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Wgnc34 Holes In Fuel Maps?


lilcrash
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I'm starting to wonder if it is normal for there to be holes in my fuel maps where my car will lose power then pick up again after a few hundred rpm. At first I thought it may have been the cams but not really sure.

Thanks for any info

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damn straight there are. stageas standard ecu is very intolerant of changes like more boost, zorst etc and starts to pull timing out of the tune and dump extra fuel in much sooner than the ecu in the skyline (same motor, different tune).

what mods, if any, have you done?

assuming that is the problem you should add something like HKS fuel cut defender or SAFC. Or if you have plans for future mods consider an aftermarket ecu.

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I've got k&n panel filter, 3" just jap dump, hks high power cat back, empty cat case, just jap stealth intercooler, splitfires and boost turned as high as the restrictors will allow. I was considering mayb a nistune but am considering haltech or power fc now.

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shit i wish i read this thread before i went off andbought new coilpacks. my car is doing the exact same thing. btw nice bit of work to ya car sounds like it will be fun once the faults are ironed out.

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I've got k&n panel filter, 3" just jap dump, hks high power cat back, empty cat case, just jap stealth intercooler, splitfires and boost turned as high as the restrictors will allow. I was considering mayb a nistune but am considering haltech or power fc now.

That'll do it, probably R&R kicking in. I've got pretty similar mods and am only running 11psi and have a sitc and safc and still have issues with r&r some times but its better than it used to be. Will get around to an aftermarket ecu one of these days. I've got a couple of mates with R33's and we've all got very similar mods running same sort of boost etc... and their cars seem (well do actually according to dyno sheets) have more power and are more responsive going by a seat of the pants drive than my Stagea and netither of them have safc's or sitc's. The power difference isn't huge but its noticable espically with the extra weight in stageas. I don't know if its different factory maps, different cams (although I can't see why Nissan would use different cams) or what but its quite annoying.

Edited by Mr_RS4
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QUOTE (lilcrash @ 23 Sep 2009, 10:51 PM)

I've got k&n panel filter, 3" just jap dump, hks high power cat back, empty cat case, just jap stealth intercooler, splitfires and boost turned as high as the restrictors will allow. I was considering mayb a nistune but am considering haltech or power fc now.

I have almost identical mods in my 98 series 1 with the series 2 rb25det (r34 CAS etc.) and my car hits R & R any time it gets past 9.1 psi. Before I installed the JJR stealth cooler I never hit R & R, even when it hit 10 -11 psi. I guess the increase in airflow (?) from the install of a bigger cooler tipped the a/f ratios over the edge. I think if I had a series 2 I would definately go the nistune for price point, but considering I have the pleasure of owning a series 1 I am thinking of getting an emanage ultimate. I was originally going to go the safc/sitc route, but at ~ $320 for an sitc and ~$250 for an safc, I might as well pay $675 for the emanage ultimate and get something that is scalable over 200awKw :)

harts.

Edited by stageaharts
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That'll do it, probably R&R kicking in. I've got pretty similar mods and am only running 11psi and have a sitc and safc and still have issues with r&r some times but its better than it used to be. Will get around to an aftermarket ecu one of these days. I've got a couple of mates with R33's and we've all got very similar mods running same sort of boost etc... and their cars seem (well do actually according to dyno sheets) have more power and are more responsive going by a seat of the pants drive than my Stagea and netither of them have safc's or sitc's. The power difference isn't huge but its noticable espically with the extra weight in stageas. I don't know if its different factory maps, different cams (although I can't see why Nissan would use different cams) or what but its quite annoying.

As for engine mods mines got:

Splitfires

.8mm Gapped plugs

FMIC

Pod in box with reinforced intake bike

3"front dump to gutted cat to 3 1/4 " cat back

12 psi on ebc

SAFC II

SITC

Before the SAFC and SITC it had a horrible looking power curve on the dyno. After they were in a tuned it was alot better. I have NEVER (TOUCH WOOD) had any R & R issues on my car (97 S1 RS4V). It will happily run 12 psi day in day out.

As for the 33 feeling like the go harder once their rolling ect yes i agree but nothing rwd beats the launch of a tuned stag if you know what your doing ;)

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Yer it's a series 2. I would happily have a go at the Vipec/link if anyone wants to supply one as a reasonable deal/research development. Nistune is looking like a good possibilty. Has much gone wrong with them? And is there an awd dyno/nistune tuner in south east Qld.

