TOD controller - knob, wheel, or buttons?

[mbeach]

Some of you may have been following the TOD controller thread from a couple of months ago, here's an update and a poll to get some feedback.

I've designed and built a PWM generator, capable of operating at 50Hz (optimum for the e-clutch), and varying its duty cycle from 5 to 95%. This is enough to control the torque split through the transfer case.

I still need to develop:
-a switch that activates the TOD controller (turns off the AUTO mode, and turns on the controller). I was thinking that a Trooper 4WD switch can do this.

-a method of driver input -hence the poll. We have a few options here; many have mentioned that they want a knob, others have asked for a sliding switch or even buttons. The Rally VX uses a 4 position switch, with discrete torque values assigned to each position. We can also do a potentiometer, with infinite torque values available, however there will only be 4 display options.
I can also do buttons or even a vertical wheel.

I'll build whatever people seem to like the most.

Even if this is not a mod you are considering, I'd still like to see your input. I have to think about ergonomics, etc. and the more ideas, the better.
I have the component count down to a minimum, so the thing can most likely be built for less than $15 (!), will operate with the TOD display, and be hooked up by splicing only 4 wires.

[AREA 51]

knob is best. can't accidentally bump it or inadvertently change positions

[ZEUS]

I'm all over that option!!! As for what style I would like to see on my dash for the control of such a cool option, I personally think a switch to fill one of the blanks would be appropriate. I think the Trooper switch you mentioned is like that isn't it? As for regulating the percentage of torque I don't know where I would put a knob but I could see a vertical wheel next to the switch working and looking really nice. I'll have to go through your previous posts on this! Good luck...

[AREA 51]

you could probably mount the knob on a switch blank

[steelzeus]

what would be nice is a knob that had a cover over it so it does get changed on accident like the "nos" switches your see all the time.

[ZEUS]

I really didn't know if I would like how a knob would look on my dash compared to a wheel but it probably wouldn't look too bad on the console near the power/winter buttons. However, mbeach has put so much time into this mod and it seems to have become his baby... I'd say he will come up with what is best for everyone even without our feedback. So whatever you come up with, mbeach, just let me know when it's ready. Kudos on all your research and development! I can't wait to try it out.

[MZ-N10]

knob....
just gimme a price...lol

ps. kudos on all ur work and research

[blacksambo]

It would be nice if it would fit where the coin slot is on the dash. Or the JDM empty dummy button on the console.

[mbeach]

I'm glad that people seem to be leaning towards the 'rally VX' style torque splits. I've reconfigured the circuit to operate with even fewer components (less cost!) as long as we stick with discrete torque values.

I was thinking about an Isuzu 4WD button, ala Trooper, to activate the TOD controller. This switch would a.) turn off the AUTO display, and b.) turn on the controller.

The knob (maybe a junkyard fan control knob from a Rodeo) will be mounted anywhere there's space -I won't build it into the controller box, so You can pick where it goes. We can lower the cost even more by using this knob to turn the controller off and on -this'll eliminate the need for the separate dash-mounted button.

I've been running the prototype with a 5 ohm load on one of my benches for the last 22 hours -at 88% duty cycle, which should correspond to 4hi. It's in a sealed plastic project box, so there's no air movement. If it's going to fail, it'll do it on the bench and not under your seat.

I've taken to calling the TOD controller the "Torque Monkey," a name which I can't take credit for (this was a pet name for a similar device prototyped (but never completed) for controlling the torque split on a auto trans WRX).

[MustangO4]

I like the idea of the protected switch of some sort, but whatever you choose, put me down for one.-John

[VehiGAZ]

Go daddy go!! Whenever it's ready, mbeach, I'll take one, too.

Sorry to hear that you had to get rid of your Dragon. Good job on the trade-in deal, though!

[VR4-Quest]

This is awesome stuff mbeach, I've been wanting to come up with something like this (we should have had it from the start) but havent had the time. Whatever you come up with will be perfect Im sure, your the man calling the shots here!

[AREA 51]

When you said knob, I figured it was the same as a fixed position rotary switch. As far as the torque splits I'd like to see the following percentages to the front : 0%---15%---50%. Anything in between and you're just slipping the clutches in the tod, right? The 15 & 50 are factory figures and should be safe for the tod, although I'm curious about the tod clutch slippage at 15%.

I'll most likely buy one whatever the splits end up being.

Thanks

[LiquidVX]

I wish for buttons. But it seems I am out numbered.

[mbeach]

I wish for buttons. But it seems I am out numbered.

Buttons aren't a far jump from a knob. The knob just integrates all of the buttons into one fixture.

