Freezing the Slushbox. Torque Converter on-demand lockup switch.

[abogart]

SUCCESS! I got it to work by grounding the TCC ENABLE wire through the switch and left the PWM wire cut. I found this article that clued me in to the fact that the solenoid gets grounded to apply the TCC.

http://www.motor.com/article_pdf_dow...rticle_ID=1039

So I now have a toggle switch next to the shifter which simply grounds the TCC ENABLE wire from the tranny to the engine block. I guess this wouldn't have been such a problem had I known that the solenoid had to be grounded instead of energized through that wire.

I can now definitely see how the auto tranny likes to upshift early, which usually results in rumbling, which I'm guessing is the TCC slipping due to low hydraulic fluid pressure. Strangely enough, I can flip the switch on at a stop with the vehicle in gear and it doesn't stall, in fact I don't think it even tries to engage. I'm guessing there must be a pressure switch or check valve somewhere in there that prevents it from engaging at low pressure. Now I just have to re-train myself how to drive this thing.

[ngrimm]

Congrats on getting it to work Abogart. I assume the shift points are controlled by the ecu instead of a vacuum modulator which could possibly be replaced by one that is adjustable. I recently added a manual lockup switch to my 88 Bronco II. I wish my converter would lock up in 2nd gear instead of just 3rd and overdrive. Sometimes going around corners at less than 20 mph it will unlock. Can see a definite mpg improvement climbing hills according to the MpGuino. I'm now wondering about adding a manual fuel cut for coasting and pulse and glide.

[abogart]

My problem now is that I can't keep it in 2nd gear. I have a PRN[OD]DL shifter and L (low) holds it in first until it either redlines or vehicle speed reaches about 22 MPH. When you let it sink below 22 MPH in L it slams (like *WHAM*) down into first. Not a good thing with TC locked. I've only done that once so far, looked in rear view mirror for gears and tranny fluid.

I can also tell now by the *feel* of it where it used to lock up before. Always in 1st (not sure if it's only when the shifter is in L), and whenever decelerating after a few seconds in any gear. And of course above about 47 MPH in 3rd or 4th. It won't engage in first from a stop but appears to seamlessly engage after a few MPH. It will however stay engaged when coming to a stop, I have almost stalled it braking while it was still in 3rd at 15 MPH.

So far, my best strategy for around town accelerating (35 MPH or less) has been to keep it unlocked and in D (not OD) until it shifts to 2nd, then flip the switch around 20 MPH and give it more gas to keep it from shifting to 3rd right away, then let off the gas and let it upshift and keep the throttle low right away to keep from slipping the clutch.

I have to say that I absolutely LOVE the fact that it stays locked on the highway now. I use so little pedal to hold 55 that rolling over the slightest hill or getting a slight tailwind gust resulted in the TC unlocking before. The only thing I'm concerned about is damaging the engine from too high of a load at low RPM. I can easily accelerate from 35 in 4th at 1000 RPM at 26-27 in. MAP (LOD doesn't work right on my car). The engine doesn't seem very happy about it, but it doesn't really shake or vibrate terribly.

How is everyone else doing with this mod? Any driving tips?

Originally Posted by ngrimm

I'm now wondering about adding a manual fuel cut for coasting and pulse and glide.

I have though about this too. Maybe just a switch to shut off the fuel pump. However, I don't really see it being practical because I'd still have to use the starter to restart the ICE. EOC is somewhat impractical with auto trannys.

[ngrimm]

My son also did the same mod to his 94 Lt1 Trans Am but hasn't driven it much since. My reasoning about the injector kill switch is to achieve a kind of manual fuel cut while coasting down our long hill or deceleration when the converter is locked. I really don't like coasting with the engine off wondering if I will have enough vacuum for the brakes. Seems like the engine should restart itself when fuel is restored with the converter locked don't you think?

[abogart]

Originally Posted by ngrimm

Seems like the engine should restart itself when fuel is restored with the converter locked don't you think?

I would imagine so, as long as it stays in gear, no neutral shifting. From what I understand, both the engine and tranny would still be spinning, so there shouldn't be any problems with hydraulic pressure. I would be worried about the ECU trying to pick which gear it should be in once engine power is restored though.

[E4ODnut]

I have some experience in this field and would like to offer an opinion.

From an Ecomodding standpoint, modifying an automatic transmission to allow manual gear selection and control of Torque Converter Clutch operation makes a lot of sense. You should be able to get better economy out of a vehicle equipped with a manual transmission than the same vehicle equipped with an automatic, given the same driving style. The reasons being that with a manual transmission there is no parasitic loss from the hydraulic pump required for an automatic, nor is there any loss from an “open” torque converter. By modifying the automatic the only loss you cannot eliminate is that of the hydraulic pump. You can minimize this loss by keeping your line pressures to a minimum and driving with a “light foot” as much as possible. Manual control allows you to be in the optimum gear for any specific driving condition and have the TCC locked as much of the time as possible. A side benefit of the TCC control is that most of the heat that causes damage in an automatic is produced by heavily loading “open” torque converter. Heat is just wasted fuel. Aside from regular oil changes, keeping the heat down in an automatic is the best thing you can do to preserve it’s life. Another side benefit is that locking the TCC on deceleration makes engine braking more efficient, which in turn extends brake life.

