Welded diffs - VOSA clarification
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- Brianmoooore
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Exactly my views on the subject, but was to lazy to type out!Barx325i wrote:does a welded diff cause loss of traction when cornering?Gibson wrote:What im sick of getting told is a blanket, across the board lecture that welded diffs are illegal. They are not, correctly insured they are perfectly legal to drive on the road
http://en.wikipedia.org/wiki/Differenti ... e)#Purpose
Now I'm not saying that you or anyone who chooses to use a welded diff is incapable of controlling their car - aka careless driving / not in proper control, but technically, if you, or a device attached to a motor vehicle causes, or initiates a loss of traction, the situation is deemed prosecuteable under UK traffic law.
The entire concept of welding your diff is counterintuitive to the function of a differential (obviously) and any defense for the use/requirement of a welded diff on a public road when presented with the road traffic act is completely preposterous.
A legal grey area, to which a definitive resolution will be defined at some stage I'm sure - however as soon as enough b-lends park their welded chariots backwards into a bus shelter crowded with pensioners, the world will begin to scratch scalps and catch on... Sadly this is the norm and it takes tragic loss to initiate a change in the law.
Picture this..
An inexperienced driver buys a rwd car, completely unaware that it has a welded diff and uses engine braking as he approaches a roundabout in wet weather.
........
Barx325i wrote: does a welded diff cause loss of traction when cornering?
http://en.wikipedia.org/wiki/Differenti ... e)#Purpose
Now I'm not saying that you or anyone who chooses to use a welded diff is incapable of controlling their car - aka careless driving / not in proper control, but technically, if you, or a device attached to a motor vehicle causes, or initiates a loss of traction, the situation is deemed prosecuteable under UK traffic law.
The entire concept of welding your diff is counterintuitive to the function of a differential (obviously) and any defense for the use/requirement of a welded diff on a public road when presented with the road traffic act is completely preposterous.
A legal grey area, to which a definitive resolution will be defined at some stage I'm sure - however as soon as enough b-lends park their welded chariots backwards into a bus shelter crowded with pensioners, the world will begin to scratch scalps and catch on... Sadly this is the norm and it takes tragic loss to initiate a change in the law.
Picture this..
An inexperienced driver buys a rwd car, completely unaware that it has a welded diff and uses engine braking as he approaches a roundabout in wet weather.
........
At anything above carpark speed and very, very tight cornering you would not know a vehicle had a welder fitted. Even with low profile tyres it is all taken up in the flex of the tyres, They dont even skip on roundabouts its literally just parking. And unless you are driving like a total prick (to a level which would be dangerous regardless of what diff you have) you wont be in a situation where a welder will cause any more loss of traction than an open diff. One of the good things about a welded diff however is that in a situation where the back end steps out, it is very progressive, and it doesnt snap back the other way when one wheel grips like an open diff.
And realistically. Weigh up the amount of people you know/have seen crashing a vehicle on a public road with a welded diff, against the amount of people you know/have seen who have parked a front wheel drive shopping trolley on a roundabout/upside down/in someones daffodils from driving like a prick. The forum i come from has very strict no street drifting rule. the very mention of it is completely banned and i honestly think the vast majority of the user base (who drive daily with welded diffs) are less likely to have a crash than your average 17-25 year old in a golf/saxo/other piece of shit showing off to their mates. We know our cars are worthless heaps, but that doesnt mean we have not put blood sweat and tears into preparing them for drifting. The last thing we want to do is have a crash on the road, lose our licenses/freedom or hurt anyone because we are petrolheads just like you, and cars are our lives.
EDIT: No one is ever going to accidently buy a car with a welded diff. No one would ever sell a car with a welder and not disclose it. and the first time it was parked it would be obvious. Actually if he engine braked hard enough to brake the traction of two tyres it wouldnt matter if he had a welder or an open diff, but at least with a welder the resulting slide would be predictable, instead of an open diff slipping and sliding totally unable to decide which wheel has more traction and gripping one side, then the other unpredictably.