The TOD's e-clutch slips itself. It's kinda hard to explain without going full nerd. Each "cycle" or period lasts for 20 milliseconds. If the E-clutch were operating at a 50% duty cycle, the clutch would be engaged for 10 milliseconds, then disengaged for 10 milliseconds, then engaged, etc...

Since this is a coil, it takes a millisecond or so to really "load up" when current is applied. To operate at 100% duty cycle would burn out this coil over time. There would be no "rest period". In 4hi, the coil is working at @90% duty cycle, this is the same as 18 milliseconds on, 2 milliseconds off, 18 on, etc...
Even at idle, there is a brief surge of current every 20 milliseconds. So, in "2wd," there is a little bit of e-clutch engagement.

My first circuit went wild with the higher duty cycle. After 24 hours or so (this will never really happen in real life), the frequency shot up in relationship to the duty cycle. In short, at higher duty cycles, the 20 millisecond period went up to almost 10 milliseconds. This means that the clutch was being pulsed 2 times as fast as it was designed to be. This is bad. I'm bench testing another design that I found on the web. It'll probably work because a.) it's simpler, and b.) I didn't design it (I'm a mechanical engineer, I shouldn't be fooling around with electricity).

I have no intention of building these things "ready to install." Frankly, my time has a cost, and if I were to spend 2 hours putting it all together, we would suddenly crack the $$ barrier. Figure in the components (still less than $10-15) and shipping and it becomes unreasonable.

I'd like to provide the schematics, as well as a PCB (printed circuit board) layout. I could even burn the PCBs here if there's enough interest. Each person would be responsible for finding the components (if it can't be bought at Radio Shack, I'm not using it), and assembling the controller. There will be some soldering involved. I'll be able to provide some nice pictures of the finished board so component assembly will go smoothly.
This should be no more complicated than those electronic kits that you can buy for your kids (like the DIY lie-detector or the DIY burglar alarm).
The real difficult parts were getting the data together and determining what duty cycle corresponds to what torque split. Now that that's done, it's just a matter of putting all of the pieces together.

[LiquidVX]

Thats awesome. Sign me up.

[sature]

thanks for putting so much time into this!!! you are awesome!!!

[climbcovey]

requesting a little clarification. this switch on the tod system would give control back to the driver in reference to % of power going to front tires? is this the equivelent to a push button 4wd system allowing me to push a button or turn a knob and change from 15% to 50% power to front on the fly like a 4 high button? if so sign me up for one sorry if this is a stupid question but im a TOD "toddler". it seems to me under adverse conditions sometime the power transfer comes a little to late like after youve lost traction!!! please reply with more info on this Thanks!!!

[mbeach]

Yup, that's what it'll do.

My gripe with the TOD is the fact that I require a little slip before torque is transfered up front. In most cases this is alright, but for me, it is unacceptable. I drive in some pretty sketchy places, and a little slip could cause a big crash. I just wanted the ability to dial in 4hi at will.

Since I have to generate a PWM to (correctly, for the coil) pull the e-clutch in to 4hi mode, it was just a few extra steps to make it truly variable (like the rally VXs). The TOD is very smart, I don't even pretend to believe that I can sense torque bias requirements as fast as it can. However, I do know that when I am decending an ice covered hill, I want 4hi WAY before the TOD says that I need it.

Also, for those following this thread, there was some discussion about the transfer case's ability to transfer torque to the front wheels in the absense of any e-clutch input (cutting a wire to get 2wd). The t-case CAN transfer torque up front when the front driveshaft is spinning at a significantly slower rate than the rear. This speed differential causes the engagement of a ball-ramp mechanism in the t-case. So even with no e-clutch, there will NEVER be true 2wd without a front-axle disconnect as found on the Troopers.

This TOD mod will only allow you to dial in MORE front torque bias than the conditions call for, never less. So no donuts or dynos.

[climbcovey]

Great!!! Thanks for the clarification as I said before I am definately interested in this so keep us posted on cost &install

[Maugan_VX]

mbeach,

Its nice to see that you're still working on this. In fact, its the only reason I came back to the site is to check the status of the project. I voted Rotary.

[mbeach]

Maugan,
I decided a long time ago, that if I were to send out a freebie test unit, I was going to send it to you.

If anyone could find a flaw in it, it'd be you for sure.


I thought that you just wanted a 4hi option -in that case, it's pretty much done.

[Maugan_VX]

thanks for the consideration :P

I've wanted a selectable torque solution ever since the "suprise" snow storm down here in Raleigh last year.

Glad to see it hasn't been abandoned.

[Maugan_VX]

mbeach... any progress?

I've got the spot on my dash picked already for the knob.

[VehiGAZ]

Leave him alone! You can't rush genius!!

No seriously, mbeach, don't think we have forgotten...

