R34 Gtt - Nismo 2 Way For 100% Street Car?

[gwilkinson34]

I know this has been asked a hundred times, and I've read plenty of threads, but I'm still not sold either way...

I'm looking at either a Nismo 1.5 or 2 way diff for my R34 (300rwkw) - this is pretty much a 100% street driven car, although I do like to drive pretty aggressively (oops). It is a series 1 so has the shitty viscous LSD at the moment. I find it behaves very well even under full power with the current diff, but getting it to hook up in a straight line is next to impossible.

Will either the 1.5 or 2 way make a big difference to straight line grip? (I've been told they will) I'm not too concerned about corners, but am a bit worried about a 2 way getting hard to handle on the street (especially in the wet) and being a pain in the arse in carparks, slow speeds etc.

I'm leaning towards the 1.5 way, 'just in case', but would love some thoughts from those that have driven either on the road...

Cheers!

[gwilkinson34]

The other option that has been suggested is a helical diff of some kind, but not sure what options are even available for my car... thoughts?

[niZmO_Man]

Get the 1.5 way

[gwilkinson34]

Yeah I think that's the way to go - found a Nismo 1.5 way that has only done two half track days - $1200 installed. Seems like a good deal to me?

[Dose Pipe Sutututu]

Helical/Torsen diff is a clear win purely for a street car that mainly does straight lines as you've mentioned above.

If you're lucky enough to get a 1-way then go for that!

Helical/Torsen Advantages:

• No clutch plates to wear out
• No need to service
• You won't chirp around carparks
• Cheaper than a clutch plate mechanical diff
• No clunks etc.
• Less tyre wear (from day to day driving/coasting etc around corners) when compared to a 2-way or 1.5 way

Disadvantages:

• Requires both wheels on the ground to work, if you're going up a driveway you'll single spin (handbrake fixes that)
• Rare, R34 GT-t S2 rear diffs are rare

[eightsixboy]

The 1.5 will be fine on the street, I have driven with a 2 way as a daily and I didn't mind it, but I guess it depends on how much you can live with clunks and noises.

If its 100% street then really anything that's an upgrade from the standard viscous will be better, if you do any drift/track then a proper clutch lsd is required.

[gwilkinson34]

Cool - well the Nismo 1.5 way is going in this Wednesday - sounds like it should do the trick!

Will post my impressions once it's in.

[r34unit]

Let me know how it goes I'm in the same situation !

[timmy_89]

I have a Nismo 1.5 way fitted in my R34 which is more of a weekend car, and sometimes occasionally gets driven to work (when I get sick of driving my Commodore lol). You will get clunks and noises and tyre churps on slow turns, but you get used to it. People look at you funny, which I find just amusing to see some peoples reactions. You will have a lot more grip in the car. I found that I now approach corners a little differently because the car 'pushes' through the corner a bit more with the diff locking up (felt almost like it was understeering).

I guess it all comes down to how much 'mechanical' like things you are willing to put up with in an everyday car. I know people that can't even put up with coilovers, so each to their own I guess. Hopefully you enjoy having the 1.5 way in

[GTSBoy]

Feels almost like understeering because that's exactly what it is making the car do. Hence why a 1 way diff is probably a better choice for a street car.

[Jim985]

Out of interest where do you get a Nismo 1.5 way LSD supplied and fitted for $1200. Seems like a great price.

[GTSBoy]

Secondhand diff plus a couple of hundred to drop and swap. Sounds about right. Plus oil perhaps.

[gwilkinson34]

Well, the diff has been in for a couple days now - also had a HICAS locker bar installed at the same time - and it has certainly made a pretty big difference to the car!

To be honest I wasn't really sure what to expect, never having driven a car with a 'proper' LSD before, and hearing all sorts of stories about clunking, noise etc, I was quite interested to see what it would be like.

I believe the actual diff I got was the Nismo 1.5 way Pro, with the adjustable torque settings etc. Set in the middle at this stage. The diff had done two half track days, which is why I got it at a good price, but it's essentially brand new, and I didn't have the hassle of having to run it in. Let me tell you, this thing is TIGHT!

The first thing I noticed was making the turn out of the garage - the inside wheel skipping to keep up with the outside, as it should - a weird sensation that many people seem to have likened to "the rear end falling apart" - it was nowhere near that bad though. As soon as I straightened up there was no noise at all, and driving in a straight line I don't notice any difference from the old diff, which is good. There's been a couple clunks here and there, when i've let out the clutch a bit quickly between gears, but I have a pretty gnarly Exedy 6 puck cushioned ceramic clutch so I've learned to be very slow through the friction point (this thing grabs like a mother) anyway, so really the clunks have been kept to an absolute minimum.

