tommis85

Well it is just RWD now with front drive shaft disconnected because of buggered diff. The tyres are near new Federals, 255 45's with just 30psi in them to give it a bit of a better contact patch while it's just RWD and can't shift power anywhere. Yeh this is just around 4000-4500 when the turbos really ramp up hard. Realy want my front diff going again so that I can feel all of the power not just up to where it breaks traction. It was quite a mess when I had 35psi in the tires - it hardly put any down.

Hey Cobra, would you mind sharing how you went with your -9's? Mine are looking much more promising now, lighting the rears up in 2nd and 3rd so am very keen on getting my front diff back up and running and a retune! At what RPMs would you be making say, 1 bar and fullboost?

I should start a "get tom's GTR up and running" charity fund on here

But unfortunately I have a rear and front diff to fix before I can resume with the turbos...although I was thinking of maybe getting the rear fixed first and then getting it tuned in RWD.

What you're referring to there is just a type of material production process. I think you may be referring to newer materials / machining processes in todays turbos? I was under the impression that the -9's weren't too bad in that area. Mine may be laggy at the mo....but there are some graphs on here that are pure porn!

Hmm not sure right now - may have to check but, it would still support the theory as the shaft, being the shape it is will cool down a lot slower than the exhaust wheel vanes with their massive surface area. It was a pretty good write up...and would explain why they can shatter at as little as "8 pounds worth" of RPMs (whatever that equates too). But either way. As far as the topic goes....I'm still sitting here with lag monsters haha - need to get at least the rear diff sorted so I can do a proper dyno run without lighting up on the less loaded side GRRRRRRR!! Not happy Jan....not happy at all about all this.

Yes true true However, not that I recommend this....but.....I was running my ceramics at a minimum of 15 pounds for 4 years and last year I ran them up to 18 pounds for shits and giggles. I studied up on the causes of the "explosion" and made sure I didn't do what is the biggest contributor to it, ie, shutting off the turbos while they're literally red hot (the theory of the ceramic wheel shrinking faster than the metal shaft thus micro-fracturing the turbine wheel's hub over and extended period of time) They've also been thru numerous track and dyno days (and that is racing, not putter around happy laps style) Right now they're sitting on my shelf and they have no play in either axis....and spin as good as any journal bearing type turbo. Offcourse, it could also be that I have a very well manufactured, faultless set of turbine wheels....ceramic's manufacture process was definitely not a reliable / consistent one 17 years ago. It would be interesting to find out exactly how many of these units have failed and under what circumstances...and, what led up to it.

Gees man, yeh my budget for all this crap is fast running out PLUS (now this makes it worse) I've also been thinking about selling the car for a while now. So I don't really want to spend big on upgrades - rather just want to replace broken parts with good 2nd hand gear like with the front diff. Damn money pits! Sounds like you're pretty happy with your new setup tho

I'm pretty sure I'm gonna be tied up with work late this week, weekend and Monday I'll be finding out what the go is in the next couple days

I'd be able to do some extreme one wheel power slides with my gtr F'ed diff's all round

I'm down with that as always! Compulsory once a month meet min! At Clint's on his elephant scrotUm couch

You're right Piggaz. I'm merely just looking at options because this whole show is already having it's tole on the hip pocket. So apart from places like RHD....where can I get these LSD upgrades from? Also, on here's probably also the best place to ask where I can obtain the bearings and seals needed for swapping out the front diff center as I've been told that it's not wise to re-use the old ones as they get damaged when removing them.

Ok, so I've just been out to a gearbox place where we had a talk about the 2 diffs. Also received a mint front diff center from Xklaba on here but I'll have to get some new front/rear and side carrier bearings along with their respective seals. It would be unwise to reuse the current ones or? Apparently they need to be removed and reinstalled - a process that damages them? (apologies for my lack of knowledge in this area) So, that there would come to about $550 labour plus the coast of bearings and seals. But, because of the money involved I've decided to rebuild the rear diff first as that makes much more sense and just leave the front disconnected for now. The gearbox fella agreed that it's probably just worn out one side worth of clutch pack plates which is why it's feeding the power to just one wheel. Looks like I'm up for a Nismo unit hey? Unless one was to go down the slightly risky second hand path and swap it out for one that hopefully is in better condition

Yeh that shouldn't be the case. It could be that it's just badly worn. Now when I think of it, even 3 years ago at QR Sprints it did funny things on the corners past the big dipper....it would always light up a bit on the inside wheel rather than light up both and step out. I have been doing some reading on diff oils too....how much would the couple different grades of diff oil affect how limited the slip is? Can you have oil in it that would make it become an open diff? Or would you only ever vary the amount of slip but never get rid of it all together?? I'm running that LXD90 straight 90 in it right now because I didn't have anything else.