[mbeach]

Ha! I was just working on this (looking for a project box) yesterday.

I've been really busy since BP's little "accident," and haven't had much time to allot shop resources to personal projects. Once the air (and my workspace) clears out a bit, I'll be able to jump back into this with both feet.

It's really not that far off, I just need to bolt it together and test it (difficult since the I-man is laid up with a leaky master cylinder and the Dragon is sold).

[Velvis]

I'm in, with questions. Are there any issues with Tone's AutoTrans Interceptor? Is there an OFF that yields exact factory TOD performance? (Can you kill the beast?) Most of my driving is good road to and from work, but off days are in wet/dry white sand and water and/or gloppy red mud (abandoned gravel mine/bar pits--Dorcheat Bayou - Webster Parish). I'm riding the stock wheels and tires and have a new set of stock tires in my attic (thanks to this forum). This sounds like exactly what I need for sloppy steep hill descents. Again, I'm in.

[blacksambo]

I think I'm ready to assemble one of your kits, too. It sounds a little like Formula 1 traction control but the driver is the robot?

[Velvis]

any change?

[steelzeus]

if you need a project box go to a radioshack and you can get them cheap there.

[mbeach]

Thanks -I have plenty here.

The final product won't require a specific project box (it will be hidden under the seat -only the pot for the controller will be visible).

I just wanted to find two boxes, one with more RF shielding to see if I could improve the performance of the prototype.

UPDATE:
The 4hi option is done -that was the easy part.
Varying the duty cycle to vary the torque split is about 80% (the frequency drifts a little -needs refinement).
The display interface is designed, but not tested.

[VR4-Quest]

Wow, I cant wait......Subaru STi and Lancer EVO owners look out, we'll have our own selectable torque split too!

[Maugan_VX]

display interface?

do tell!

(or even better, show!)

[mbeach]

The "display interface" would just ground out each of the display LEDs on the dash. It would also turn off the AUTO lamp whenever the knob were turned away from the auto setting.

I've been stupid busy at work, and with the snow melting, I have a ton of household chores to do as well. This at the top of my personal priority list, but it lags behind the job (and the wife's) demands.
Oh, to be single and unemployed again... ;)

[Maugan_VX]

Oh ok, I was wondering if you were coming up with some new slick display for it.

I know what you mean about real life getting in the way of fun. Ack.

[Velvis]

How 'bout we agree to only bug him once every couple of weeks? OK, how 'bout NOW??? Don't worry beach, we'll wait for genius. (We'll wait longer for new slick display, though.)
v

[mbeach]

I still donate a few hours every couple of weeks to this project. We are ramping up for our summer project season, so despite the 21+ hours of daylight, I'm still running out of time to get things done.

[mbeach]

TTT

Here's where I stand:
I made two circuits, both capable of varying the duty cycle of a 20Hz pulse, from 5 to 90%.
One ran perfectly, varying the duty cycle without changing the frequency. At 7 volts. Once the V came up to 14, a FET got unstable. Radio Shack doesn't carry a higher power option. I can find one, but the average guy doesn't have the same resources as my shop.
The other one could handle 14V no problem. It managed 5 to 25% duty cycle without a problem. Any duty cycle higher than that caused the frequency to drift. At 90% dc, the modulation had gone from 50 to 250Hz.
The e-clutch no like "high frequency".
Keep in mind, both of these circuits were built only with parts that could be easily found and assembled. No digital ICs, PICs or anything of the like. This is all Radio Shack stuff, and as a result, it sucks.

I've found another option, based on a comment by a member regarding a DC motor speed controller. I found a $25 kit that allows you to build your own. It has a transistor and a MOSFET that are kinda odd, but it ships with all of the components needed to work, so no part sourcing required.
It will require 4 components to be subsituted, to change the operating frequency, but they are easy to come by.
I think that this'll work -and best of all, it's designed to be assembled by someone who has no more than basic soldering skills at hand. I've ordered 2.
I'd build a prototype based on it's schematics -but I'm missing one component, so I'll just wait until the kits arrive.

I've managed to switch my TOD display (the interface) along with the movements of a 4 position switch. It was actually easier than I thought that it would be. Getting the display switch to jive with the torque splits will be a little tougher. Again, I'm waiting on those kits to show up to see if I can jam it all together.

To sum up:
If you want 4hi only; you'll cut one wire. Put in a switch, a load, and the PWM generator and you are there.
If you want 2-4 control; you'll cut one wire. Put in a switch, a load, the PWM generator, and a rotary switch, and you are there.
BUT if you want a working display, you ALSO have to tap into 4 additional wires, and work these in to the rotary switch.

I'm making this sound tougher than it is -I apologize. I just need a rainy day and those kits to finalize everything. I still have my "eavesdrop" cable sticking out from under my passenger seat, just waiting to do some good.

