Welded Differential?

[Rookey]

Hi guys,

I have recently been looking into drifting and I hear a lot about having a welded diff ..

What benefit does this have in drifting? Because to be honest, I'm not TOO sure what a differential does .. Hey Ho! We are all here to learn right!

Cheers

Dave

[COROLLA-KID]

Hey dude

right a diff makes one wheel turn faster than the other when cornering. if you weld the diff its going to make both wheels turn at the same speed.

http://auto.howstuffworks.com/differential.htm this website is quite good for explaining things like this im not too good at explainin.

hope this helps.

[scionic]

A welded differential is essentially the same has having a continually locked differential.

The differential is what allows your wheels to spin at different rates, so you can turn around a corner smoothly for example. In order to make a right turn, your left wheel needs to cover more distance than the right one (just picture it in your mind) the open differential is what allows this to happen whilst still sending torque to both wheels.

An open differential is a weakness though in low traction situations, such as off-roading, or a hard start when dropping the hammer for a 1/4 mile run because the open differential inherently sends the most torque into the wheel with the LEAST resistance, which means it will pour power into a wheel with no traction or a wheel that is slipping. That makes you slow, or if you're off-road it can make you STUCK.

That is why the limited-slip differential was invented. It uses a sort of clutch system to partially engage both sides when one wheel begins to spin much faster than the other, then the wheel with MORE traction gets more power and (theoretically) the car gains momentum and the lack of traction resolves itself.

The TRAC system in some Toyota's is sort of an electronic "poor mans" substitute for a true limited slip differential. It uses the ECU to modulate throttle and ABS braking to limit wheelspin. It delivers most of the safety and practical aspects of a real LSD, but none of the performance benefit (that's why you can switch it off in many models.)

Hope that is some help.

I'm not sure how a locked diff would help in drifting. I suppose if you're in a powerful RWD car it allows you to pour the power on through a turn/slide and keep the wheels loose in a nice even fashion (i.e. both rear wheels would get a consistent 50-50 torque split no matter what) however a locked or welded diff also makes it much harder to make normal turns because the wheels will have a tendency to hop and chirp because the outside wheel cannot turn faster than the inside wheel.

A welded FRONT differential would make no sense from any standpoint though, but FWD is not really ideal for drifting at all, even though a FWD drift is technically possible.

[stevetubbyturbo]

An open differential is a weakness though in low traction situations, such as off-roading, or a hard start when dropping the hammer for a 1/4 mile run because the open differential inherently sends the most torque into the wheel with the LEAST resistance, which means it will pour power into a wheel with no traction or a wheel that is slipping. That makes you slow, or if you're off-road it can make you STUCK.

In one way your right and in another your wrong

as most off roaders (4x4's) have diff and hub locks so you dont get stuck :P

[scionic]

An open differential is a weakness though in low traction situations, such as off-roading, or a hard start when dropping the hammer for a 1/4 mile run because the open differential inherently sends the most torque into the wheel with the LEAST resistance, which means it will pour power into a wheel with no traction or a wheel that is slipping. That makes you slow, or if you're off-road it can make you STUCK.

In one way your right and in another your wrong

as most off roaders (4x4's) have diff and hub locks so you dont get stuck :P

←

I'm not wrong at all.

The hub locks have nothing to do with the differential really.

Most off-roaders I've seen come with open differentials, which are a liability.

Many offer a limited slip differential, which is a big help.

Some (the best) offer a pnuematic or hydraulic ocking diff, like Land Cruisers, for one.

Personally I think the ideal set up is a limited slip diff in the front (so you can still steer properly) and a locking in the rear. That is how my Tacoma V6 (Hilux) was set up and it was unstoppable. Easily pushed through mountain snow over a meter deep like it was not even there.

[Bibbs]

the welded diff makes the wheels spin at the same RPM .. making it easier to loose traction and drift without re-gaining traction ..

[scionic]

That's what I figured (see above)

Makes sense. The only way that could work for you in turning is if the wheels are broken loose and that's what drifting is.

Good luck driving that car home on public roads with a welded diff though.

[Rookey]

Brilliant :) Cheers guys!

[chrisb]

There is also some good info on cars and in general on the driftworks homepage!

www.driftworks.com

CB

[Rookey]

Cheers chris! I checked that out, but couldnt find anything about a welded diff ..

[Puls]

A friend once test-drove an '80s Monte Carlo SS that some shady used car shop was selling. One turn made it quite obvious that the rear end was Lincoln-locked.

*bounce bounce bounce....*

[nrgizerbunny]

provided the car is rear wheel drive then the locked back differential will just function like a solid shaft, as stated above.

then the science bit. When you turn, you cause a yawing acceleration on the car, this causes the rear slip angle to be greater than the front, you need to apply opposite lock to keep the car going where you want. thus its easier to drift. BUT NOTE YOU WILL GET SEVERELY INCREASED TYRE WEAR in just normal driving

There is NO point welding up a front wheel drive car.

