Re: 41TE/604 operated by Megasquirt
Quote:
Originally Posted by
guhfluh
I'm a little skeptical about the need to account for wear since I've been thinking about it a little. How does any other hydraulic only transmission account for wear and shift timing? Band adjustments ala a413?
I think you're wrong on this. The timing of the clutches is critical with this transmission so accounting for wear is important. It's not like other transmissions so you can't compare it to any, especially the A413. They are pulse width modulated and can't just be slammed on or off like other transmissions.
Quote:
Originally Posted by
Vigo
The same problem has been untouched ever since Una had his van running with 604/Megashift. The available options don't auto-tune for wear. It is possible to make a megashift shift a 604 well for a time, but not possible to make it shift well forever without 'periodic' retuning or writing a whole lot of fancy code.
I do plan on going back in occasionally to make adjustments for wear.
Re: 41TE/604 operated by Megasquirt
What I mean is, there are more transmissions out there that have to release one element and apply another for a shift. Not all of those transmissions are computer controlled solenoid operated. The 2-3 shift in an a413 is this way, as are other earlier Chrysler autos. How often do people adjust the kick down band to account for wear, timing and flare? In my race car with carbon band it was fairly often because I was meticulously trying to keep it alive and perfect. In my modified Cummins built 47RE, never. Periodic adjustment of the clutch timing will be needed over time for sure, but automatic CVI learning, etc. I don't think may be necessary right away, only a nice add-on.
Re: 41TE/604 operated by Megasquirt
Quote:
How does any other hydraulic only transmission account for wear and shift timing? Band adjustments ala a413?
Until driver perception and expectation in shift quality and lifespan became important did anyone bother to put the controlling logic in there ? 'good enough' worked for detroit, not because it was the best.
Re: 41TE/604 operated by Megasquirt
Quote:
Originally Posted by
A.J.
I totally forgot to update this. Thanks for reminding me.
I ran into a major road block. Chrysler uses a digital signal to tell the TCM what gear you have shifted into via the gear shifter (park, reverse, neutral, drive). There are four wires that are either open (no positive or negative voltage) or ground. For example when in park, wire 1 will be ground, wires 2, 3, 4 will be open. In reverse wire 1 will be open, wire 2 will be ground, wires 3 & 4 will be open. In neutral, wires 1 & 2 will be open, wire 3 will be ground and wire 4 will be open, etc. Well Tuner Studio, the tuning software for Mega Squirt, wants to see an analog signal (voltage). So I bought a potentiometer and set Tuner Studio for park to be 1 volt, reverse to be 1.5 volts, neutral to be 2 volts, etc. I turned the potentiometer to get the desired voltage and Tuner Studio did indicate it recognized the voltage and indicated it was in that selected gear but reverse never was indicated and the voltages it was seeing was off. For example I selected drive which was 2.5 volts, it might indicate it was in drive at 3.7 volts. So with AZ being so hot and my experimenting having to take place in my 110* shop, it's on hold until it cools off, which it's doing. The range selector problem can be worked out (if possible on the bench) so if and when I can over come this hurtle will dictate this moving forward or not.
I'll have to look at the 41TE manual again, but I don't remember the range selector being a big problem before. Does factory use individual wires to the TCM grounded, or is it one common input that gets grounded through different resistor values at the selector in the trans? I vaguely remember it being the latter, but it's been too long.
It seems like maybe a pullup resistor and different resistance for each gear selection wire to ground would work to create a common analogish input for the MS...?
Re: 41TE/604 operated by Megasquirt
Quote:
Originally Posted by
A.J.
They are pulse width modulated and can't just be slammed on or off like other transmissions.
They can and have been before. The VB passages, accumulator, etc. still regulate the time it takes to fill and drain. Driven at 100% duty may have long term effects on the solenoids or drivers, but 100% on/off doesn't always mean it's going to be an instant apply or release of the clutch in this trans without modification of the passages and possibly the solenoids themselves.
Re: 41TE/604 operated by Megasquirt
Quote:
Originally Posted by
guhfluh
I'll have to look at the 41TE manual again, but I don't remember the range selector being a big problem before. Does factory use individual wires to the TCM grounded, or is it one common input that gets grounded through different resistor values at the selector in the trans? I vaguely remember it being the latter, but it's been too long.
