Lithium

Cheers, will look into that though I would have thought if the CAS was playing up it would be in the entire rev range? Was listed in the initial post that it did +/- 5 across all six...

Cheers A comment in that thread stands out and refers to something we'd planned to try in the next couple of days - which is checking or "improving" the earths - haven't ruled out that there might be a dodge or insufficient one somewhere and the more I think about it the more I could imagine this problem coming from one. I should have elaborated when I said we went out and checked the mixtures... the tune was one of the top suspects despite the fact the car had been driving fine on that tune for over a year, so we went out with the wideband to watch such things. The airfuel ratios are all normal everywhere until the misfire event happens, there is no gradual leaning out or going silly rich - it just suddenly misfires. The map also looks completely sensible, if you view the 3d representation of the map there are no stand out holes in the map which don't follow the normal "terrain" which would indicate there could be a trouble area. The problem basically came out of nowhere. It had been driving fine for a while with no changes to the car before it developed. Going to also replace the fuel filter and then this weekend hopefully try some factory R33 coils/ignitors and see what that does, my faith in the wasted spark ignition setup is waning as I've had other misfire related issues with it too.

Yeah thats what I thought too, I was just wondering if Adriano knew something I didn't - have been a learning n00b with these things long enough to know that no matter how much you think you know you know that suddenly a whole new thing can show up and prove you don't really know exactly whats going on it there haha

Cheers Adriano, the car is an hour away from where I am so I have to wait till I have a chance to get to it to try it out though I can't believe I hadn't tried that so far. The O2 sensor registered lean spikes when it happened, though if it was fuel related it would also show lean spikes- if not caused by a lean miss aye?

I don't have a scope I can unfortunately, though the Ignition module has 3 LEDs - one for each channel, and lights up each time it gets a signal.... will have to try it out and see what happens. Stupidly enough I haven't tried to free rev it and specifically pay attention though conceivable it may rev through so quick its not noticeable. I actually tried racing it a couple of weekends ago at the drags, and I tried launching at around 6000rpm and don't recall it fluffing until the tyres hooked then the revs dropped to the evil area then got all shitty.

Thats the spirit, none of this girly stuff... its a mans world, going clubbing doesn't mean dressing like a homo and shaking your tush to synthesised drum beats, alpha male shouldn't be the best dressed most cultured and well to do - its all about bigger, harder, faster, more! Whoa betide us if being bigger wasn't being better, imagine if it wasn't that way - if when journos were overwhelmed by the Skyline GTRs domination they labelled it "Skink" or perhaps "Newt"? But thank god they and we know the truth - that the man who has the most boost, the most CCs, the most PSI, the greatest hp/litre - will get dyno sheets to which all will bow, no meal will escape him and more females will be dragged to his cave than any other. Amen, Brother DirtGarage.

Cheers man, might have to hit you up on that PS, I have known for ages you were you... if nothing else the diving whale and fascination with VTEC gave it away

Time to make it 3litres+?

Put the VN coils in about a year ago, and tried another set this weekend just passed. I have a Series 2, there is no factory ignitor and I'm hesitant to spent ~$1kNZ to buy a set of coils when it may not even be a weak spark issue. I am however hoping to borrow a set of coils and an ignitor(s) to see what happens then.

We went one better and replaced the leads and plugs and no change. I haven't gapped the plugs further down as I believe replacing the plugs, and the fact that the missfire is not load dependant suggests to me the plugs are completely innocent. There is no ignition break down under full power above 4000rpm, which is where the plugs have to work the hardest to jump the gap - yet at 2500rpm at minimal throttle it misses. It makes the whole thing that little bit more confounding.

Hi all, I am fully running out of ideas for a very annoying ongoing issue I have with my Skyline. The symptoms are that it has a serious misfire/hesitation which only rears its head when the car has been warmed up and driven for a while, and is mainly in effect between 2500-3500rpm at any load level - straight cruise or at full load. The car will cruise fine at 2000rpm, or at 4000rpm+ (even wide open throttle above 4krpm is perfectly fine) - but in between gets very iffy. Does anyone have any ideas on what it could be? Information on the setup: - R33 GTS25t with the original RB25DET, compression test a couple months or so ago gave +/- 5psi across all 6 - Runs a upgraded (Garrett GT3076R) turbo on 1bar of boost - Running a GTS Link plugin ECU (MAP sensor, no AFM) - Has stock inlet and exhaust manifolds - Has been dyno tuned, and on the road aside from when the miss happens mixtures seem sensible - though the uncombusted air I assume would be responsible for the lean spike on the LM2 when it happens - Runs a wasted spark ignition system using GM/Holden Commodore VN V6 coils and a Link 3channel ignition amplifier with NGK "BCP" heat range 6 plugs gapped to .8mm Things we have tried to diagnose this issue so far: - Changed Spark plugs - Changed coil packs - Changed ignition leads - Changed exhaust manifold - Done a road test with wideband to check mixtures All of the above things resulted in no change whatsoever. Thats all I can think of that might paint a picture of whats going on, any input would be greatly appreciated - feel free to ask any further questions... I am at a wits end with this now, its unlike anything I've seen before and makes the car very hard to enjoy. Cheers, Dan.