As for the series 2 r33 chat. A guy at work has a claimed 400hp 11second r33 and I'm pretty sure it's only the gearbox that makes them faster, on diffrent occasions His 3rd and 4th pull harder but my 5th pulls harder and 1st and 2nd are about even.

And my car only rarely hits 10psi

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I'm starting to wonder if it is normal for there to be holes in my fuel maps where my car will lose power then pick up again after a few hundred rpm. At first I thought it may have been the cams but not really sure.

Thanks for any info

Try Toshi perhaps? http://www.skylinesaustralia.com/forums/Po...ad-t210097.html

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is it mainley between 4500 rpm and 6000 it feels flat as shit ?

mine does . it has fmic and exhaust and less boost than standard and its still does it

someone posted the timing figures for a rb25det ecu with more air flow . cant be bothered finding it bit it was like 17 btdc up to 4500 , chopped it back to 6 btdc between 4500 and 6000 then back up to 17 btdc after 6000 . all figures very VERY vague ish but yeah thats the main problem

some days mine has good days and goes hard and some days its a waste of time . my car only gets driven like once a month tho .

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Yeah mine has good and bad days too. Sometimesit can just be a good few minutes. And yer it starts to lose power from about 4500 til about 5200 then it pics up again. Originally I was considering clutch as it only started when I fitted splitfires. Mayb it's just the splitfires. There isn't really any info saying they will definately improve your performance.

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well my car has hardly been touched just a pod, iridium plugs, valve blocked off and a boost controler and im having the same problem about 4500 to 5500 rpm it dies in the ass and gets back strait after. i think it mmust have somethin to do with the air fuel mix when thers less air restriction. did it start with anyone else as soon as they went from standard air box to something else?

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My understanding is that even stock RB25DET's have a flat spot in the a/f ratios in the mid range, the suggested bang for buck fix for this is the HKS FCD (Fuel cut defencer i think) if you are keeping the car relatively stock, i.e: pod and boost control. If you have more serious mods, particularly with the Stagea as the ecu tune is different to a skyline (don't quote me :banana:), such as larger intercooler and full zorst, then the ecu daughterboard (Nistune - S2 only, unless you want to piggy back another nistunable nissan ecu to your stock ecu... apparently quite involved.) or piggyback/ecu upgrade (Emanage, vipec etc.) and full dyno tune is the way to go.

Incidentally, I enquired about tunes today. Apparently the emanage ultimate is best for low to mid level tunes to around 240awkw, and the vipec is appropriate for a mid to high spec tunes (Obviously the vipec would also work well in a low spec tune, but if you didn't plan to go further than the mild tune it could be considered overkill.). The reason for this being the greater control and tuning resolution within the various maps themselves, apparently the vipec is very easy to tune and the resultant curves come out very 'smooth'. FYI the costs to install and tune the emanage ultimate (with PnP loom) were $450, whereas the vipec (No PnP loom, so a little extra cost is included in the $900 for fabricating a loom here too) was $900, perhaps indicative or the increased levels of tuneability involved in the vipec (More cost = more time 'hopefully' = more comprehensive tuning?).

harts.

Edited by stageaharts
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Yeah the FCD sorted my problems out, straight back to a nice even curve. that was front mount, zorst and 14psi boost.

If you want more a remap (nistune, yoshi, whoever) or emanage or hks fconv or unichip or any other piggyback would be the choice assuming its auto.

If its manual or you're not too worried about the longevity of the auto, any other ecu for rb25 can be used - powerfc, link, motec, vipec, haltec, microtech, autronic etc etc etc. Not too sure why people are happy to put vipec on mild tune cars (unless there is a good salesperson somewhere) as they are expensive to buy and install compared to say powerfc, and do not have the shift logic built in for autos so they are as bad as every other ecu.

has anyone ever tried the minor rewiring requiring and then running a stock r34 skyline ecu? I think it might be a good option for mild tune cars (up to say 200kw)

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The Nistune is not equivalent to the Jaycar DFA. The Jaycar DFA alters the airfuel ratios in the same way that the Apexi SAFC does. But the Nistune is a chip which sits inside the stock ecu and enables most of the important parameters to be adjusted - airfuel ratios, timing, rev limits, max speed (gets rid of the 180km/hr limit) etc - so for less than the price of a DFA and SITC it does more. However it is not available for the S1 and I suspect will not be for some time to come.

Re Duncan's suggestion of the S2 ecu in a S1 - by the time my tuner had finished piggybacking an R32 ecu on my S1 he too was wondering whether it would have been easier to get a s2 loom and ecu. I look forward to seeing someone try it!

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