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LSD. how ramp angles and preload settings work?


seaneylad

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Following on from my last post im set on the 3j nxg LSD just info on how they settings work :)

 

It notes:

a choice of ramp angles (25/70, 30/60, 30/90, 45/45, 35/35, 40/90 and 50/90) which along with the three factory preload settings of 10-15,25-35 and 60-70lbs/ft)

 

 

Was advised 40/90 and 25-35 pre load.

Butalso advised 45/45 and preload 50.

 

Am I right in thinking the lower the first number the easier it kicks in? Just after advice or basic info on how thesettings and preload work?

What out the two above setting is better for road use and occasional track day, also want it to be fun for some side ways hooligan fun. Its on 3.54 diff with a 2L pinto.

 

Thanks again Sean :)

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40/90 will only lock the diff under load and not coasting which is good for road use, the 30lb rating is fine for 2.0lt pinto

I've just ordered mine for xflow at 50/90 25/30 from James at hpe 3j nxg £575 and he's going to fit for a small very reasonable fee

Cheers paul

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40/90 will only lock the diff under load and not coasting which is good for road use, the 30lb rating is fine for 2.0lt pinto

I've just ordered mine for xflow at 50/90 25/30 from James at hpe 3j nxg £575 and he's going to fit for a small very reasonable fee

Cheers paul

Thanks for info

 

Does that mean the 45/45 will lock up alot easier, when under load as much? how does the preload rating affect it?

 

Sorry im not do clued up on how these LSD works, intresting though to read up on them.

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No the lb rating determines how easy it will lock so the lower the rating the easier it will lock

The ramp angle determines when it will lock ie

45/90 under load ( burnouts, drifting etc )

45/45 will lock under power and coasting which is under braking conditions

There's a top explanation of all this on www.intothered.dk

Type in lsd ramp angles and enter the above

Cheers Paul

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Just get a Quaife ATB and forget about ramp angles!!!!

(that's sure to cause a riot!!!)

 

Get that 3:54 diff ripped out while you're at it and stick a 3:9 in there, or a 4.1:1 if you've got a 5 speed box. Best performance upgrade you'll do, it'll feel like you've got 200 horses!!!!

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Just get a Quaife ATB and forget about ramp angles!!!!

(that's sure to cause a riot!!!)

 

Get that 3:54 diff ripped out while you're at it and stick a 3:9 in there, or a 4.1:1 if you've got a 5 speed box. Best performance upgrade you'll do, it'll feel like you've got 200 horses!!!!

Have you got a Quaife fitted to yours?

 

I have read various discussions on an ATB Vs LSD and they both have their pros and cons. 

 

Seems the biggest argument against an ATB is when one wheel lifts off the floor. However, if we are considering that most people are just going for fast road use and a bit of sideways fun in the factory car park on a Sunday morning, then for me this would suffice.

 

Very interested on your opinions on this if you have one fitted, buddy.

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Yeah, had a Quaife in my old set up. It was a fantastic diff.

I was running a 190 hp 2.1 Pinto, with a leaf sprung rear end and it handled like a dream.

As you mentioned, I never had it on 3 wheels on the road though!!

Always felt sure footed, and had no problem flinging it sideways  either when provoked.

Everyone seems to discount them, preferring a plate diff "'cause that's what the rally boys use". 

Sure, they use them because they spend a lot of time on loose surfaces and on 3 wheels, plus they can change ramp angles to suit surface conditions to change braking and understeer characteristics.

Personally, I just want something that I can fit and forget. You'll never forget you have a plate diff fitted, because the constant banging and clunking at low speeds will remind you of that!!!!!

It is a personal choice, but I would have another one in a heart beat.

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Yeah, had a Quaife in my old set up. It was a fantastic diff.

I was running a 190 hp 2.1 Pinto, with a leaf sprung rear end and it handled like a dream.

As you mentioned, I never had it on 3 wheels on the road though!!

Always felt sure footed, and had no problem flinging it sideways  either when provoked.

Everyone seems to discount them, preferring a plate diff "'cause that's what the rally boys use". 

Sure, they use them because they spend a lot of time on loose surfaces and on 3 wheels, plus they can change ramp angles to suit surface conditions to change braking and understeer characteristics.

Personally, I just want something that I can fit and forget. You'll never forget you have a plate diff fitted, because the constant banging and clunking at low speeds will remind you of that!!!!!

It is a personal choice, but I would have another one in a heart beat.

 

That's the reply I was hoping for. :-)

 

I have been meaning to replace my diff this year, but have only spent about a 6 weeks at home due to working abroad.  Money is set aside for a few jobs and this is high up on my list. Fingers crossed, I am back home permanently in January and get a few things ticked off my list.

 

Cheers, Buddy...

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  • 2 weeks later...

Ideally (as Paul mentioned) for road use you want as setting that will lock when you are powering, and unlock when you are off power so the differential does it's job by letting the wheels turn independently.

 

As for an ATB, pass, I have never used one myself as I have been using plate type LSD's for years with no issues.

 

PS- BigBubba, it seems you have been a victim of the "off the shelf LSD" myth. Buy a plate type LSD from Burton's and it's sure to make horrible noises when turning corners at low speed due to excessive static preload intended for race cars with big sticky tyres. They need to be setup correctly for their intended use and if that is "fast road", it won't be any noisier than an open diff

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Ideally (as Paul mentioned) for road use you want as setting that will lock when you are powering, and unlock when you are off power so the differential does it's job by letting the wheels turn independently.

 

As for an ATB, pass, I have never used one myself as I have been using plate type LSD's for years with no issues.

 

PS- BigBubba, it seems you have been a victim of the "off the shelf LSD" myth. Buy a plate type LSD from Burton's and it's sure to make horrible noises when turning corners at low speed due to excessive static preload intended for race cars with big sticky tyres. They need to be setup correctly for their intended use and if that is "fast road", it won't be any noisier than an open diff

Cheers for Info James :)

 

Just orded mine from burton but got a local guy (up north) who is going to set mine up properly for me like you say so it wont be noisey etc.

 

 

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The Gripper is by far the best of the LSD's and yes, they will set them to what you want. They do 'quiet' plates for the road which keep the noise down. Grippers are also very good for Competition with the correct settings.  Please remember that they do not lose their preload like a ZF because of the different plate arrangements.

As for quiet, maintenance free use the ATB is very driver friendly.

I have built hundreds of Atlas axles over the years ( but don't anymore ! ) and have seen the results in both road and competition so base my comments on practical experience.

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