If you drive so carefully - why do you need a welded diff? If your car 'steps out' with enough regularity to require a welded diff, perhaps you should drive a little slower.
The whole idea of a welded diff is a bodge up. It's wrong. On any roundabout, the laws of physics (which I'm sure you will argue about) mean that the inside wheel needs to rotate at a different speed than the outer one. That is an inescapable fact. One wheel will thus be trying to break traction, winding up the driveline and putting a lot of stress on the driveshafts, input shafts, planet/sun gears and the CWP.
Perhaps we should have a nationwide 'welder' register so I know which £300 shitbox to avoid like the plague. Thankfully, you're 200 miles away from me so I don't have to worry unduly about your antics.
The whole idea of a welded diff is a bodge up. It's wrong. On any roundabout, the laws of physics (which I'm sure you will argue about) mean that the inside wheel needs to rotate at a different speed than the outer one. That is an inescapable fact. One wheel will thus be trying to break traction, winding up the driveline and putting a lot of stress on the driveshafts, input shafts, planet/sun gears and the CWP.
Perhaps we should have a nationwide 'welder' register so I know which £300 shitbox to avoid like the plague. Thankfully, you're 200 miles away from me so I don't have to worry unduly about your antics.
You seem to be labouring under the misapprehension that street drifting is cool, and that's the reason they're fitted. Wrong again.
99% of cars with welded diffs belong to drifters - and the massive proportion of those have their diff welded for track events. Having a welder on the road is a side effect of using the same car to get to events as to use at the event.
My diff isn't welded for the road - it's welded for going to drift days. Why do people fit slippers in road cars? If everyone here drives like a saint on the road, there's absolutely no need for a slipper.
You lot should stop your street racing ways, it's probably killed a lot more people than drifting has tbh.
Limited slip diffs on road cars, whatever next, it's preposterous.
99% of cars with welded diffs belong to drifters - and the massive proportion of those have their diff welded for track events. Having a welder on the road is a side effect of using the same car to get to events as to use at the event.
My diff isn't welded for the road - it's welded for going to drift days. Why do people fit slippers in road cars? If everyone here drives like a saint on the road, there's absolutely no need for a slipper.
You lot should stop your street racing ways, it's probably killed a lot more people than drifting has tbh.
Limited slip diffs on road cars, whatever next, it's preposterous.
You mean you don't know the answer to that?drew555 wrote:Why do people fit slippers in road cars?
Among the long list of benefits, it's largely viewed as a safety option:
"Limited slip differentials have many advantages over open differentials. Limited slip differentials offer more control in tight corners and reduce many road hazards potentially encountered in inclement weather. The invention of limited slip differentials has made it possible to control the drive force that is allocated to each wheel from the engine. The ability to control each wheel makes it easier steer the vehicle when rounding corner and allows for steadier speeds"
"Due to the increased control that limited slip differentials provide, safety is increased exponentially. When turning around a corner in wet or slippery conditions, if a wheel spins out do to a differential slip, it can cause the vehicle to veer and a driver could possibly lose control. Limited slip helps keep the wheels in check and reduce slippage in inclement conditions. Limited slip can also help the driver recover from a hydroplane in wet road conditions and reduce the chance of a spinout and possible accident"
"Limited slip differentials offer the best power efficiency for sports cars. When sports cars round corners at high speeds, a differential slip can slow the car down considerably. This power loss can be considerable in situations where the driver is trying to achieve high performance from the vehicle. Limited slip also offers a greater amount of traction, which increases the speed and performance of the vehicle"
Walked into that one don't you agree?
Still rattled then? clearly a spiteful vindictive tonedrew555 wrote:Wrong again
- Kos
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The clue is in the name
LIMITED slip is active when required but to a given percentage , a welded is permanent and 100%
An LSD will help and provide traction when required.
Welders provide a function on the track if you want to drift but serve no funtion on the road.
LIMITED slip is active when required but to a given percentage , a welded is permanent and 100%
An LSD will help and provide traction when required.
Welders provide a function on the track if you want to drift but serve no funtion on the road.
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Sawyer_E30
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Involves bikes but I think it's appropriate..
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No, you are right, they dont. We dont run welders on our purely road cars. But do on one which will see the drift track.Kos wrote:The clue is in the name
LIMITED slip is active when required but to a given percentage , a welded is permanent and 100%
An LSD will help and provide traction when required.
Welders provide a function on the track if you want to drift but serve no funtion on the road.
And i regularly take my car to Santa Pod "Drift what you brung" the sister of "Run what you brung"
If my car was purely a road car i would not have a welder. I dont have an LSD because bmw slippers are pretty poor for drifting, they only have 25% lock and get old and worn quite quickly when you are asking that much of them, making their locking characteristics unpredictable. Again this isnt me inventing things, i have used bmw slippers and they arent worth the £250 price tag they command (for drifting, they are obviously worth it for fast road cars)

Your not listening are you? The welded diff is for when i take it to Santa Pod. This is when it makes a difference, When i drive it on the road i have no use for the welder. We already established this.Andyboy wrote:If you drive so carefully - why do you need a welded diff? If your car 'steps out' with enough regularity to require a welded diff, perhaps you should drive a little slower.
Of course they are trying to rotate at different speeds, what you are not allowing for is the natural give in automotive tyres. On anything but the tightest of turns there is enough free movement that it absorbs any difference in road speed. At low speed (we are talking parking, <5mph, hardly unsafe) the inside wheel will skip. We are not saying its the perfect solution, but it is perfectly acceptable (and legal) for what we are doingAndyboy wrote: The whole idea of a welded diff is a bodge up. It's wrong. On any roundabout, the laws of physics (which I'm sure you will argue about) mean that the inside wheel needs to rotate at a different speed than the outer one. That is an inescapable fact. One wheel will thus be trying to break traction, winding up the driveline and putting a lot of stress on the driveshafts, input shafts, planet/sun gears and the CWP.
If it worked the way you think it does, quad bike would be totally undriveable in anything except perfectly straight lines or on full opposite lock. Im sure you are aware this is not the case.
I have tried to present a reasoned and fair debate without resorting to name calling and keeping swearing to a minimum. But comments like this make it difficult. I know you are a bit of a guru on all things E30 and not a daft kinda person so i pick my words carefully:Andyboy wrote:
Perhaps we should have a nationwide 'welder' register so I know which £300 shitbox to avoid like the plague. Thankfully, you're 200 miles away from me so I don't have to worry unduly about your antics.
Go fuck yourself with a cactus.
Last edited by Gibson on Sun Aug 05, 2012 5:06 pm, edited 2 times in total.

