Well, just wondering about something... I know that the stock set up is a 1-way helical LSD up front and a 1.5 way LSD rear. What would be the most appropriate way to upgrade both? Probably looking at a 80% street / 20% track. Thoughts?

 

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bump for u...i wanna know too lol!!!

 

In terms of handling, it might be more effective and cheaper to upgrade your suspension before upgrading the diffs. The stock ones are prety good as is. I do know that shepard offers a Transfer case upgrade that includes an upgraded front diff.

 

It depends on whether you want corner entry, mid-corner or corner exit stability. That is where the choice of 1, 1.5 and 2 way LSDs come into play. Ofcourse there is also viscous (not on EVO) clutch, spring or helical types to think about.

The model year EVO you have, also plays a part because the 03 and non RS 04s have open front diffs ...

 

Bump...
I have a IX and I was wondering...
Its been said, the LSD will give you better traction powering out of corners than the stock open diff, the best reason to buy one is to avoid breakage of the weaker stock open differential.
How much power is too much for the stock open differential?
Is the IX's front diff any better then the VIII's

 

The 05 & 06 cars already come with a front and rear LSD as well as ACD for the center diff.

The non-RS 03 & 04 cars are the ones with the open diff. I upgraded my 03 open diff to the ralliart unit. Big difference in performance but it still doesn't feel as good as an 06 with ACD.

 

You have a front lsd.

 

If you are not going to see some serious track time or produce 400whp+ the OEM diffs are more than sufficient. Below is an updated version of the LSD speech that I have been giving on Honda boards since the late 90's.

There are also three distinct types of "lockup/slip" for clutch LSD's:
1way - activates only on accel
1.5way - fully on accel and partially on decel
2way - fully on accel and decel

Novice drivers should stay away from 2way diffs because they will either destroy their car or cause other people to wreck on the track during decel situations. Understeer will be more pronounced with a 2way diff.

The rate at which lockup/slip occurs is also controlled by the contact angle inside of the pressure ring (30*, 45* and 55* are the most common angles in Japanese designs) for the pressure plate and the design of the pinion. The pressure plate is often referred to as a "CAM" since the profile can be manipulated.

Holding strength of the diff will depend on:
The number of plates used (normally 10 to 20).
Type of plates used - metal or carbon
Oil flow - many early LSD's failed prematurely because of poor oil flow.
Quality of the metal used for internal parts of the diff.

Some of the clutch lsd makers:
ATS - 1.5/1.8/2way
Cusco - 1/1.5/2way
KAAZ - 1/1.5/2way
Rigid - 1/2way made by Cusco and use the Alpha spec housing
Ralliart - F 1/1.5way R1.8/2way
Tomei - 1.5/2way

Aftermarket Torsen:
Quaife - 1way
Route 6 - 1way
Xebec - 1way

Hybrid: Torsen + clutch plates
OS Giken - 1.5way only

Clutch LSD's need specific fluids for the plates and need scheduled overhauls but are rebuildable and can be tuned specifically for tracks and drivers.

Torsen LSD - low maintenance; no special fluids needed; Quaife has a lifetime warranty on failures. Can not be tuned for lockup type or rate of lockup.

Hybrid - best of both worlds

ATS had the best description of LSD's a couple years ago but they dropped that information when they upgraded their site with more glamour!
Tomei LSD descriptions
Another Tomei description
Cusco LSD description