Jump to content
SAU Community

Change Diff Or Strengthen It

4drlvr
 Share

Recommended Posts

4drlvr Proficient

4drlvr

Posted
Posted

Hi People,

As the topic states, Im looking at strengthing my diff to handle the conversion of the rb26 in it. Now the car previously was a rb25dett auto which is now a rb26dett with an r34gtt gearbox in it.

What i want to know is it worth taking it to a diff place and strengthing it or buying a new one.

Also what diff do i have in it if the car from factory was a R33 gtst 1996 s1.5 4door auto no hicas with abs(if that made a difference).

Also does anyone know good diff places in melbourne nothern suburbs such as epping,cambellfield, somerton, tullamarine, etc if people are recommending strengthing the diff???

Any help will be good.

Ray

Link to comment
https://www.sau.com.au/forums/topic/304515-change-diff-or-strengthen-it/
Share on other sites
Ryno Experienced

Ryno

Posted
Posted

I wouldn't be worried about breaking the diff, they're bloody tough, so you'll usually break something else before that goes.

Your question should be: will my viscous LSD centre be able to put the power down to the ground?

You won't know that until you go for your first drive, and see if it spins both wheels off the line.

4drlvr Proficient

4drlvr

Posted
  • Author
Posted

Hi Fellas, thanks for the reply.

Both wheels spin most of the time but ive noticed a weird knock that comes in sometimes after a bit of trashing which disappears after a bit of easy driving. I have changed the oils so what would be the best way to go, kazz lsd 2 way or should i just get this diff fixed??? and if to get it fixed anyone got any recommendation on a diff shop????

Ryno Experienced

Ryno

Posted
Posted (edited)

I wouldn't waste any money on the standard VLSD, and an aftermarket 2 way is usually a fair amount of coin, unless you find one second hand.

A couple of better value options are:

The R32 GTR diff. It's a mechanical (clutch type) that is a good upgrade, but you will need to find someone wrecking a GTR, because you will also need the half shafts and rear hubs (as they are a larger diameter, and your half shafts wont bolt up).

The S15 Helical LSD, out of the manual turbo. It's a mechanical Helical centre, that has awesome reviews from everyone that uses one. As they are helical, they do not wear out like "clutch types" so it's a safer bet when buying second hand. They run 6 bolt half shafts, so you will need to get them as well to make it bolt up, but you won't need to replace the rear hubs (like when upgrading to the R32 GTR diff).

I have just purchased an S15 rear diff (with half shafts) for $250, so it's a pretty cost effective upgrade. It also comes with a 3.7:1 ratio, so if you stick with that it will effectively make your gears all 10% taller. I'm going to try it with that, and see how it goes (as I find first gear too short in my car, and am also looking forward to saving some fuel by cruising at lower revs in 5th). But worst case, if I don't like it I can swap the crown wheel and pinion from my old diff back into it, and run the old 4.1:1 ratio.

Edited by Ryno

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GTSBoy
      Another little story of weird shit happening