[Tobert]

You can create parts lists for digi-key that are pretty much one-click to fill your cart if I understand properly. I've been eyeing the Megasquirt kit for a while now to mess around with but haven't had a vehicle I really wanted to mess with in a couple years.

http://www.megasquirt.info/
http://www.megasquirt.info/v3bom.htm

http://www.digikey.com/

This way you could source whatever parts you think are appropriate and anybody here can easily order them.

[darkl4805]

So basically the switch will let you choose TOD Off, TOD Auto, TOD 15/85, and TOD 50/50?

Is there a front differential? If not what happens to the built up tension?

Very cool work, put me down for one whenever you are done!

[Groovium]

Truly & duly groovy! Sign me up -- those long highway hauls on cruise control would benefit from the (properly elegant) cutout frobulator...

[mbeach]

You can create parts lists for digi-key that are pretty much one-click to fill your cart if I understand properly. http://www.digikey.com/

Digi-Key is one of my usual suppliers for work. I wanted to avoid too much "parts shopping" by the members -it just gets too confusing with similar part numbers and interchangeablity.


Is there a front differential? If not what happens to the built up tension?
There is a front differential. This part (2wd) of the mod will just prevent the TOD clutch from modulating. If the clutch provides no friction (and your front hubs are unlocked), there can be no torque sent to the front driveshaft. It might spin, but without resistance (either from the clutch or the wheels) there will be no torque. This is the fundamental principle that allows the TOD to work.
Example: You're driving some old rig with an open rear differential. You drop one rear tire into a hole, and the other is just hanging in the air. You're stuck. The tire that's in the air is just going to spin -until you apply the brakes a little. This brake friction will redistribute the torque to the wheel that needs it -the one in the hole. This technique (using the brakes -ABS- to modulate individual wheel torque) has been in use for a decade or more. Land Rover might still use it. The VX's TOD works on the same principle, but it's front to rear instead of side to side.

[ZEUS]

Hey mbeach, I don't mean to be pushy but I was curious about the progress you might have made on this invention of yours... Had any developments?

[BigDave]

Hi,
Great work ! I'll be in for 1 of what ever you come up with. I'd go for using the vacant switches giving the options of the existing auto, 15/85, 30/70, 50/50. Nice and simple.

I tried my JDM out in the snow a couple of weeks ago and can testify to the understeer. Overall, if I had the choice, I'd go for an ordinary old 4WD and a big toe on the brake where necessary.

Cheers........ :cool:

[crager34]

This is going to be a sweet MOD. I want in when it's complete.

[Knigh7s]

Hey Mbeach,

Just wondering how this project is coming along? I could really use one with my manual hubs from Spazz.

Peer Pressure, Peer Pressure, Peer Pressure

Just kidding. Hehe

[Knigh7s]

^ Wut he said ^ ooh wait that was me?

[taylorRichie]

Thread Resurrection

Wondering if anyone has any further details on this project. I was thinking of developing exactly what mbeach was working on. I've pm'd him hoping to get some response that could save valuable development time.

Just reading this thread and knowing he has had success is enough to make me start the development whether I'm able to get info from him or not.

Does anyone have Pin Out, or TOD wiring, or detailed information? Or know of where resources that give that information?

Seems like this would be the one mod we would ALL like to have. Especially those of us who have winter. Being able to give a true 50/50 split would be nice. Or to shut off the front wheels during our daily drives.

If anyone has any info please point me in that direction.

[Solitude]

I am thinking about going the manual front hubs direction as far as the isolating the front end out of the equation.. I liked the replies I received from this thread

http://www.vehicross.info/forums/showthread.php?t=13588

congrats on finding a powervault 2

I am GREEN with envy..

awesome work on your ride thanks for the log.

Jeff

[VehiGAZ]

I remember this project well - mbeach is an electroinics tech of some sort, so he was definitely the man for the job. He rigged an oscilliscope into one of his VXs (he had two, IIRC) to see what the inputs and outputs of the ToD controller were doing in various circumstances. He tried to get it to happen, but I believe he gave up on it when he realized that the speed-variable square wave generator needed to trick the ToD was too complicated to make as a simple workshop project, and he didn't want to get involved with making them. This was a shocker for some people, because the JDM VX and the Trooper ToD (which offered a 2W-Hi option in addition to ToD and 4WD-Low) could easily be modded to force a 4WD-Hi mode. That mod, however, does not work on the VX. Similarly, since our front hubs do not unlock, we don't want a 2WD-High option, because the front wheels will still end up spinning their drive hardware all the time even if you decoupled the front axle at the t-cases.

