Nont ya meen "I AINT THAY GUY!"

 

Completely forgot about that thread, but the subject came up again elsewhere, so there: Yes and no - "overdrive" refers to the transmission gear ratios only, so while you can indeed make up for the lack of OD gear in the trans by running numerically smaller gears in the axles, it's a trade off due to losing overall ratio in the low gears, unless you have a lower 1st gear - for instance the Allison 545 is a 4-speed non-OD trans that you can this to due to the lower 1st gear ration than the C6 and the E4OD. Have you even observed your own transmission's operation? Go ahead and lock that converter at low speed, I dare ya The converter in almost any auto trans locks up when the trans is in a higher gear and the vehicle is moving fast, meaning when there is little load across the converter - when you floor the throttle the converter usually unlocks too. And by the way, the E4OD converter when unlocked in OD and under heavy throttle gives you about the same overall gear ratio as when you're in 3rd and lock it - mine is on a manual switch so I've played with it a lot, at part-throttle you can actually use it as a gear splitter And don't forget the matter of heat generation, a "standard" converter (what's standard about it?) will always make more heat than a lockup converter with its clutch engaged, that alone is a decent benefit I think. Oh really? I'm going to entirely skip the whole subject of the E4OD being based on the C6 but with lots of upgrades, and I'll go straight to your GV statement - where did you come up with 6 forward gears and 2 reverse? Do you even have an idea how the GV operates? At best you'll get 5 forward gears (1st, 2nd, 2nd over, 3rd, and 3rd over) and still ONE reverse, but I'll let you figure out on your own why that is. With the GV you also get increased driveline drag, on top of the stupid amount of power already sucked down by the C6 - so in the end you have more power loss, more heat generation, more crap to break, and you're out $2k or so - yeah, no thanks, I'll keep my E4OD, and if I need extra gears the GV unit will be the last on my list. That said, you are going somewhere with the whole C6 + OD unit for the sake of avoiding electronics, but personally I'd use a AT545 and a 3spd mechanical auxiliary transmission of some sort, as having a 1U-2U-3U-4U-1-1O-2-2O-3-3O-4-4O forward pattern and 3 reverse gears would be a whole lot more useful than 1-2-2O-3-3O with 1 reverse Oh, an no need to be a *** to Mark Kovalsky, he has been of more help to us (at least to me) than you can ever be if your post that I quoted is any indication of your knowledge of the E4OD...

 

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Mark, so the VFS works off current, and not voltage? Do you think it would be possible to use the TPS voltage change to control the current applied to the EPC solenoid through some sort of a variable resistor? In other words, the higher the voltage reading at the TPS, the lower the current to the VFS, resulting in a higher line pressure - much like the C6 operates with vacuum modulator, only our system will be electric.

Then build the pushbutton box for controlling the shift solenoids... Or, here is another thought, use the MLPS and the factory shifter - 1st position is 1st gear, 2nd is 2nd, OD position gets you 3rd reag, and you shift in and out of OD with a button much like the factory seyup. This way we still have the neutral, revers and park positions and gears operational. And since i mentioned it - reverse is full hydraulic application, correct, no solenoid action required to engage it?

 

I'm no electrical engineer. I have no idea how to build something to control pressure off the TPS.

I once built a system that used the MLPS to control the shift solenoids. I didn't need overdrive for that project so it only worked 1-2-3, but it worked. I didn't control EPC pressure, just left the solenoid disconnected which made max pressure all the time. It worked well until the forward clutch drum came apart. It didn't like max pressure.

 

There is "MegaSquirt" that was working on adding transmission controls to their EFI system.

Forums
www.MSefi.com &bull; Index page

 

Mark, is there a forward clutch drum that can handle max pressure? Also, what other parts you suspect may fail next assuming the drum holds up?

Archangel, that would possibly be a good thing for those adding a electronically-controlled transmissions to vehicles not previously equipped with such - I think I've seen you around the IDI diesel forum here, our fellow member there David85 from Canada would be a good example of that. However, what I'm really trying to do, is non-electronic manually-controlled E4OD - essentially an automatic that works like a manual trans, only without the darn clutch (I hate clutches more than I hate stuff that shifts on its own, lol). Basically I'm trying to eliminate any kinds of brains and PCMs and what not, just basic switches and relays and resistors and such.

 

C6 does not have a lock up convertor.

 

I don't know what's available in the aftermarket. Check with some trans sponsors from this site. They may know.

 

Well, the pressure is just an electronically adjustable variable valve, so I don't see why you can't just add an adjustable/variable potentiometer/switch to the throttle connection somewhere that will give you more trans pressure when you give it more throttle.

And as for the shifting, the solenoids are activated in a sequence that determines the gear you are in, so making a switch panel to activate the required solenoids as you push the button for that gear should not be hard either.

The charts I have only show the one way and friction clutch applications for the gears, but I do remember seeing something when at Ford that showed the solenoid applications per gear.

If you set up indicator lights to the solenoid power wires and record them as it shift it and you should be able to figure it out.

You will have to remember to push the correct button as you shift the lever into the desired positions as the trams is a combination of timed electrical and mechanical shifting.
For manual 1 and 2 you get engine braking and the coast clutch is applied in them as well as reverse.

You should be careful as if you move the lever and fail to push the correct button, there might be an incompatibility issue that could cause damage, but I don't know.

I do not envy the shifting you will have to do in the city pushing buttons as you are going up and down through the gears, but at least the lever can stay where it is in "D".

 

well thought I might interject I have several C-6 in both small block and big block, but never thought that they would be as efficient as the newer stuff like aod and so on.
but I am still trying to find some answer to my sons dilemma, I guess I am going to pull it and change the reverse clutches and band plus the plunger. hope it works JNT

 

Well, some of the efficiency is in having more gears and the lock up converter is not all that it's cracked up to be.
More complication and more possibility for break downs.

But think of this.
2 trucks set up exactly the same except for the trans.
#1 has the C6 with a 1:1 high gear and a 3.00:1 rear end has a 3.00:1 FDR.
#2 has the E4OD with the .72 overdrive and 4.50:1 gears has a 3.24:1 FDR.

The FDR of the C6 is .24:1 higher than the E4OD

Even if the torque converter slips 10% in the C6, take off 10# of the FDR and it's still 14% higher than the E4OD, and that should more than make up for it.

Yes, more gears has more versatility, but at the expense of reliability?

I don't think it is worth it.

BTW, the auto manufacturers only make things more complicated so consumers are less likely to repair it at the local shop or at home.

When they redesigned the C6 into the E4OD, they could have done it easier by simply adding something like a gear vendor to the rear of it.

Give me a C6 and a simple add on OD unit any day.