2-way LSD Question

[urzu725]

Hey everyone,
Right now, I have a welded diff. As you can imagine, whenever I turn to full lock at low speeds (like in parking lots), my tires squeal and it is difficult to turn. I'm replacing my diff and was thinking about a 2-way lsd. If I do get a 2-way lsd, will I still have the same problems with low speed lock turns? Thanks.

[saiGone]

You shouldn't unless the pre-load is set wrong

[Deuce Cam]

To some degree but it won't be nearly as bad. U turns and sharp 90* turns from a stop will often result in a few chirps from the tires with an aftermarket clutch lsd. At least you can use neutral when possible to get the wheel speeds to vary in slow tight turns like in a parking lot.

Another thing to consider is the clunks usually associated with aftermarket clutch lsd units. Sometimes it can be real obnoxious.....e.g. people will stare in parking lots and you'll have to explain the racket to passengers.

[gotzoom?]

It has a lot to do with the amount of acceleration you use. If you're driving sensibly in a parking lot and need to make a tight turn to enter a parking stall, you will notice a big difference. The 2-way will feel like an open diff under those circumstances. If you are using heavy acceleration, the locking action typically increases, which will make it behave closer to a spool. I'm running a Tomei T-Traxx 2-way, which has one of the highest amounts of lockup available for the AE86 and I get wheelspin if I use too much rear swaybar or get a wheel in the air for some reason, so even a heavy locking diff will allow some amount of spin.

[Deuce Cam]

^Good point.

With a mechanical clutch lsd your throttle percentage basically ramps up the engagement of the lsd under acceleration. Cusco describes it as applied throttle load (aka throttle position) under acceleration, and engine braking load under deceleration for 1.5 and 2 way types. There's some graphs as examples here for visual thinkers: http://www.cusco.co.jp/en/catalog/pdf_c ... e_lsd.html

A clutch lsd can start engaging, or even fully engage at any point under acceleration, it all depends on how heavy your right foot is. Keep in mind that it takes a medium-to-moderate amount of throttle percentage and revs just to keep up with traffic when accelerating from a stop with a 4 banger, especially with the 4age's lack of tq.

When driving sensibly on the street the quirks are most noticeable when making turns in 1st gear while accelerating up to speed (i.e. tire chirps, clunking, shudder). As gotzoom? mentioned it's not too bad in parking lots as long as your easy on the throttle and just creep along. Better yet coast into the parking space while in neutral when possible. I usually just push the clutch in when making tight 90* turns in parking lots, not just when parking....trying to make those clutch plates last longer....