Jump to content
SAU Community

Recommended Posts

why?

My Splitfire coils are less than a year old and I have had two die on me. Same thing, would mis like crazy when on full boost and up in the revs. put two stockers in and it runs perfect. easiest way to check is just put in stock ones, process of elimination!

My Splitfire coils are less than a year old and I have had two die on me. Same thing, would mis like crazy when on full boost and up in the revs. put two stockers in and it runs perfect. easiest way to check is just put in stock ones, process of elimination!

No I was asking why gap the plugs down? It's a stupid idea that people have got into their heads that it is MANDATORY to buy 0.8mm gapped plugs. Nonsense!. If you only have mild mods up to 250rwkw then you start at 1.1mm and work your way down slowly. If you need to run 0.6mm gap then there is something else wrong. I have cars running 400+ kw with more than 0.8mm gap and no issues.

I have had people come to me before with missfires, frig around with the coil packs, checking fuel pressure, replacing filters, plugs, other coil packs for hours and hours and find out the CAS has been wound forward. Causes the same issue.

Set your base timing first, then do the other checks.

The tuner says of there is something wrong with the CAS, during the tuning it would already pick it up. It should cause the timing to go all over the place during the tuning process. But since it did not happen he eliminates the problem CAS first.

what do you call high boost, could still be blowing out! even with splittfires I have to run a .6 gap to run any higher than 17 psi

Well that clearly shows you have a problem elsewhere… You know that ye?

I was 24psi, 350rwkw, stock RB25 coils - 15 years old. They were very good condition obviously - 0.8mm no problems.

I wouldn’t call 24psi "high" when I know of many over 30psi using either stockers or splitfires and not having to run a filthy 0.6mm gap.

So if on near new coils you're having to go down to 0.6mm you have other issues to look at.

Could be ignitor (depending on series), the loom, connections, plugs any anything else inbetween

So in saying that

No I was asking why gap the plugs down? It's a stupid idea that people have got into their heads that it is MANDATORY to buy 0.8mm gapped plugs. Nonsense!. If you only have mild mods up to 250rwkw then you start at 1.1mm and work your way down slowly. If you need to run 0.6mm gap then there is something else wrong. I have cars running 400+ kw with more than 0.8mm gap and no issues.

Here here. 400rwkw & 0.8mm = no problems in the world with SERIOUS boost, not some small mans 17psi :D

For less than 20psi you should have a very nice gap margin on PULP

Well that clearly shows you have a problem elsewhere… You know that ye?

I was 24psi, 350rwkw, stock RB25 coils - 15 years old. They were very good condition obviously - 0.8mm no problems.

I wouldn’t call 24psi "high" when I know of many over 30psi using either stockers or splitfires and not having to run a filthy 0.6mm gap.

So if on near new coils you're having to go down to 0.6mm you have other issues to look at.

Could be ignitor (depending on series), the loom, connections, plugs any anything else inbetween

So in saying that

Here here. 400rwkw & 0.8mm = no problems in the world with SERIOUS boost, not some small mans 17psi :D

For less than 20psi you should have a very nice gap margin on PULP

thanks nismoid you could be onto something, maybe it's my bad tuneing, maybe its not, since my car now runs 380 rwkw at 24 psi useing the same coils and same plugs! maybe it's more common a problem than you think!

That result honestly means nothing, unless of course you still need a gap of 0.6 to achieve it... in which case you still have a problem.

So indeed it is a common problem, a common problem in that people think 0.6 is acceptable (that is the problem).

Its hiding the fact there is something else in the setup letting the overall down.

fair enough, I was only offering an idea to try, I could possibly run a higher gap but i'm too lazy to try, it idles smooth, gets good economy, goes like stink and doesn't miss a beat, I have put on a larger turbo and havn't tried larger gap yet, maybe the inlet temps play a big part?

So indeed it is a common problem, a common problem in that people think 0.6 is acceptable (that is the problem).

Its hiding the fact there is something else in the setup letting the overall down.

I think I love you.

Probably not it, but ill ask anyway, what boost controller you running?

I had a similar issue on the dyno, car started sounding like it was missfiring anything over 18psi and couldnt work out why. Then i remembered that the Profec was set to a max boost cut of 18psi, anything over and it sounded like it was missfiring, turned it off and she was all sweet.

