Legionnaire

But flange orientation on the dump pipe seems to be made for a stock manifold

Not necessarily so. The CPU itself may be the same/similar, but its peripheral devices can be very different - it's an ECU architecture thing. E.g. RB26 ECU may incorporate multiplexing/decoding logic you were talking about. Sure, it is all speculation only. The best way to do it is to open ECU case and take a look what's in there. And assembly code would be handy also. But I seriously think they are all sequential, otherwise they would use crank sync trigger instead of CAS. By the way 16-bit processors are seriously faster than 8-bit in this particular case because all AFM values and load calculations use 16-bit arithmetic.

Neo motors use 16-bit processor, different family and higher performance. R34's use Mitsubishi 7700 processors, earlier Skyline ECUs use some kind of Motorola 8-bit clone manufactured by JECS, if I'm not mistaken. EDIT: I mean I'm agreeing with you I'm just explaining why full seq. mode is easier for later ECUs

Multiplexing can be a bit tricky in real-time applications like engine management. Requires some cleverly arranged synchronization. On the other hand, it depends on how exactly CAS/load-calc-output data flow is implemented. By the way I'm pretty sure I've read somewhere that R32 RB26 uses fully sequential management.

Turbo/manifold nuts probably got loose - it happens from time to time. If that's the case, tightening them will fix the problem, but check it asap, or the gasket will be ruined by hot gasses and you'll have to take off the turbo. Good thing is that it's not too hard to check/fix it yourself though - remove turbo heat shield and you'll see top two nuts right away. Bottom two are a bit more tricky to get to.

Siemens Deka IV injectors, 650cc or 860cc long ones, wide spray 650cc's have been working with Nistune on a neo motor with spaced out factory fuel rail for more than 1 year, no problems encountered. 480cc Nismo ones, purple - obviously work flawlessly and are drop-in. Deatschwerks (or whatever is their name) make highflows for neo/VQ35 engines, drop-in replacement, no first hand experience. InjectorDynamics make Bosch highflows in 725, 1000, 1600, 2000 cubic cm sizes - haven't tried these, but very keen to. Apparently they are nearly drop-in also. Plenty of possibilities, just search.

A bunch of programmers here haha. Not a lot of additional code would be required to implement fully sequential injection/ignition. You basically just need slightly more sophisticated CAS decoder subroutine and cylinder counter and assign calculated outputs to different output ports based on that counter (using it as either input variable or index on inj/ign subroutine call). It's just one more routine and a couple of additional RAM values. Those old CPU's are not very fast, but fast enough to handle engine management (some of early factory ECU's have hardware cap of 8000 rpm - been tested by Nistune developers, don't remember if RB20 is one of them). The only reason for not using fully sequential management I can think of is CPU may not have enough output ports.

Needs to be analyzed vs. valve head diameters (particularly exhaust), lobe separation angle, and some other parameters. Also solid lifters in Neo head have to have some clearance betw. lobe and tappet, so subtract that from cam lift figure.

803712-5001 is p/n of the turbo. Not sure what the other number means.

OK, thanks, I'll see if I can find them in Nistune ROM database.

Yeah, well, you see those small can actuators were giving troubles to the owners - wouldn't hold boost, etc. Large can actuator is only available in 18 psi spec, but is better in keeping WG flapper shut. Added: You should possibly do a lil bit of search about "big can", one of the results of that search would be this thread

Yep, that's why i'm keen to see the factory map of a vehicle that came BOVless, just like you. What cars were like that again? I never knew there were any

AFAIK ER34 also has closed throttle maps, but suffers badly from non-recirculated BOV. As do some other cars with CT maps.

Some girl back in 2002 could do that. Nowadays girls strip only when they hear whining of a straight cut gearbox

Apparently some BOV users accept this fact.

Hey Mick_o, what rear housing have you got? And can you please take and post a pic of that small plate with turbo part number? And that doesn't look like big can WG actuator.

Got any p/n's for ECU that came with bovless vehicles? I can check maps in Nistune and post 'em here.

Interesting bit of info nevertheless, thank you.

What is this, a random phrase generator? Not every set of put together randomly picked car related words makes sense.

