Torsen 1 or Torsen 2?

spikey · Postby **spikey** » Sun Nov 29, 2015 12:16 am

Has anyone ever heard of Torsen 1 breaking in normal use or occasional track work on a standard engine? can anyone also explain what is the main difference in performance between Torsen 1 and 2, I have dríven on both and can't tell the difference.
Thanks
Terry

The American · Postby **The American** » Sun Nov 29, 2015 7:38 am

Hi Terry,
I've dríven both. I had the T1 in my NA8 and I've got a T2 in my NB8C.

To be fair, these cars don't have too much in common, but I have noticed what feel like differences in differential behaviour.

The T1 felt much more positive when powering out of a corner, and felt more inclined to step the car out under power than the T2, in spite of having a lot less HP. I also noticed that the T1 appeared to be more aggressive on deceleration. On many occasions the inside wheel would hop on decel into a corner. The T1 felt much more like it locked up (although it clearly didn't)

The T2 by comparison feels more gentle - I don't really notice the 'kick and step sideways' that came with the T1, and the decel partial lock is not noticeable. In long corners, I can feel the unloaded wheel spinning slightly at the limit of the torque it can transmit, which gives the feeling of being slightly 'open'. I never experienced that with the T1, but that could be the HP difference between the cars.

I've used both in Motorkhana context, and the T1 again felt more aggressive, but they both worked for the purpose fine.

spikey · Postby **spikey** » Sun Nov 29, 2015 11:13 am

Thank you for the input Mr.American, I have sold my car it is a NB8A and I put a Torsen 1 in it, but the buyer has been told by his mechanic to put the Torsen 2 because the Torsen 1 might break, i have never heard of them breaking, to me they T1 and T2 felt similar but don't drive the car to its limit, you know that:) the car is a standard Nb just with cold air intake and mazdaspeed diff back exhaust.
Thanks
Terry

manga_blue · Postby **manga_blue** » Sun Nov 29, 2015 11:21 am

My T1 has done about 200,000kms and almost 4,000 laps and it's still fine. They eventually get a bit of free play but I haven't heard of them breaking.

spikey · Postby **spikey** » Sun Nov 29, 2015 11:50 am

I have never heard of one breaking either

manga_blue · Postby **manga_blue** » Sun Nov 29, 2015 12:07 pm

Its more likely that the mechanic doesn't understand what a torsen is. They use gears to transfer torque, as opposed to clutch style LSDs which use clutches to more or less lock things up. Clutch style ones can wear or fail more.

flycasta · Postby **flycasta** » Sun Nov 29, 2015 1:49 pm

The T1 uses a hardened steel spring pin that stretches across the width of the big wide gate and travels through the centre of the Spur gear and is held in each end by approx. 10mm of the actual case only.

The T2 is all encased in the body of the Torsen casing and is eventually held together by the crown wheel bolts.

I have seen a T1 explode in a much higher horsepower car, not an MX5 T1, so they can break. I would think for me the strength of the T2 case, housing all of the gears, is much stronger and more durable than the potential of the hardened steel spring pin being able to flex under high load from a big horsepower car. That said for a road car with 25% more power than standard the T1 would be quite ok. Over time though the wearing of the Steel spring pin will weaken and ultimately cause a failure.

chrons_rotary · Postby **chrons_rotary** » Sun Nov 29, 2015 11:12 pm

We'll i can tell you now that the T1 TorSens do break.
I was at my local hillclimb track, and just as i was spinning the tyres to heat them up just before my run, i heard/felt a big bang.
Opening it up i found that the helical gears had all broken.
Was replaced with a T2.
From what i've read the T1 is better for racing, but weaker, while the T2 is more about road comfort.

spikey · Postby **spikey** » Mon Nov 30, 2015 12:40 am

Has your car got a standard engine? probably not, any diff will break depends on what hp you put through it.

chrons_rotary · Postby **chrons_rotary** » Mon Nov 30, 2015 3:45 am

spikey wrote:Has your car got a standard engine? probably not, any diff will break depends on what hp you put through it.

Yeah typical 250hp+ Nitro Dann turbo setup.

spikey · Postby **spikey** » Mon Nov 30, 2015 10:22 am

Thank you for the reply, I will put the T2 into the car for the buyer as requested, so there will be a 4.1 Torsen 1 pumpkin for sale,let me know if you want one.

The American · Postby **The American** » Tue Dec 01, 2015 7:31 am

Terry, as always, you are an incredibly generous fellow.

spikey · Postby **spikey** » Tue Dec 01, 2015 10:53 am

Thanks Hanson, we always try to make the buyer happy with their purchase without regrets, it has gone to a good owner so it was worth it.

Waz man · Postby **Waz man** » Tue Dec 01, 2015 12:05 pm

Hopefully someone who want's to come out and play at motorsport.
I have seen lot's of car sold over the years and people don't bring them out to play???
They don't know what they are missing!

StanTheMan · Postby **StanTheMan** » Tue Dec 01, 2015 12:25 pm

I think the only time they break is when they don't have lubrication filled in, excess HP.....or when the crown wheel isn't lined up correctly.
Ive had my T2 for 10 years & it still works fine. But I only have 60 RW killer wasps.