I went for a fair drive, and by the end of it the diff had obviously warmed up, and the surging / skipping around tight turns had settled down considerably. I noticed this morning when it was cold again the surging feeling was worse, but soon lessened again once everything warmed up.

Now, the good part! My car has always struggled for traction - running E85 it makes 300rwkw by just after 5.7k rpm, so it's very torquey through that 4-6k rpm range. With the old diff when it let go (which it did in 1st and 2nd with anything over half throttle), it REALLY let go - it would either break out totally sideways, or the thing would spin one wheel and redline in an instant - acceleration would pretty much stop until I changed gear, Even backing off it didn't grip back up easily. Now though, while I still can't floor it in the lower gears without wheelspin, it acts very differently when it does let go (which it still does, but a fair bit later) - it generally stays straight if the road is good, spinning up both wheels, but the difference is even though it's losing traction it still pulls hard! If I back off just a touch it will regain grip very quickly, and you can really feel the diff working to keep the car straight. There's also a noticeable 'pushing' sensation that was absent before. I've taken a couple mates for a spin who have been in my car (and driven it) plenty of times, and their reaction was basically "holy f**k dude!". Lol. So while the difference is not night and day with pure traction, it certainly has a hell of a lot more acceleration in 1st and 2nd, which is obviously very bloody good! I feel it has definitely made more of a difference to getting the power down than the other things i've done, such as pineapples and zero camber. I guess they all work together to help though.

I haven't had a chance to test the handling too much around town, but i've given it a few quick turns and roundabouts, and I can certainly see why people run proper LSDs for track cars - you get a real sense of the diff doing its job, and can really feel it working to straighten the car up, especially out of turns when given some stick. Places where my old diff would have just hung the back end out, the thing now straightens up and takes off. While i'm not 100% used to it yet, nor have I taken it anywhere near its limits, it certainly has given me a sense that there's more confidence and predictability there. Even my GF (who hates the car, to be honest!) - once convinced to come for a spin - said (without prompting) that she felt much safer now than before - so that's a bit of a litmus test I guess! I will take it up into the hills at some point soon and see how it handles around some proper corners - so far I haven't noticed the '.5' part of the lockup on lifting the throttle / deceleration but I imagine I will with a proper thrash.

It rained a bit here last night, and while I was out I had to chuck a quick u-bolt - and wanted to test what would happen if I just dumped the clutch and went round - man, did it go around quickly! It went a lot faster than I thought it would, but I just gave it some opposite lock and pulled it back (from about 45 degrees too far around) to straight again without any drama - I can see how it could be fun (and a tad scary) in the wet!

Also having the HICAS removed was a good idea - I was never really aware of what it was doing before, but I certainly am now. The car feels a whole lot less 'floaty' than it did before - it tended to wander around a bit when the road was bumpy, with the big wheels on the front obviously making the HICAS react. Now it's just totally planted, and it feels much more direct in the steering than it did before. It gave a slightly heavier feel to the steering wheel as well, which was a bit odd at first since i've driven this thing just about daily for six years, but i'm used to it already and it feels much, much better.

So in conclusion - is it an improvement? Damn straight it is! Are there drawbacks? I guess so - it's mildly annoying in car parks with the wheels chirping (although clutch in fixes that), and it surges quite a bit when cold around tight corners, but once it warms up that all goes away to an extent. Can I live with it in a daily driver? Without a doubt. The combination of ceramic clutch, loud exhaust and fairly solid suspension already means it's not the 'easiest' car to drive, although when just cruising casually it certainly isn't too outrageous and is still very comfortable. Would I recommend it? Again, most definitely - if you have a decent amount of power and already deal with a good clutch etc then it really isn't anything that will bother you too much.

And just to finish off, here's a quick 'up skirt' snap of the diff and HICAS locker bar!

Edited October 3, 2013 by gwilkinson34

[D.I.Y. Mik]

Sounds good, im waiting for my Kaaz 2 way.

[Howaitonaito]

I'm doing a LS swap with T56 in my V35 250GT at the moment it has the RE4RO1B auto found in the R34 GTT.

I found a diff 2way for the LS motor swap but will it grenade my auto if I put it in now