Mbeach sold one of the VX's, and he hasn't been around here much since then - his last visit was 2.5 months ago. Anyway, if you REALLY know your electronics, he's the guy to talk to about this (if you can get in touch with him).

Good luck!!

[taylorRichie]

Hey Vehigaz thanks for the response...

I actually found the thread where Mbeach explained where he left off...

The difference between his approach and the approach I'll be taking is... he was just going to add home brew components to the TOD unit in order to accomplish what we all want... Variable TOD...

I will be working with my Brother (electrical Engineer) and he would build custom software to emulate whatever we need.

I'm quite confident we can make this happen, it's mostly a matter of getting the time to do the initial experimentation, and diagnosis. I'm also sure that the knowledge in MBEACH's head would prove invaluable to resurrecting this project.

We'll see how it goes...

----

Thanks Jeff!
That's a great thread, I've read over it a few times... I think the best combination would be a TOD controller, and manual hubs :D

Richie

[taylorRichie]

Where the project left off

This one has been beat to death, and sadly, I never got to finish my work on it before I sold 0723. Now the test mule (complete with my custom made TOD eavesdrop harness) is laying dead behind a BMW dealership in Anchorage...

The E-clutch that engages the TOD is activated by a modulated voltage -NOT direct current. While DC will lock up the clutch, engaging the front driveshaft, it will also burn out the e-clutch over time.
You might be able to search my gallery for photos of the TOD computer in operation (look for the o-scope pics).

In order to have reliable 4hi, you need to generate the 88% (iirc) PWM signal that simulates the TOD computer's signal, and send that to the blue wire.
Google "DC Speed Controller" to get an idea of how PWM is used to control inductive devices like motors and clutches.

A few of us got a long way into figuring this out, and we pretty much had the solution on paper. Picture a knob, that allowed you to dial in the exact amount of torque you wanted to go to the front axles. Pretty cool.
However, no one really managed the jump from paper to reality for whatever reason.
Mine was a lethal combination of laziness and wife.

There are also two huge reasons that this knob solution never took a priority:
1. The Ball Ramp Mechanism. The original purpose of the TOD controller was 2hi, not just 4 hi. Two-wheel-drive has all kinds of practical daily benefits, not just the occasional mud run. Unfortunately, even with the blue wire disconnected (toggled), there is a mechanism within the Borg-Warner T-case that still transfers rotation to the front driveshaft. The e-clutch simply modulates this rotation to create torque. Tone discovered this phenomenon on a 2wd dyno, with disasterous results. So, unless your front wheels are suspended in the air (no friction at all), 2hi is unobtainable.
2. TOD is awesome. There was an army of engineers behind this one, and us lowly mortals could never improve its function. The truth is, that with a mechanical T-case, there is no way to reliably control it's doings from the driver's seat. The DCCD in the Subaru STI is on a viscous center diff, like the Evo -this is not a mechanical transfer case. I know that the Baja VXs have a torque controller (at least you can see the knob from the pics), but they also have a warehouse full of spare parts...

So, Tad's solution on PI is great, but use it with care (just like the owners of Air Lockers do). If you leave it on for an extended period, you will break something -it's about the size of a hockey puck and it's buried deep within your transfer case.

Not finishing the TOD speed controller has been one of the greatest automotive letdowns of my life. I really wanted to finish this one up, if only to say it was done.
I still have all of the files though...

[taylorRichie]

I PM'd MBEACH asking for any details on his project... I think he provided me with invaluable information. I've passed the details on to my brother (the engineer) and I'm anxiously awaiting his response.

This project seems like it'll be cake for him (since Mbeach did basically everything but the final build)

Thanks again for the response MBEACH!!!!

Richie

[Ldub]

I PM'd MBEACH asking for any details on his project... I think he provided me with invaluable information. I've passed the details on to my brother (the engineer) and I'm anxiously awaiting his response.

This project seems like it'll be cake for him (since Mbeach did basically everything but the final build)

Thanks again for the response MBEACH!!!!

Richie

Put me towards the top of the list if this comes to fruition...:thumbup:

Then get the Bro to work on a program so that we can tweak the ECU for greater mileage, performance & the ability to tune to the fuel/air sweet spot in supercharged applications.:_wrench:...:cool:

[blacksambo]

Hear, Hear... great! Nice that somebody is able to work on this project. You know, you can turn off the TOD on the Trooper but not the VX.

[Knigh7s]

This is good news!!! I was pretty bummed when the original project halted...

So now that we are on topic of TOD and stuff. Anyone know exactly what JDM TOD unit/parts would be needed to do a conversion?

[taylorRichie]

can't help on the jdm conversion but can give an update... We've started some prelimary design... By we I mean my brother...



