govich

He's right. Do it with maths. An RB25 making 670Nm peak in the midrange is going to drop off a bit towards redline, and will still be making over 550Nm at 6500rpm, given good flow capacity. 550Nm at 6500rpm gives 375kW at the flywheel. Your reading was 213 wheel kW, so make your own conclusions. I've been conservative..

Well they make 200 wheel kW peak at around 6500rpm, which, if you call it 240kW at the flywheel, corresponds to just over 350Nm when it's running out of puff, so is it hard to imagine that torque would peak at around 400Nm in the midrange?

You can get a rough idea by estimating engine power from a dyno readout around the midrange (with the stock turbo). Using my graph with 0.7bar on the stock turbo, at around 3800rpm it's making 125rwkW which we'll call 160 engine kW - corresponds to 400Nm of torque. Which sounds about right for peak, maybe a tiny bit enthusiastic.

24 bar vacuum would be interesting

High, I love this thread. (where's that cat pic??) Geez guys, get serious, we're not kidding around here John: add boost juice

http://www.skylinesaustralia.com/forums/Vo...70#entry3377470 Enjoy!

Yep, obviously no comparison between them, the GTR was Nissan's idea of a proper performance car while the GTS turbo was a comparatively mild stepping stone from the family cars in the rest of the range. The GTS does have the advantage of lighter weight (~200kg) but the GTR is better to the point where you don't think about it because everything else is that superior in performance terms. If you're after performance there's no question really, even coming from a modified GTS.

I'll offer $200 (pickup)

To me it sounds like something (wiring, relay, etc) might be loose somewhere and is intermittently losing contact. Is it blowing any fuses? To be honest though, there's a lot of things it could be. You could try checking if there's any fuel pressure in the lines straight after it cuts out, to see if failure of the pump causes it to cut out from starvation.. These days whenever i read cut-out the first thing that jumps to mind is loose AFM contacts. Here is a thread on repairing the AFM. Intermittent problems where there are no real traces of the problem are probably the most annoying, so good luck.

Dry solder joints in the AFM are a fairly common problem. There's a thread around with instructions on opening it up and resoldering. Try this: http://www.skylinesaustralia.com/forums/Fi...-s-t113284.html

Stock injectors should handle that much power with the factory regulator, if not get a hold of an aftermarket fuel pressure regulator and make sure you've got a pump that'll flow enough. They shouldn't need much more pressure at 1 bar. A lot cheaper than new injectors (unless you can find s15 injectors cheaply). A walbro will be fine, just make sure you get the 'high pressure' version.

Nice. I guess it just shows how little we really know about nissan's ecu.. It'll be interesting to see the printouts

Are you sure the ECU is internally standard? I'm a bit skeptical because noone seems to have come across this before..

Fair enough. Perhaps it's got something to do with NVCS? The ECU could be programmed to limit the amount of airflow into the engine with the advanced timing on the inlet cam. NVCS is active until 4500rpm i believe. Purely speculating but it could make sense.. That or it maps timing vs airflow or similar and doesn't like going past whatever value.

Boost pressure and airflow are not necessarily directly related. There are a lot of other factors including the compressor size that will have a large impact on how much air will pass through the AFM. A smaller compressor will have lesser flow capability, all else constant, than a larger compressor. So assuming the AFM measures air flow, and Nissan's ECU is programmed to not like high flow values, the bigger turbo will create more problems. The ECU actively monitors the voltage output from the AFM throughout the operating range of the engine and uses it to ...well..run the engine. It doesn't guess how much fuel is needed to get programmed air fuel ratios.

You're playing with people's money. At 300 wheel kW you have to know what you're doing to keep the engine alive. This guy has written off 2 low powered cars, is not yet off his Ps and wants a RWD car with too much power. He will blow the engine up. And then he will come back whinging that you told him it was 'easy'. What is this supposed to mean?

It does make you inferior in understanding the stuff you would have been taking notes on. How don't you get this? Personally i'd be pretty nervous telling people their stock RB25 will handle 300 wheel kW easily.

