1967 Cougar build (over 500 pictures and videos)
11-12-2018, 01:19 PM
#961
Dang - well, as we originally thought, the devil is in the programming.
Edit --- thinking on this some more, it's possible that some changes in your alignment settings may allow the unit to interface more effectively with your car's suspension/steering geometry.
Edit --- thinking on this some more, it's possible that some changes in your alignment settings may allow the unit to interface more effectively with your car's suspension/steering geometry.
Last edited by Michael Yount; 11-12-2018 at 07:02 PM.
11-12-2018, 08:44 PM
#963
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I won't bore everyone with the details, but I have it working now so the level of assist varies based on speed. With the limited driving that I did today (it was raining very hard) it seems a lot better! Once I get more miles on it, I will post more driving impressions.
Andrew
Andrew
11-12-2018, 09:14 PM
#964
TECH Senior Member
Glad you have it working better! I think it will do a great job once you get the programming sliced and diced!
BTW, I gotta get one on of those T-shirts.... I wonder if Roadkill has them...
Checked, nope...
BTW, I gotta get one on of those T-shirts.... I wonder if Roadkill has them...
Checked, nope...
Last edited by G Atsma; 11-12-2018 at 09:27 PM.
11-12-2018, 09:47 PM
#966
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I am mildly optimistic with my results today. To address your point about alignment, I think I have a pretty good alignment already. It might need a little negative camber, but that shouldn't change on center feel.
Right now it is:
0 camber
.25* toe in
5* of caster
The other issue that I need to overcome is powering up the steering ECU. What I didn't tell you is that I have two Toyota ECUs. One is from a Scion Xd, that is the ECU I was using at first. The one that I installed today is from a non-ABS Toyota Yaris. This is the only ECU in the Toyota lineup that does not get its speed information via the CAN. Instead, it takes a conventional, square wave speedometer signal, directly into the ECU. However...
The Scion ECU powers up as soon as power is applied to the #5 pin. The Yaris ECU doesn't power up until it has power on the #5 pin AND sees a speedo pulse on the #6 pin. So as of right now, The EPAS doesn't kick on until I start moving, then after that, it stays ON. It really isn't a big deal, but I have some ideas as to how I can make the Yaris kick on as soon as the ECU is powered up. Maybe y'all can have some ideas as well.
I have the ability to create a PWM+ output on the Dominator. I can configure this output to be on a timer. The PWM+ signal is very similar to a square wave pulse and the Toyota ECU doesn't seem that picky. I was thinking of running the PWM+ output to the same #6 pin on the Yaris ECU and have it pulse for 5 second as soon as the ECU powers up. I think it might work...
Thoughts?
Andrew
Right now it is:
0 camber
.25* toe in
5* of caster
The other issue that I need to overcome is powering up the steering ECU. What I didn't tell you is that I have two Toyota ECUs. One is from a Scion Xd, that is the ECU I was using at first. The one that I installed today is from a non-ABS Toyota Yaris. This is the only ECU in the Toyota lineup that does not get its speed information via the CAN. Instead, it takes a conventional, square wave speedometer signal, directly into the ECU. However...
The Scion ECU powers up as soon as power is applied to the #5 pin. The Yaris ECU doesn't power up until it has power on the #5 pin AND sees a speedo pulse on the #6 pin. So as of right now, The EPAS doesn't kick on until I start moving, then after that, it stays ON. It really isn't a big deal, but I have some ideas as to how I can make the Yaris kick on as soon as the ECU is powered up. Maybe y'all can have some ideas as well.
I have the ability to create a PWM+ output on the Dominator. I can configure this output to be on a timer. The PWM+ signal is very similar to a square wave pulse and the Toyota ECU doesn't seem that picky. I was thinking of running the PWM+ output to the same #6 pin on the Yaris ECU and have it pulse for 5 second as soon as the ECU powers up. I think it might work...
Thoughts?
Andrew
11-12-2018, 10:51 PM
#967
I wasn’t thinking about it in terms of good (or bad) alignment Andrew - rather, alignment specs that might help geometry compensate for steering unit behaviors that were less than desirable. More caster to enhance self centering for example.
But with your success today I think we’re past that. And yes - some negative camber would likely help the car with front cornering force. As I recall those Ford front suspensions didn’t have the most helpful camber curves going positive under compression. I’d throw a degree or two of negative camber in there if you can.
Your idea on power up sounds reasonable to me. Show my ignorance - why the power up from the dominator - can’t you have hot from ignition on fire up the steering ecu?
