Rolls

Yeah I am only going by what Ive been told. Often it does what you said, just kills the top end power and the curve still looks smooth.

In that case I suspect air leak, get a smoke test done at a workshop, and get them to check all error codes with a consult cable.

that is also in mmHg afaik

The gauge isn't in psi, it is in mm of mercury. What does it read in that? If it is 7x10mmHg it is 14psi which absolutely explains the misfire.

Go see a workshop, or search the forums.

o2 sensor has nothing to do with the on load fueling only around town. It is possible it is the cause of poor fuel economy though. Get a consult cable and find out what sensors have failed. Actually an air leak will make the car run rich hence rich misfire, it will also cause bad fuel economy.

There you go chances are it is running more boost than stock, eg R&R what number does it hit on the stock gauge?

no exhaust? pod etc? Mines ECU? Wrong spark plugs? Wrong spark plug gap?

Read my post. The coilpacks are fine, your car is running a stock tune and hitting R&R, this coupled with bad spark causes a misfire, sometimes new coils make the spark strong enough it "Fixes" it, but often it does not.

Sometimes see weird dips at the top end that get worse and worse

Why would you buy a remap for a different car? Could get a nistune fitted, tuned and installed for only ~$700 Would transform the car, surely it is a bit doughy down low with it running ~10% richer?

7psi on stock turbo doesn't = 7psi on this turbo which is why it feels so much better. it is pumping a lot more air. found the same thing with my gcg highflow, tiny bit of lag but massive increase in midrange torque made it almost feel more responsive!

A truck engine isn't a skyline engine. Totally different rev range, flow rate, pressure ratio blah blah. Read the dyno thread, see what worked for other people and duplicate it. Garret gt3076 is good for 300kw ish which imo for a 2.5L would be the max you'd want before the lag starts to get serious. You can do that on a stock motor, or a built motor with cast pistons if it is tuned correctly. If you want to build a motor just buy a full rb30 from rips, do it once do it properly, 3L and it will probably cost almost what you'd pay to rebuild yours a few times after the first time it grenades because the builder wasn't experienced.

Recommend reading the dyno thread and seeing what similar people have used to get their results. Remember your 500hp is generally less than ours, also not sure if you guys measure at wheels or translate to at the flywheel, but take that into account.

its more because it isnt worth their time there is no markup from selling an exhaust to you.

http://www.skylinesaustralia.com/forums/topic/261613-hypergear-hiflow-service-continued/

Some of the nuts are a bit of a prick on the dump pipe, only get half a turn on a spanner there.

post this in the hypergear thread

What is SAE J607, an older standard?

500 US hp could be done on a stock motor if you wanted to.

I leave mine off, but if they are brand new then who cares, will last forever.

It is a rich misfire from running more boost on a stock tune. Turn the boost back to stock and it will stop doing it, if you have an exhaust, fmic etc then you need a remap nothing else will fix it. If the coils are on their way out replacing them can fix it, but often you need to lean out the mixture as well, it can drop to 9:1 on a stock tune if you run ~12psi. At least that was as low as the wideband went.

It doesn't but there are a variety of sandwich plates available for ~30-40 that have two spots, one for oil pressure and one for oil temp.

oil pressure/temp/water temp gauge is a very good investment imo, will make you aware of problems before it is too late. what sandwich plate are you looking at using?

Good news about the oil test, that must be a relief! Could it have just been from when you say changed the oil filter? Some usually splashes out then.