So it is 100% missfiring and not just sounding like it is?

Edited by PM-R33
mr benno is first in line i believe...

Yes, he broke the news to me tonight.....didn't even tell me to my face, bloody phone call.

He told me you are actually alright in person, I thought you were a flamin mongrel all these years :down:

Spark plugs an shit (just to keep it on topic)

Splitfires are shit these days, mine have done exactly the same, swapped them out for stockers and my intermittant miss magically disappeared. Although stockers still arnt good enough for higher boost so it's onto plan C...

Didn't the HKS Drag GTR use stockers?

No I was asking why gap the plugs down? It's a stupid idea that people have got into their heads that it is MANDATORY to buy 0.8mm gapped plugs. Nonsense!. If you only have mild mods up to 250rwkw then you start at 1.1mm and work your way down slowly. If you need to run 0.6mm gap then there is something else wrong. I have cars running 400+ kw with more than 0.8mm gap and no issues.

I have had people come to me before with missfires, frig around with the coil packs, checking fuel pressure, replacing filters, plugs, other coil packs for hours and hours and find out the CAS has been wound forward. Causes the same issue.

Set your base timing first, then do the other checks.

quick question in regards to base timing ...

my base timing is set to 17 degrees (R34 GTT) and I'm pretty sure that's not the factory base timing ... we only found out AFTER the ecu was remapped. The tuner said to leave it, it shouldn't be an issue ... but I have occasional misfires.

Could this be due to the base timing being set to 17 deg? I was told by the tuner if we change the base timing now, the remap tune would be useless and we'd have to do it again.

It all depends on how much timing correction he has put in on the tune.

Going back 2 degrees is not going to make a hell of a lot of difference to the power - although it can make 10hp difference in most cases. But where the timing is set too high, it can mean the difference between life and death for your engine. It's not a matter of whether 15 or 17 is right, it's a matter of it being correct everywhere.

I can't tell you whether your tune has been done correctly because 17 deg base timing is not exactly a bad thing, but check it out all the same, it may be causing your problem, it may not.