It seems like maybe a pullup resistor and different resistance for each gear selection wire to ground would work to create a common analogish input for the MS...?
they used to use a much simpler switch on the earlier units. dont remember what year gearbox una was using in his car when they were setting this stuff up.
the MS guys could grab the patent document flowcharts for the original 604 to program in the CVI stuff as the patents detailed alot of the system.
brian
Re: 41TE/604 operated by Megasquirt
It looks like Una was using a single input wire to MS, not the 4 wire individual inputs, and wired just like I was trying to describe. You'll have to play with the resistance values on each wire to get the voltage range for each position you're looking for. https://youtu.be/oebM1Xwl9fI
Re: 41TE/604 operated by Megasquirt
Quote:
Originally Posted by
guhfluh
It looks like Una was using a single input wire to MS, not the 4 wire individual inputs, and wired just like I was trying to describe. You'll have to play with the resistance values on each wire to get the voltage range for each position you're looking for.
https://youtu.be/oebM1Xwl9fI
I did find the one wire going into Micro Squirt to play with the voltages. I did consider building a four wire in,one wire out converter box kind of what like is described. But like I said, I'm waiting for it to cool off to play with this some more.
Re: 41TE/604 operated by Megasquirt
OK...*really* dumb question because I don't know and can't remember:
the older cars didn't have any switches on the PRNDL, so are we talking about a later car with the "slap shift" (that didn't really work well), or an integrated unit in the tranny?
Re: 41TE/604 operated by Megasquirt
Quote:
Originally Posted by
Reaper1
OK...*really* dumb question because I don't know and can't remember:
the older cars didn't have any switches on the PRNDL, so are we talking about a later car with the "slap shift" (that didn't really work well), or an integrated unit in the tranny?
Older cars? How old are we talking about because the A604 has been used since 1987. I think you might have the A413/31TH hydraulic transmission confused with the A604/41TE electronic transmission. If you're referring to A604/41TE, this had PRNDL switches too.
Re: 41TE/604 operated by Megasquirt
It's integrated into the transmission, and as far as I've known, always been on the A604/4xTE.
Re: 41TE/604 operated by Megasquirt
Early and later 604s have different 'range sensors' mounted in different places.
As far as just switching solenoids off and on, the thing about timing one thing to apply as another releases is that while you can change apply time from the 'outside' with pressure and PWM changes, you can't really change release time as it's controlled by a combination of the return spring pressure and the size/resistance of the passages that fluid flows out of.
Re: 41TE/604 operated by Megasquirt
That is true. I'll have to look at what passages are recommended to drill/enlarge. MS Trans control does have a delay time setting for release vs apply that you can set, but I'm not sure if it'll need more resolution vs load or rpm.
http://i321.photobucket.com/albums/n...009_165041.png
Re: 41TE/604 operated by Megasquirt
I am curious about this? How much torque can an A604 and megasquirt handle? How often would the tuning have to be tweaked?
Is there potential for them to handle 600+ ft-lbs?
Re: 41TE/604 operated by Megasquirt
It wouldn't handle that torque in 4th for sure. 1-3 should be able to clutch wise when fully applied, but may need an ignition cut or retard on the shift. It was claimed to be able to handle 750hp in 1-3 by AJ *something* years ago, but not sure how he was controlling them. Steve Lockett put 650hp worth through one and it lived without issue, but I believe he had ignition cut also and tuned with a PCS controller, as well as some VB mods. No one I know of has run one long enough on MS to know how long it'll take before needing to tweak the shifts.
Re: 41TE/604 operated by Megasquirt
Quote:
Originally Posted by
A.J.
Older cars? How old are we talking about because the A604 has been used since 1987. I think you might have the A413/31TH hydraulic transmission confused with the A604/41TE electronic transmission. If you're referring to A604/41TE, this had PRNDL switches too.
So as far as I can remember none of our cars had any electronics going to the gear selector in the car at all. That started with the "cloud cars" and the Prowler. Meaning that the switches are integrated into the valve body. It's been a long time since I've messed with this stuff, so trying to blow cobwebs off of clouded memories! LOL
Re: 41TE/604 operated by Megasquirt
Just for a baseline, what is the most hp/tq a stock early 90's a604 (in a minivan) could be expected to handle?
Re: 41TE/604 operated by Megasquirt
Quote:
Originally Posted by
Reaper1
So as far as I can remember none of our cars had any electronics going to the gear selector in the car at all. That started with the "cloud cars" and the Prowler. Meaning that the switches are integrated into the valve body. It's been a long time since I've messed with this stuff, so trying to blow cobwebs off of clouded memories! LOL
September 1996 the 4xTE went to the integrated NSS/PRND 'range sensor' on the valve body. Prior to that it was still the stand alone old school NSS and I guess the range sensing was done via a physical switch inside the car ?
Re: 41TE/604 operated by Megasquirt
Do you really need the range sensor though? I'm pretty sure the solenoids only need to be controlled in drive for the trans to work.
Re: 41TE/604 operated by Megasquirt
That's what I'm saying, the range sensor is NOT in the car...it's in the transmission someplace, probably part of the valve body.