Does that camera phone have a Hi res mode?

Nah, it's a peice of ####.
This is my H165, fitted with a spring loaded locker unit.
I wont get to try it out untill my new engine is all together, but I can't wait.

Big thanks to Paul (1200 coupe) for all his help, he was a massive help.

I can try it out for you if you want , next time you need a photo taken, call Doctor D, he'll fix you right up.

If it works well, how much can we buy them for?

If it works well and priced decently im keen.

They are diff specific, custom made to fit each diff personaly.

1200rc was pioneering this center bout this time last year i think it was, I'm quite sure he said ghe could get em done for 200 bucks,
he liked it better control but gave when there was alot of pressure ie turning corners etc, but still had the benefits of a locker.

Best to PM him to get the full report on what he thinks

Cheers
Damo

In theory, it should work well. A lot of it comes down to the accuracy of the tolerances, within the unit.
You can't just make a "one size fits all" unit. Every diff will be different. I was extreemely lucky, this unit only cost me $5 to make. should it work, I'll need to find some more springs, so I can fit one into the L20B B310 coupe aswell.

the rally car I bought has one of these things in it's H190. The guy made it himself and has been doing it for years - they are nothing new.

Anyway, I wasn't a fan of them in principle before, and I'm even less interested in them now that I've driven with one. This rally car would be lucky to have 100bhp at the wheels and has only done 1 short course event since being built, plus the khanacross I did in it. The diff was unpredictable in its operation, cutting out half way through corners (in a slide) and even when they do decide to work, they don't have much effect. The net result is a horrible feeling to drive and no confidence in the back end of the car. I'll be throwing mine as far as I can and welding the centre.

I plan to use mine predominantly for drag racing. Knowing how they work, I'm fairly confident that the jarring shock of a hard launch will make it do what I need it to, give me two wheels driving to get me out of the hole.

Perhaps <100 hp with a big diff like a 190, and the loose surface of a rally ciruit, you can't keep enough load on the plates to keep the axels locked.

I guess the proof of the pudding's in the ET.

It highly depends on how its made
i had one which cost me $250 that works awesome (for 2yrs now in my old rallycar) and supposed to work upto 200hp

i could make one myself for #### loads less but have only done one so far (for bro's sprinter)

they can be made diffrentley and i guess it depends on how well the one you have is made

it shouldnt cost much more to do it properly its just in the design of it

im confident they are a good thing, i just havent made enough yet, still mucking around with the design a little and havent put the effort into testing them

tempted to go into production of them and sell some, will have to make one for my h190 (a15ett) and if that works then i can be confident in making them for all the h-series diffs for us all

this bloke's been making them for years and swears by them too. I guess the guys who put all the time and effort into making them obviously believe they will work even before they've tried them. not the most objective appraisal of their actual performance.

remember that even an open diff will always apply torque equally to both axles, and will spin both wheels off the line until there is a speed variation between them, then one might break loose, reducing the amount of torque you can generate. These things we're talking about will never lock the axles together. Never. They can try to limit the amount of slip, but I found in the rally car that once there it gets past a certain point of slip, it just totally lets go and behaves like an open diff until you back off and let them come back to an equilibrium and then apply the power more gently to keep the thing working. The more powerful the engine, the worse this thing is going to perform.

The problems I described with the way it works in my rally car might not be such a problem on the street, because you'll never be pushing it at 9 or 10 tenths. And straight line is the best scenario for these diffs. It will raise the point at which one wheel of your open diff starts to breakaway.

just a thought .... i have them every now and then, but they hurt alot more on weekends , has anyone looked at a smaller verion of an air locker diff set up similar to what 4x4's can run. i've got one in my patrol and it works a treat ... locks the diff completely at the flick of a switch, flick it again and you're back to a single spinner
just a thought keeping in mind i have know real idea how a diff works

Another thing too with a drag racing take off, is the torque of the motor tends to lift one wheel a bit. My L20b 310 shreads one tyre at the slightest thought of a hard launch. Datsun bodys are hardly as ridgid as a mack truck. But like you say, straight line application should benifit from this addition.
Putting the power down is half the battle.

Win lose or draw, I can't wait to pull out the welded up diff. They are a complete pain in the arse on the street.

For drag racing, the Detroit locker is King & they work very well in the rear of 4x4's too, but forget it for the street. The spin resistant type of limited slip diff is the best compromise for the street & this is but one example of the design.