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


  • Similar Content

  • Latest Posts

    • My thing I'd be doing, is pulling it out, and just getting the tune cleaned up for now. Before that even happens, checking over everything, like vac hoses, fuel hoses, etc. No point dropping thousands on sensors if the moment you start it back up all the oil leaks out, or it has massive vacuum leaks etc.   But really, to know what to do, depends on what your use case is. Hard core track car? Throw most sensors available at it. Street car, I'd probably just run oil pressure, oil temps, water pressure, water temp, probably fuel pressure too. I don't know exactly what the Link can handle and do with those though. And if it's mainly just to cruise the streets, rather than mountain runs, you can probably skip most of the above if you've already got them in as gauges and warning lights.   PS, inb4 "sell it and buy a modern sportscar"
    • Keen to see the turbosmart data, to date I've only seen negative things in terms of response for them. Very small sample size though.     Hawkins is a big advocate in his videos of the larger rear housings. I managed to make similar power with a lower spec motor on the smaller .8 rear, keeping decentish spool.  The people he works with now are big power cars compared to mine though, mine really is setup to drive around and enjoy.  I don't have any back pressure monitoring though, so couldn't say if its good or bad on my car, just that it does what I want it to do.   Future I want a higher compression more cubes motor to give a bit more bottom end and hopefully the new g35-1150 gets me to the 850 rear comfortably.  But maybe I won't due to exhaust back pressure.
    • No, I refuse to buy their cheap ass crap! I do need to order a bunch of different nuts/bolts to refill my nut/bolt wall though. Maybe you could go for a walk through Bunnings for me? (Or send me some stuff from your work? )   I really struggle to work out how the US standardised to Metric in what the 70s or 80s, and yet, half a century later, there's been little done to actually bring it into fruition. It truly baffles me    On the whole Fastenal thing, I went reading their site (My god they sell a lot of varied stuff!), and it seems like it really depends what store you're near if you can walk in and just grab a few small things, or if that branch is primarily distribution with only a small window of "counter time" available (if at all). That definitely makes it harder, as move locations and it drastically changes your ability for success   For things like your M6x1.0, if you want to work on your own Skyline, and you also have a "home workshop" I'd recommend setting yourself up a small Nut/Bolt wall/section. It doesn't even need to be big at all. Most things depending on the diameter, will be a specific pitch, like the M6x1, M5x0.7 etc. Bigger bolts is mostly 1.5, except for a small number of things and that will come down to torque. From memory bolts for the brake calipers (and other things that need a lot of torque) will end up being a 1.25mm pitch. Save up a few dollars, and order a range of nuts/bolts. If you want to minimise cost a little, buy something like M6 x 40, and M6x70mm (1mm pitch) in both. In addition, buy yourself an M6x1mm thread chaser. That way you have long bolts that you can cut down to size, and then chase the threads out. Funnily enough, I find what I'd pay here for ordering 5 bolts, I can pay about 50% more and you'll get 100 of them.   If that doesn't quite work out due to space / ability to buy plenty up front, then each time you need some bolts, order 100 of what ever you're getting. Put them in clearly marked containers. Over a few years, you'll acquire plenty of different sizes, and will end up ordering less and less. And the cost for 100 bolts won't be much more than you paid for your 5 you needed to order anyway  Just takes a little planning ahead, by investigating what nuts/bolts you'll need, and ordering them before doing the job.     Edit: If it's also primarily for working on just the Skyline, for some reason my brain is screaming that at some point, either Nissan, Nismo, (Or possibly a third party) was selling a "kit" of every nut and bolt in a Skyline, purely for people restoring/rebuilding. It'd likely be quite expensive, but would give you every/any nut/bolt you need for stock/factory things. I'm not sure if it's still available, or even if it actually fully came to market, it's just something niggling in the back of my brain that you could look into further if that sort of thing interested you? (It might have been for the R32 GTR or something specifically too, and not just any Skyline)
    • 90lb/min @ 20psi is wonderful, not so much of a problem with the G35-1050's compressor efficiency (aside from how bad they roll back at higher pressure ratios).  The issue is more to do with the turbine's flow, which is why I'm not sold on going an even higher flowing compressor with the same turbine.  I'd say go back over Motive DVD's testing of the G35 1050 and Hawkins's comments regarding exhaust back pressure issues with it, I'd need to go back but I have in my head he went to the biggest hotside and ended up sacrificing a lot of spool (so it ended up behaving like a bigger turbo) and still had EMAP issues.  I've heard various other experiences along the lines of that. At this stage at least I rate all I've seen about Xonas (for transparency I've not used one directly, but I have spoke plenty with people who have) to have low exhaust restriction for the response they offer for any given setup - basically they allow the engine to breathe, which is good for the engine and makes making power a lot easier.  You arguably don't have to even push quite the same amount of airflow through an engine to make the same power if you don't have the bum plugged up with exhaust gas struggling to escape the engine due to an underflowing turbine.   In terms of reliability, to be fair I've had great luck with Garrett turbos as well - my GT3076R lasted forever, then I sold it and the next owner had no issues, then that car got sold and it was still going strong last I ever heard about it.  The trick is with the old GT-series turbos the compressors etc were no way near as efficient as what we have these days, it was almost hard to push them into severe overspeed situations without having a boost leak or something - and that is what often starts the failure situation.    In terms of your G35 I'm pretty sure you're running yours within sensible limits, something people with Xonas and Precision turbos aren't often so inclined to do.  The "compressor maps" are "Joe blogs ran 45psi through his 6466 so I can do the same" and built their setup to send it to the moon.  I've seen EMAP and compressor speed data where people have actually set that stuff up on Precisions and Xonas which have been run hard and the comp speed numbers are very very exciting at times - like I've seen 76mm Precisions run at rpm that you ideally shouldn't run a G35 1050 lol.   I know people who have run G-series Garretts hard and hard a failure, then replaced them with Pulsar turbos as a cheap "get it going" stop gap with the intent of doing a proper upgrade when THAT fails... and are still running the same thing.   Like anything, ymmv and it's not always to do with the quality or trustworthiness of said product. I've been provided with a bunch of compressor maps for Turbosmart turbos and will update my list based off that, they could prove to interesting reading and an interesting alternative as well.
    • Just cage it, call it a race car, and then fall in love with the chirp chirps through pit area!   Also, this is coming from someone with a completely locked diff...
×
×
  • Create New...