More info about limited slip differential

[Turbo]

Think really seriously about embarking on this project, building competition cars eats up money & time like nothing else! Especially if you are building something oddball like you are suggesting! You will have to build it to current regulations, either FIA or the Italian version of the MSA. These change every year so if you take too long building it the safety specs might have changed so you may have to do some redesign.

In the UK the MSA rules are getting ever more tighter, making building your own car even more difficult & expensive!

Then there is the issue of stuff going out of date. I have a 205 MI16 track/sprint car I built myself. It hasn't done many events but if I want to enter an MSA event I will need to spend nearly £1000 to replace a perfectly good set of seats & harness plus extinguishers just because they have exceeded their expiry date! Then there will be another few hundred quid on a Hans device plus a suitable helmet. Unless I go on a serious diet I will also need a new rally suit, another £200!

Motorsport is a very expensive hobby if you want to compete at sanctioned events! No matter how careful you are you will rarely get back what you spend building a competition car if you sell it. My suggestion would be to buy a car someone else has already built & spent all their money on.

Track days are a good way of having fun without needing to have the car built to the latest motorsport regs.

 

[Rkweld]

If you are nearly broke maybe then an lsd is probably not worth looking at, for a novice you are probably only going to avoid a bit of low speed traction loss when accelerating hard. Are fiddle brakes an option if you want it to get out of situations when you are stuck? If you are going to fit a bike engine why not fit 2 and have twin engine rwd like the autograss cars? Then you get constant drive to both rear wheels. Or look at a hill climb car because they have different classes like autograss to make the sport more accessible. Maybe dont get hung up on a modified car if you are starting out with no money, have you considered classic rallying? Some of the best rallying I have seen was classic rallying through the local woods, the guys with the biggest smiles on their faces were nit the guys with the modded 4wd but the guys in the fwds and rwd slipping and sliding and driving the nuts off a car that was designed to be on the road. Probably the only time I have seen a skoda estelle over take a ford capri too!

 

[Memmeddu]

Think really seriously about embarking on this project, building competition cars eats up money & time like nothing else! Especially if you are building something oddball like you are suggesting! You will have to build it to current regulations, either FIA or the Italian version of the MSA. These change every year so if you take too long building it the safety specs might have changed so you may have to do some redesign.

In the UK the MSA rules are getting ever more tighter, making building your own car even more difficult & expensive!

Then there is the issue of stuff going out of date. I have a 205 MI16 track/sprint car I built myself. It hasn't done many events but if I want to enter an MSA event I will need to spend nearly £1000 to replace a perfectly good set of seats & harness plus extinguishers just because they have exceeded their expiry date! Then there will be another few hundred quid on a Hans device plus a suitable helmet. Unless I go on a serious diet I will also need a new rally suit, another £200!

Motorsport is a very expensive hobby if you want to compete at sanctioned events! No matter how careful you are you will rarely get back what you spend building a competition car if you sell it. My suggestion would be to buy a car someone else has already built & spent all their money on.

Track days are a good way of having fun without needing to have the car built to the latest motorsport regs.

Unfortunately ACI (MSA Italian equivalent) is worst than FIA.
Hill climb you can use whatever you want .
But off road rally (which is what I'd like to do ) have pretty restricted rules .
The car has to be street legal
don't ask me why, because I still have to understand that
Welded 6 or more point roll cage .
Every single part of a street car have to be usable (headlights, indicators, windscreen wipers ,rear mirrors)
Weight it has to weight at least 520kg with the driver .
Seats ,seat belts etc
The funny part is that here in Italy
Roll cage, welded strut bar, racing seats,5 point seatbelts, adjustable suspensions, engine swaps, engine upgrades , muffler swaps, brakes upgrades , wheels upgrades ,air filters upgrades , practically every single mod on a car are not legal .
FIA and ACI say reverse gear has to be ensured by a mechanical or electrical motor either directly or not connected to the main engine .
It has to move the car at least for 5 meters .
Italian laws + FIA and ACI restrictions doesn't allows you to have much room for mods .

