I'm using $32B mask, since my car is a 4+3.

For me, its not worth the trouble to hack all of the OD logic into a $6E masked bin, they are essentially the same otherwise. $6E does make more use of the MAT signal in a few instances, but that's about it, as far as I can tell.

The additional crank fueling of $6E is easily duplicated.

 

I was referring to the ALDL speed more than anything. If I recall, $32B is 160 baud only.. $6E will do 8192..

The OD logic I didn't think of. My car is originally a 700R4 car, ZF6 now. Converted to a '730 ECM. I did lose some dash functionality. (but I'd love to lose the whole dash!).

I know guy locally with a 4+3 trans in an '85 with a singleplane manifold. He's running a megasquirt ecm (http://www.megasquirt.info/)
with a manual OD switch. (enables it once he's in 4th on the highway). He seems pretty happy with the setup. His name is Mike, and he's on here but I don't remember his handle.

-- Joe

 

I've got something new to try.

Next attempt will be to run the 05+ Ford MAF signal into the fuel pump voltage pin (B2) and correct the MAF reads from A/D channel A to A/D channel 6 in the bin.

I think this will work.

 

Update:

I tried the 05+ Ford slot style MAF output on the fuel pump input pin (B2) along with a new bin to read A/D channel 6 for the MAF instead of channel A.

Its sort-of working.

I can see the voltage varying at the fuel pump signal, and the resulting MAF unlimited airflow value and filtered values are responding to the changing voltage.

Unfortunately, the conversion from volts to airflow is off by a factor of 5. A/D channel 6 must behave differently than A/D channel A. There must be a voltage divider upsteam of the D/A on channel 6 to extend the range to 25.5 volts.

When I applied 11 volts to B2 for a test, the MAF raw (unlimited airflow) signal only read 47 gm/sec. This is the reading that should occur at 2.2 volts with my bin.

I've created a new bin that multiplies the A/D value by 5, but I'm out of blank eproms and don't have an eraser on hand. Its going to have to wait until tomorrow for further testing.

Amplifying the MAF sensor output may be a better solution to avoid losing resolution. As it is now there will only be 50 steps available between 0 and 5 volts with this input. Plenty of headroom for an extended range calibration, though...

The car starts, but stalls quickly since its running pretty lean.

I think this is going to work.

 

I think I've found a better input to use to get around the voltage divider and a/d multiplication and resultant loss of resolution that I discussed in the previous post.

A/D channel 0 (Pin D8) MAP2 appears to be well suited for the application, since there is no pull-up or voltage divider on this input.

A/D channel 3 (Pin C11) MAP should also work since its an equivalent circuit.

I should be able to test tonight.

Here's a nice 165 schematic that was very helpful:

http://www.cruzers.com/~ludis/1227165schematic.html

 

Your a smart cookie!

I was tinkering with $8D for awhile trying to figure out how to use the second map input (for a 2 baro connector). I wanted to try and add a
BPW multiplier based on MAP, and a spark retard routine based on the same. Never materialized.

Are you editnig the binary directly, or are you compiling a source hack?
I could edit the $60 hack since it compiled w/out error but I could never find a $8D source that would recompile.

-- Joe

 

Thanks Joe,

For simple stuff like this, I'm just editing the bin directly. No need to bother with an assembler or disassmbler.

If I was smart, I'd have started with the schematic. It is nice to see that the schematic actully fits with my previous trial-and-error observations.

The beauty of this set-up is that it will only require an additional resistor to convert to an extended range sensor, since the Hitachi MAF is supposed to continue to output up to 12 volts with increasing airflow.

Want to increase the range by 50%, use a 25 k resistor on the signal line. Want to increase the range by 50%, use a 50 k resistor. It couldn't be much simpler.

The 5 volts that the ecm sees can represent 255 gm/sec, 382.5 gm/sec, 512 gm/sec, whatever is desired with the corresponding voltage divider and programming changes.

 

It works!

The Ford 05+ MAF signal is connected directly to pin D8 (MAP2) on the ECM and I'm reading the MAF signal on A/D channel 0 in the bin file.

I've set it up so I can display the MAF voltage, MAF raw input and MAF airflow signal with TunerProRT.

I just fired it up and logged some data at idle and blipping the throttle for a few seconds in the garage. With the stock maf calibration, things are a bit off, but that's to be expected.

Its idling a little rich around 1 volt and approx. 15 grams/sec in a cold desired idle at 1200 rpm. Its also pretty cold outside maybe 20 F, so I expect rich running under these conditions.

