car is a daily driver. and by theis i mean it gets a minumum of 26 miles EVERY day. i dont want a loud, jumpy, clunking rear end. i want it to be as civil as possible while being able to handle the 5-6k clutch dumps when i take it to the track every few months or so. sometimes longer. what are the pros and cons to each one? this will be in a strange 12 bolt.

 

What power levels? This will differ according to power. A posi uses clutches that let the inside wheel slip while going around a turn thus making it slow down so it doesnt skid or slide while a locker uses gears and is similar however much stronger than a posi and makes noises around turns as the gears unlock allowing it to do the same thing as a posi around turns and a spool is a solid axle that while going around turns will not allow either wheel to slow down thus making it skid across the road. Spools are very dangerous in the rain so if you must drive it EVERY day in and out of different conditions this is not for you. Spools are by far the strongest then lockers and as for posi........... with the right amount of power. Im not an expert but if I was building a car I would go with posi 0-400 HP, Locker for 400-800 HP and a spool anything above 800HP also you have a M6 therefor it is harder on drivetrain so I wouldnt even consider a posi in an M6. Well i hope this helps and if im wrong about any of this or you have something to add please chime in and correct me. but beware....... ...J/K

Joe

 

well its about to have all the bolt ons so im guessing 340ish to the wheels. but there is a possibility of a cam swap although slight. are lockers really noisy or just like a click as they unlock?

 

Get a 31 spline soft locker, they are not bad at all. You wont regret it.

CMC

 

I love my Detroit Locker in my 9" (thanks Hawkcmc!). It is funny to see the looks on peoples faces when they hear the rearend clicking when I make tight low speed turns........

 

At those power levels (< 400 to the wheels), with a 12 bolt and never anything stickier than a Nitto DR, a True Trac should be just fine.

 

Plus a True Trac, being a gear driven posi, is more street friendly than a locker and a spool.

 

i was under the impression that a true trac wasnt available in the strange 12 bolt?

 

That's strange... no pun intended.
Another difference in lockers and posi diffs is that lockers are speed-sensitive, meaning when one axle speeds up more than the other, like in a curve, it will unlock and freewheel around the turn while the other axle stays locked and drives the car. Pulling onto a main road, you may go through a few gears(if not all gears) and feel the car want to kick to one side. Nothing bad, just the axle that freed up while you turned onto the road hasn't re-locked yet. Lockers have to have a bit of slack made into them so that they work reliably. This makes them harsher on U-joints, driveshafts, and other stuff. If you're not willing to accept it and adjust your driving accordingly, then stick with a posi.

Posi diffs can be of two different kinds, one of which I dunno the technical term for. Gear-driven posi units, and some clutch/cone types, are torque-sensitive. Meaning the more load you apply to the unit, the harder it will be to overcome the unit and make only one wheel spin. These are the preferred posi units, with the real cream of the crop being the gear-driven ones... they drive like an open diff until you hammer down and break the tires loose. Other clutch and cone types simply use the friction pieces to add friction to the gears, making the unit tighter and more difficult to differentiate.

 

Me too. From my research, it seems you'd have to go Moser 12-bolt to get a true trac, although there seems to be some confusion about this issue.