on development for our platform LOL

guess we are back to the DJCKT..

@djuosnteisn...ready to get back into production??

[taf0422]

subbing.

[Erich]

I am running a 2150 RV, and targeting (with good success) in the 2030-2050 range. I don't seem to get any cut on the rare occasion it spikes to above 2071. Maybe something they changed from the MS6 to MS3 ECU. Has Cobb looked at the MS3 ECU for this as well as the MS6? Do they know if the same hardcoded bullshit is in the MS3 ECU?

[Ziggo]

Just when things were looking up...


Zigatapatalka

[superskaterxes]

chris,

why dont u ramp up FP so that u dont get a spike?

[SSinstaller]

Originally Posted by superskaterxes chris, why dont u ramp up FP so that u dont get a spike?

I've tried every possible FP combination and it still spikes..

I tried targeting 1000psi at WOT and it still pegged the sensor with the 2350 and 2050psi RV's..

IMO, the only reason my car is driveable is the OEM RV opens at 1886psi, and can bypass a shitload of fuel.. I still sometimes see logs where my FP touches 2050psi..

[Ziggo]

I would not put much stock in the injector duty cycle value. It is known to have issues and doesn't account for the DI rail pressure. With DI it seems the soft fueling limit is found by spark blowout not by running lean so I wouldn't say you are out of fuel till you start seeing blowout.

I bet your MAFCAL cal is spoofed lower than actual to adjust for those injectors. That's the only way we have to account for fueling changes right now. (spoof the MAFCAL low to force smaller injectors pulsewidths for upgraded injectors that flow more, spoof the MAFCAL high to force larger pulsewidths to account for E85....)


Zigatapatalka

[SSinstaller]

Originally Posted by Ziggo I would not put much stock in the injector duty cycle value. It is known to have issues and doesn't account for the DI rail pressure. With DI it seems the soft fueling limit is found by spark blowout not by running lean so I wouldn't say you are out of fuel till you start seeing blowout. I bet your MAFCAL cal is spoofed lower than actual to adjust for those injectors. That's the only way we have to account for fueling changes right now. (spoof the MAFCAL low to force smaller injectors pulsewidths for upgraded injectors that flow more, spoof the MAFCAL high to force larger pulsewidths to account for E85....) Zigatapatalka

The InjDC numbers may be off, but when VD consistently shows my HP start to level off as the DC passes 100% I have to think that the DC is the cause.. It may not be a lack of fuel, but fuel injected too late. All the soot we get is a good indication of incomplete combustion..

I don't know that I agree about the spark blowout issue, I've logged some very high maf g/s numbers and never had blowout issues... Maybe the oem fuel spray pattern is wetting the injectors(and my injectors somehow don't have the same issue), or it could be my lower compression... There are way too many variables to say hitting the fueling limit is causing the blowout.

I really don't know about the MAF cal, I made my adjustments to fix the fuel trims and match my WOT targets, but I haven't seen enough big maf sensor cals to say if mine is skewed any.. IIRC on my cal the 3.25" housing tops out somewhere around 600~650g/s, but I need to rescale it since I installed the MAF straightener.

[Ziggo]

Originally Posted by SSinstaller The InjDC numbers may be off, but when VD consistently shows my HP start to level off as the DC passes 100% I have to think that the DC is the cause.. It may not be a lack of fuel, but fuel injected too late. All the soot we get is a good indication of incomplete combustion.. I don't know that I agree about the spark blowout issue, I've logged some very high maf g/s numbers and never had blowout issues... Maybe the oem fuel spray pattern is wetting the injectors(and my injectors somehow don't have the same issue), or it could be my lower compression... There are way too many variables to say hitting the fueling limit is causing the blowout. I really don't know about the MAF cal, I made my adjustments to fix the fuel trims and match my WOT targets, but I haven't seen enough big maf sensor cals to say if mine is skewed any.. IIRC on my cal the 3.25" housing tops out somewhere around 600~650g/s, but I need to rescale it since I installed the MAF straightener.

