From what i've peak torque is generally where the greatest fuel requirement is and if ve tables are the main fuel supply, then i expected highest table value to be at my peak trq areas which i thought would be 4500 ish but it may be higher as 5000-5200 looks to be leaning out even tho table values arent really increasing. Then again i am not sure. With the fuel pressure rising from second pump maybe my table isnt going to rise like expected.

 

The number of fuel pumps supplying the fuel system will have no affect on injector pulse requirements.

 

What is the fuel pressure under full boost?

-- Joe

 

It would change the injector flow rate if the pressure does spike however i do not know what the pressures are when it kicks on. Its just my guess as to whats goin on because i really dont see where the extra fuel comes from unless its the afr fuel ratio table as i have it taper off as boost goes up. I could try disconnecting the second pump. My pe mode afr targets same values at those low boost ranges so that cant be it. Unless thats the reality that under more boost it doesnt need as much "ve" fuel but that makes no sense to me as more power requires more fuel.

 

If your fuel pressure regulator is functioning properly, there will be no pressure spike when the second pump comes in, and if there was, it should be so short, that you wouldn't see a continued drop in necessary fuel requirements.

 

Installing a fuel pressure sensor and logging it is an eye-opener. I won't have it any other way on a high perf vehicle.

RBob.

 

exactly, i chased down a gremlin with my rig until i figured out it was an FPR failure. if it was in the datastream i probably could have figured it out alot sooner

 

Peak torque and peak VE go hand-in-hand. Peak HP is where the greatest total fuel requirement is. I believe this is what you meant as the rest of your post states this. As the RPM increases the injectors fire more often, so there is more fuel being delivered.

The peak VE is typically a tad above peak torque as the engine has frictional losses.

It is very possible that the second pump is driving up the fuel pressure. I recently went through the same thing, but worse. The primary pump was not able to keep up at 100 Kpa (0 boost).

Then when the secondary pump came on at about 3 psi the fuel pressure went to 58 psi. So the engine was going from being lean to so dead rich it would start to choke on the fuel.

RBob.

 

I will have to try logging it to see what happens. I dont have a gauge in the line where i can see it while i drive but will need to figure something out. Oh well as long as motor gets the fuel it needs i dont care what ve table looks like. I dont think i am close to maxing out first pump with just 4 psi and 3600-4000 rpm. So i wouldnt think second pump coming on would be a huge spike but its the only thing i can think of to describe what i am seeing

 

I have dual pumps with a gauge in the car, I also can logg the fuelpressure.

I'll se if I can take some notes next drive on how the fuel pressure changes when the nr2 activates. For what I recall there is a slight bump in pressure if I activate nbr2 during cruise, using a boost switch I'm not sure the pressure rises need to check.

My fuel system is AN8 to a Y-block then dual AN6 to fuel lines then a Aeromotive regulator and a AN8 return.........

I also chased a fuelproblem for very long time, and it led me to the current setup with AN8 and a Y-block.......

 

Your -8 return (1/2") will help a lot in keeping the fuel pressure in check when both pumps are running. The stock f-body return is a 5/16" line. The car I'm working with has a 1/4" return line. Which is easily overwhelmed.

RBob.

 

I got -8 feed but -6 return and everthing is in series. Should be enough fuel system for 1000hp.

Gta when does your pump come on? Mine is a hobbs switch at 4-5 psi

 

What is the total GPH flow?

Why don't both pumps always run?

-- Joe

 

Dont need them all on all the time. Just wear them out and heat the gas more. I rotate which pump stays running and which one is for boost from time to time. Just twin walbro 255's. Setup has done 1000-1100 hp on lsx stuff

 

Interesting. Just doesn't seem worth it.

I'm running a single 255 in tank. As long as the fuel pressure stays under 60psi they will push 50gph which should support 600hp.

-- Joe

 

Yep and for me 600 would be close to 6 psi so having it on at 4-5 seems to help. This new combo should make much more power than old so maybe thats a reason why it seems to increase fuel so much at the 4-5 psi mark and 4000 rpm? Perhaps my pressure is dropping so much by 4 psi that the second pump is now supplying fuel to stabilize pressures? Maybe my ve entries at the 5psi areas are correct and i am just over compensating the 100-130 kpa map spots to deal with falling pressure? Who knows

But has boosted 730 8d code been developed and used successfully?

 

Joe, didn't Junkcltr burn you a code with boost multiplier for the $8D once? How did it work for you? Was fooling around with the $8D awhile back but then when an entirely different route...

 

Rotating between the two pumps is a good idea. That is the issue I'm having with the primary pump, it's just plain worn out. Since I'm not pushing boost as far as I can I'm just running the secondary pump for now.

RBob.

 

Worked fine on the corvette with the powerdyne, simple BPW adder, car made like 5psi.

Problem was logging was useless as it reports 100kpa whenever under boost.

I was hoping he would eventually distribute a version with a XDF so the bpw multiplier could be altered with tuning software, and perhaps altered ALDL stream to report actual MAP. I don't know if he decided to discontinue working on the project or not, but this was about 5 years ago now...

I switched the car to $58 before I sold it. The kid who bought it replaced EFI with a carb and a mechanical dizzy.

