LSD - 2 questions

[Chaz23]

Right due to me being a bit of a numpty when it comes to this type of technically things I could do with some help.

 

1) What are the benefits of having an LSD appart from doing donunts?

2) How much and how easy would it be to fit one myself? (That bit I am not such a numpty on)

 

Reason I am asking is because I am wondering if it is worth me going for the upgrade or not.

 

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1993 De-Dion 1700 X/FLOW

[akakubi]

I may be missing a few bits, but the main benefit of an LSD is having traction on both wheels at the same time. For instance, when you corner, the inside wheel will tend to lift off the ground. In an open diff, the power goes to the wheel with least resistance. So in effect, when you press the throttle, all the power goes to the unloaded wheel and get wasted in a cloud of smoke. At that time, you do not have throttle control. With an LSD, you will have some power (this varies with design and model) transfered to the loaded wheel and give you control - and allow to play naughty. 😬

 

Fitting one is exactly the same as fitting a regular diff. It will require "some" rear suspension disassembly to get the driveshafts out. But then, you simply undo the retaining bolts and dropped it off. It's a winter job, I would say.

[stevefoster]

It also has enormous benefits under on the limit braking. The rear is more stable as the diff helps prevent the lightest loaded wheel from locking up.

 

If replacing like for like then it's a one man & a trolley jack job - done in a couple of hrs.

 

If you have a LSD fitted then it needs setting up. Road and Race transmissions were the people when I had mine done - guess they still are.

 

Add lightness, says the man with a VX :-)

My 2002/2003 racing pics

here

General pics (mostly of 7's and cars).

here

 

 

Edited by - stevefoster on 2 Jun 2008 21:50:57

[bstark]

Fitting a Quaife ATB made an enormous difference to my car on and over the limit - but I do stress "the limit", as in during a sprint.

 

Before, balancing the car was a bit knife edge if you wanted the maximum cornering speed without risking a tank slapper as I was throwing the car in to get a drift going. With the LSD it's all much more controllable with the throttle, and much more forgiving.

 

On the road, yes you can get your power down earlier but I never really had a problem before.

 

Bob Stark

Supersprinter

[stevefoster]

One more thing to add - driving in the wet is much more progressive - much less likely to get a tank slapper or squirrel all over the road on over exuberant use of the right foot.

 

Add lightness, says the man with a VX :-)

My 2002/2003 racing pics

here

General pics (mostly of 7's and cars).

here

 

[Chaz23]

Thanks for the info guys - still a bit confused over the benifits but I guess what you are saying is that I should have better handling if I start to loose the rear of the car.

 

Steve how much would I be looking at if I got Road and Race to sort me out? Or do is there a website/contact about anywhere? Currently I don't have a LSD and I don't know what my diff is but guess that it is the one that came with it 15 years ago.

 

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1993 De-Dion 1700 X/FLOW

[Beelzebub]

One added benefit which is especially relevant on more powerfull cars, is that it reduces shock loads on the drivetrain. IE if the inside tyre lights up & then suddenly finds grip again

 

D.

[Ray Pearce]

I changed my diff as part of the Quaiffe ATB bulk buy here

 

Without the bulk buy the ATB unit will cost about £500, then you have to take out your current diff and take it to either Quaiffe or R+R for them to fit the ATB unit to your diff. This will cost from £100ish (at R+R with no new bearings) up to maybe £200 if bearings are shagged. Then you fit it back in. Removal and refitting should only take a couple of hours with only basic tools and the ability to bench press a heavy lump of diff while someone else fiddles about trying to get the top bolt back in place (while not dropping the shim washers into your face)

 

End result - car feels more controllable when pushing on around corners and don't underestimate the joy of donuts (Mmmm, donuts!)

 

[Chaz23]

Right I better start saving for an upgrade to get that done sometime during the summer while I don't need the 7 as much during the week.

 

So let me get this straight about the process of fitting:

 

Remove current diff

Take current diff to either Quaiffe or R+R

Give them some dosh

They do what is needed

Take diff home and fit

Go and burn though my tires at the next handling day doing donuts

 

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1993 De-Dion 1700 X/FLOW

[stevefoster]

Sounds about right.

You can reuse the blue propshaft bolts - threadlock & torque setting are in the build manual.

Observe and refit as was the diff washer spacings.

Don't drop diff on finger nail as it is heavy and hurt (eh Phil W 😬)

 

 

Add lightness, says the man with a VX :-)

My 2002/2003 racing pics

here

General pics (mostly of 7's and cars).

here

 

 

Edited by - stevefoster on 4 Jun 2008 21:35:22

[akakubi]

Second that! 😬 The thing is hefty and always wants to escape from your grip.

 

If you want to keep it quieter, don't forget to add the LSD additive to the diff fluid.