I am not saying that its not an issue, I have been harping about the fueling limitations ever since DJ did his investigation a long way back. Even if its inaccurate, fueling towards the spark is a problem like you said you don't get that full power out of the extra flow at that point. I am just saying that based on what I have seen, we hit the HARD limit for fueling when we get spark blowout, not by running lean. It may not be optimal, but you can still gain power by pushing the IDC beyond 100% and making soot. Late shitty combustion of fuel injected late is still better better than less fuel/air.

Originally Posted by SSinstaller I have no idea how the maf cal correlates with the load, but for me at least 400-450 g/s is 2.5-2.8 load..

MAF correlates to load directly thru RPM.

LOAD*(some constant)*RPM = MAF

RPM being constant, a higher MAF value will result in higher load.

[SSinstaller]

Originally Posted by Ziggo I am not saying that its not an issue, I have been harping about the fueling limitations ever since DJ did his investigation a long way back. Even if its inaccurate, fueling towards the spark is a problem like you said you don't get that full power out of the extra flow at that point. I am just saying that based on what I have seen, we hit the HARD limit for fueling when we get spark blowout, not by running lean. It may not be optimal, but you can still gain power by pushing the IDC beyond 100% and making soot. Late shitty combustion of fuel injected late is still better better than less fuel/air.

At least in my case there seems to be no power to be had much past 115%, and EGT's start getting out of hand.

Originally Posted by Ziggo MAF correlates to load directly thru RPM. LOAD*(some constant)*RPM = MAF RPM being constant, a higher MAF value will result in higher load.

We don't know how the ECM is actually using the MAF value in the load equation, is it directly off the voltage, or the maf g/s, or the % of the max mafV or MAF g/s.

The calculated load is actually derived from the MAF, IAT, RPM, and BARO--which is why I stated that using a different manufacturers MAF with different scaling on the IAT could throw off the load calculation.

[phate]

Originally Posted by SSinstaller But, we don't know how the ECM is actually using the MAF value in the load equation, is it directly off the voltage, or the maf g/s, or the % of the max mafV or MAF g/s.

It is g/s. This is the only way it could work, really. My E85 scaling wouldn't work if the MAF V:g/s conversion didn't happen.

Actually, if you think about it, if it wasn't g/s we couldn't do MAF cal's, run larger diameter intakes, run different fuels at different stoich ratios, etc. g/s has to be the driver.

[Realgib3]

Originally Posted by Ziggo I would not put much stock in the injector duty cycle value. It is known to have issues and doesn't account for the DI rail pressure. With DI it seems the soft fueling limit is found by spark blowout not by running lean so I wouldn't say you are out of fuel till you start seeing blowout. I bet your MAFCAL cal is spoofed lower than actual to adjust for those injectors. That's the only way we have to account for fueling changes right now. (spoof the MAFCAL low to force smaller injectors pulsewidths for upgraded injectors that flow more, spoof the MAFCAL high to force larger pulsewidths to account for E85....) Zigatapatalka

Yeah I've recently found that load plays a huge role in fueling still. I'm actually having a major issue with it right now and I'm completely lost as to why it's happening, but I'm gonna have to run "load cap' like scaling to get it to run right until I figure it out.

Problem: Fuel pressure drops and I go rich at high load. I originally thought this was due to a dying set of pump internals, but it's not. How do I know? I ran 4 MAF's in my car last week trying to find one that worked for me to dyno on.

My stock MAF= FP problem, hitting 2.3x load
Toyato Ech MAF= FP Problem even worse with MAF scaled down a tone, hitting 2.6-2.8x load
Subaru MAF= NO FP Problem with MAF scaled UP 18-20% and hitting only 1.8-2.0 load
Used MS3 MAF= FP Problem, hitting 2.3-2.5x load again...

I'm totally baffled by this, so I'm either throwing the Suby sensor back in, or scaling all my tables to run this sensor, but show lower load.

I'm boost tuning and there aren't any load cuts/targets I could be hitting in the map that are doing this either form what I can tell.

Also... If you didn't catch it... shouldn't I be showing MORE load if the MAF is scaled way UP? and LESS load if it's scaled way DOWN? Cuz I'm seeing exactly the opposite now...

Ugh, my brain is fried right now. HELP!