I never had interest in tinkering with the source myself. If someone wanted to work on replacement ECM code in C I'd be all over it, but frankly you couldn't pay me enough to play with assembler..

The '730 supports two map inputs. The way to do it, in my opinion, is a second map input for both the ALDL stream, and the BPW adder. When MAP1 hits 5 volts, lookup the BPW adder table and add to the PW calculation.

I don't know what the process loop looks like in $8D, but if this stuff was written in C it would be a 10 minute code change..


-- Joe

 

Yeah the setup i have is simple to adjust which pump is primary. Just a simple connector switch in the harness

 

I thought about a second pump, like a trex or something to help with volume, but I'd just run 'em both full time. These things are soo cheap and I've never owned a race car that I put more than 15k on anyway without rebuilding or parting it out.

-- Joe

 

That's what I had guessed to do it with.
A separate table reading the boost level/RPM would be the best way to not loose resolution on the main table by rescaling it to go higher.
Seems that it would not be that easy though...

 

Why complicate matters by using a second MAP sensor?

I'm running a 3 BAR and $59, with great driveability, no need to worry about "resolution".

 

Yeah my car seems to be working very well now. 401 with 245cc heads and 246 deg hyd roller cam over .640 lift. Really surprised how docile it drives even with 115 lb inj.
8d would be awesome for those with great experience using that code but $59 hasnt been to difficult to learn. Few quirks back in the day with some idle stuff but i have it figured out now

 

My nbr2 FP start at 2psi or by a manual switch.....

 

Less things to change. Leave alone the functionality that makes it work great off the 1bar, and simply add a PW multiplier to runs off the second map for "boost".

I think there is enough inputs left on the '730 to run both a wideband and second map sensor.

I'd be leery about replacing the map with a 2bar and halving everything...

-- Joe

 

You see now that would be great for our cars, something along the lines of what Bob did with the SFI-6, where the ECM would switch back and forth from 1-Bar, 2-Bar and 3-Bar simply when the need arose for it to do so to maintain proper resolution, and maybe call it SFI-8. When we replace hard code addresses with labels in $58, and as I was reading, and changing "org C000" to reflect "org 8000", then adding "fill 0,16384" after the last line of code (FF7D) to create a 32k from a 16k chip, then the resolution will greatly suffer when we start fudging the numbers with the MAP multiplier and VE tables, although it definitely works for $59 users though as I can't take that away from them...

 

I am interested in this!! I tried a search with no results. Is there a thread with this info or a keyword that I can use to search?




Wow, things are little off topic but a great discussion.

 

Using two MAP sensors give better resolution for NA and BOOST fueling. The $8D code I did uses one 2-bar MAP sensor. When I went to 3-bar with the $0D code I went to two MAP sensors (1-bar and 3-bar).

1) Simplest way for the end user and decent resolution is to remove 1-bar and replace with 2-bar. Read in the 2-bar value as normal and do a 2x on the A/D value. Scale and save that as your original 1-bar.

2) Use the raw 2-bar A/D and if above 128 then subract 128 and do a 2x, this is now your boost value and spans a tables worth of range (0-255).

3) Assume the 2-bar is linear and use this value to index into the boost spark reducer and VE multiplier table. Get the value from the table and apply to the spark and injector PW.

Do all in baby steps, get "1" working. Get "2" working by just reporting the index and table lookup out through the ALDL. Then do the fuel mult, then do the spark mult.

 

I need an ECM bench...

-- Joe

 

I don't know of any modified GM code to do this in a stock ECM. With an EBL set up there are eight 10-bit ADC channels with a 0 - 5 volt input range. Makes it easy to connect various devices for data logging and display. Note that only a pressure sensor and WB input can be displayed on the WUD. While the data for all eight channels is available in a log dump.

For various reasons I've moved from the Autometer pressure sensors to Honeywell sensors.

RBob.

 

Is the comm layer for the EBL documented if someone wanted to write their own logging/display software ?

-- Joe

 

Why do it half-***. Just look at the conversions from some GM code ($8F, $58) and do it the right way. Then when you want to move to a 3-bar MAP you have an idea of how to do it properly. And can create the proper MAP conversion from the data sheet.

Note that using a 1-bar in conjunction with a 2-bar isn't really required. Yes, it will help a little, but not enough to make writing the code worthwhile.

With a 3-bar MAP, yes, it is worthwhile having a 1-bar MAP to use when not in boost.

RBob.

 

It is documented (it has to be for us to develop and maintain the WUD), but not publicly. If you are interested in the data stream format let me know. We've let a few folks know the format along with some data locations (and the conversion for that data).

The main reason it isn't public is so we don't have to support it to the customer base. Makes it a whole lot easier to be able to make changes to the data stream as required for new firmware releases.

RBob.

 

That is exactly what I just told Joe, as Eric Marshall basically scrapped the whole $59 code concept, reworked the $58, rewrote the barometric pressure, then added some of his own features to reflect some similarity with his 6.0-6.1 TB chips. We're still talking OBD1 here, and nobody wants to burn chips anymore, but this really is long overdue nonetheless. Someone start a new thread and lets get it done already, I have no problem testing the code on my turbo GTA that will be seeing over 20-pounds of boost pressure...

