LSD - significant benefits on a NA?

[Polypedates]

Is a LSD a worthwhile upgrade on a standard N/A (Mk1b)? I ask because my gearbox off the car as part of my restoration and wondered if it makes sense to fit one whilst it is relatively straightforward.

I presume the downsides are the cost of a quality product (e.g. Quaife or similar) and I am assuming that installation is not a DIY affair either.

[IanParkhouse]

No.

It'd help in the snow and that'd be about it.

[PW@Woodsport]

I'm doing a special on 6 speeds at the moment for the Mk1, that can come with LSD.

[stenky]

Atb or torsen is worth on any car. What it does not is help in snow or on ice.

[elbon50]

Is a Mk3 LSD worth fitting to a Mk1

[synXero]

It'll have the same benefit as on any non NA!

[PW@Woodsport]

I wonder why the question is even asked, surely it is better to have both wheels getting traction than just one and the other not?

For me LSD is a no brainer.

[Lauren]

Traction though, is hardly an issue on a MK1 NA and therein lies the rub.

Given all that weight over the rear wheels the MK1 NA rarely has the power to spin the rear wheels.

An LSD would be great in the wet and other times when grip is low, but on a dry warm day, you'd probably not make much use of it.

[PW@Woodsport]

I agree with that, it's just when traction does become an issue it's nice to have both wheels trying to get grip and not just one.

[stenky]

Traction though, is hardly an issue on a MK1 NA and therein lies the rub.

Given all that weight over the rear wheels the MK1 NA rarely has the power to spin the rear wheels.

An LSD would be great in the wet and other times when grip is low, but on a dry warm day, you'd probably not make much use of it.

there is however weight transfer during cornering that makes the torque "escape" through the less laden wheel. with an open differential, you are not putting down your torque effectively. with a torsen, you are. not sure how the clutch type behaves here as the wheel velocity difference might not be enough for it to engage.
if you do spin one wheel, tosren is of no use. it is good for compensating for torque loss. only clutch type LSD helps with one wheel spin.

this topic and the answers really depend on what type of LSD are we talking about and what do we want that LSD to do.

if the task is to improve wheel traction during cornering, then the only answer is torsen or ATB.
if the task is to improve straight line traction, then none of them is superior to open diff.

[IanParkhouse]

The dif is there to allow the wheels to spin at different speed round corners. My LSD gives the car a desire to understeer when applying power in bends. It's quite subtle but it's there. Lift off and the car turns in, power and it goes straight(er)

Paul's 6 speed box would be a good upgrade though



I've just learnt something about torsen diffs

[Polypedates]

Thanks for all the replies. It is the cost benefit ratio that interests me as I'm not made of money and I imagine a decent LSD is not a small investment so I wondered whether I would realize any significant benefits.

I understand what an LSD does but if it only comes into play in extremis then I doubt I can justify the expense. If it benefits the broader driving experience within the performance envelope of an otherwise standard Mk1 then it starts to look more appealing.

My only experience of LSDs is in FWD applications. Indeed my ATR has one but to be honest I can't remember the last time I came across a corner on the Public road that could be taken hard enough to feel it doing much. It is mightily impressive when it does its thing in the Honda but you cannot exploit it in most tight bends because line of sight becomes the limiting factor. I can't say I notice it doing anything in more open, better sighted bends.

As such, whilst I like having it in the Accord I wouldn't shell out for one if it wasn't already standard in the Type-R and wondered if I'd see more benefit in a RWD application like the MR2.

Still not sure to be honest and although the 6 speed option sounds impressive I can't say I've found the 5 speed gearbox lacking and do intend to keep the car broadly standard but with subtle upgrades only: uprated bushes, braided brake lines etc.

[elbon50]

Is a Mk3 LSD worth fitting to a Mk1

I don't know what type of LSD is fitted to the Mk3 (roadster) box

Just wondered if that is a good unit to fit to the Mk1

They seem to be easily available at a cost that almost seems too cheap to be true

[PW@Woodsport]

Torsen.

Yes.

Yes.

[Polypedates]

So is the Mk3 LSD a direct fit to the Mk1 gearbox? If they are available for relative peanuts then it seems a good idea to go for it.

I had assumed the cost would be more around the £500-600 mark as that is what Quaife's seem to go for although I couldn't find one for the AW11, only the SW20.

[PW@Woodsport]

It's one of my mods i discovered many years ago, the Mk3 LSD will fit into a C52 casing, but you need to swap the C52 diff side bearings and crownwheel onto the Mk3 diff, and adjust the diff preload, which is super important, that requires specialist equipment.

After that you need to run Mk2 NA driveshafts, which will be plug and play into the diff and Mk1 hubs, the Mk1 driveshafts won't work.

The Mk3 speedo cog will also work fine with the Mk1 speedo drive.

[PW@Woodsport]

For me, if you are going to all the trouble and time stripping a gearbox to install the LSD, then why not strip a Celica C60, mate that to the C52 bellhousing, fit your LSD in the same way and you have yourself a 6 speed for £100 more (current C60 price).

In fact it seems silly not to, if you have the skills to rebuild a gearbox then the above is a no brainer and makes your Mk1 special.

[PW@Woodsport]

Actually i wrote an indepth article on how to do it yourself on the Mk1 club, forgive the fact it's on my 6 speed build service thread, i like to give owners the opportunity to build their own instead of paying me to do it....

http://www.mr2mk1club.com/showthread.ph ... n&p=155195

[kaiowas]

Is there any reason you need a Celica box Paul? If you got a facelift mk3 6 speed with an LSD is there anything stopping you from putting the lot into a C52 casing?

[PW@Woodsport]

A Mk3 is no good because the gear shift assembly comes out the back side of the gearbox, the Celica comes out the front, like a Mk1 does.