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It all depends on how you drive it, it should hold up if you dont do too many clutch drops/pops. Also for some extra security i'd get a clutch pack LSD cause the torsens are a little on the weak side (heaps of US drifters are smashing them with stock and turbo power).

I'd say there would be quite afew members on here that are making that kind of power with just the 1.8 diff thou!

Dave

Sheck wrote:It all depends on how you drive it, it should hold up if you dont do too many clutch drops/pops. Also for some extra security i'd get a clutch pack LSD cause the torsens are a little on the weak side (heaps of US drifters are smashing them with stock and turbo power).

I'd say there would be quite afew members on here that are making that kind of power with just the 1.8 diff thou!

Dave

commodore IRS type diff?
I think thats what NFS has albeit modified! don't quote me on that though!

you could wack in a cut down ford 9 inch!
but your motor will porbably struggle to turn the half shaft's!

I would think that a Torsen is going to be your best bet if you cant afford any of the Nissan R200 or S5/later RX7 diffs. Using a plate diff with that much power will probably cook it in no time so that would need constant rebuilding. The crown wheel and pinnion will also be a bit iffy once you start to get over 200-250nm of torque.

If you take it easy off the start and dont do any really high rpm starts with lots of wheel spin and treat the diff ok theres probably no reason it shouldn't last you.

I have been told there are guys running around in IPRC in rx7's that have around 300hp and they dont break diffs.....it all comes back to how you treat it.

I'm fairly sure there are more than a handful of 300hp MX5s in the states running the 7\" NB torsen.

IMO for track work there is no need for anything stronger, but again, if you treat it badly it won't last forever.

Boags

Don't bother with Kaaz etc and go for a Cusco clutch pack lsd.

Only issue will be having to service it more often.

Mike, it's worth investigating the Series IV/V RX-7 diff as you can still utilise the MX-5 rear subframe and wishbones....not sure about the uprights though (to suit the RX-7 half shafts). You will need to add a torque reaction mount to the front of the diff. If you can get access to pictures of the \"Bullet\" rear end you will see exactly how to do it. They all run the Series IV/V RX-7 diff with minor updates to the torque reaction mounting detail.

However, I personally think an NA8/NB8 assembly with a Torsen will be more than suitable for a circuit MX-5 with rotor power. I've been running at least 260 rwhp through a standard 1982 626 differential gearset and clutch type LSD (same size gearset as NA8) with Toyo 888's on the track for the past three years and have not had an issue to date. I'm not kind to it either . Forget it if you're planning to take it to the drags or do copius amounts of circle work (go the first option then).

Cheers,
Danny

Put a GURU centre in it, she'll be right rated for 600hp....

BJ

bjones wrote:Put a GURU centre in it, she'll be right rated for 600hp....

BJ

Except they are shite. Get a spool. We all use them, they are excellent and will easily take 200rwkw. Get in contact with the QLD racing guys - a fellow up there had some made and I hear only has a couple left. His first name is John....

CT wrote:

bjones wrote:Put a GURU centre in it, she'll be right rated for 600hp....

BJ

Except they are shite. Get a spool. We all use them, they are excellent and will easily take 200rwkw. Get in contact with the QLD racing guys - a fellow up there had some made and I hear only has a couple left. His first name is John....

What about them is shite? The mechanism - as in, the way they lock up?

I always thought they were good, only cause that's what I've heard, I haven't ever dríven a car with one in, so I'm curious to see what you don't like about them.

Boags

Boags'MX5 wrote:

CT wrote:

bjones wrote:Put a GURU centre in it, she'll be right rated for 600hp....

BJ

Except they are shite. Get a spool. We all use them, they are excellent and will easily take 200rwkw. Get in contact with the QLD racing guys - a fellow up there had some made and I hear only has a couple left. His first name is John....

What about them is shite? The mechanism - as in, the way they lock up?

I always thought they were good, only cause that's what I've heard, I haven't ever dríven a car with one in, so I'm curious to see what you don't like about them.

Boags

Yeah me too! Whats shite about them CT (How you goin by the way)

BJ

With MX5 race cars usually you run in to a problem with lifting the back wheel going around corners,espesicaly with slicks...Torsens start to spin as soon as you unweight one wheel,so for racing applications Torsens don't usually work...I have just gone to a lock diff. in my SE.

If you want to run a LSD you usually need to run a tight clutch type set up which are pretty expensive and need to be rebuilt,stick in a spool and you never touch it again.

Torsens and Gurus work fine in road cars...

Spool is a completely locked diff center...both rear wheels always turn at the same speed...

A spool is not a differential. HTH.

My Datsun track beastie has a locked diff and it is prone to understeer on high speed corners. Do you have the same problems, or does the superior handling and turn-in on the MX overcome this?

Boags

If you plan to run in a lot at the track, get the spool. Give John a call on 38120616 if you want one made up. Driving on the street is a bit of a pain though. However, as boyracer and CT said, bouncing off ripple strips is not an issue with the spool.

As for the understeer issue, change your driving style. Accept that the rear end wants to turn wheels at the same rate, so it will need to slide somewhat across the face. On the slower corners, you may have to square it off a bit and roll around a bit more before mashing the throttle, but with lots of grunt that is hardly an issue. Watch the lines of a V8Supercar, and use pretty much close to that.