All that's needed now is a little time to fine tune the calibration (weather permitting) and button up the wiring.

Tomorrow, or this weekend I'll try using a 25 k resistor along with a 150% extended range calibration in the bin to test the plausibility of this concept.

Next step is to make use of the Hitachi MAF's integrated IAT sensor to get some accurate blower discharge air temperature readings as an added bonus. I'll have to figure out how to calibrate the temp sensor, but that shouldn't be a big deal.

Update #1:

On Saturday, I worked up a calibration look up table in the TunerProRT *.ads file for the integrated IAT/ACT sensor and verified it using a hair dryer, heat gun and thermocouple for measurement confirmation at a few data points (35 F, 105 F, 150 F, etc.).

I'm simply substitutuing this new IAT signal for the existing MAT sensor using the existing ecm input and wiring with a simple wiring extension. I no longer have EGR and it is also disabled in my chip, so there is no negative impact to using the new sensor with a $32B mask bin. $6E would require a little more work since it makes additional use of the MAT sensor.

This will be very interesting data to monitor the blower discharge air temperature under boost. I think it will be much more interesting than the conventional MAT sensor data. I also tweaked the MAF tables to correct the MAF transfer function to improve idle and low speed running by mimicking a typical Ford MAF transfer function. Things are looking good.

Update #2: I tested an extended range calibration (150%) with a corrected MAF transfer function and supporting fueling changes along with a resistor to complete the voltage divider on the input circuit. It is also working as expected, at least idling in the garage and during the initial 5 volt sensor pulse. This mod should provide measurable flow data up to approximately 380-400 gm/sec which should be adequate for 400-450 RWHP without excessive reliance on PE for fueling.

I will be focusing my efforts on this configuration, since it best suits my own application.

Moving on to the next step: I decided to go ahead and try a 200% extended range calibration for up to 510 gm/sec. It appears that this will be possible with my existing voltage divider due to the shape of the MAF transfer function.

I've now also corrected the load calculation to compensate for the modified airflow scaling. Overall, I don't see any downside with this set-up. It should be able to measure the airflow and deliver accurate fueling for up to 500-600 Hp.

New info: According to other sources, the Ford 05+ slot style MAF will only output a signal up to 6 volts. This should still provide range into the 400-450 RWHP territory, so I think it will be fine for me. With my 3" tube, present transfer function and voltage divider, 6 volts will be approximately 380-400 gm/sec. If additional range is required, it looks like the HPX sensor is the way to go for additional cost.

Now considering the 6 volt working range of the sensor, a 10 k resistor should suffice to complete the voltage divider and reduce the output range back down to 5 volts for the ecm. Of course, this requires another re-work of the MAF tables, but should result in improved resolution due to full use of the MAF tables over the 5 volt range.

Now I'm just waiting for the snow to melt to dial things in....

 

Here's a pic:

 

Just a quick update:

I had a chance to go for a test drive tonight. Since the blms were looking safe in cell 15, I went ahead and opened her up.

The peak MAF voltage observed (after the voltage divider) was 4.59 volts at WOT in 2nd gear at 6300 rpm. This is about 5.5 volts at the sensor. The voltage divider is reducing the sensors 0-6 volt output down to 0-5 volts to extend the useable range.

The sensor has sufficient range as installed, but clearly would have pegged without the voltage divider. Working exactly as intended.

This output voltage should correspond to around 400 grams/sec, so I'm building the MAF calibration/MAF transfer function around this flow level and voltage output.

The Narrow band O2 looks reasonable reading over 900 mv with an 11.5:1 AFR target.

Interestingly, my MAF transfer function is shaping up to be very similar to the stock Ford GT500 MAF transfer function in the lower-mid flow region.

Since I expected the GT500 based calibration to go rich up top, I also limited the max maf table to 400 gm/sec above 4800 rpm. Next iteration, I'll refine the MAF calibration tables around the data and raise the max maf table limits.

Also worth mentioning, the blower discharge air temp under boost was observed as high as 195 F at the end of 2nd gear. This was read from the Ford MAF's integrated IAT sensor.

 

That seems excessive. What was the ambient temperature?

I'll have to convert that out, but it sounds like something around 60% efficient. I thought the belt driven powerdynes ran cooler..

-- Joe

 

Ambient was about 30 F tonight.

Most runs, the peak discharge temps were in the 160-180F range. The worst one hit 195F.