Good to hear its back and working, and don't get put off working on your own car - just make sure you know exactly what is involved when you set out on doing something with the car. There are plenty of FAQs around here and elsewhere on what to do just in case you may not have thought of everything

They are both good turbos, there is no better out of the two - there might be one which is more suited to what you want but nothing in your question suggests what that would be. A GT3037S (GT3076R in Garrett speak) is very very similar to a GT3071R, everything on the turbine side is identical - the 76R just has a bigger compressor wheel and compressor housing (which also has antisurge ports). The GT3076R will make an extra maybe 50 or so hp but with that comes a little more lag.

Although from what you are describing the tuner is quite possibly to blame for your problems, for informations sake I am running a now phased out base model version of the plug in Link (GTSLink) and my car runs really well with it - the new G4 series links are very very good, there are a lot of "high end" track/drift/drag and street cars in NZ running them already and tuners/owners alike sound very happy with them so far.

Damn awesome, sounds like the stuff dreams are made of to me - having HKS build you up a street weapon. I'd probably go with the GT2835s myself but just because it'd be part of my dream, having a very "90s" Japanese build - huge HKS turbos on a big HKS motor.... I'm having a happy moment. Looking forward to seeing how it comes out even though its going to be a bit more restrained, will have some amazing power delivery As if I wasn't already in my happy place - when you say one of their drag cars, is it a customer car or are HKS still playing with their own drag projects? Care to share any more detail on this?

Interesting that (aside from Manny Cruz) the fastest stock internal RB25 and RB26 times are usually very similar. In NZ the fastest stock RB26 I know of is high 10s, vs 10.6 for the fastest stock RB25, vs ~8.9 for the fastest stock bottom end RB30 (had twin cam head).

What kind of manifold did you have with the GT35R - any chance that it was less than ideal? Do you have dyno plots or anything to back up what you're saying? Its at odds with most I have experienced and seen but if it turns out a T04Z can be some how made to be better spooling than a smaller turbo with newer design then its always worth looking at

Awesome, congrats! That will be a good mix - 1.06 might be a little bigger than I'd have gone with but she'll certainly have some top end rush Look forward to hearing how it comes out.

On the cases I have seen so far in NZ, similar to a .82a/r GT3582R and in my opinion the boost threshold on the GT35R (running a GOOD exhaust manifold and cam setup) definitely gives nothing away to them. The GT2530s seem to reach 20psi in the mid 4000rpm range, GT3582R similar (if not a little earlier). The GT2530s on Dynapacks over here seem to get from 390 to 430kw @ wheels, GT3582R... quite a bit rarer on RB26s so haven't seen the upper limit but we've seen 400kw so far, and thats not with an ideal setup. Hopefully will be able to report closer to 430kw in the new year I wouldn't bother with a GT3076R on an RB26 personally, I think if you are going to go to the effort of upgrading you may as well make good power - you'll always be wanting for more. I have never heard of something running GT-SS or N1 turbos and not at some point along the line asking "What should I got for - GT2530s/GT2860s or should I consider GT-RS" type questions. A T04Z on the other hand in my opinion is a bit too big for an RB26 used for street and if I DID want to go something like that, as DP motions towards - a GT40 based twin scroll setup would be my choice in a heartbeat. A GT3582R will definitely feel like you have a big turbo on the car, but not so much so that its a pain in the arse - they are right at the "fun" level, when they pass 4000rpm things become lots of fun. If you NEED more grunt down low, go a GT3582R or a T04Z and run an RB30 bottom end - the response and grunt from down low is insane. If you have a GT35R on an RB26 and aren't able to make it work on a track when there are people like Roy with a RWD RB20DET powered car with a "big" turbo on it eating GTRs around tight tracks, the engine/turbo set up is NOT your problem.

Its a Dynapack, one of the MOST accurate non-engine dynos. What ramp rate, correction method, dyno software type, car tranmission, tyre type, track condition etc etc etc are you assuming with your estimate?

Speedtech Motorsport do all the tuning on my car, have done great things with it and solved some real headaches with the car. Not that it will be of any use to you guys, they are in NZ - but nonetheless haha. They also tune the quickest/most powerful GTR in the world

Eek is it just me or does that Billet turbo have a very unforgiving surge line?

Sounds about consistant with the few I've seen do. A GT35R on an equivalent 2.6 seems to get 1bar by 4000rpm and 25psi around 4500rpmish - so everything seems to happen nearly 500rpm earlier on the GT35R.

Yes it is, the core is the same tech as the GT35R but the wheels are pretty much the same as an old T67. Yuck things, though work really well on 3litres - probably as much as anything as by 3litres you are getting to the point that anything which isn't completely stupid will work well.

Cheers - it was rather effortless lol, made it seem so cheap. They were 26x11.5x16s, not what I would have gone for width or type wise (already solid on the MT ET Street Radials) but someone called me that week and said he wasn't going to be racing and would like to see how mine would go with them - offer I couldn't refuse. I put them on R32 GTR rims.