I have to go with stevetubbyturbo. All proper off roaders have diff locks. a limited slip diff is not going to get you out of the strife that some of those green laning people get into!

as for limited slip differentials there are 3 main types I'd say.

Viscous coupling, electronic and also mechanical variety.

viscous coupling works when there is a large difference between wheel speeds. it pressurizes a fluid and this causes the unloaded wheel to get more torque than it would normally receive.

the electronic sort is where the engine management system applies brakes to the unloaded wheel and this causes the torque to go to the wheel with traction.

finally the mechanical type was really pioneered by Audi in the world rally. They use Torsen differentials which are worm-wheel type diffs. wheels can only be driven and the mechanical arrangement locks up when the wheels spin.

hope this helps

[Tom.B]

An open differential is a weakness though in low traction situations, such as off-roading, or a hard start when dropping the hammer for a 1/4 mile run because the open differential inherently sends the most torque into the wheel with the LEAST resistance, which means it will pour power into a wheel with no traction or a wheel that is slipping. That makes you slow, or if you're off-road it can make you STUCK.

In one way your right and in another your wrong

as most off roaders (4x4's) have diff and hub locks so you dont get stuck :P

←

I'm not wrong at all.

The hub locks have nothing to do with the differential really.

Most off-roaders I've seen come with open differentials, which are a liability.

Many offer a limited slip differential, which is a big help.

Some (the best) offer a pnuematic or hydraulic ocking diff, like Land Cruisers, for one.

Personally I think the ideal set up is a limited slip diff in the front (so you can still steer properly) and a locking in the rear. That is how my Tacoma V6 (Hilux) was set up and it was unstoppable. Easily pushed through mountain snow over a meter deep like it was not even there.

←

So youre saying our works brand new Landrovers dont have diff locks /slip diffs? funny that could have sworn we were looking at them today at work....then again it wasnt on a pc screen it was in real life so I could be wrong

[stevetubbyturbo]

Thats one car that has the best off road capiblility i have ever seen as it can lock all its diffs and or let them slip accordingly to whatever surface its on, a very clever system indeed.

[scionic]

An open differential is a weakness though in low traction situations, such as off-roading, or a hard start when dropping the hammer for a 1/4 mile run because the open differential inherently sends the most torque into the wheel with the LEAST resistance, which means it will pour power into a wheel with no traction or a wheel that is slipping. That makes you slow, or if you're off-road it can make you STUCK.

In one way your right and in another your wrong

as most off roaders (4x4's) have diff and hub locks so you dont get stuck :P

←

I'm not wrong at all.

The hub locks have nothing to do with the differential really.

Most off-roaders I've seen come with open differentials, which are a liability.

Many offer a limited slip differential, which is a big help.

Some (the best) offer a pnuematic or hydraulic ocking diff, like Land Cruisers, for one.

Personally I think the ideal set up is a limited slip diff in the front (so you can still steer properly) and a locking in the rear. That is how my Tacoma V6 (Hilux) was set up and it was unstoppable. Easily pushed through mountain snow over a meter deep like it was not even there.

←

So youre saying our works brand new Landrovers dont have diff locks /slip diffs? funny that could have sworn we were looking at them today at work....then again it wasnt on a pc screen it was in real life so I could be wrong

←

No, what I said was most new 4x4's I've seen do not come with a limited slip diff as standard equipment. Some offer it as an option and the best offer a locking diff.

A limited slip diff, a locking diff and the locking hubs steve refered to are THREE distinctly different things, mate.

Locking hubs have nothing at all to do with the differential.

I'm not sure what you were looking at on your work's new Land Rovers, but a limited slip diff isn't anything you can see from outside the car. If you're refering to switches on the front hubs or "locking hubs" like I said, those have nothing whatsoever to do with a locking differential, those are simply for more basic 4x4's that are part time 4x4 to engage front wheels manually. It's not an advantage, it's just the simpler precursor to electronic switches.

I don't know what options are on Land Rovers, but they are supposed to be legend as 4x4's so it wouldn't surprise me that much if they, at least, came with a rear LSD or something. If not then they really aren't all that legendary after all.

A 4x4 with open diffs at both ends is no where near as capable as most people would imagine it to be.

[Tom.B]

Cheers matey for clearing that up...Ive only been an engineer for 10 years now....and I think I know where a diff is and what it does..thank you!!!!!! Now on that note Im having a cold one!!!

[scionic]

Cheers matey for clearing that up...Ive only been an engineer for 10 years now....and I think I know where a diff is and what it does..thank you!!!!!!   Now on that note Im having a cold one!!!

←

I guess I was confused because what you said was "we were looking at the Land Rovers at work" as if the LSD was something you could see. I don't know how else to interpet that sentence.

I try not to make assumptions about how much people know, sorry if I sounded patronizing. I was trying to be helpful, honestly.

Like I said, most 4x4's do not come with an LSD as standard equipment. At least not in the U.S.

Various electronic traction control schemes of different types are being using increasingly instead of a genuine mechanical LSD unfortunately. <_<