Torsen or Trd lsd??

Hi ive just bought another supra TT auto. Its a GZ model with a torsen lsd in it but i have a trd lsd lying about. So wanted to know if i should keep the oem torsen setup or change it for the trd lsd? If anyone has changed from torsen to trd it will be nice to get your feedback on your thoughts about both please.

TRD is a LOT better than the Torsen, which actually does very little, especially if worn. The OS Giken one is in a different class to either, but also a lot dearer. For road usage the TRD is a good choice. For track you need a Giken if you want the best traction and slow speed turn in. They have really trick internals.

Ok then i think i will swap out my torsen for the trd then.

To be honest the stock Torsen is a bit of a waste of time, they are that loose.

i believe you've got a OSG on your own car don't you chris?

what's it like in a road going environment? an noise etc? ill effects

basically looking for a nice behaving diff to give me the best grip i can, but don't want to loose any of the refinement of the basically do nothing torsional haha

Tim

I hope there aren't any massive drawbacks to an OS Giken diff on a road car because I've just ordered one...!

It's in my Skyline, so with a straight cut sequential dog box in it, Rose jointed suspension, race spring and damper rates, and floating discs the noise means any diff chatter would be pretty much unnoticeable. the ones I have fitted to normal road cars have been quiet and chatter free *IF* used with the correct and VERY dear Giken oil. It has friction modifiers in it, and I would recommend you only use this Giken oil if you want to be sure it doesn't chatter. Great diffs, great company, and you can get ALL spares for their products. Try that with HKS or or some other popular suppliers......

Chris,

I've been toying with running a spool/welded diff on my track car. I knew a guy who used to run one in a Silvia S12 race car. Bad Idea?

Lyndon.

Whilst spools have been successfully run on track cars on street circuits and "normal" race tracks, they are few and far between. The Group C Porsche sports prototypes are perhaps the last that I can recall. They used radical suspension settings on a very stiff chassis and had huge power to break traction if needed. They also had massive amounts of downforce. They only ran spools at very selected circuits, too. I would say that for a track car based on a road car it would be a ridiculous way to go. It'll have terminal understeer in slow corners and be twitchy in fast ones. You need a plate type diff with what the Japs call 1.5 ramping. The difference between a good plate type race LSD and an OE Torsen or a loosely torqued road car plate LSD (rare these days) is staggering. Karts get away with no diff by having massive amounts of front caster angle that unloads the inside rear tyre by literally jacking it into an near unloaded condition diagonally through the frame ((chassis). This is why a race kart is so heavy to steer, given their minimal weight. People have tried similar means on full size race cars, via various means, but the LSD has had donkey's years development and in 98% of cases is the way to go.

Similarly the difference between good dampers and brightly anodized junk with internals from the dark ages makes a massive difference to how a car handles and in aprticular puts its power down in the wet or on a bumpy surface..

You seriously need to write a book Chris.

Before the intake of local ales starts to have a detrimental effect.

You seriously need to write a book Chris.

 

Before the intake of local ales starts to have a detrimental effect.

Agreed. Interesting stuff...

Uh, I don't know about the local ales thing!

I find some of my best and most honest advice is given under the influence, but I have lost a few friends along the way

thanks for the feedback. i think i will have to try and find someone with an OSG or TRD diff for a passenger side and see for myself, if i can find someone whos kind enough

Tim

TRD ones are totally civilised, fitted loads of them. The few Gikens (3 maybe?) I have fitted to road cars have also been totally civilised. All have used the correct Giken supplied oil and have been maintained with it, too. I doubt a Giken will disappoint from a civility point of view, and it certainly won't from a functionality point of view, they are absolutely superb.

TRD ones are totally civilised, fitted loads of them. The few Gikens (3 maybe?) I have fitted to road cars have also been totally civilised. All have used the correct Giken supplied oil and have been maintained with it, too. I doubt a Giken will disappoint from a civility point of view, and it certainly won't from a functionality point of view, they are absolutely superb.

Good news!