It will have a small LCD screen and two buttons for changing your tod front percentage

[PK]

This is good news!!! I was pretty bummed when the original project halted...

So now that we are on topic of TOD and stuff. Anyone know exactly what JDM TOD unit/parts would be needed to do a conversion?

I believe our JDM TOD boxes are totally different. They are made by Aisen (spelling?) and not the same as the brand you use.
That is why we get all the goodies like -
2wd
Dipstick
Fill tube.

Now that you guys are green with envy, I will retire into my bunker down under.:p

Of course the down side is - we can't buy any bloody parts for ours!!!!

[PK]

Sorry guys, just noticed I was on 13 posts.
Can't leave it that way - my TOD might fall out on the way home.

PK

[taylorRichie]

We've got the concept proven...

We're now working out what will be best for everyone? Do you think we need the ability to "fine tune" to an exact percentage, or is: 5%, 25%, 50%, 100% enough?

What do you think?

[Knigh7s]

We've got the concept proven...

We're now working out what will be best for everyone? Do you think we need the ability to "fine tune" to an exact percentage, or is: 5%, 25%, 50%, 100% enough?

What do you think?

That is great news! As for the percentages, just curious, would there be any difference between 0 to 5% while driving, I'm sure it wouldnt be to noticable of a differance at all? we are talking about the torque split to the front right? so couldnt you just do 0, 25, 50, 100? well, if 5% isn't really significant of a change, then it shouldnt matter... Bleh, rambling.. sorry...

[taylorRichie]

Can't do the 0%, it's too much stress on the clutch that holds the front from spinning. I believe TOD operates at 5% minimum which is why we would need to have this be our minimum. However 5% coupled with manual hubs turned off should give you nearly the same results as 0%.

Just want to be safe. Also 5% and manual hubs still isn't safe for burnouts, 2 wheel dynos etc.

[Thmstec]

REALLY?!?!?! :dance:This is exciting! I would love it! :dance:

As for selections, I'm no pro as to guessing what torque splits would be best, but 4-5 selections total would be most desirable for me. My best guesses as to what the best choices would be is: 5%, 20%, 30%, 50%, 70%.

I'm assuming when you listed percentages you meant % going to the front wheels. So obviously 5% for as much power sent to the rear as possible. Now I won't confess to having as intamte a knowledge of the TOD as I'm sure you have now, but wouldn't 100% have the same problems as 0%?:_confused And honestly, I prefer power going to the back anyway. As for 20, 30, 70-- I'm just guessing, but I think some testing would reveal the best splits.:_steering The only reason I don't include 25% is because of all the cars I've seen/heard of with driver adjustable splits, I've never seen a 25/75 split

[orion]

the rear wheels are not controlled by the TOD at all. the front "shares" torque with the rear. so 100% the the front is just all the torque it can receive, not no rear torque. I like a simple 4 way split, I can't see why I'd need 67.4% the the front :bwgy:

[Knigh7s]

Can't do the 0%, it's too much stress on the clutch that holds the front from spinning. I believe TOD operates at 5% minimum which is why we would need to have this be our minimum. However 5% coupled with manual hubs turned off should give you nearly the same results as 0%.

Just want to be safe. Also 5% and manual hubs still isn't safe for burnouts, 2 wheel dynos etc.

Ah! the light, I now understand. I wasn't really going for a 0%, I was just curious as to why you would have to do something as low as 5% instead of just 0. But I sees the light! :)

I would prolly stick to you percentage splits, it seems the most logical out of it all. ( 5%, 25%, 50%, 100% )

Keep up the great work!

[VehiGAZ]

I can't see why I'd need 67.4% the the front :bwgy:

That's a really good point. It's nice to have choices, but what would you do with all those intermediate choices? I mean, what driving conditions really demand only a 25%-75% split and nothing else?

The only "forced" split ratio I am interested in is 50%-50% F-R (or 100% engagement of the front axle - however you want to look at it). That would be the equivalent of full-time 4WD-hi, which we don't have. I find the ToD system to be at a loss on smooth dirt or somewhat snowy roads when there is enough traction loss to confuse the ToD system (that constant on-off-on-off-on-off). That's when I find the system lacking and I want a locked 50%-50% split. When the conditions get worse, you go to 4WD low range and slow down. If they improve, regular ToD operation is fine.

I would also suggest to include a 0% front-axle engagement setting or a circuit that cuts power to the ToD entirely in order to achieve RWD (when used with unlocking front hubs). The ToD clutch pack is designed to operate with some slippage constantly, so I am not worried about trashing it with a 0% setting or cutting the power.

[taylorRichie]

I figure the intermediate choices may come in handy, I don't know... With winter driving I'm not sure what split will give the best control between over and understeer. Basically it's not an issue to add it so why not? The only expense would come if people wanted to have infinite control 0-100%. But I didn't think that was necessary.

