I picked up a 6 speed 04 mazdaspeed miata transmission yesterday. Strongest as the gears are treated. The only thing left to complete my drivetrain setup now is a differential. Now, a few people say go with the clutch style RX-7. But others say the 94+ miata torsen. So, what is everyone here using? And how much hp on it and for how many miles? I plan on running 300 to 350 rwhp long term, but not sure which one to go with, but leaning toward the torsen. I want to get the differential and install it first before the 6 speed, Bully Stage III Clutch, and Fidanza Flywheel, because I don't want to kill my open differential. After I take it apart I will have 4:10 gearing for sale, as I am putting 3:90 in. Also going to have the 5 speed for sale, with 86k or 87k miles on it for sale soon as I swap the 6 speed in.

 

My preference would be 3.63s and an RX7 clutch pack, but it's really all about how you're using the car. A torsen will be less forgiving to trailing throttle ***-arounds.

 

I want 3.636 gearing, but I haven't found any for a good price, so I am just sticking with the 3.90 I have for now. Are you using the clutch pack yourself?

 

^agreed - you'll want the 3.63 with the 6 speed for a boosted power level and IMO the clutch lsd is a better choice for a sports car.

 

So, 84-88 clutch pack it is, anyone else care to share where they got 3.636 gearing for less than the cost of an arm or leg?

 

I have some on the way from Mazmart. They did a group buy on them at M.net back in Jan. They might be doing another buy here soon. Don't be in a hurry to get them though as they have to come all the way from the other side of the planet. Apparently they have some Japanese guy swimming them over on his back*.

*this is a joke. I'm not really in any sort of rush anyway and i was told it would be a while.

 

LOL, come on now. The boat only takes 30-50 days.
Oh, then there's customs.

 

Boat who are you kidding?? I just wish you would have choosen a stronger swimmer.

 

with the 6speed-3.6 and clutch type LSD for higher power
lower power you are ok with the torsen
you can find used 3.6's every now and then, a good price would be around $300

 

FWIW, I love my Kaaz clutch pack LSD, even on stock power for the moment

 

Dibs on your 4.1 open.

 

Alright, soon as I pick up a differential I will let you know.

 

From what I've heard, a torsen is better for 60' times and drag racing as it locks in should* put equal power to the wheels. A clutch type will only put so much torque to a wheel that's slipping, and that number is governed by the preload on the clutch packs. Torsens don't wear out, clutches do. However, it seems torsens do break. Some suggest they are not as strong as the stock open diff. Clutch types don't seem break, but they offer limited lock up and wear out over time. Personally, I'm welding up my open diff.

*I've heard they really don't lock 100% like they should and are not as predictable as it would seem they should be. For example, some swear a spool is A LOT better than a torsen at drag racing, though in theory they should both be locked.

 

you might consider looking at a TII rear for that level of power, but it certainly will NOT be bolt in. It WILL however, not break . They also came stock with 4.10, I'm don't know if you can get lower gears for them, I would assume you could get them, but I don't want to say yes and have it be no. I don't have a need for the lower gears, so haven't bothered to look.

 

I've always heard of spools as a cheaper, stronger, lighter alternative to an LSD for drag.

 

But shouldn't it feed the power in more smoothly, rather than coming in a little more harshly like a clutch-type?

That is to say, ham-fisted retards who have issues with trailing-throttle oversteer prefer the clutch-type because it masks their driving inadequacies?

Go away.

 

go with tomei 2-way or kaaz 1.5-way

 

 

It's going to depend on the Torsen. A Type1 won't be as likely to come out compared to a clutch type.

You'd better not ever take your foot off the gas around a curve in my car.

 

So the torsen is not able to handle 300 to 350 rwhp and last forever?