Diff ideas
 

Any body used the ctsv diff and axles... Been looking for a good diff swap to hold up to the high horsepower engine that I have at the machine shop getting built... I'm not the kind of person that does cheap used second hand parts.. I just seeing the options out there that can handle 400+hp

A lot of the V8R guys run them. I have a custom setup for sale, but its not going to go for pennies. 3.7 gears, torsen diff, FAR stronger 8 inch ring gear. PM me if interested.

It's a built torsen? Hmmmm kinda uneasy about torsen.... That always just seemed like ticking time bombs... What kinda power and torque can it handle... Was originally looking for something that came from the factory in a car that already made to handle higher numbers.. That's kinda why I was looking at the getrag set up cause it come with 32 spline axles that On the cheaper end start at 400bhp

Torsen diff is out of an FD while the gears and carrier are out of a manual 929. It also runs stock TII shafts (which hold up in 600hp FC's on slicks). If your afraid of the FD torsen, you should REALLY run at the site of a CTS rear end. Look up CTSV rear end failure... They were common.

Other options include-
Martins 7.5 Ford rear end
V8R's 8.8 Ford rear end
Boss Frogs 8.8 Ford rear end (don't plan on running exhaust around this unless you think smashing 2.5 inch pipes is your idea of good flow)

When I was building my V8 car, I chose to run Boss Frog kit with 8.8" Ford rear end. It's considerable cheaper then any other setup and it's strong enough to hold upwards of 600wtqe. I should still have a housing somewhere...

At some point in my quest for insanity, I know I'll need to do something for the rear when I start living close to a 1/4 mile track.

The V8r 8.8 kit, from what I've read, can be optioned to include a drive shaft that works with the miata transmission. So you would get the super strong 8.8 rear, super strong axles and a good selection of lower gear ratios for people who want to exceed ludicrous speed, and still be able to use the miata 6 speed gear box.

However, I'm positive you can build your own setup for much cheaper if you do some smart shopping. But as a package deal, it's not bad at all.

OP, we really could use some more details on what your plans are. What motor, what the car is being built to do, etc...

The ford 8.8 is a solid rear end and won't that effect handling in the corners? I don't wAnna change the handling unless it's for the better... Mainly building a powerful track car that I'm still gonna drive on the street when the weather is nice

There are IRS pumpkins for the Ford 8.8 and 7.5 rears. There are also LSDs, but IIRC Savington has said that they are not on par with Torsen or os Giken, and he seems to know his stuff. Just something to consider...

And anything you do will add weight, which always effects handling. You might want to look at the maita.net v8 swap forum and v8miata.net for ideas if you want to make your own custom mounts.

We've got an IRS 8.8 setup with an Auburn LSD going into our shop V8 build, so we'll see how that works.

Someday, OSG will make a diff for the IRS 8.8, and that will become the holy grail of Miata diffs.

OP, the factory Miata diff will do 400whp if you don't wheelhop it off the line, and even then you'll break the factory Torsen unit and not the R&P. The factory 7" diff is not a weak unit.

I am building a 3.636/OSG diff for Theseus this year, and I'm not concerned about its reliability.

I would like to find something that's a bolt in because I work offshore and don't really have time to fab a way to mount an outsourced diff. To me its easier to spend a little more money to save myself the headache. Mainly why I was checking out the getrag. I think it's FM (may be wrong) that offers a whole bolt in kit for that setup. What ever I get needs to hold up to 400hp for a fun day and around 325hp daily.

Have a 3.6 geared 7 inch unit built with an rx7 clutch pack diff and rear housing. You'll be looking at around 1200-1400, but it'll bolt right in and the weakest link would be the axles.

If you have more money then time, why not have someone else build the car? What's your location when your state side?

Sav, what about this diff? Still limited like the factory torsen, but better then the Detroit as it won't trash your rear end like trutrac has been doing to people lately.

http://www.sparktecmotorsports.com/qua-qdf29z.html

Are you talking $12-$1400 dollars... For that I could just get a giken or similar.. What i dont have time for is trial and error fabrication work, As for building the car the machine shop is doing most of the assembly To the motor but I'm actually putting it in the car myself and doing all the suspension and brake work.... At the moment I live just north east of Jackson MS...

wtf? I had a 7" rx7 clutch diff installed for under $300.

I'm talking about the whole thing. Diff, rear housing, carrier, 3.6 gears, gear install.

I mean, I could have used the loaded 3.909 gears...but still.

Do you still have the diff. Assy. ? If so, what is it and how much? How much power do you think it will safely handle?

thanks,

Rex Franklin

If you are talking to me, its my screen name at yahoo dot com.

Any issues with the FD torsen?

None yet. FD guys only have issues with them when they put large slicks on at the strip.