We can add it, but it will be with a strict warning, I really don't want to be responsible for damage to people's vehicles, and MBEACH really cautioned us against this.

[VehiGAZ]

With winter driving I'm not sure what split will give the best control between over and understeer.

Good point!! I like the balance when in 4WD-low, but who knows what will feel best at higher speeds in 4WD-high.

Normal ToD operation is somewhere around 90%-10% to 85%-15%, so there's not much point in doing a 75%-25% on top of that. Maybe 66%-33% and 50%-50% would be good increments. If I had my druthers, it would be these choices:

ToD Off (100%-0%)
ToD On (85%-15% nominal)
Locked 66%-33%
Locked 50%-50%

[twistedsymphony]

I'd be happy to help in the electronics department if it's needed... I do lots of custom circuits in my spare time (Meche by trade EE by hobie ;) )

as for the splits...

if you're going to split it PERFECTLY 4 ways you're looking at
5% - 20% - 35% - 50% that a clean 15% change with every "click"
however I get the impression most people are really only looking for this:
5% - AUTO - 50% where "auto" is simply letting the TOD do its thing, 5% gives you the best fuel eco and 50% gives you the best traction.

if you wanted it to be really snazzy you could go with "wheel" type adjuster (think like the scroll wheel on your mouse but tighter to hold itself in place) that "clicks" on both ends... meaning wheel it all the way down and click for 5%, wheel it all the way up and click for 50% and then infinite adjustment in the middle... you could have a 2nd switch that would allow you to switch between TOD control and whatever you have the wheel set to.

[taylorRichie]

Thanks for the offer, and insight.

We're thinking 4 positions just as you said, and more than likely it'll be a 5 position dial. This is the where we haven't fully decided.

5-20-35-50-TOD

We have all the firmware and circuitry done, just waiting for another project to wrap before getting the boards shot.

[twistedsymphony]

sounds like you're using an MCU... are you going PIC or AVR... or something else altogether?

[taylorRichie]

Using a PIC microcontroller from Microchip.

And I can't really say "I'm" using anything... My brother is using it ;)

[twistedsymphony]

cool I've done a few PIC projects in my day.

anything you can tell me about the design? which chip model and language are you using, internal or external clock? I'm curious how "picky" the VX is on the timing... I'm assuming not very since people got full lock by just applying 12V.

Are you adding any kind of power cleaning circuitry? automotive 12V systems is crazy harsh since the voltage and amperage spikes and drops all over the place whenever something kicks on or off.

Have you started working on a PCB layout yet, or are you still prototyping the circuit?

Obviously these are more questions for your brother...

excuse me if I'm excited... but it's not often I get to talk about my love of car modifications and circuit hacking at the same time :smilegray

I understand if you want to keep the design to yourself for resale purposes.

[Ldub]

Thanks for the offer, and insight.

We're thinking 4 positions just as you said, and more than likely it'll be a 5 position dial. This is the where we haven't fully decided.

5-20-35-50-TOD

We have all the firmware and circuitry done, just waiting for another project to wrap before getting the boards shot.


Using a PIC microcontroller from Microchip.

And I can't really say "I'm" using anything... My brother is using it ;)

Youn didn't think we were just going to forget about this...DID YOU???:rolleyesg


Oh if only I had a dollar for every promised VX mod I've seen since 04...:sighwgray


Somebody had to stir the coals...:smilewink

[Thmstec]

Somebody had to stir the coals...:smilewink


Haha, I was thinking about this thread when I posted in the thread about the brake light. Was going to wait a day or two so I didn't look as desperate! Thanks for beating me to it :p

[twistedsymphony]

I lost interest in this when I decided that I'm going to do a 5-speed swap in the spring... in doing so I'll be losing the TOD system.. and gaining real 2WD and 4WD in the process :p

it will still be interesting to see how this turns out though. :D

[taylorRichie]

Hey I've been thinking about this thread for the past two months...

I hate the fact that it's "Done" but I'm not the capable party to finish it... so it's in my brother's hands.

And now with me going in to surgery this week... I don't know when I'll be able to help him wrap it up. Maybe a more realistic timeframe is a Moab 2009 Release ;) But it's honestly an afternoons work (for him) then getting the circuit printed, housings ordered, and building up a few.

:(

I'll try to put a fire under him now.

did I tell you I'm starting a Diesel engine swap and a 5 speed conversion ;)

(just playin' of course, just another over promised under delivered claim) :D

[twistedsymphony]

hey the only reason I'm not doing the 5-speed swap right now is because My garage (not to mention my wallet) is currently tied up with this project

http://solid-orange.com/wp-content/uploads/2008/09/silvette0.jpg

You know, I need at least ONE car on the road at a time. :rolleyes:
5 speed swap is cheap money compared to this project.;)

[taylorRichie]

New strategy developed on the TOD Over-ride...

