Truly & duly groovy! Sign me up -- those long highway hauls on cruise control would benefit from the (properly elegant) cutout frobulator...
Printable View
Truly & duly groovy! Sign me up -- those long highway hauls on cruise control would benefit from the (properly elegant) cutout frobulator...
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.Quote:
Originally Posted by Tobert
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.Quote:
Originally Posted by darkl4805
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.
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?
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:
This is going to be a sweet MOD. I want in when it's complete.
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
^ Wut he said ^ ooh wait that was me?
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.
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
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!!
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
Where the project left off
Quote:
Originally Posted by mbeach
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:Quote:
Originally Posted by taylorRichie
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:
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.
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?
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
I believe our JDM TOD boxes are totally different. They are made by Aisen (spelling?) and not the same as the brand you use.Quote:
Originally Posted by Knigh7s
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!!!!
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
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...Quote:
Originally Posted by 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.
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
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:
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! :)Quote:
Originally Posted by taylorRichie
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!
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?Quote:
Originally Posted by orion
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.
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.
Good point!! I like the balance when in 4WD-low, but who knows what will feel best at higher speeds in 4WD-high.Quote:
Originally Posted by taylorRichie
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%
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.
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.
sounds like you're using an MCU... are you going PIC or AVR... or something else altogether?
Using a PIC microcontroller from Microchip.
And I can't really say "I'm" using anything... My brother is using it ;)
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.
Quote:
Originally Posted by taylorRichie
Youn didn't think we were just going to forget about this...DID YOU???:rolleyesgQuote:
Originally Posted by taylorRichie
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
Quote:
Originally Posted by Ldub
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
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
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
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/u.../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.;)
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.
Quote:
Originally Posted by taylorRichie
Awl rahght thayen...we'll just-a-wait owver here...:smilewink
http://www.vehicross.info/gallery/da...slingblade.jpg