I dont remember ever saying this, I remember at one point it may have been said in Jest but i cant even find that post any more. And if it was said, then we all know you are correct and its total balls anyway. You dont run a welder on rare or valuable cars, or on a car that will never see the drift track. That would be stupid. But on the flip side its perfectly legal if insured properly to drive a vehicle with a welded diff on the road, if you so wanted to. I cant afford a recovery truck, so i do drive my drift car with a welded diff on the road, and it is insured such.Barx325i wrote:indeed gibson, good points, but iirc a previous arguement was put forward saying that a LSD is a pile of rubbish and we should all weld open diffs on every car..

oh but it is, it's massively noticeable even with the hugely reduced track..Gibson wrote:If it worked the way you think it does, quad bike would be totally undriveable in anything except perfectly straight lines or on full opposite lock. Im sure you are aware this is not the case..
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Sawyer_E30
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Sawyer_E30
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OK then! 
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macas
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My mechanic who i bought my lsd from had been racing e30s for years and when i asked him to why i couldnt just weld my open diff up he said it would be fine in the dry,but its when its damp or wet is when it becomes dangerous.
Enough said i thought,havnt looked back since fitting my lsd.
Enough said i thought,havnt looked back since fitting my lsd.
I can see why he would think that. But drive any car like a dick in the wet and it will be dangerous. I have been driving mine for 3 years in everything from heatwaves to 6 inches of snow. I certainly have not crashed backwards on fire through a bus stop full of nuns. Infact in the snow it was absolutely superb, 2 wheels with traction is much better than 1. It was embarrassing some vastly more expensive four wheel drive stuff when it came to being able to move.macas wrote:My mechanic who i bought my lsd from had been racing e30s for years and when i asked him to why i couldnt just weld my open diff up he said it would be fine in the dry,but its when its damp or wet is when it becomes dangerous.
Enough said i thought,havnt looked back since fitting my lsd.

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sweep
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A wewda is where its at and thats final.just because i live with my mum at home and smoke old hub nut does not make a limited slip spliff more feesable what do you guyz no anywayz? with your own skills and talents you have made your soon to be classic (cult cars) very nice but so wot,just because every fortnight i put enough petrol it to turn that orange light out makes no diiference........and a mk1 modeo is retro actually....a 
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Grrrmachine
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It seems that both sides have come to the conclusion that a welded diff is inappropriate for a purely road car. And considering this thread was started about MOT and VOSA regulations (which pertain to road, NOT track use), then it seems that fitting a 100% locked diff of any sort, welded or not, is inappropriate on the road.
Is that the end? Have I missed something? I can call someone a fat ballbag if it makes you all feel better, but I don't know who.
Is that the end? Have I missed something? I can call someone a fat ballbag if it makes you all feel better, but I don't know who.
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And as long as that vehicle is insured correctly that is perfectly legal.Barx325i wrote:You missed somethingthe whole road legality point was raised due to the fact that getting said shed to and from the track/playground it needs to be driven on the road.
BAM. End /thread

- Kos
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Not that simpleGibson wrote:And as long as that vehicle is insured correctly that is perfectly legal.Barx325i wrote:You missed somethingthe whole road legality point was raised due to the fact that getting said shed to and from the track/playground it needs to be driven on the road.
BAM. End /thread
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Makes me think of this scene from My Cousin Vinny:Kos wrote:The clue is in the name
An LSD will help and provide traction when required.
http://video.mail.ru/mail/fairyv/308/312.html
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And very shortly you we will have the proof from the DfT that says they are fine. Until that point. No more speculation from people who dont know.Kos wrote:Not that simpleGibson wrote:And as long as that vehicle is insured correctly that is perfectly legal.Barx325i wrote:You missed somethingthe whole road legality point was raised due to the fact that getting said shed to and from the track/playground it needs to be driven on the road.
BAM. End /thread
Construction and Uses endorsement codes can be used for points and a fine
CU20
Causing or likely to cause danger by reason of use of unsuitable vehicle or using a vehicle with parts or accessories (excluding brakes, steering or tyres) in a dangerous condition

- Kos
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I think one thing we can all agree on is that it's a PITA having varying authertive bodies having their own legislation.
It needs to be addresed and some clarity

It needs to be addresed and some clarity
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Gibson wrote:Go **** yourself with a cactus.
Made my day that comment has
Will the debate ever end I wonder