Brother has to finish a couple projects before we can focus on this one. :( He wouldn't make any promises to me.

[Ldub]

New strategy developed on the TOD Over-ride...

Brother has to finish a couple projects before we can focus on this one. :( He wouldn't make any promises to me.


Awl rahght thayen...we'll just-a-wait owver here...:smilewink

http://www.vehicross.info/gallery/data/500/slingblade.jpg

[taylorRichie]

We've come up with a simpler idea, it's going to be a 6 position dial, all the way left is off, one click, is "simulated Two wheel drive" next click 25% front, next 50%, next 75%, next 100% or (50/50 split between front and rear, "true 4 hi"

The dial will just require you to drill a small hole where ever you'd like to mount it, and then attach a nut and knob. You'll still have to install the small TOD Override box under your seat, and splice in several wires.

Your position on the knob will also be indicated on your TOD Christmas Tree. First click, no bars, second 1 bar, third 2, fourth 3, fifth 4 (there are four lights correct?)

Sorry it's taking so long, If I knew what I was doing I'd have it done, and if my brother bought a Vehicross he'd probably have it done the first night, but since he doesn't have anything driving him ('cept me) it's taking a bit longer.

[ZEUS]

Rich, that is so cool you guys are taking this over - I was so ansy to have this mod when mbeach first mentioned it! It's good to know there is still hope. Tell Justin (if that is the brother doing this) that since I spotted his H3 over so many obstacles, we can call it even IF he finishes by December! :bwgy:

[twistedsymphony]

(there are four lights correct?)

only 3 unfortunately

[VehiGAZ]

Make it 3 selections, then.

("Off" means normal ToD operation, right?)

[taylorRichie]

("Off" means normal ToD operation, right?)
Correct So it'll be 5 Posltion

1: OFF (TOD operates as normal)
2: 0% (simulated 2WD) | No lights
3: 33% | 1 Bar on dash
4: 66% | 2 Bars on Dash
5: 100% (50/50 split standard 4hi) | 3 Bars on dash


only 3 unfortunately
Guess I need to drive the VX more often :)

[VehiGAZ]

PERFECT!!

Now git yer brother to git 'er done! Winter is coming...

[taylorRichie]

Rich, that is so cool you guys are taking this over - I was so ansy to have this mod when mbeach first mentioned it! It's good to know there is still hope. Tell Justin (if that is the brother doing this) that since I spotted his H3 over so many obstacles, we can call it even IF he finishes by December! :bwgy:

Unfortunately not Justin... It's my older Brother, with a family, a business of his own, as well as working for another company. I'll keep prodding him :D We'll see how receptive he is.

[Octamog]

Is it possible when (or should I say "if", considering how long this has been a topic) that the TOD controller could be used as a dedicated TOD controller for a possible 5-speed swap?

As I understand it, the TOD controller gets feedback from the ABS system which reverts the TOD to the minimum torque transfer during ABS braking. I'm not sure why this is desired or necessary, but would this TOD controller allow for such behavior?

[taylorRichie]

I don't think the unit will work with a 5 speed swap, but I'm not sure... All we're doing is emulating the signals that are sent to the TOD unit, making it think it needs to send "X" power to the front wheels. We're not manipulating any input signals, only sending our own output signals. If that makes sense.

So maybe it's possible... I don't know.

[Shawn Seeback]

Hey guys are you still working on this development? well sounds great so count me in aswell!! If not i will be soon starting on my own desighn.

[Thmstec]

Shawn, I believe this one died once again. I bet richie will fill you in on all of his discoveries if you want to take the task on. And I'd be interested in buying one if you complete it.

[circmand]

But with a cover like in an attack plane to prevent accidental changing

[Shawn Seeback]

i will be working on something, but i dont know wat it will require yet so maybe the prior people who workned on this will hand over the desighn or the parts they allready know will work, then it will be much easier as a starting point if not i have lot of research till i can get this to work but will try my best

[Shawn Seeback]

Also i like the attack plane idea very much!

[Shawn Seeback]

Well it doesnt look like its gonna be awhile b4 this one so maybe someone else will tackle it?

[BigMeatVX]

What happend to this? I am going to make something simmilar soon....

[Ebenezr]

Ha ha ha. R.I.P. TOD controller Mod thread. Heck I just want a button to turn it on and off. Since we don't have "winter" down here in Fla I thought maybe I could make that button shut it on or off????

[BigMeatVX]

yep its easy...do a search for it...