May I ask why it is no good for street use. I thought it would be a good compromise between open and locked since it turns into an open centre whilst cornering. By all means tho a LSD would be the best. If only they wernt so bloody dear.

Quote: Well it's been more than 2 years, but now that I have seen the question about Detroit lockers, I can post a response.

The Detroit locker unlocks the outside wheel when cornering. This wheel freewheels & over-rides the drive as it is turning faster than the inside wheel. You will sometimes hear a heavy metalic click as the mechanism rachets as a result of the outside wheel/axle over-running the drive dogs.

This means that you really have only one wheel drive in the corner & it's the inside one which is trying to push you straight, so the more power you pour on, the greater the understeer.

If you are silly enough to change gear when powering on in a turn, you suddenly release the asymetric thrust when you hit the clutch & all that extra lock that you dialed on to counterbalance the force of the one wheel drive comes back to bite you as the vehicle suddenly wants to go where the wheels are actually pointing.
A lane change to the inside of the turn is a distinct possibility for the unwary.

If you hit a patch of something slippery while powering on in a corner, & the one driving wheel suddenly starts to spin [that's the inside wheel remember] the rotational speed suddenly catches up with the outside one & at that point the diff locks into 2 wheel locked drive with an almighty bang & you can suddenly have a situation on your hands. If the inside wheel suddenly stops spinning as a result of being locked to the outside one, you now have 2 wheels pushing you straight, but with the inside one no longer spinning, the outside one will rotate faster & the diff will unlock & revert to one wheel drive/asymetric thrust.
This can get interesting as I found out on a Police driver training skid pan in Canberra.

If the road surface is slippery, & the diff locks into 2 wheel drive with both wheels spinning, you then find yourself in a turn with NO latteral [sideways] support at the rear end, so the rear tries to overtake the front. Keep in mind that additional steering lock has already been dialed in to counter the asymetric drive, so this will add to the excitement.
If you back off suddenly, then you had better be ready for the snap back, particularly on a sealed surface, but not quite so bad on a muddy road.

A Detroit locker must be driven gently or it will bite badly, or at least this is what I found after fitting one to a Falcon Van in the late 80's when I did a 4 month evaluation on it for possible inclusion in my fleet. It worked wonderfully when driven properly, but was deadly in the hands of someone who did not pay attention all of the time.

I recomended against it with a 20 odd page submission to the management. Too dangerous in the hands of the ordinary driver.

Damn this is actualy a good thread and im glad i read it all... But 1 question. How does a sping locker work? I think i have veige idea after reading all that.

There is a slot in the plates which the idler gear shat runs in. (Like a semi circle) The tough of the the slot is very very close to the pin. The slot is not actually a perfect semi circle. Is kind a half elipse. The two plates are held apart by springs. The spring thrust force against the side gear faces makes the plates try and twist. This causes the pin to sheer against the slot, jamming it against the sidegear and preventing it from rotating.

Quote:

Well I'm certainely not hear to start any arguments. All I can say is that I have investigated these things in the past and didnt believe that they worked so I went about designing one for my rallycar so I could find out for myself. One of the things that I became aware of in the early days was "the more accurate the design the more chance of it working"
I dont know anything about the one L18-B110 has in his rally car so I cant comment on the tollerances, however when designing mine I kept to very strict tollerances and made a few design improvements along the way. The result is that it works and does not display any of the problems that L18 talks about. I have done over 800 competitive Klm's since first fitting mine and it is still doing the job. I cant stress enough how important it is to stick to very close tollerances (read 0.0005" in some places) and ensure that the centre it is being fitted to is in good working order and the spider and idler gears run true on all the contact faces.
I have herd many differing opinions on these devices, most say thay are crap and maybe it has something to do with production tollerances being used, all I know is the one in my coupe does not display the problem characteristics that L18 has mentioned.
I instructed A14 force on how to manufacture his own, a pretty long process via email, but in the end he finished it, I will be interested to hear if his works. Sorry to "let the cat out of the bag" but A14 made a small mistake in an area of manufacture that I believe to be very important so it will be very interesting to hear feedback from him once he gets his supercharged A14 back together. That should give some indication if close tollerances are indeed as important as I believe.
L18-B110, I am very fussy about developing my coupe and I wouldnt leave the plates inside my diff centre if they weren't doing what they were intended to do, I would have gone back to a welded centre a long time ago because the tendancies you mentioned sound bloody frightening at speed.

may i have the drawing? i would like to built one too.my email mfakhrin@yahoo.com. Thanks.