You have to buy a purpose built car to do what I want ,so not really a great deal I might even build the roll cage alone using pipes (it has to pass a crash test ) but it should be 51mm in diameter and 2mm thick seamless high tensile strength steel tube .
It's every day worst ,I should talk with a friend who is the president of a rally company

 

[Memmeddu]

If you are nearly broke maybe then an lsd is probably not worth looking at, for a novice you are probably only going to avoid a bit of low speed traction loss when accelerating hard. Are fiddle brakes an option if you want it to get out of situations when you are stuck? If you are going to fit a bike engine why not fit 2 and have twin engine rwd like the autograss cars? Then you get constant drive to both rear wheels. Or look at a hill climb car because they have different classes like autograss to make the sport more accessible. Maybe dont get hung up on a modified car if you are starting out with no money, have you considered classic rallying? Some of the best rallying I have seen was classic rallying through the local woods, the guys with the biggest smiles on their faces were nit the guys with the modded 4wd but the guys in the fwds and rwd slipping and sliding and driving the nuts off a car that was designed to be on the road. Probably the only time I have seen a skoda estelle over take a ford capri too!

I'm not considering ... I'd like to do exactly classic rally but look at the up above post .
Fiddle brakes?
I know about electronic systems which automatically engaged brakes to make the open differential act as an LSD .
But it's a budget suicide

 

[bricol]

If you've not competed in motorsport before, building a car, or even buying an already built competition car, is for me not the way to go.

Find the street class - take your road legal, unmodified, car and compete in the production class. You'll be slow, make mistakes, come last - but at this point you can claim its the car, despite knowing its really you who braked too soon, took the wrong line, missed the gear, etc. And when you clonk the kerb, and bend a supension arm, wheel, you can replace it easily and cheaply from the local junk yard.

A bespoke car - you have to buy expensive parts or make more.

Once you've learnt something, ie if you even enjoy it, or if you do, how to control the car, how to get the most out of it (competition driving is nothing like how you drive on the road, regardless of how hard you think you are going) , then maybe think about modifying.

But building something completely bespoke to begin with? You've more chance of ending up with no money, and a pile of junk in the shed, no enthusiasm left, and won't have turned a wheel in any competition.

Find your local motor club, go see them, and get out there now in your street car and enjoy it.

 

[Rkweld]

Unfortunately ACI (MSA Italian equivalent) is worst than FIA.
Hill climb you can use whatever you want .
But off road rally (which is what I'd like to do ) have pretty restricted rules .
The car has to be street legal
don't ask me why, because I still have to understand that
Welded 6 or more point roll cage .
Every single part of a street car have to be usable (headlights, indicators, windscreen wipers ,rear mirrors)
Weight it has to weight at least 520kg with the driver .
Seats ,seat belts etc
The funny part is that here in Italy
Roll cage, welded strut bar, racing seats,5 point seatbelts, adjustable suspensions, engine swaps, engine upgrades , muffler swaps, brakes upgrades , wheels upgrades ,air filters upgrades , practically every single mod on a car are not legal .
FIA and ACI say reverse gear has to be ensured by a mechanical or electrical motor either directly or not connected to the main engine .
It has to move the car at least for 5 meters .
Italian laws + FIA and ACI restrictions doesn't allows you to have much room for mods .

You have to buy a purpose built car to do what I want ,so not really a great deal I might even build the roll cage alone using pipes (it has to pass a crash test ) but it should be 51mm in diameter and 2mm thick seamless high tensile strength steel tube .
It's every day worst ,I should talk with a friend who is the president of a rally company

So you can use a standard car with a roll cage and safety features fitted?

 

[Rkweld]

Fiddle brakes are like you would find on a jcb 3cx, where you can chose which wheels you are braking with. A jcb has a split pedal with a link bar to make it just one pedal when you want. The off road club in the uk people used to use a "fiddle brake" for each wheel on separate levers like a 4 handbrakes aswell as the standard brakes.

 

[Memmeddu]

So you can use a standard car with a roll cage and safety features fitted?

Yes and no
Once it has the roll cage installed it needs new homologation to be considered street legal again 2k euros

 

[Memmeddu]

Fiddle brakes are like you would find on a jcb 3cx, where you can chose which wheels you are braking with. A jcb has a split pedal with a link bar to make it just one pedal when you want. The off road club in the uk people used to use a "fiddle brake" for each wheel on separate levers like a 4 handbrakes aswell as the standard brakes.

That's not possible since rules say 1 pedal to brake all the wheel

 

[Memmeddu]

If you've not competed in motorsport before, building a car, or even buying an already built competition car, is for me not the way to go.

Find the street class - take your road legal, unmodified, car and compete in the production class. You'll be slow, make mistakes, come last - but at this point you can claim its the car, despite knowing its really you who braked too soon, took the wrong line, missed the gear, etc. And when you clonk the kerb, and bend a supension arm, wheel, you can replace it easily and cheaply from the local junk yard.

A bespoke car - you have to buy expensive parts or make more.