      By GTSBoy · Posted

      Well, after the full circus this week (new gearbag, 14 psi actuator on, injectors and AFM upgraded, and.....turbo repair) the diagnosis on the wastegate is in. It was broken. It was broken in a really strange way. The weld that holds the lever arm onto the wastegate flapper shaft broke. Broke completely, but broke in such a way that it could go back together in the "correct" position, or it could rearrange itself somewhere else along the fracture plane and sit with the flapper not parallel to the lever. So, who knows how and when exactly what happened? No-one will ever know. Was it broken like this the first time it spat the circlip and wedged itself deep into the dump? Or was it only broken when I tried to pry it back into place? (I didn't try that hard, but who knows?). Or did it break first? Or did it break between the first and second event of wierdness? Meh. It doesn't matter now. It is welded back together. And it is now held closed by a 14 psi actuator, so...the car has been tuned with the supporting mods (and the order of operations there is that the supporting mods and dyno needed to be able to be done first before adding boost, because it was pinging on <<14 psi with the new turbo with only a 6 psi actuator). And then tuned up a bit, and with the boost controller turned off throughout that process. So it was only running WG pressure and so only hit about 15-16 psi. The turbo is still ever so slightly lazier than might be preferred - like it is still a bit on the big side for the engine. I haven't tested it on the road properly in any way - just driven it around in traffic for a half hour or so. But it is like chalk and cheese compared to what it was. Between dyno numbers and driving feedback: It makes 100 kW at 3k rpm, which is OK, could be better. That's stock 2JZ territory, or RB20 with G series 550. It actually starts building boost from 2k, which is certainly better than it did recently (with all the WG flapper bullshit). Although it's hard to remember what it was like prior to all that - it certainly seems much, much better. And that makes sense, given the WG was probably starting to blow open at anything above about 3 psi anyway (with the 6 psi actuator). It doesn't really get to "full boost" (say 16 psi) until >>4k rpm. I am hopeful that this is a feature of the lack of boost controller keeping boost pressure off the actuator, because it was turned off for the dyno and off for the drives afterward. There's more to be found here, I'm sure. It made 230 rwkW at not a lot more than 6k and held it to over 7k, so there seems to be plenty of potential to get it up to 250-260rwkW with 18 psi or so, which would be a decent effort, considering the stock sized turbo inlet pipework and AFM, and the return flow cooler. According to Tao, those things should definitely put a bit of a limit on it by that sort of number. I must stress that I have not opened the throttle 100% on the road yet - well, at least not 100% and allowed it to wind all the way up. It'll have to wait until some reasonable opportunity. I'm quite looking forward to that - it feels massively better than it has in a loooong time. It's back to its old self, plus about 20% extra powers over the best it ever did before. I'm going to get the boost controller set up to maximise spool and settle at no more than ~17 psi (for now) and then go back on the dyno to see what we can squeeze out of it. There is other interesting news too. I put together a replacement tube to fit the R35 AFM in the stock location. This is the first time the tuner has worked with one, because anyone else he has tuned for has gone from Z32 territory to aftermarket ECU. No-one has ever wanted to stay Nistuned and do what I've done. Anyway, his feedback is that the R35 AFM is super super super responsive. Tiny little changes in throttle position or load turn up immediately as a cell change on the maps. Way, way more responsive than any of the old skool AFMs. Makes it quite diffifult to tune as you have to stay right on top of that so you don't wander off the cell you wanted to tune. But it certainly seems to help with real world throttle response. That's hard to separate from all the other things that changed, but the "pedal feel" is certainly crisp.
    • Murray_Calavera
      Steps to DIY sanding car back ready for respray....

      By Murray_Calavera · Posted

      I'm a bit confused by this post, so I'll address the bit I understand lol.  Use an air compressor and blow away the guide coat sanding residue. All the better if you have a moisture trap for your compressor. You'd want to do this a few times as you sand the area, you wouldn't for example sand the entire area till you think its perfect and then 'confirm' that is it by blowing away the guide coat residue.  Sand the area, blow away the guide coat residue, inspect the panel, back to sanding... rinse and repeat. 
    • Rezz
      DeAgostini 1/8 scale BNR32 Nissan Skyline GT-R Nismo

      By Rezz · Posted

      The detail level is about right for the money they charge for the full kit... AU$21.00 each issue, 110 issues for a total of $2,300 (I mentioned $2.2K in the first post when the exchange rate was better). $20/week is doable... 😐
    • Keeper
      SAUNSW - World Time Attack Challenge - 5 & 6 September

      By Keeper · Posted

      If planning on joining us for the day(s) please indicate by filling in this form. https://forms.gle/Ma8Nn4DzYVA8uDHg7
    • soviet_merlin
      DeAgostini 1/8 scale BNR32 Nissan Skyline GT-R Nismo

      By soviet_merlin · Posted

      You put the driver's seat on the wrong side! Incredible detail on all of this. It looks like you could learn a lot about the car just from assembling the kit.
×
×
  • Create New...