Dyno Graph

[TurboWood]

Hi Guys and girls,

I have a completely stock 97 R33 Gtst Series 2, it has 82000Km's on it. Had it on the Dyno the other week because i have had some fuel economy issue. Just though i would post up the graph and get any comments, thoughts, opinions.

Just though some of you guys might be curious.

Ps. i know there is a dyno section but i was after some comments so i though i would post it here.

Cheers,

Dan

[R31Nismoid]

It's quite lean for a stock ECU.

Rare to see one @ 12:1 around peak torque. I'd almost be inclined to say your fuel pump is perhaps on the way out.

Otherwise though it's not unsafe, and totally fine/to be expected in terms of result.

[TurboWood]

Thanks for the reply,

The tuner also mentioned that there was an issue with the o2 sensor as he said it was pumping in way to much fuel under certain loads (Sory cant remember where) around 30% more. The o2 sensor itself seemed to be in ok condidtion so he suspected a wiring issue or something along those lines for it to be misreading.

Other than that he seemed to be happy with it.

[GTScotT]

Agreed that it looks like a fairly normal graph for an average GTST, would get that pump changed though.

[tridentt150v]

Just get your fuel system flow checked first, it could be a filter instead?

[R31Nismoid]

Yeah could be anything in the fuel system

Just get the pressure checked, filter swapped and then have a look.

Might be nothing, but 12:1 is just a tad leaner than the stock ECU normally behaves so it might not even be a problem as every car and ECU does respond a bit different

[HEKT1K]

O2 sensor does zip when you under heavy loads mate, i'd say your AFR issues lie elsewhere (as previously mentioned)

[Dose Pipe Sutututu]

NisMoiddddddddd looks fine to me, I still had the wb O2 on my GTS-t when I returned her back to stock and noted the A/F. I played with the CAS +2/3 degrees and noticed it ran a tad leaner than usual on full load.

Economy, go replace your stock O2.

Who's the dyno operator? O2 is only for cruise when the plenum is -ve pressure. On load, O2 does nothing.

[R31Nismoid]

Ye it looks fine to me too dude. I never said it was bad.

Just a little leaner @ 4500-4800 than you'd expect. But by no means is it unsafe how it currently is and would be fine to use. Its perhaps just a sigh something might be needing attention. That is all.

[TurboWood]

Thanks for the feed back guys, dyno was done at unigroup.

First import, still learning about all of these things. didnt add this before but he seemed to think that the ecu was reading the o2 sensor wrong, it was pumping in fuel even though it was getting plenty. I know i keep brining o2 sensor up but he said it will more than likely be the issue behind the economy issues (i am struggleing to get to 300 city driving and even cruising on the highway i am bearly making 400km to a tank, that was on a good week).

I will also have a chat to him about the fuel pump now that you have bought it up, and i assume you say that purely bassed on it not pumping enough fuel through the system, hence running lean.

Apologies for lack of understanding but im still learning learn.

Regards,

Dan

[DVS JEZ]

he is right, the 02 sensor being faulty will have a big affect on fuel economy.

replace it then enjoy the economy,

the dyno graph doesn't show any part of the tune that uses the 02 sensor.

[tridentt150v]

The main thing is, it goes lean [but not engine destroying lean, just leaner than you want it to be] when you increase the revs. It is not lean until you get up in the range. This means that it passes enough fuel for down low but leans off up high = a lazy pump or a clogged filter.

[gotRICE?]

Ye it looks fine to me too dude. I never said it was bad.

Just a little leaner @ 4500-4800 than you'd expect. But by no means is it unsafe how it currently is and would be fine to use. Its perhaps just a sigh something might be needing attention. That is all.

Id agree with that. Its better to be safe than sorrry.. bad batch of fuel or a stupidly hot day perhaps? Is that that area of the stock ECU where it pulls a bit of timing too?