Hidden flow rate modifiers (feel free to chime in Neo, I mean... Chris)

[DSteck]

I've noticed that some operating systems change the injector flow rate despite the modifiers we have access to all being set to 1. Later systems seem to have a bigger variance. Why do I bring this up? Last night, I was dealing with a CTS-V that was converted to a boost referenced return fuel system. As a result, the flow rate was entered as the same value at every pressure. However, when logging, I noticed the flow rate increased as alcohol content increased (it's been converted to flex fuel with an ethanol sensor). Beyond that, the flow rate would increase greatly when going WOT on ethanol. It jumped from 98 lb/hr to 105 lb/hr, which made it lean on the ethanol. On gasoline, it didn't do this. Now... I know that the mass flow rate does indeed increase as ethanol content increases, but it seems there are modifiers that we don't have access to throwing this thing off.

Any chance some digging can be done to see what's up? I think I have a log of what's going on, so I'll try to post it this evening.

[Bluecat]

[Bill@HPTuners]

post the log, the stock hpt file & modified one and we can take a look.

[DSteck]

post the log, the stock hpt file & modified one and we can take a look.

Don't tell me what to do!

[NTIMID8]

For shiggles if it were me, I would disable all the flex fuel and set the Stoich rate to match and then re-test to see what it does. I have converted a couple and then unconverted due to this and one other oddity I couldn't get around.

[DSteck]

Here's the log. You can see it change drastically at about the 2:00 mark.

Attached is a stock file for the car, and file with the flex fuel stuff enabled as well as ID850 data in boost referenced format.

[Frost]

For shiggles if it were me, I would disable all the flex fuel and set the Stoich rate to match and then re-test to see what it does. I have converted a couple and then unconverted due to this and one other oddity I couldn't get around.

I did ONE and had the same result (and also didn't leave it converted).

[DSteck]

There's ways around it. It's not a big enough concern to stop converting. This was probably the 30th one I've done and finally decided to say something.

[Chris@HPTuners]

ok I added two extra tables, there are no more left to add! Only added for E67 OS 12632176 for now but will be added to all E38/67 over the next week or two.

2.24.503 or later.

IFR Mult vs. Fuel Flow
IFR Mult vs. MAP

BTW, I've also been testing a new OS patch to enable the pressure delta to go into boost, instead of maxing out at equivalent barometric pressure. This means the IFR table will actually go into boost areas without the SC Fitted option being set.

Chris...

[ke5gnz]

Chris, i have a question once you add these tables to the E38/67 how will we be able to retrieve? Do we need to reload download the software or what? thank you

[DSteck]

ok I added two extra tables, there are no more left to add! Only added for E67 OS 12632176 for now but will be added to all E38/67 over the next week or two.

2.24.503 or later.

IFR Mult vs. Fuel Flow
IFR Mult vs. MAP

BTW, I've also been testing a new OS patch to enable the pressure delta to go into boost, instead of maxing out at equivalent barometric pressure. This means the IFR table will actually go into boost areas without the SC Fitted option being set.

Chris...

Like I said... Neo. You rock. Seriously, I very much appreciate the effort put forth to give users the maximum control over their calibration. I wish I had some way to help.

It's interesting that there's the initial IFR vs Delta Pressure table, and them a multiplier based on MAP. Come to think of it though, the worst offending cars are cars with a FPCM, so maybe it's related to the the dynamics behind varying rail pressure instead of relying on the internal regulator.

How much of a bribe is required for the IVT coefficients?

Very cool on the patch. Was there ever any headway on adding access to be able to kill barometric pressure updating? I know the enhanced OS automatically kills it, but it'd be nice to be able to do it on a stock OS too. I'm demanding, I know.

[planethax]

Chris, i have a question once you add these tables to the E38/67 how will we be able to retrieve? Do we need to reload download the software or what? thank you

Yes, download latest from your customer page when tables are added.

[Chris@HPTuners]

Like I said... Neo. You rock. Seriously, I very much appreciate the effort put forth to give users the maximum control over their calibration. I wish I had some way to help.

It's interesting that there's the initial IFR vs Delta Pressure table, and them a multiplier based on MAP. Come to think of it though, the worst offending cars are cars with a FPCM, so maybe it's related to the the dynamics behind varying rail pressure instead of relying on the internal regulator.

How much of a bribe is required for the IVT coefficients?

Very cool on the patch. Was there ever any headway on adding access to be able to kill barometric pressure updating? I know the enhanced OS automatically kills it, but it'd be nice to be able to do it on a stock OS too. I'm demanding, I know.

I think the options are there to cater to the different types of pumps, mechanical/electrical regulators and if constant pressure or vac-referenced. For a vac referenced reg there might be some dynamic that depends on the manifold vacuum that isn't quite linear.

[DSteck]

Is there anywhere I can send money as a thank you for continued development and support?

[Chris@HPTuners]

Is there anywhere I can send money as a thank you for continued development and support?

hahaha!!

[DSteck]

I was serious.

[planethax]

Is there anywhere I can send money as a thank you for continued development and support?

https://www.hptuners.com/customers/upgrade.php

LOL
Sorry couldnt resist.

[NicD]

BTW, I've also been testing a new OS patch to enable the pressure delta to go into boost, instead of maxing out at equivalent barometric pressure. This means the IFR table will actually go into boost areas without the SC Fitted option being set.

Perfect!

I second what dsteck said about the Baro updating as well...

[Bill@HPTuners]

This is what we like to refer to as "opening a can of worms" lol

[DSteck]

Any word on when these additional parameters will be rolled out on the other E38/E67 setups?