mx5cartalk.com

hey guys the next mod i will make will be an lsd. I was wondering if anyone could give me some opinions on the factory torsen type 2 dif or the mazda speed unit. Is the mazda speed unit worth the extra dough?

The Mazdaspeed is a little tighter and more consistent under pressure. Still streetable though.

For my money, the torsen was pretty good, so I reckon in hidhsight I wouldn't have bothered upgrading from the torsen to the Mazdaspeed. Mind you, I have heard that under big-power turbo applications the torsen gets a little lost.

But the torsen won't wear out, whereas the Mazdaspeed does have a lifespan.

how long is this lifespan you talk of/cost to rebuild.

Torsen 2 is great.....but next time i'd prefer something a little more agressive like the Mazdaspeed.

in normal driving. you will not notice a difference in the torsen.

If you drive fast enough that you can get one wheel off the ground. Or if you've got a very torquey engine I'd go the Clutch-pack diff. If it's a normal car that's mostly street dríven you'll be happier with a Torsen. It doesn't chatter and vibrate the car. It doesn't have clutches wearing out which I've been told is 80,000km's before you'll have killed it. Or 25,000 with heavy track work on a decent power car. That was somewhere off the miata.net forum but it's a number if that's what you were searching for.

I've got a Tomei clutch pack and I like it... Mine chatters and shakes the car when parking if you have any throttle applied. Irwins is even worse though(Tomei re-shimmed to be tighter)

Being is his car with the semi-slicks on at low speed is hilarous..it's like your in an earthquake.

16bit wrote:how long is this lifespan you talk of/cost to rebuild.

Hellmun is on the money. By 80k of street driving it's stuffed. But there's a bit of adjustment in it, so you can get it taken apart every 20k or so to get it made tighter again.

You usually get about 2 or 3 adjustments before it's really gone.

Cost of rebuild...well it's probably not much more expensive to just buy a new one.

80k of street driving it's stuffed

Ummmmm......I think you may be a little pessimistic. Not saying you are wrong, just a little pessimistic. I would agree with one of those terrible viscous LSDs leaving the party early but not a proper metal clutch based unit.

I have owned a few cars with clutch LSDs (all V8s) and they kept doing the limited slip thing long past 80k kms. Not as strong as the Detroit Locker (not a clutch type LSD) on my old mans GT (~300k kms), but still good with 351ci of Fords finest.

I will be interested to see how my ATS Clutch diff ages over the next year. It still limits slip without a problem, juddering around carparks like the wheels are square

torsen it is - i don't won't shudder. I have had zero take up button clutches before and i hate shudder. probably worse by the sounds of this. Thanks for the help guys. much appreciated.

how long is a piece of string...you will have to try both and see which u like for yourself to suit a. your driving style b. how often you drive c. how much money you are willing to spend d. what power figures are you aiming for

adamjp wrote:

80k of street driving it's stuffed

Ummmmm......I think you may be a little pessimistic. Not saying you are wrong, just a little pessimistic. I would agree with one of those terrible viscous LSDs leaving the party early but not a proper metal clutch based unit.

The 80k estimate was just from my experience with a TRD LSD, which had a bit of trackwork mixed in with street driving. I reckon the trackwork really shortens the life of an LSD though and some drifters have to rebuild their LSDs once a year

I'm running a KAAZ (KAZZ not sure of spelling) and i was disappointed because there was no shudder to speak of!!! I was looking for screeching wheels when doing u-turns but i got quiet and smooth turns. It still locks up no problems, but doesnt shudder. It's now time for an oil change in the diff and i can sometimes hear the plates rubbing when u-turning but zero shudder.

I just followed the run in procedure and am running the KAAZ oil and its sweet.

Dave

PS the torsen does have a life span its just that you wont know its goin untill it grenades inside the housing - many US drifters have killed them with stock N/A power.

You could break a welded diff drifting though...possibly even with the 1.6 but you'd be hard pressed to not kill the clutch or gearbox first

I followed the instructions with the Tomei diff for running it in but mine was imported and didn't come with the tomei hypoid gear oil. I'm using Royal Purple max gear 75-90. Mine does smooth out a fair bit when the diff oil gets really hot but if it's not been worked hard mine is fairly chattery (car shakes quite a bit when you reverse it out of the driveway first thing in the morning). You could probaly control the chatter to a degree with less friction modifier but most of the diff oils come with a decent amount mixed in already from what I read after I got the diff.

i heard you can shims the torsen to be more tight

its a long story & I'm no expert, but my experience was I had a Kaaz LSD installed in my SP for a short while & hated the shudder & hated the understeer it induced even more so I replaced it with a Torsen Type 1. The Torsen works really well for street & spirited driving, doesn't sacrifice the fantastic balance MX's are known for & you would barely notice it was an LSD until you hit the gas in a corner or in the wet ! However I agree the Kaaz or clutch type diffs would have advantages in out & out grip for trackwork so I guess it depends on what you're looking for. In case of the Kaaz, they have a choice of 3 levels of preload which can be set when you assemble them, this being either soft, medium or hard which determines the level of slip the clutches will allow before they lockup tight - hence the shudder some cars have when in tight slow turns. The setup can be changed by dismantling the diff & changing the preload setting. Meanwhile I believe you can also fine tune the initial clutch friction by using Redline normal ( 75W90 I think ) Gearoil & fine tune the degree of slip by adding incremental amounts of their seperate LSD diff additive until you achieve either the setup required or normal LSD oil chemistry - if that makes sense. Its the same additive as blended into normal LSD oils, so you are basically blending your own LSD oil to tailor the amount of slip - I didn't try this myself as it was a new Kaaz diff. Of course Kaaz may not warrant the diff if you had a failure & they found the oil was not up to normal LSD specs. But from what I was reliably advised, the additive in LSD oil is not necessarily the best thing for a diff anyway, but then again, I don't suppose the additional load on your drive train, universals, clutch, engine etc fighting against an overly aggressive clutch type LSD is not all that good for them either.