Once you've learnt something, ie if you even enjoy it, or if you do, how to control the car, how to get the most out of it (competition driving is nothing like how you drive on the road, regardless of how hard you think you are going) , then maybe think about modifying.

But building something completely bespoke to begin with? You've more chance of ending up with no money, and a pile of junk in the shed, no enthusiasm left, and won't have turned a wheel in any competition.

Find your local motor club, go see them, and get out there now in your street car and enjoy it.

There's something not practical here too.
My car it's not suitable for the task ,I should put a roll cage anyway .
New clutch .
And it's famous for its deformability ,the chassis is too weak even to be driven on public streets .
I can buy a 126 and use it as is just putting a roll cage in it

 

[Memmeddu]

Ah of course here in Italy "rally driving license" can be obtained for free you just need B driving license and participate to some hours of theory and some of practice (group N and group A cars)
But it allows you to participate to rallies only in Italy.

 

[Rkweld]

Does ut need to be lsd or could you make a diff lock?

 

[Memmeddu]

Does ut need to be lsd or could you make a diff lock?

I can do both things but an LSD it's better

 

[Munkul]

I think you need to walk before you run.

 

[Rkweld]

I dont think it will be cheap either way. You could try and pick up a chain drive diff. Atv, go kart etc. You can get them lsd type.

 

[PhillipM]

You have to buy a purpose built car to do what I want ,so not really a great deal I might even build the roll cage alone using pipes (it has to pass a crash test ) but it should be 51mm in diameter and 2mm thick seamless high tensile strength steel tube .
It's every day worst ,I should talk with a friend who is the president of a rally company

Unless you have a rotary draw bender, or access to one, don't even consider it. Especially if you've never made one before. Buy a prebuilt one and weld it in.

Like many here have said, you're getting way ahead of yourself and I don't think you're really realising just how much the basic safety gear, cage, seats, belts, helmet, hans devices, etc are going to cost you before you start any work on the car. And then tyres, transport, event entry and running costs like pads, discs, bushes, clutches, oils, etc, are a huge chunk too.
Start with something basic, racing is expensive, just for the bare minimum of gear. You want to be modifying as little as possible, and after some rallies when you know where the weakpoints are and what keeps breaking.
Try to do everything to start with and you'll be wondering where 20k and 3 years has gone.

 

[Nick DV]

Unless you have a rotary draw bender, or access to one, don't even consider it. Especially if you've never made one before. Buy a prebuilt one and weld it in.

Like many here have said, you're getting way ahead of yourself and I don't think you're really realising just how much the basic safety gear, cage, seats, belts, helmet, hans devices, etc are going to cost you before you start any work on the car. And then tyres, transport, event entry and running costs like pads, discs, bushes, clutches, oils, etc, are a huge chunk too.
Start with something basic, racing is expensive, just for the bare minimum of gear. You want to be modifying as little as possible, and after some rallies when you know where the weakpoints are and what keeps breaking.
Try to do everything to start with and you'll be wondering where 20k and 3 years has gone.

Couldn't agree more, and also there is always the chance of wrecking the car on the first run out/event - one hell of a reality check but something that has to be considered too.

 

[Memmeddu]

I'm conscious about the costs ,if I'd want to use the original engine it will require alone 8k just in parts to make it able to be used at such high stresses.
Roll cages sold for this particular car are bolted and not welded , and they "can't" be welded without losing their homologation (900 euros for the roll cage)
Those cages are not usable in rally over here
Seats and belts are around 600
There's lots of things to think about.
Fuel lines for example are 35 euros meter (fire resistant tube , stainless steel armour)
Fuel tank it's another important thing.
Brakes .
Every single thing have a cost

 

[Memmeddu]

That's one of those 126
They built it in 5 year
Those are long run projects
They started with a fiat Uno prepared for gymkhana.
Welds are pretty horrific
R1 engine RWD
Unfortunately I don't know if there are English subtitles.
That's on an extreme level.
My idea was not to have so much power on the wheels or make it reach high speeds , just torque and the necessary speed.
Fiat 126 stock reaches 120km/h which is enough close to the speed limits in rally (50km/h in city tracks and 130km/h off road)
I was surprised to discover that.
Even group A cars like the ford fiesta wrc doesn't go faster than 170km/h
Yaris 240
What I've understood is that in those types of competition what's important is acceleration and how fast you can turn

 

[123hotchef]

It's definitely not a good idea on a front axle as you need the wheels to be able to rotate at different speeds for the steering to work

unless its for drifting on a FWD!