During steady cruise in 4th at 2800 rpm or so, it was typically running about 100-110F. 80-90 F in 4th OD at lower rpm.

Immediately before throttle tip-in at 30 mph prior to the high temp event, the IAT was showing 114 F. It rose quickly to 195 F, then quickly cooled back down to 110 F after lifting out.

 

Hrmm.. I was looking at some of my scans when I had the Vortech S-trim. It looks like on full blast shots, 12psi put me around 175f from 50f ambient.
I'm not sure how much boost your running, but based on your numbers I'd say the powerdyne is a hair less efficient than the S-trim.

I can't remember the calculation for figuring out adiabatic efficiency,
it's scribbled in a book somewhere in here.

-- Joe

 

Just a quick update on my Ford maf project:

I've just upgraded to the Pmas HPX sensor since I was pegging the stock Ford MAF above 5,200 rpm even when extended to 6 volts with the current pulleys (stock 7.2" crank/3.12" blower pulley). This pulley and impeller combination makes about 10 psi at 6,000 rpm.

I've also eliminated the 10k resistor on the MAF signal wire that I was using to complete the voltage divider to extend the range of the stock Ford sensor. It is no longer needed due to the increased range of the HPX sensor.

I still have some more fine tuning on the MAF tables to do, but so far the HPX appears to offer a more stable signal and runs a little smoother than what I had before with the Ford MAF and voltage divider extender. It shouldn't peg at 5 volts until over 600 rwhp, so it should offer plenty of range for my set-up.

For anyone else wishing to proceed down this path, I'd suggest starting with the HPX sensor since it is a more capable sensor.

I still need to do some WOT testing to see just where the voltage peaks with the new sensor, but I expect it to be around 4.3-4.4 volts based on the transfer function for my tube diameter.

Update: It hit 4.84 volts at the top of 3rd gear at 6,000 rpm. I must be losing some range due to the bends in the tube near the sensor. Still sufficient for my needs, but not as much extra range as I expected to have.

 

Do you have the airflow calc code worked out so you can see CFM ? I'm curious what that thing is putting out for CFMs.

Last time I had mine out I almost lost it. I can't believe how fast the car is now. Been working on the house since though (over a month). Hopefully it starts in a week or so, so I can put it away for storage.

For 'crap' little blowers, these powerdynes make plenty of power.


-- Joe

 

Joe, I believe you when you say your car is fast.

According to the HPX calibration tool that I have, 4.84 volts in a 2.85" ID tube should be about 600 gm/sec or about 80 #/min. This would be a little over 1100 cfm corrected flow.

In a 3" ID diameter tube, the flow increases by about 10%. I don't know for certain if the tool is calibrated for OD or ID, but I'm assuming ID.

I don't believe my actual flow is anywhere near that high. I think its more like 460 gm/sec or about 60 #/min which would be about 830 cfm. That's the flow that I'm fueling for anyway and it seems to be pretty close.

I believe 900-1000 cfm could be achievable at 42-43,000 rpm before the pressure ratio falls off dramatically. If you would be willing to spin it higher, it should continue to flow more air up until the tips or the air velocity entering the inlet go supersonic.

The flow number by itself doesn't mean much knowing impeller rpm and pressure ratio.

With the impeller upgrade, I think it compares to an Si-trim Vortech.

I think I even had a little wheelspin around 90 mph. In any event, the little powerdyne is making good power. The 70-91 mph interval was 1.9 seconds which suggests a little wheelspin. Fortunately the car tracks arrow straight during wheelspin.

Blower discharge air temp as measured by the MAF's integrated IAT reached 224F at 6,000 rpm and 91 mph.

 

Glad it is working out for you...

The slot style is the way to go, the tonsil style sensors (Lightning) are pretty old at this point and it shows. The slot style is much easier to tune and gives a much smoother signal, and seems to sample much better in blow through.

You can also use the factory GM frequency based slot style meters with my flanges.

As you pointed out, the HPX has plenty of range.

 

thanks for sharing

 

I know you're way beyond this now but, we're using a newer LT1 style MAF in place of the factory bosch unit in my 85. It's now got a Vortech supercharged LT1 in it but it still runs on an '89 computer. We used a little box like someone else mentioned on here in a previous post. It converted the frequency signal to a voltage signal so the computer could read it properly, plus, it allows for tuning as well. It's got a lot of other benefits but what impressed me was that it can adjust all types of MAF signals (LS, Ford, Mitsu, etc). You can check it out at http://www.maftpro.com/tgen2info.shtml

I've been impressed with it so far.