But with your success today I think we’re past that. And yes - some negative camber would likely help the car with front cornering force. As I recall those Ford front suspensions didn’t have the most helpful camber curves going positive under compression. I’d throw a degree or two of negative camber in there if you can.
Your idea on power up sounds reasonable to me. Show my ignorance - why the power up from the dominator - can’t you have hot from ignition on fire up the steering ecu?
11-13-2018, 06:45 AM
#968
Andrew, does the PCM need to know how fast it's actually moving or does it just need to know that it's moving? I guess the question depends on is the assist variable with speed or is that a possibility? Initially you mentioned something that led me to believe it was.
Your current plan of sending a PWM trigger to the power steering ECU sounds solid to me and I can't think of a reason it wouldn't work.
11-13-2018, 10:04 AM
#969
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iTrader: (7)
Andrew, does the PCM need to know how fast it's actually moving or does it just need to know that it's moving? I guess the question depends on is the assist variable with speed or is that a possibility? Initially you mentioned something that led me to believe it was.
Your current plan of sending a PWM trigger to the power steering ECU sounds solid to me and I can't think of a reason it wouldn't work.
Note, it only take 3 wires to hook up: (2) 10 gauge power and ground and (1) 12+v signal wire to trigger the internal relay that powers it up. This trigger wire can come directly from the car ignition system or, as I have chosen to do, comes from the Dominator ECU (I did this for simplicity reasons). Either way the unit comes alive as soon as the ignition key is ON. Also note, that the Prius ECU has no VSS input. The sped information is communicated via the Toyota CAN protocol (which obviously I can not emulate). This unit, once powered up, operates in "failsafe" mode, which from my driving experience was not optimal.
The second Toyota ECU that I have is from a 2007 non-ABS Yaris. This is the pinout diagram for it:
Note that the connectors are all the same. It needs the two big power and grounds and the same 12+v signal wire, on the exact same pins. However, this ECU also has a pin for a VSS signal. This particular ECU does NOT power up when the 12+v signal wire is triggered. It powers up only after seeing a waveform on pin 5. After it sees the waveform it will stay on until the ignition is turned off, regardless of whether the vehicle is moving or not.
The VSS waveform does impact the level of assist. I wish I knew the exact logic that is built into the Yaris ECU, but sadly, I do not. All I have to work with is some data that was generated by another experimenter and this is what he found using a generic square wave generator on his bench:
"At 5 pulses per second it has full assist, at around 45 PPS it changes to a lower assist and mildly dampens rapid movments, at around 75 PPS it changes to a very mild assist and greatly dampens rapid movements. The damping goes away of you jerk the wheel as in an emergency lane change."
My buddy Paul was kind enough to create the attached spreadsheet to calculate pulses per second into the equivalent pulses per mile (PPM) given whatever MPH I choose. So by manipulating the PPM signal that I program the Dominator to output, I can change the trigger point of the middle level of assist. I obviously can't change the trigger points individually, because that it programmed into the logic of the Yaris ECU, but I can shift everything to a lower or faster speed. That's my only "tuning" option.
I hope this makes sense and I appreciate all the input.
Andrew
Last edited by Project GatTagO; 11-14-2018 at 09:33 AM.
11-14-2018, 07:23 AM
#971
I figured as much and makes perfect sense. So the main differences between the ECU units is programming related which we can't easily hack. The good point is the non CAN based ecu is speed sensitive if you can supply the proper pulses at the appropriate time. Interesting.
Why didn't the schematics show up? There were a few previous points where you mentioned an image or two that didn't appear for me - but I see most of them plus the spreadsheet link. Are you hosting in different methods?
Why didn't the schematics show up? There were a few previous points where you mentioned an image or two that didn't appear for me - but I see most of them plus the spreadsheet link. Are you hosting in different methods?
11-14-2018, 11:00 AM
#973
TECH Senior Member
11-14-2018, 02:28 PM
#974
TECH Resident
Another neat project!
I've had good success with rattle can painting by heating part in the oven @ 165F or 180F. In my mind, the finish is harder when baked... Kind of like poor man's powder coating. But I haven't tested this formally. And an item can be put in to service after an hour or so in the oven. Fumes don't remain long. Don't tell my wife her oven was used in this way.
Interesting info on tuning the EPS. Look forward to more updates.