Just make sure the in-tank wiring is well insulated and not exposed anywhere and you should be fine. It could be that the pump moves around a bit and any exposed bit of wire touches part of the tank. Although i do think this is unlikely. If it's not any of the wiring inside the tank i'd try running a new wire from the fuel pump relay to the positive terminal of the pump (i forget which terminal of the relay goes to fuel pump positive, check the diagram in the other thread, or just follow the wire colour). All you have to do is make sure you have the right wire, snip it close to both ends, run a new wire (doesn't have to go through the same physical path as the stock wiring) and see if it blows again. Next step would be fuse to the relay, then battery to fuse etc. Do NOT do this. Connect the two ends of a multimeter set to voltage ONLY, not an actual wire. If you connect a plain wire to the battery and there's a ground somewhere, things will get ugly.

So it's blowing the fuel pump fuse as soon as it's replaced? check the wiring to the fuel pump, it might be grounding on the tank or similar. Try this: get your multimeter, chuck it on V (MAKE SURE it's measuring voltage not current), put one end on your battery positive and the other on the positive wire to the fuel pump (with the ignition off). If it reads 12V or close, the wire is grounding somewhere. Do this after putting a new fuse in (with the keys out of the barrel). definitely DON'T try giving the pump a direct feed from the battery...i'm gonna edit that into the other post..

http://www.skylinesaustralia.com/forums/in...t&p=3382664

Standard ECU with e-manage ultimate. I suspect the shop that installed the e-manage cut some of the wires instead of splicing into them (should have done it myself, had no time). I was hoping there was something else in the circuits that could be the problem..

Hey guys, I've got a quick one, just got a hold of a GReddy Informeter which takes power from the consult connector under the dash (R33). It doesn't want to turn on so i've tested the plug and it's got no power, i can't get the ECU to flash the error codes either (by bridging the appropriate pins), which confirms it. Has anyone had this problem before? Are there any fuses in line with any of the circuits? Just hoping someone can save me some effort before i go off and test everything.. Thanks

Well i gave an example, the stock R33 GTS pump is noticeably bigger than the higher flowing walbro GSS342. Having worked at repco and seen a lot of the fuel pumps they retail for everyday cars, i have to say that a large number are about the same or slightly bigger than the walbro (and flow less - generalising here and not considering pressures - because NA falcodores and corollas don't need the flow). I'm sure Bosch could condense their pumps into smaller packaging if they tried, with the possibility of using electromagnets etc but that's a line of thinking i'm sure noone cares about it would also hike up cost..

Interesting that the stock GTR pump flows more than the walbro. This still doesn't change the fact that if you want to run sane turbos on a (street) RB25, the walbro will perform well. It will theoretically flow enough to max out 550cc/min injectors up to about 25psi boost pressure at 13.5V (from the first graph). I really don't understand why everyone feels compelled to have fuel pumps capable of flowing 200+lph at very high boost pressures (>30psi) in their RB25-powered whatever that will never see above 16-18psi (generalising to the majority of examples here, obviously there are extreme examples that need the flow). Maybe it's just all the engineering lectures (and experience) steering me towards picking something that suits the application rather than allows ridiculous safety margins. PS. I disagree with your physical size comment. There is more to an electric motor than "the size of the rotor" - number of windings, magnet strength (material density) etc. I would be willing to bet that there are fuel pumps around that are physically bigger than the walbro (as it is pretty damn small) with lesser flow capabilities. Even the stock R33 GTS25t pump is noticeably bigger.

I'm not talking about the non-HP pump. I'm not even sure why that pump comes up in discussions, since it clearly was not made for turbo cars, and is marketed as being for relatively low-pressure NA applications. No-one should be putting one into a turbo skyline. UAS in sydney sell the HP version for $240. Have you actually installed one of these? Sure the nismo is easier to install since you don't have to actually do anything, but I fitted the walbro myself and it was nowhere near the headache you're suggesting. It's a matter of cutting the bottom plate off the stock bracket (normal wire cutters will do it), putting 2 clamps on to hold the walbro and using 2 crimp connectors to connect the wires. I'm not exaggerating how easy it was. Also, my walbro sits lower in the tank than the stock pump. Why do you say the walbro is lesser quality? The nismo is expensive so it must be made of unobtanium? Nismo are a bit of a jack of all trades, i'd say a manufacturer specialising in fuel pump/fuel delivery systems would have the know-how to build the highest quality pump.