350 afr 195 heads,comp cam 268 xfi.
350 afr 195 heads,comp cam 268 xfi.
TPI with 5.7 liter, ECM part # 1227730?
dave w
Yes sir and I have more specs on cam and headsOriginally Posted by dave w
will be using Moates autoprom and tuner pro
Year- 1992
Make- Chevy
Model- Camaro
Transmission- 700R4
Displacement- 350CI
Compression Ratio- 10.5
Comp Cams- 268XFI
Duration @ 50- Int 218/Exh 224
Valve lift- Int:534/Exh:5.30
Lobe Seperation- 113 deg
Intake Centerline- 109 deg
Cylinder Heads- AFR Enforcer
Intake port volume- 195
Intake flow @ .500 lift- 250
Exhaust flow@ .500 lift- 186
Combustion chamber volume- 64cc
Fuel injection brand- Bosh
Flow rating- 32 lbs. @ 43.5 PSI
Thermostat temp- 185 deg
Factory intake manifold- ported
Factory runners- ported
Factory plemuim- ported
Throttle body- factory
Oh, seems like you are asking for a custom modified .bin file?
dave w
Drew1992 --
Has this engine been running with an existing BIN or are you just beginning? If the latter, the BIN Dave provided is a good starting point. Spark may be a bit high for those heads and CR, but easily adjustable once running. Another thing noticed are the injectors at 32#. Injectors of that size on a modded 350 will likely result in an extremely rich idle as well as rich above-idle. Take a look at this as it explains the issue and provides some recommendations: http://gearhead-efi.com/Fuel-Injecti...oltage-Offsets
If it was easy --- everybody would be doing it!
New engine, not driving yet , bought injectors on advice from Southbay Injectors , I think 28 would be good. This is all new to me.
Is this where I 0 pw?
20211215_135410.jpg Is tis whereI zero pw20211215_135410.jpg
Difficult to read pics. I assume you want to zero the Low PW table. That would be the table in the left pic below.
Voltage offsets (right pic) should not be zeroed. Rather, see the info below if you do not have injector manufacturer's data:
PW Tales.PNG
Also, select the option in the switch below that provides the highest and most consistent voltage based on logs:
Voltage Selection.PNG
HTH, Elky
Setting Injector Low PW and Voltage Offset Tables
Low PW
A low PW calibration table value is added to the code-calculated PW when it's less than Xms. It's widely accepted that when installing B3 injectors, all values in the Low PW table should be set = 0.
When this table is zeroed, how then must AFRs/BLMs be adjusted to desired values? Only two ways:
1. Adjust VE values, and/or
2. Where applicable, change the Injector Flow Rate
These are the primary tools available aside from changing fuel pressure.
So lacking low PW information, we ignore the B3 low PW flow characteristics and rely solely on VE values for proper tuning. Therefore, we have essentially taken the position that B3 low PW injector data is not needed and tune accordingly.
Injector Latency (aka: Lag time or Dead Time)
The attribution for this was unfortunately lost: "The purpose of injector voltage offsets is to account for physics. Injector components have mass. It takes time for any mass to accelerate and begin moving. The voltage offset table attempts to account for this and adjust for the fact that the injector parts move slower with lower voltage and faster with higher voltage (but never move instantly)".
Very true! Here’s an example. Without VOs, if the code-calculated PW is 4.0ms, the injectors will go through the following phases during one open/close cycle of delivering fuel (ms values are examples only):
0.0 - 0.3ms: ECM commands injectors to open and move toward fully open
0.3 - 3.9ms: Fully open (3.6ms of fuel delivered)
3.9 - 4.0ms: Fully open to closed (takes much less time to close than to open)
The opening 0.0 to 0.3ms and closing 3.9 to 4.0ms in this example represents 0.4ms of latency/lag/dead time, during which no fuel, or less than the calculated fuel, is delivered. For simplicity, we’ll assume no fuel is delivered during this period. So without VOs, only 3.6ms of fuel is delivered when 4.0ms was calculated (commanded). The VO table attempts to account for this lack of fuel delivery by merely increasing the calculated PW, solely based on voltage at the moment.
Further assume 13.6 volts are being supplied to both the ignition switch and the fuel pump, and assume the VO table contains:
12.8v = 700 micro seconds (Us)
14.4v = 100 Us
Because this table is linearly interpolated by the code and because 13.6 volts is midway between 12.8v and 14.4v, 400Us ([700Us + 100Us] / 2) will be added to the calculated PW of 4.0ms. Said another way:
Actual PW to ECM (4.4ms) = Code-calculated PW (4.0ms) + Latency/Lag/Dead Time (0.4ms VO)
Here, 0.4ms is added to the 4.0ms calculated PW to account for the time during which no fuel will be delivered. The 4.4ms PW is sent to the ECM, the ECM commands the injectors to remain open 4.4ms; and during that time, 4.0ms of fuel is delivered as required.
