is there front LSD available ?

[P_G]

Out of curiosity what tyres are you running when this phenomenon happened to cause you to consider a front LSD? LSD's have their place no doubt but if the actual emchanical part that contacts the road isn't up to task then no LSD in the world will compensate for a better tyre for set conditions.

[AKmotorsport.net]

PetrolDave: there is always something to fix after a manufacture. He is going for mass market. I don't own a rs4. I will have RS4 B7 gearbox in my race S2.

Everybody chose it's way for mods. Some put 22 inch wheels and some try to make their car handle best possible way. To get there you need LSD all around + good brakes + best possible suspension (shocks, springs, sway bars + some other mods). With a setup like that you can go for a racetrack.

For daily driver RS4 is very good car form the factory, but it can be modified to handle better than stock. For daily driving I use RS6 C5.

In my race car I'm running something like 275/35/18 wheels.



I have rear LSD and I was looking for front one for RS4 B7 and I hope I have found it. Will know first week of next year.

[adsgreen]

I have tracked many different cars and an LSD is not always a straight yes choice as there are downsides.
Depends really on the track, grip and engine power. I've found that in general unless you are running alot of power with 2wd. With the rs4 I'd be very surpised if a front LSD would make any noticeable difference. Under normal circumstances it's a 60/40 power split so you're talking less than 160bhp before losses to the front.

on track every tenth of a second counts. If the wheel is in the air than the other wheel will not put any power to the ground. Clutch LSD solves that problem. Torsen will put the power to the other wheel only if the other has minimum grip.

For street fun rear clutch LSD would be recommended just like in M-Power cars.

Hmm - I would argue that if you are at a cornering scenario where the inside wheel is airborne and you're trying to put power through then you have other problems. Any grip potential lost from the inside through load transfer is always more than that gained on the outside wheel.

[AKmotorsport.net]

Ok. So why the race cars (WRC) or up hill race cars even on dry tarmac use LSD all around ?

As I have stated before. For street use there is no need for front LSD, rear ... there could be some discussion. In my opinion it is good to have one, that is why Audi did add Audi quattro Sports differential to S4 B8 car.

[P_G]

WRC cars also have bionic suspension to allow maximum usage of their LSD's thought. No huge gain to have if one part doesn't compliment the other?

[AKmotorsport.net]

what about sprint and hill climb cars ? what about the N Group Impreza and Evo's ? They don't have bionic suspension and still use LSD's.

[adsgreen]

I'm not saying lsd's are useless but they are often thrown on and end up masking fundamental suspension setup flaws.
Rallying and autocross feature corners and scenarios you simply won't find on traditional racetracks.
Just because one type of car uses it doesn't mean its a global silver bullet. More a case to make sure the lsd is fitted for the right reason.

[AKmotorsport.net]

More a case to make sure the lsd is fitted for the right reason.

Agreed.

[adsgreen]

Just watched the Audi vid - nice, but way more than a bog plate differential. Certainly won't get torque vectoring with an lsd!

[irvind]

LSD = Limited Slip Diff?

[Ice_Coffee]

LSD = Limited Slip Diff?

either that or Albertsz is planning on giving his car some illicit drugs to help it get round corners quicker.

[PetrolDave]

I don't own a rs4. I will have RS4 B7 gearbox in my race S2.

It would have saved a lot of time if you had said in your first post that it's not actually a B7 RS4 car, but a one-off special that uses some B7 RS4 parts.

Have to agree with all the comments that suggest you consider whether your suspension is up to the task. Even with an LSD a wheel in the air is wasted power, you want all 4 wheels on the tarmac and with sufficient load to handle the torque/power you want it to handle.

[AKmotorsport.net]

I have Ohlins 3-way adjustable dumpers in S2. They will do the work

[PetrolDave]

I have Ohlins 3-way adjustable dumpers in S2. They will do the work

Do you have sufficient wheel travel, on both bump and rebound to ensure the wheels are always firmly on the tarmac?

[AKmotorsport.net]

lol ... yes I have sufficient wheel travel on the dumpers and spring. Don't worry about that. I had people form Ohlins design the suspension from zero.