Actually I have a lot to say about this, but it would be seriously OT here + I'm a bit lazy ATM and don't feel like typing everything I have to say. I'm not saying anything about valve events. I agree with you, valve events and valve timing play major part in the equation. Pressure and vacuum waves that travel through intake and exhaust tracts depend on LOTS of parameters - temperature, RPM, port geometry, etc. Usually we have some of that parameters fixed - say, port and exhaust runner cross-section - that's why variable valve event systems, like vanos and variocam, are so beneficial. Ultimately of course we want infinitely variable valvetrain - with independently controllable opening and closing points and lifts. There are some very interesting experiments and studies about this, done by Audi and Fiat, I hope to see the results of those on production engines soon. For the time being though we have to deal with much less flexibility. Generally, we have 3 problems with fixed cam profiles: exhaust reversion, intake reversion and overscavenging. With the second, we have to carefully choose cam geometry and some sort of VVT is desirable. The exhaust scavenger virtually eliminates the first problem, but makes the third one worse. Whether advantages of the former oveweight the drawbacks of the latter is to be tested. The whole superscanvenger idea may benefit from relocation of the valves in the chamber and its reshaping. An interesting thing to investigate would be power expenditure of the engine throughout non-power strokes for superscavenged vs. exhaust-tuned n/a engine. It obviously happens with either system - it does not matter how exactly exhaust vacuum is created, it creates overscavenging and wastes fuel unless correct exhaust valve closing point is utilised. And that point is not the same for various loads and engine speeds. And I never said he was using some imaginary negative pressure. If you set a zero to be at 1 atmosphere, then the minimum pressure will be at -1. The point of that statement was that pressure can not be lower than vacuum, i.e. there exists a lower limit for pressure. I was using absolute pressure in my post, hence no negative pressures. Good to know, thank you. In what case the flow will be greater? I see that you're not disagreeing with me, admit my statements to be not 100% scientifically correct and appreciate your input with terminolody cleaninig. I was trying to express my ideas in a simple way, without maths and physics, as not everyone is into reading phormulas on an internet forum, and was trying to avoid over-complication of the tread with details - there are books, lots of them, and not thin books at that, that discribe different aspects of the subject.

That's cool. Cheap too. 140 family pad? Been drooling over Alcon XR6 calipers for some time. However I'd think fat calipers like this require some pretty heroic wheel offsets.

Nobody uses cams with zero overlap on n/a engines. So exhaust charger is n/a on 0 overlap n/a engine. But even if we are to use 0 overlap engine, vacuum in chamber prior to intake event wouldn't make cylinder filling good, because it's gas we're dealing with here, so when your engine opens its intake valves, gas just loses density, it won't "rush in". On n/a engines with some overlap, vacuum does not do the major part of cylinder filling. Gas momentum does. This momentum is created because some mass of gas gets moving - it moves because of pressure differential betw. chamber full of hot burnt gasses and atmosphere. You basically suggest to lower the past-valve pressure below atmospheric, make pressure differential greater and thus increase gas momenum. Good thinking, but it comes with the penalty. On a well-engineered exhaust manifolds exhaust events are arranged in such a way that when some cylinder opens its valves and commenses exhaust stroke, there is already vacuum in the manifold - it was created by exhaust stroke of the previous cylinder and consumes no engine power. Your idea is the same in that it lowers exh. manifold pressure too - but unlike "extractors" it uses engine power. By the way, there is no need to because it significanlty reduces engine fuel efficiency, and SFC rises. The whole idea is not worth the hassle IMO, because of 1 fundamental reason. You can not drop pressure below vacuum, i.e. there is no such thing as negative pressure. You're trying to increase pressure differential across the engine. In the best possible scenario there will be 1-0 pressure diff - atmosperic at the intake and 0 past the engine, and density of air trapped in chamber will be somewhere in between, i.e. below atmosperic. On the other hand you can make the same pressure differential by adding 1 bar of boost to intake side. Same diff, this time 2-1 though, and density of air again will be somewhere in between, but now between 2 and 1, above atmosperic. Bonus - more airmass - bigger bang! And another bonus - boost pressure does not have to be 1 bar - it can be 2, 3, sky is the limit. So with n/a engine you should just add a supercharger. And some more about this. Engine consumes air by volume, but makes power based on air mass - that's why VE is not all that important on supercharged engines. To be more precise, on SC engines VE is meaningless without pressure and density ratios. By pressurising air you make is denser - more mass per volume. By sucking air you make it less dense - less mass per volume. While you may observe some slightly increased VE, your actual cyllinder filling may drop. So in reality you should just use supercharger instead of "superscavenger" (or supersucker?) But it's very nice to see you defending your idea like that, even it's not the best idea. Discussions like this one make people want to think and learn, and it's one of the better things an internet forum can do, so please, by all means keep posts coming. Maybe it's because most people here have cars with turbos that do exacly that - pump hot gas full of carbon? Why, don't be so negative, it's a good discussion. Much better that one more "whats the best turbo for my RB25" thread.

Agreed, hence my question about boost, timing and AFR in .63 achievable without detonation.

Whoa, did you really run it that lean of AF meter was a bit off? I understand, meth injection and all.. but 12.3-12.5 AFR - it's a whole 0.5-1.5 point leaner than most setups I've seen. How much boost/timing and what AFRs did you setup tolerate without WMI though?

Rear brakes on many cars have rotors 28mm thick, I reckon that's the reason for 18mm thick pads. I don't think 18mm pads can be used with 30mm rotor, they may be 1mm too thick. But with the price and availability difference like mentioned above - $190 for common and easy to find 18mm pads vs. $250+ for a rare 16mm set I would not hesitate to grind off 1mm of friction material from each pad end enjoy the ride