GTSBoy

I would suggest it's a US$5000000 R&D exercise to come up with a workable design for retro to the RB26. If HKS make it work, it will cost about the same to buy it from them!

I think you'd need to go camless Koenigsegg style valve actuation. So you can pop the valve open when you want it, rather than just move the whole normal valve event forward and backward wrt the normal lobe centre. It really is last gasp stuff though, because the petrol engine is going to stop making sense sometime real soon.

Yeah, I rubbished the idea last time the HKS project for this was mentioned (a couple of months ago). Not so much because it is a bad idea. Just because there seems to be far too much other crap beyond just a "retrofit sparkplug" required to make an old engine** work this way. **Where "old engine" was specifically an RB26. But really this has to be true for almost everything.

Use a 10mm hole punch & hammer?

Yes, this is aimed at using the VQ ECU and most of the VQ engine loom to go with it, but mashing it together with what you need out of the R34 engine and body looms to make it all work together.

No. Think more along the lines of laying the new VQ harness down on the floor, taking off all the insulation, stripping out all the wires in it that will not be needed in the R34, then working out how to put back in all the wires needed to work up against the R34 body harness (ie, dash, fuel pump, ABS signals, etc etc etc). See the Skid Factory video on YouTube on doing an engine transplant loom merge. There is no easy way. Only the lots of work way. And lots of understanding what the wires are for too.....

Which is when you then drop in the LS to suit the gear ratios.! /sneaky.

You will need to make a hybrid loom out of both the original car loom and the new engine loom. There is no easy way to do this. Quite doable. Just needs the work put in.

I think the answer is not to faff about with crappy old Nissan junk and put a TR6060 or something similar in.

Usually the gauge/sender. The correct approach here is to hook up a mech gauge and look at that instead. Then you will see what the actual pressure is and can decide if it's the electronics or the engine.

The rom packs are all available on the Nistune site.....stock maps in all of them.

I'd put a dollar on a dead output transistor in the ECU.

Did you clear the original code? Won't go away immediately.

I thought the intent of the thread was "optimisaton" anyway.

Yeah, but apropos of nothing this thread was still a huge WTF. Now it has more than nothing.

Yes, apropos of nothing this post is an huge WTF.

Do we know that it is a Blitz? OP just said "return flow".

17 psi at lower revs (and hence power output) = less air flow than 17 psi at higher revs (and hence power output). Pressure drop goes up with the square of flow rate.

This caused by this It's a simple fix. And then add more boost.

No. It is not that simple. What pressure difference between the plenum and the combustion chamber are you using to drive that flow? 100 kPa? 200 kPa? 300 kPa? 400 kPa? 500 kPa? There are people running that sort of boost on spark ignition engines. Each one of those larger numbers will mean more flow through the valve. It is not as simple as you seem to think it is. It's not even that simple in an NA engine where most people assume that you can only have almost exactly 100k kPa pressure drop across the valve, because there are many things you can do to get much better volumetric efficiency at certain points in the rev range. It is certainly even possible to get >100% VE on a stock head with the right cams and some intake tuning. Boost is the great ruiner of your theory. Not enough flow? Just add more boost.

What was "true" for Jap tuners who couldn't deal with the ITBs in the 90s was never really true at all. And what is that number? What boost are you chucking at the head? Air flow keeps going up with more boost. The limits turn up elsewhere (mechanical limits in the bottom end, detonation limits from the fuel, etc etc).

To be fair, this is a bit of a nonsense because if you're changing cams and therefore able to consider valve springs, then you can add enough spring to overcome any float issues that might be caused by high boost levels and you can run as much boost as the rest of the engine can handle. So, if you have tough enough rods, pistons and oiling, ability to run to very high revs (from the cams and springs) and sufficient fuel quality to handle the boost, you can just keep cramming more boost in and making more power. If it were an NA engine then the question might be more meaningful. But the native flow capability of the head is not really the limiting factor until you have gone all the way out into rocket science territory with other parts of the engine.

Or, you could just, you know, call XForce and ask them? Otherwise, in the absence of off-the-shelf systems, you can just buy some XForce (or whatever brand takes your fancy) mufflers and get your local exhaust shop to make something from scratch.

No, I didn't mean stock. I meant if you put rally suspension on them. Perfectly possible on an STi. Perfectly stupid on a Skyline.

To be fair though, that's mostly because the Toyota twin system is actual aids with all that back to back sequential bullshit. There are few options to improve it and many things to not want to keep. By contrast, at least the Nissan system uses 2 actual identical looking and reasonably normally specced turbos. So there are options and therefore reasons to allow the inertia (of staying twin) to prevent the tear-it-up-and-start-again approach from being the first option.