Originally Posted by SSinstaller I really don't know about the MAF cal, I made my adjustments to fix the fuel trims and match my WOT targets, but I haven't seen enough big maf sensor cals to say if mine is skewed any.. IIRC on my cal the 3.25" housing tops out somewhere around 600~650g/s, but I need to rescale it since I installed the MAF straightener.

My 3.25 cal on Mazda sensors are in the 620 range, so yours sounds about right.
My Toyota sensor was all the way down to like 500 and my Suby cal is at 725 peak g/s

[SSinstaller]

Originally Posted by Realgib3 My stock MAF= FP problem, hitting 2.3x load Toyato Ech MAF= FP Problem even worse with MAF scaled down a tone, hitting 2.6-2.8x load Subaru MAF= NO FP Problem with MAF scaled UP 18-20% and hitting only 1.8-2.0 load Used MS3 MAF= FP Problem, hitting 2.3-2.5x load again... I'm totally baffled by this, so I'm either throwing the Suby sensor back in, or scaling all my tables to run this sensor, but show lower load. I'm boost tuning and there aren't any load cuts/targets I could be hitting in the map that are doing this either form what I can tell. Also... If you didn't catch it... shouldn't I be showing MORE load if the MAF is scaled way UP? and LESS load if it's scaled way DOWN? Cuz I'm seeing exactly the opposite now... Ugh, my brain is fried right now. HELP!

The MAFv and IATv are used in the load calculations.. If the IAT is significantly different the load calculated will be different as well..

[Realgib3]

Just got a pm back from jacksonms3. I had told him it looked like he may be having some of the same issues I was because of what his logs looked like, but I originally thought hismaf was scaled way up for some reason, but it's not. His maf cal peaks out in the 400snew g/s and he's seeing crazy high loads. Like 2.8-3.0 load...

Am i missing something here or is this strange?

Since when does bringing the MAF cal down make load read way higher? In the load cap days... we scaled it way down to make load read lower... when did this change?

[Dano]

this is news to me but I don't have much experience with the larger 30 series and larger turbo cars.

so when you neg scale do your g/s get lower and load still goes up?

also make sure all your TRLS ABS targets are above the cobb 2.5 load range...not sure how that would effect fueling but get them out of the way anyway.

[SSinstaller]

I have no idea how the maf cal correlates with the load, but for me at least 400-450 g/s is 2.5-2.8 load..

[Ziggo]

Different MAF sensors will certainly screw with things, and i wouldn't expect other manufacturer sensors to be plug and play, but the beauty of hot wire MAF sensors is that you get density for free. MAF voltage is directly proportional to the mass of air flowing past it, its not measuring speed that then has to be corrected for density of the air. That proportion is what we calibrate.


Zigatapatalka

[Realgib3]

scaling with my new mazda maf actually worked as it should, not like I experienced with other mafs. So. Neg scaling gave me less calc load and visa versa.

Iats seemed dead on with the other sensors tgough too so I think its something else in the equation causing these oddities.

[Grab21]

Any updates from cobb?

[Erich]

Nope, their ATR release yesterday looks like it added some FP monitoring, but nothing to scale the FP Sensor (in fact it looks like they removed the tables to do that on the GenPu)

[Alpha]

Originally Posted by Erich Nope, their ATR release yesterday looks like it added some FP monitoring, but nothing to scale the FP Sensor (in fact it looks like they removed the tables to do that on the GenPu)

I heard they cut it until they could release the total FP Sensor scaling ability.

[superskaterxes]

^^^^ this is correct

[06Speed6]

Anthony were you the one who bought the sensor upgrade? Steve at versatune was wanting to get his hands on one to help him decipher and test the code.

[superskaterxes]

Originally Posted by 06Speed6 Anthony were you the one who bought the sensor upgrade? Steve at versatune was wanting to get his hands on one to help him decipher and test the code.

if im not mistaken kmac did as well. does he want to purchase/borrow it from me? send me a PM/email if so.

[06Speed6]

0265005303 is that the bosch part number that you have?

Nm I read back in the thread.

[Erich]

Discuss here:
Fuel Rail High Pressure Sensor Upgrade