TRD ones are totally civilised, fitted loads of them. The few Gikens (3 maybe?) I have fitted to road cars have also been totally civilised. All have used the correct Giken supplied oil and have been maintained with it, too. I doubt a Giken will disappoint from a civility point of view, and it certainly won't from a functionality point of view, they are absolutely superb.

yeah I've used OSG on alot of cars and always been very happy just never used one on a road car. I've been put off TRD's a little because the 2way where i figured a 1.5 would be better for an everyday road application, and on the 3sgte models on full lock turning its very clunky and in some applications can jump the rear of the car slightly, say your manoeuvring around a carpark or something like that.

The TRD lsd can be used in 1.5 or 2 way. You just have to configure the internals i believe.

The TRD lsd can be used in 1.5 or 2 way. You just have to configure the internals i believe.

On the TRD website, they said all FR cars are only 2 way and the Vitz is the only 1.5 way & FF selective

http://www.trdparts.jp/english/parts_lsd_mechanical.html

The TRD mechanical LSD is 1.5-way selective, and can optionally be switched over to a 2-way without any additional parts. (It can only be 1.5-way on Vitz models and 2-way on FR vehicles.)

I was asking about the TRD vs the OsGiken after I seen Chris mentioned it before; I heard the OsGiken can tend to hop versus the TRD. I am just looking for something civilized for my car too with an acceptable oil change interval.

OsGiken sounds like the oil might be an issue to get

D-TD102061405-S Spec-S OS Giken Super Lock LSD 938 GBP off Nengun

http://www.nengun.com/os-giken/super-lock-lsd

The TRD Diff was around 550 GBP off RHDJapan last I checked, site appears to be down now

I found my 2 way Carbonetics to be fine for every day use, no hopping etc just the oil change intervals is why I am getting rid of it. She stuck to the road and in the wet/ dry instant traction compared to the open diff I have in it now. You could make her step out if you wanted to , but you are in control as opposed to what I have now, she does try to catch you out.

Just curious how the TRD drives compared to the OSGiken, can you get oversteer in the OsGiken 1.5 way too if you want. Just want something fun to drive out of a corner but when you want some spirited driving or something you can put down some BPU levels of power in the wet. Plus a realistic or close to OEM maintenance, maybe too much to ask?

A heavy and high power RWD car with pretty small rear tyre width due to suspension kinematic limitations, and next to no downforce, will always work a LSD hard. It will also always need regular LSD maintenance. For sure given enough power and the right (wrong?) driving style you can make pretty much any RWD car oversteer. Whether that's appropriate for the quickest lap times though is another matter. The whole point of good suspension and LSD design is to keep traction maximised and oversteer in check. Lots of oversteer looks dramatic but it is really just torque being wasted. It shows a lack of driving finesse, or inadequate down force, suspension, throttle and traction control, depending on corner speed. A really quick lap often looks tame, almost slow, from within and without. Flailing arms, tyre smoke and show boating usually puts you towards the back of a competitive grid "Drifting" is the science of making a possibly potentially good handling car do pitiful lap times. To me "fun" handling is when the car in front of you on corner entry is 20 feet behind you on corner exit I know where you are coming from though, and I am sure any 500 BHP RWD car can oversteer given the right steering and throttle inputs, pretty much on demand, or by surprise. As many an Armco barrier and recovery crew will testify

Lol, Chris; I am more into circuit racing too not a big fan of drifting but just trying to guage is the osgiken worth the extra cash, its nearly an extra 40%

If it's for track days, yes it is worth the extra. For a fast road car, probably not. To get the most out of the Giken you would need to corner in a way a judge would consider "dangerous driving"

Thanks again Chris

Looking on the Supra Forums site ; they highly recommend the OsGiken and a lot of guys like the Carbonetics 1.5 way or KAAZ but I came across some members having issues installing the OsGiken ; most people that have experience with multiple brands of differentials seem to prefer either the Carbonetics or OS Giken over everything else

http://www.supraforums.com/forum/showthread.php?653740-Carbonetics-Carbon-LSD/page2&highlight=carbonetics

http://www.supraforums.com/forum/showthread.php?620218-Stupid-LSD-Questions&highlight=osgiken+lsd

http://www.supraforums.com/forum/showthread.php?562632-Which-LSD-is-best-for-road-racing/page2

Interesting OsGiken Install Issues

http://www.supraforums.com/forum/showthread.php?693386-OS-Gilken-Diff&highlight=osgiken+LSD+install

This has to do with proper installation of the OS Giken Super Lock LSD and a mod that is apparently required for some JZA80 diffs to make it fit right, but it's not clear to me what diffs need this mod.