Thanks for the clarification gents....muchly appreciated! Yes well I was under the assumption too that it is an LSD, just not as complicated as the A-LSD in the Vspec models where it splits torque from left to right etc. Ok, well I guess I'll go suss out some costs for those couple options. This is probably why my car is also pulling to the left even though I've only just had it aligned....it's definitely getting more power to one wheel and for all I know it's only driving one wheel full stop 1-wheel drive GTR....now I know how commodore drivers feel

Thanks for that. Nah mines just a standard GTR. So what would be going wrong with my diff if it's so easily lighting up on just one wheel? Once upon a time I did know what diffs are in what but right now I can't quite remember what's in a 33 GTR (and also late R32 etc). I'm assuming it's not a full LSD? Hypnoid something?

**double post if anyone wants to delete it**

Hi peeps, Some of you may be aware of that I've been driving around with the front prop shaft out because of my shagged from diff (new front diff has finally arrived so will have it in soon)...however, in the mean time I've noticed something peculiar with the REAR diff. The past week of wet weather has made a mess of my dirt/grass driveway and when I go to drive up to the rear shed the car will start to spin on just one rear wheel. It can no longer shift torque to the front because of the missing shaft etc so it just lights up on one wheel and gets bogged down. My question to you guys is, is this normal? Is a R33 GTR meant to light up on both rears or will it select one like a normal differential? I've never had diff issues before so am not up to speed with how all the different ones work in the GTRs...all I do know is that the front one is a plain LSD and differs from the rear etc. I've also noticed that in the past when it did have the front connected it would feel rather odd at the rear when full throttle...as if one side was putting down more power than the other side.....a kinda twisting of the car. I'm thinking that the torque split had effectively masked a problem with the rear diff? Any help would be greatly appreciated....thanks guys!

Yeh well I was looking at those steel wheel kits you can buy before the -7's caught my fancy. A set of steel wheeled stockers with some extra preload on them and EBC would be mental through a mountain pass!! Anyone who's still running ceramics should realy throw on some adjustable actuators and brace themselves Yeh mate, I think in the 7 years I've had these cars with all sorts of turbo combos I think I'm more of a response man. The lag is all cool when you want to impress your mates but at all other times I personally just find it a pain in the ass. Big singles with their light switch on/off delivery are much more fun for that anyway.

Yep that's pretty much how it is. And then there's also those tuners out there who whisper sweet little things in your ear about that they can make anything come on lightning quick and then stop talking to you as soon as you handed over your dough Some of these places have no shame or pride in what they do - simply in it for the money and just give you lip service till they get it. One more thing you can throw into the mix is hybrid versions of these turbos - like, in my travels I came across a set of 2530's with bigger compressor wheels and competition split dumps for the price of new -9's. They probably would have been good but you gotta always ask yourself why they were selling them for if they were so "fantastic" etc.

I hope mine will come good like his did haha, that is a fantastic result for that fella....the graph looks amazing!

Lol yes that's true but I have read thru it all and it's about GT-SS's which from what I've read are near identical to -9's. It's funny though...there are many claims across all these forums of what the -9's / GT-SS turbos perform like. Claims of where full boost of around 20 pounds is reached vary from 3800 to 5700 with the average, especially on my thread, being around 4500rpm (the later sounding quite reasonable) Then there're those who claim that they are more responsive than ceramics, while others claim they're similar to, followed by those who say they're far more laggier and should be avoided. Then, for all these claims we have various dyno plots for cars with similar hardware where one could swear they're all running different turbos haha....that's how varied these -9 results are. Offcourse, all engines are different....not to mention the skills of the tuners that work with them. I guess I'm just trying to say that it's quite hard to get a proper feel for what these turbos "could" be like.

Haha looks like someone else is having some fun too ;-) http://www.skylinesaustralia.com/forums/topic/142530-rb26-gt-ss-turbos-when-should-boost-kick-in/

Ah ok that's what I thought Well I'm definitely going to have to see your results with the gears. I'm not going to touch mine for a while as I need to put in a new front diff first before I can go anywhere near a dyno. It is currently Australias only RWD R33 GTR

Oh nice...I googled them I guess that's the other end of the extreme hey? Bet that thing is awesome at gymkhanas and mountain runs!!