RexNuts Subaru Forums

Is anyone running a obx helicoil front lsd? are they any good? I'm currently building my gearbox I put a cusco 35:65 Tarmac gear ceter diff I also want a front and rear lsd

Apparently you dont need the Rear LSD for a Tarmac Gear as its an open diff. But I would Certainly get one!!

Heres what LSD's you can get
1 way LSD: Specially suited for front wheel drive cars and AWD front axle cars. Activates under acceleration, and acts as a true LSD when the throttle is off. The 1 way LSD will improve lap times without a doubt. (This will enable you to go wild on the accelerator through the corners without so much understeer)
1.5 way LSD: Activates under acceleration while the under-steer under deceleration is less than on a 2 way LSD. (Recommended for those of us who have a hard time with under-steer.)
2 way LSD: Recommended on rear wheel drive cars and AWD rear axle cars. Activates on both acceleration and deceleration. Recommended for those who prefer aggressive driving and big angle drifting.

Now because you plan you run the Tarmac gear, the car is going to get tail happy on the exit of the corners (as you apply throttle to build the power coming out of the corner) So to give the car a little bit of balance I would go with a 1-way front LSD and a 1.5-way rear LSD. This should see the car act a bit more friendly while reducing that understeer. Steer clear from a 2-way for street driving, its only really for race car applications in my opinion, and even then, some racers use 1.5ways as the 2-way is very unforgiving.

Also if your going to street the car, I'd suggest changing the lockup to around 55%-60% otherwise LSD's are notorius for clunks and bangs while doing slow sharp turns, like in the shopping centre car parks.

Cusco's are good although I have heard some of the gears are a bit weak, KAAZ are also apparently really good, havent used one to confirm though.

Hope that helps a wittle

A rear LSD is a MUST for a Tarmac gear or you will be spinning the inside rear tyre a lot, i know as i have a Tarmac gear in my car!

I also have a Cusco RS LSD in the rear and yes the side gears have failed on me before, but the good news is that the replacement side gears i got were much beefier in there weak point and shouldnt be much of a problem now.

How much did you pay for the replacement side gears and where did you get them? Could be good info for people

Adam from Tuspeed was able to get them for me, cost was roughly about $300 for the pair i think