I used to drive a 1995 500E Mercedes, which on which I modified the suspension a bit (lowered it, tastefully). This was one of the predecessor to the AMG / M type super car sport sedans of today. It had something like 12 or 14 degrees of positive caster, which increased the self-centering affect and effort at speed. It used a mcpherson strut front suspension design and I realize different geometries and architectures behave differently. This also was one of the last E-class (if not last) with a steering gearbox, not rack. Still, interesting data point, I think.
Doug
I've had good success with rattle can painting by heating part in the oven @ 165F or 180F. In my mind, the finish is harder when baked... Kind of like poor man's powder coating. But I haven't tested this formally. And an item can be put in to service after an hour or so in the oven. Fumes don't remain long. Don't tell my wife her oven was used in this way.
Interesting info on tuning the EPS. Look forward to more updates.
I used to drive a 1995 500E Mercedes, which on which I modified the suspension a bit (lowered it, tastefully). This was one of the predecessor to the AMG / M type super car sport sedans of today. It had something like 12 or 14 degrees of positive caster, which increased the self-centering affect and effort at speed. It used a mcpherson strut front suspension design and I realize different geometries and architectures behave differently. This also was one of the last E-class (if not last) with a steering gearbox, not rack. Still, interesting data point, I think.
Doug
11-14-2018, 06:16 PM
#976
TECH Senior Member
Thread Starter
iTrader: (7)
Another neat project!
I've had good success with rattle can painting by heating part in the oven @ 165F or 180F. In my mind, the finish is harder when baked... Kind of like poor man's powder coating. But I haven't tested this formally. And an item can be put in to service after an hour or so in the oven. Fumes don't remain long. Don't tell my wife her oven was used in this way.
Interesting info on tuning the EPS. Look forward to more updates.
I used to drive a 1995 500E Mercedes, which on which I modified the suspension a bit (lowered it, tastefully). This was one of the predecessor to the AMG / M type super car sport sedans of today. It had something like 12 or 14 degrees of positive caster, which increased the self-centering affect and effort at speed. It used a mcpherson strut front suspension design and I realize different geometries and architectures behave differently. This also was one of the last E-class (if not last) with a steering gearbox, not rack. Still, interesting data point, I think.
Doug
I've had good success with rattle can painting by heating part in the oven @ 165F or 180F. In my mind, the finish is harder when baked... Kind of like poor man's powder coating. But I haven't tested this formally. And an item can be put in to service after an hour or so in the oven. Fumes don't remain long. Don't tell my wife her oven was used in this way.
Interesting info on tuning the EPS. Look forward to more updates.
I used to drive a 1995 500E Mercedes, which on which I modified the suspension a bit (lowered it, tastefully). This was one of the predecessor to the AMG / M type super car sport sedans of today. It had something like 12 or 14 degrees of positive caster, which increased the self-centering affect and effort at speed. It used a mcpherson strut front suspension design and I realize different geometries and architectures behave differently. This also was one of the last E-class (if not last) with a steering gearbox, not rack. Still, interesting data point, I think.
Doug
Good to see you are still around! Great call on baking the painted parts. Maybe next time I will use my smoker...LOL
As for alignment, I am lucky to get the 5 degrees that my suspension currently has. As I recall, the stock alignment specs call for zero caster! No dought this was done for easier steering effort at the expense of high speed stability.
Andrew
11-16-2018, 11:13 AM
#977
TECH Senior Member
Thread Starter
iTrader: (7)
Alright. Awesome news. I wanted to temporarily try the PWM+ trigger to turn on the steering ECU. I am able to configure the output on the Dominator all in software. So I simply reprogrammed the original speedometer output and created the PWM+ output and assigned it to the same pin as the speedometer output (the speedometer output had to be virtually unpinned from that location). Anyway...
I set the frequency to 1000Hz and a duty cycle of 50%, so half the pulse is on and half the pulse is off, very much like a speedometer signal. Turned the ignition off, turned the ignition back on, and immediately had power assist. The diodes will be here tomorrow so I will add the second wire to the steering ECU speedometer input. The result should be having immediate PS as soon as the ignition is turned on and there after, it will receive the speedometer signal and operate by changing the level of assist based on speed.
Andrew
I set the frequency to 1000Hz and a duty cycle of 50%, so half the pulse is on and half the pulse is off, very much like a speedometer signal. Turned the ignition off, turned the ignition back on, and immediately had power assist. The diodes will be here tomorrow so I will add the second wire to the steering ECU speedometer input. The result should be having immediate PS as soon as the ignition is turned on and there after, it will receive the speedometer signal and operate by changing the level of assist based on speed.
Andrew
11-16-2018, 03:51 PM
#980
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iTrader: (7)
Andrew