One more stab at the accuski/perfect pass dilemma

[davidgree1]

I just talked to Eric at PP.  He said his system will work on Toyota but the throttle linkage may be difficult.  They did put one on a Toyota and it worked.  He will try to find the pics if a few people want one.  The tach output of Toyota is different but they have a chip that will work.
They tach input is only needed when using in RPM mode.
So the real issue is modifying the throttle linkage (something about the air intake being in the way, but there is a Home Depot solution).

[davidgree1]

I talked to Carl at PP.  He said PP will work on Toyota, but the throttle linkage is difficult.  They put one in a Toyota and it worked.  He might be able to dig up the pics of the set up if enough people were interested.  The tach input is different then most engines but they already worked it out and will work in rpm and mph mode.

[toyotafreak]

All things being equal, I think the best solution is to press Accuski and Cyclone to rigging our units for the paddlewheel.

Pete, I like what you talked about regarding throttle response and the control response (whether Accuski or PP) being higher than with normal-displacement engines. That's been floating around inside my cobwebs for a while.

The Accuski route is the closest thing to OEM that we have, the unit is high-end and has buttloads of bells and whistles. ALSO>>>>> any move to get Accuski's invlovement with out Epics more current will decrease the obsolescence risks inherent with our boats.

I say we press the paddlewheel/Accuski solution.

[cyclone]

Here is Guys response to my recent email. Since they can't read speed from our ECM, they use the one pulse input of the MMDC for our tach. If we had an interface from our ECM to the ECM input of the MMDC, it would free up the pulse input for a paddle wheel speedo. I think the right place to start would be to connect one of those OBD2 readers to our ECM and see what we can see. Who's got one?

It sounds like they are working on the closed loop control tuning for MPH mode. I think it is the same for all boats that use Accuski, not just Toyota.

Hi Pete,
Our MMDC will not run a paddlewheel on a Toyota.  This is because the MMDC only has one pulse input.  When we use the pulse input for the paddlewheel we read the rpm off the ECM.  This works fine on boats such as Malibu and MasterCraft.  Unfortunatley, the MMDC only reads ECMs made by American engine manufacturers and won't read the Toyota ECM.  
Venturi's respond faster than pitots, but the lag comes from the computer being 18' away from the venturis.  Air is compressable.   That's why a paddlewheel performs better with speed based control.
We are working on improving the speed based performance with the software, but it will be at least next spring before we release anything.  Have you tried switching to rpm based control?   It performs better.  On the tricks or wakeboard setup menu screen change mode to "rpm".
thanks,
Guy
 
Guy S. Haggard
Accuski, Inc.

[cyclone]

My point is and was that Accuski's main problem is crappy programming, not slow speedos. If you can control the speed adequately in manual, by applying feedback to the throttle based on visual observation of the speedo reading, then a control system can model it and produce the same results.

It sounds like Accuski has produced the hardware, I wonder if we could buy the throttle linkage from Accuski then use PP? Not having seen either system, I can't say whether something like that would be possible.

I don't give a hoot about RPM control, I will upgrade to one system or the other this winter. My speedo flat sucks, I've had it.

Any pictures or information about the PP install on a Toyota would be great.

[davidgree1]

Call PP.  They will talk to you about installation on a Toyota.  They might even be able to send you pics of an install they did.

[cyclone]

I am currently in high level negotiations with PP about Toyota,  there must be a way, even if we have to fabricate hardware. I think we can muster the awesome resources of the Epic family to do what needs to be done. I will do it this winter, regardless. I have given up on Accuski, they were not really interested in making their substandard system work, though I still may try to purchase hardware from them if they are able to produce. Not likely.

[toyotafreak]

Pete: my two cents....

1) You go buddy !!!

2) We could fabricate linkage for sure.

3) Truthfully, I still wish we could get Accuski interested in getting their bugs worked out if for no other reason than to keep them involved with our boats.

4) Please go back and peak at my comments about the linkage-less throttle control option. We could rig up a series of relays so friggin easy, there would only be electronic adjustment and no lag whatsoever between throttle change command and actuation. It would require the PP or Accuski controller to output a sigle analog signal instead of the three signals required to drive a servo. Different, but better, and the same deal would work on all Epics.



Keep up the good work!!!!

[cyclone]

Derek,
Wow, I hadn't read all of your post, what you said makes a lot of sense. If Toyota were still in the biz, I'll bet they would have added a cruise control feature from existing parts/firmware like you suggest. It is way too much trouble for me to try to make that idea work, it would take more than PICS making simple time duration outputs. We would need a PLC with PID control that we could adjust to model to the response time of the boat, weighted different ways. We would have to have a user interface to change setpoints (MPH) and some kind of user modifiable gain control to vary response based on weighting. Too much work. PP has all this, it will be a cinch to adapt it to Toyota. Turns out it is much easier than I was lead to believe. Good news for us! It is somewhat redundant since our boats are already "fly by wire", but why reinvent the wheel? The money is well spent, I already spent mine. I am buying the big time version of PP, with the response numbers I nail down, and those from someone with a Vdrive, you will be able to buy the cheap version of PP preloaded with numbers that will work for your Toyota with weight!

[toyotafreak]

OK one last try (for now). Here is how I see the existing throttle components back at the engine. Linkage pushes on a sensor, and the sensor drives a motor.... fly-by-wire as Pete says. My one main assumption is that the sensor is a potentiometer which varies between say 0 volts (throttle closed) and 12 volts (wide open throttle).

[toyotafreak]

Next slide, please...

Here's what Pete's installing with Perfect Pass, and what some others have had installed with Accuski. The motor somehow takes control of the linkage when 'cruise on' is active. The servo's driven by the cruise control; the servo drives the sensor.

[toyotafreak]

And finally...

Let's assume that it would be fairly simple for PP or Accuski or to output a signal like 'between say 0 volts (throttle closed) and 12 volts (wide open throttle)' based on what power it requests from the engine.

A second output from the cruise control unit would be a simple 'cruise on/off' signal which we'd use to energize the relay. Fail safe.

No real moving parts. Maybe a little more responsive.

Just another persistent thought.

[toyotafreak]

Ok, once again speaking before doing homework....

I spent a litle time in the manual this morning and I was wrong about the architecture of the stock throttle scheme.

The 'Accelerator Pedal Position Sensor' is actually two potentiometers (built in redundancy/error checking). The outputs of these ganged pots vary between 0 and 5 VDC in proportion to the accelerator pedal (throttle/shift lever). A description can be found around page DI-49.

The pots send their two outputs to the ECM module.

The ECM module will then do all of its fancy engine control stuff and (among other things) send control signals to the Throttle Control Motor, which drives the Throttle Valve when the Magnetic Clutch allows it to. The Throttle Valve position is measured by the Throttle Position Sensor, which is part of the feedback loop to the ECM).

The good news is that the Accuski/PP end of the deal is simple (if a little scary) - use a relay to hijack the two inputs to the ECM that are fed from the 0-5VDC Accelerator Pedal Position Sensor. The ECM picks up our throttle command and makes its gazillions of adjustments in order to 'make it so, number one.'

***** I wonder if any of the newer towboat engines are throttle-by-wire like our Epics?

[cyclone]

The throttle actuation also moves a mechanical linkage that moves a plenum plate that changes the length of the intake runners. We can't bypass the pot totally.

I have not yet figured out how to hook perfect pass in with the stock shift linkage. I would really like to see a picture of an Accuski installation, the system has to be very similar.
More pics to come, including some that show exactly how perfect pass works.

[toyotafreak]

Dang...