On their site http://www.osgiken.net/techcenter.php

Long story short, the actual axle stubs that Toyota used with these differentials have a surprising amount of variety, considering the consistencies everywhere else in the car. For instance, when installing a clutch type LSD in a Supra or Soarer that came with the 200mm diff and a factory LSD, the axle stubs from LSD-equipped cars are slightly too long for a proper fit with a TRD or other clutch type LSD. For the most part, this is usually taken up by tolerance creep between parts and no problems are experienced, and the tension from the installed axle halfshafts themselves usually keeps the axle stubs in place, but this sometimes becomes problematic when wheelhop, etc, is experienced and the axle stubs actually pop out just enough to induce a gear oil leak, and because of that possibility, many LSD makers list a need for the factory Toyota OPEN differential axle stubs to be used when installing a clutch type LSD.

Since the 220mm diff as found in the pre-'minor change' JDM 6-spd TT models (which includes ALL of the US TT 6-spd's and European delivered TT big diff vehicles, I should mention) always came with a Torsen LSD, the axle stubs are also slightly longer than would be used with most clutch type LSD's. The TRD LSD was probably designed to accommodate those stock axles, but because of possible fitment issues, OS Giken has published this just in case a tolerance issue arises and those axles have occasion or cause to pop out under wheelhop conditions, etc. As long as your LSD is working normally and no leaks or problems with the axle stubs popping out has been experienced, I'd say you're probably just fine.

But if you go back into the diff for any other reason, probably wouldn't be a bad idea to take the stubs to get milled down as shown in the pics to ensure that it never becomes a problem later on.

Cliffs:

If you've got a clutch type LSD in a 220mm diff, and you're experiencing an issue where the axle stubs pop out after hard launches, high speed pulls, or after wheelhop, and thus cause an oil leak, pull both axle stubs and have them milled in accordance with the pictures. The TRD LSD was probably designed to accommodate the stock axle stubs though.

If you're installing an OS Giken Super lock into a 220mm diff, you might as well have your axles modified 'while you're in there' during the installation. The modified axles will not affect the stock torsen LSD should you chose to revert to the OEM Torsen for any reason.

I have never had an issue, but always feel for the snap ring engaging properly, and I give the inner C/V pots a quick lever to be sure they are properly located by the snap rings. "Milling" would entail completely dismantling the inner joints from the shafts, plus they are damned hard, so you'd need decent tooling. I would just take a flap disc in a small angle grinder and do them assembled, by hand to be honest, *IF* you have a clearance issue. (Engineers Blue on the tips would also show any interference).

I had a Kaaz LSD in another Skyline and the noises it made were horrendous, it worked, but passengers were convinced something was seriously broken when manoeuvring. Chrysler Cherokee Jeep LSD friction modifier helped, at about double the normal dose, but didn't by any means fix it completely. (Chrysler have had terrible issues with Cherokee diffs in general, and grabbing, clunking LSD ones in particular, so most dealers keep the friction modifier fluid in stock, I added 2 bottles).

OsGiken Super Lock LSD

**Not too sure if the output shafts are modified?

Output Shafts: http://www.rhdjapan.com/toyota-oem-differential-output-shaft-24020-aristo-supra-soarer-60904

LSD: http://www.rhdjapan.com/os-giken-1-5-way-super-lock-lsd-spec-s-jza80-jzz30-jzz31-uzz30-60873

Brand: OS Giken

Product: Super Lock LSD Spec-S 1.5 Way JZA80 JZZ30 JZZ31 UZZ30

Part Number: D-TD102061405-S

PRODUCT NOTES:

- Required for all vehicles: Toyota OEM Output Shaft (41309-24020) x2 needed for installation

COMPATIBILITY NOTES:

- JZA80: Only for Vehicles before 5/96