 

Do you have any links on what Eric did? The name isn't familiar to me.

I don't mind testing stuff either.

-- Joe

 

Eric runs Turbo Tweak over on the Turbo Buick websites, both him and Bob Bailey reworked the $58 code for the Ty/Sy members, but added a lot of features into it. Almost positive they called it the Velosyty chip...

Edit, yes it is called the Velosyty chip, here is the link. I'll have the details in code in a bit...

http://www.turbotweak.com/velosytydoc.pdf

 

That is interesting. I wonder if it's based on pure $58, or $60. Bruce did a good job of documenting $58 into a 32k assembled bin.

http://members.cisdi.com/~anesthes/p...49/60/2bar.zip

I experimented with it for a while in 2004.

I guess the question here is how do we satisfy everyone. People may or may not need emissions control, TCC lockup, fan control, electronic WG, and so on.

For someone like me all I need is fuel and spark, but I might be the minority.

-- Joe

 

I thought $58 had alot of issues with pulsewidth control or something like that on larger injectors and it seemed like everyone who tried it couldnt get it to work properly on non syty motors? Hence $59's existance? Some things were modded and improved i thought. I havent tried $58 but i have 115 lb high imp injectors working fine on my car with 730 ecm running $59

 

The idea would be to create a boost encoded $8D without the need for repinning anything, as if it were factory, just drop it in and go. That is all I am going to say about that, because once we get into resolution differences we're going to have members screaming at each other about which one is better and why. Code 59 works for quite a few members, but by adding two code references to an essentially new 2bar-3bar flag bit for easy selection would be the way to go with a boosted $8D...

 

I had some problems back in the day with $60, which is essentially $58 with the code moved to $8000. I had mentioned to Bruce that I didn't believe the switch from sync to quassi injector firing was working with the cylinder select set to 8.

Idle either missed or was pig rich.

You don't repin from $8D to $58 on a '730. I think when you run $58 on an actual '749 you need to move C1 to another pin or something, but on a native '730 it works 100%.

The problem with $58/60 is the big injector control, the resolution on the tables, lack of functionality for emissions on v8, some other issues I'm forgetting. Oh the knock stuff is quirky on $58/$60. Not sure if it's fixed on $59 but random knock counts, incrementing by the hundreds is not uncommon. (at idle even)

-- Joe

 

What about F6 to F4 for the TCC, though? Not that that is too complicated to do...

 

You got me. I've never owned an auto, so that has never come up.

-- Joe

 

RBob was right all along Joe, all that is really needed is to adopt the $8F code to the $8D code and change the initial timing and min/max timing parameters to compensate for the lack of DIS. We should just do this and get it over with already...

 

$8F and $8D appear to be two different animals entirely. What is the plan?

What happens when you load $8F in a '730 ? I realize it's native to a '727 in a gtp.

-- Joe

 

From what I am reading on the TGP websites it is a direct drop in for the '730, the only difference is we need to add a WB patch and correct for the DIS, that, and of course tune the fueling, but overall the datastream seems to be essentially the same...

 

$8F works fine in a '7730, that's what I ran in my turbo Jimmy, back before I got into actual tuning.

 

Years ago, I remember Bruce was running DIS on the '749 with $60. If I recall he said something about flipping things around to switch from DIS to Dizzy.

Here is some comments from the $60 source:


MAXADV2: FCB 0, 85 ;Max Advance Relative to Reference
; 60.12 Deg.
; Swap with retard for DIS

DIAGADV: FCB 0, 0 ;Diag Mode Forced Advance
; 8.09 Deg.

ESCDADV: FCB 0, 91 ;ESC Diag Advance
; 31.99 Deg.

;----------------------------------------------
; Threshold to exit ESC diagnostic mode:
;----------------------------------------------

DIARPML: FCB 42 ;RPM Threshold to Exit ESC Diag Mode
; 1050 RPM

DIARPMH: FCB 48 ;RPM Threshold to Enter ESC Diag Mode
; 1200 RPM

MAXRTD2: FCB 255, 43 ;Max Retard Relative to Reference
; 3.52 Deg.
; Swap with Advance for DIS

Was this with DIS or a Dizzy?


-- Joe

 

I did my conversions all correctly. I was offering up a simplified example for the people that want to get something working. Instead of months creating it, the simplified could be done in weeks. If you have more information you would like to share on how to write the code I am sure they would like to hear it.

Read my comments about my $8D and 2-bar, and $0D and 1-bar and 3-bar. You repeated what I wrote.

 

That is the flaw in $58 code. Did the $59 authors re-write that part? Back in the day no one seemed to have a handle on it. I messed with it and read through the code only to find that adding to the $8D was a better solution.

I looked at the $8F and it looked a lot like the $58 from what I saw. Maybe it is much better than the $58. It would be interesting to see someone with a 350ci, 220/220/110 cam, headers, TPI/SRam/etc, and 55#/hr high-z injectors tune the $8F to run properly at idle and low MAP. $58 had fits with it. $8D does it perfectly.