Differentials

Clouds
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Differentials

Postby Clouds » Sat Aug 30, 2014 7:32 pm

Will an open differential cause more understeer than limited slip differential?

Thanks for any answers in advance.
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jondee86
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Re: Differentials

Postby jondee86 » Sun Aug 31, 2014 12:42 am

A limited slip diff will be more likely to cause understeer on an AE86
than an open diff (power on, turning into a curve with both rear wheels
getting grip).

Cheers... jondee86
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Clouds
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Re: Differentials

Postby Clouds » Sun Aug 31, 2014 5:59 am

jondee86 wrote:A limited slip diff will be more likely to cause understeer on an AE86
than an open diff (power on, turning into a curve with both rear wheels
getting grip).

Cheers... jondee86

Thanks, Jondee. :)
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yoshimitsuspeed
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Re: Differentials

Postby yoshimitsuspeed » Sun Aug 31, 2014 5:41 pm

It will really depend on a few things.
One thing to consider is 1 way, 1.5 way and 2 way.
A one way gives LSD performance under acceleration but acts as an open diff under decel. This will give you off throttle turn in and cornering much like it is now. Once you start to get on the throttle it will help tie the two tires together.
2 way acts as full LDS in accel and decel. This can really cause understeer tendencies coming into corners.
1.5 way is somewhat inbetween and gives some LSD characteristic on decel.

The other thing is if you are breaking loose the back tires. Drifters like LSDs because it makes it easier to break it loose, helps keep both tires spinning and makes it easier to maintain oversteer. On the other hand if it's not broken loose the LSD is going to try to lock the tires together making them want to rotate at the same speed which will make the car want to go straight.
So it really depends on a lot of different things. It will change the handling of the car but exactly how will depend on the diff, the situation and your driving style.

Clouds
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Re: Differentials

Postby Clouds » Mon Sep 01, 2014 2:25 pm

So a one way acts the same under deceleration as open diff, but is more stable when applying throttle, a two way always try to spin the wheels at the same speed and causes some understeer because the wheels spinning at the same speed tends to make the car want to keep going straight, and a 1.5 way differential is in between both of those and acts kinda like a two way under deceleration.
That is what you were saying, right?
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.TRD.TRUENO.
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Re: Differentials

Postby .TRD.TRUENO. » Mon Sep 01, 2014 8:38 pm

1.5 is Full lock in acceleration and Half lock in deceleration. So when you let of the throttle, it will not exactly act like an open diff and will give you slight lock. But not as much as a 2 way with full lock decel.
Also, I'm rocking a welded diff at the moment. And I don't have any understeer issues. I do get a lot of chirping and hopping at low speeds and parking cause its always locked.... So I'm looking into getting a 2 way.
So yeah, choosing accordingly to what type of driving you plan to do. Don't let the thought of understeer deter you away from a 2way.

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Re: Differentials

Postby Clouds » Tue Sep 02, 2014 5:20 am

.TRD.TRUENO. wrote:1.5 is Full lock in acceleration and Half lock in deceleration. So when you let of the throttle, it will not exactly act like an open diff and will give you slight lock. But not as much as a 2 way with full lock decel.
Also, I'm rocking a welded diff at the moment. And I don't have any understeer issues. I do get a lot of chirping and hopping at low speeds and parking cause its always locked.... So I'm looking into getting a 2 way.
So yeah, choosing accordingly to what type of driving you plan to do. Don't let the thought of understeer deter you away from a 2way.

Alright, thanks for the elaboration.
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Deuce Cam
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Re: Differentials

Postby Deuce Cam » Wed Sep 03, 2014 8:43 am

Here's a good comprehensive explanation of how common mechanical clutch type lsd units work: http://www.cusco.co.jp/en/pdf/LSD%20Guide%20Final.pdf