Modern electronically controlled automatic transmissions are relatively complicated, expensive things, and it seems that the newer they are, the more complicated and expensive they get. To the people who have contributed to this thread, that have done some modifications, I take my hat off to you. It takes a lot of nerve to mess with a factory system even if you have a complete knowledge of how it is supposed to work, what the limits are, and how any modifications may affect different functions of the transmission. Having said that, as long as you are very careful with what you are doing, you should minimize the probability of doing any damage. Most of these transmissions operate on the same principals, but there will be differences. I would advise that if you are planning to modify anything, get as much information about your particular transmission as you can get and study it thoroughly before you commit yourself to change anything.

I can only speak of one transmission, the Ford E4OD. I have one in my motorhome, and one in my daily driver. The stock shift scheduling and TCC operation drove me nuts, especially in the motorhome. I’m not a great fan of automatics at the best of times, but converting to manual in either of these vehicles was not a practical option. I had hoped to find an aftermarket transmission controller that I could buy to give me manual control, but at the time (over 7 years ago) I could find nothing, so I built my own. This was a huge job, and I won’t go into details, but briefly, this is how it operates.

With the manual lever in Park, Neutral, Man 2 (2nd gear), Man 1 (1st gear), and Reverse, the transmission operates as stock with the exception that I have TCC control in Man 2. With the lever in Drive, gear selection and TCC control is done with a 4 axis joy stick on the dash. Shifting is sequential, like a motorcycle. Pulse back, shift up, pulse forward, shift down. Pulse left TCC lock, pulse right, TCC unlock. There is no automatic control of gear selection. Line pressure control is automatic and programmable with separate maps for steady state cruise, 1-2 shift, 2-3 shift, 3-4 shift, TCC lock and decel. There are permissives for TCC lock on decel. It must be in a gear that will support engine braking, the throttle must be closed, and the engine above 1200 RPM.

As a side note, both of these vehicles have programmable engine management, so I have a manual switch that will cut the fuel injectors on decel if I wish. This is a great fuel saver in hilly country. The motorhome also has an exhaust brake of my own design (very rare in gas engines) that is of great benefit on steep grades.

These controllers have been in service for over 7 years with no issues of any sort. Since installation, I have never seen the temperatures exceed about 180F. The daily driver has over 240,000 km on it now, so I couldn’t have done too many things wrong.

How did this improve economy, you might ask? Well, to be honest, I really don’t know. With both installations many things were done at the same time so it would be impossible to accurately tell what contributed to what. The daily driver keeps gaining weight. E10 fuel hasn’t helped the mileage on either. The improvements probably aren’t significant, maybe 2 or 3 percent, but any gain is a good gain and the project was fun, even if there is no economic pay back.

If anyone is interested in a stand alone controller for the Ford transmissions, Carl Baumann of Bauman Engineering offers one, or at least I think he still does. It was available when I built mine, but didn’t have some features that I required.

Another more recent entry is the transmission controller from the Megasquirt boys. It was under development when I started but I believe it is available now with applications for the GM transmissions and perhaps others.

[abogart]

One thing that I have been wondering about is the effect of factory ignition timing retarding at higher load. I can now accelerate at full load at any engine speed, but ign timing drops from about -32 at cruise to -15 or so at close about 80% load, depending on engine speed. The knock sensor doesn't pick up any knock because I use premium fuel. I understand that it is necessary to retard timing under higher load for proper combustion, and I know that I should be gaining efficiency with the higher compression, but I just wonder if I am losing efficiency due to less spark advance, in which case it would negate the efficiency gained from higher compression.

[E4ODnut]

From my experience, if your vehicle came with factory EFI, it's pretty hard to make many improvements on it, especially at full throttle when most are in open loop. I don't know what changes you've made to your engine but if you have raised the compression and still have a functioning knock sensor with the stock ECU, it may be pulling back the timing before you can hear it, even though you are running premium.

I'd suggest doing a bit of experimenting. If you can disconnect the knock sensor without setting any codes, try that and see if you can hear any pinging. Try it with regular grade gas and see if you can hear anything. If you still don't get any, try advancing your base timing by a couple of degrees. This will offset your advance over the whole range. Does this result in any pinging? Does it result in any gain or loss in power? On some engines, you can advance to the point where it will start to lose power before it will start to ping.

It gets a bit complicated.

[abogart]

Originally Posted by E4ODnut

I don't know what changes you've made to your engine but if you have raised the compression and still have a functioning knock sensor with the stock ECU, it may be pulling back the timing before you can hear it, even though you are running premium.

I meant higher cylinder pressure, not compression ratio, oops . I haven't made any modifications to the internal engine, it still runs 9.5:1 compression from the factory. I have the Knock Retard gauge in SG which tells me how many degrees that timing is being retarded due to knock, which is independent from the IGN gauge. It stays at 0 for the most part when running premium. I never have to use more than 40% throttle (according to the TPS) to achieve 29" MAP (which I consider "full load" for lack of a better means of determining engine loading). The engine has fully electronic ignition, no distributor. So I really can't do anything about it without making some serious mods.

Originally Posted by E4ODnut

It gets a bit complicated.

I like complicated.

[skeeterb]

I know this may be an old thread, but seeing this thread and the TCC Locking wiki entry gave me an idea for a manumatic setup using a PIC microcontroller. I'm still working on its functions, but right now I have an activation switch and shifter buttons set up. I'm gonna be playing with it a while but I hope that I can come up with something that would work with little changes in code.