We can see that with precise VO data, there is theoretical exactness! But even with this exactness, we still don’t know if it will provide the desired AFRs/BLMs -- just that the mechanical characteristics of the injectors have been, “on average”, accounted for, (“on average” explained below).
That's the theoretical world. Let's now look at reality. How do injector manufacturers account for:
- flow at different constant fuel pressures
- flow at different constant voltages
- variances among injector internal masses for various flow rate injectors, and
- possibly fuel temperature affecting flow rate in addition to the above
They test a large lot of similar injectors and come up with an “average latency” at various pressures and voltages. These averages become the VOs at each pressure tested.
But when the pristine injector test world is vacated and the injectors are installed in the real world, how are these VOs used to increase PW? Three ways:
- While cranking: VOs are added to the calculated fuel requirement
- While engine is running: VOs are added to the sum of the calculated momentary fuel requirement and the Speed Density (SD) AE-MAP (required PW)
- As-needed while running: VOs are added to the sum of: (i) SD AE-TPS, (ii) DFCO Stall Saver and (iii) if AC turned on
Remember that VO table values are linearly interpolated; but the VO data in between table voltage values is likely non-linear. That would interject an error, albeit small.
So, what to do when VO data are not available? We could disregard VOs altogether, zero the VO table and adjust above-idle VE values a certain percentage to increase PW across the board. That’s exactly what the VOs are doing based on voltage, rather than using RPM, manifold pressure/load. But doing this is not the solution because at some point more fuel may be required than those adjustments can provide. VE Table limits could be exceeded and the VO values are needed to compensate.
Suggested Approach When Exact VO Data are Not Available
The suggested approach is to begin with estimates of VOs. But the purists will say this is unacceptable; we must have precise VOs to 6 decimal points. Really? What about the inaccurate linear table interpolation? What about tuning with WBo2 sensors using AFR rather than Lambda when using E10 gasoline? AFR will be off 3-4% from actual depending upon the Stoich AFR used for E10. This error is accepted without realizing it, but very precise VOs are required. Really?
We only need to estimate VO values that cover cranking, idle and above idle. Voltages below and above those occurring in those engine states can be disregarded. With a sound electrical system and alternator, there is normally little difference between idle and above-idle voltage. On average, cranking voltages run between 9.5 and 12v, and engine-running voltages between 13.5 and 14.5v. That says there are really only 4 VO table values that are meaningful -- those at 9.6v, 11.2v, 12.8v and 14.4v.
So it’s recommended to begin with some reasonable estimate of the values (perhaps 75% of the factory Multec values, what is believed to be correct manufacturer data but you’re not sure, etc. – just start with something). Then log and review BLMs. Adjust VE as required It’s acknowledged this procedure is far from exact, but so are many other factors far from exact as previously discussed.
To summarize:
- Disregard B3 low PW data, zero the Low PW Table and tune with VE
- Estimate VOs that will be added to calculated PW, knowing that the VOs are not exact
- And even if we have exact injector-matching low PW and VO data, we still have to dial-in AFRs/BLMs over the entire engine operating range with VE values, which is what has to be done with inexact VO data.
Bottom line, desiring to get VOs "absolutely precise" for a street car and even for a Saturday night street drag car is like trying to fine tune an old gear-driven clock using Swiss clock precision.
Finally, one thing that tends to get lost in all this is that PW for any injector is the same (=the amount of time it's to be open). But PW has absolutely nothing to do with how much fuel is supplied during that time. That's a function of the individual injector.
If it was easy --- everybody would be doing it!
Are you using Tunerpro rt
Yes, but apologies. What you are seeing in the pics is from the S_AUJP v7 XDF. Descriptions change among versions of XDF files. That's why the addresses of XDF items should be used and that's that I should have included; because unlike names, addresses don't change since that's where items are located in the Calibration in the BIN file.
0x40B = Injector PW Compensation if PW < 3.90ms
0x3FA =Injector PW Correction .vs. Fuel Pump or Ignition Switch Voltage
Don't know what XDF you are using, but to find the above items:
- In TunerPro, search by address: (Ctrl-F, Then in the rightmost "Find" list, select "At of Containing This Address")
- Enter an address above without the 0x.
- This will present the associated XDF item description
- Double click the presented item and the Scalar, Flag or Table will be displayed
If it was easy --- everybody would be doing it!
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