GTSBoy

Only have to change one "i" to a "u".

Oddly enough, although possibly because I dislike both the profile of R33s and nearly everything that Veilside have ever done........that looks bloody good.

I guess the other logical/correct engineering approach would be to have more than one compressor (parallel, series, whatever) and sophisticated control so that one of them is doing the work at low altitude and either both of them or just the other one doing the work at higher altitude. This is something that a twin-charge system could probably help with a lot. Use the blower to add some boost and air flow capacity back to the turbo only at higher elevations and use a properly mapped control valve to throttle it into and out of operation and de-clutch it completely at the lower elevations.

The correct engineering approach is to design it to make the power you need within sensible margins (or only just outside) in the worst case (at elevation in this case) and not actually push the turbo as hard as it could go in the other case. That is so long as you aren't happy to have the power fall off with elevation.

Well, if you're pulling the head off then you HAVE to replace the gasket. So you might as well put a decent MLS one in there. But be aware of the surface prep/finish requirements. Also, don't put a thicker HG in there if your aim is to reduce the compression. That's '90s thinking.

Don't change the head gasket unless you're aiming for serious power. Just put ARP studs in one at a time.

Gearbox input shaft is probably fairly firmly in the clutch. If there are no bolts still holding the gearbox to the engine, no earth straps, starter motor, etc, then it can only be the input shaft. You may need/want to release the gearbox crossmember and support the box on a trolley jack so you can change the angle of it to help it disengage.

Yet, you said, out loud to the hearing of all in this forum, that the idle speed is adjusted with the screw on the idle valve. That was after you had been told multiple times that the ECU was in control of it. Yup, and it will remain so whilst the voltage is being measured and reported by someone in whom we have no trust in their technical capability. I can tell you right now that I would not expect to measure a DC voltage on either terminal of the knock sensor. Perhaps all your buggerising around has broken something in your ECU. That would be a logical expectation on our behalf. This is news to us. In your previous post, did you not express no knowledge of how filters work? Wat? No. As posted above by Ben, THE ECU DOES NOT POWER THE KNOCK SENSOR. As I posted earlier, the knock sensor is a microphone and GENERATES the voltages that turn up on its terminals by the piezoelectric effect. You really should read what we post and then go look up that which you do not understand. No. No. No. No. There is no way that I can tell you how far arse-backwards you have that scheme. No, a signal can be carried with almost no current at all. If you use an input circuit on your receiver (the ECU in this case) that has massive impedance (let's say some megaohms) then all that happens is that the voltage applied to the input terminals is directly measurable at that point with almost no current flowing. This is the principle of measuring voltage. In this case however, I don't know the input impedance of the ECU's knock sensor terminals, so I will make no representation of what it is. I would, however, expect it to be very high. No. You are talking the difference between passive and active microphones. All that active powered microphones have is basically a method of increasing the signal level at the microphone itself. Almost all microphones are passive and they need to be plugged into an amplifier to turn their tiny signals into sufficiently high level to drive a speaker. Conventionally that is a chain of a mic pre-amp followed by a power amp, simply because the various different sorts of microphones generate different sized signals compared to line level audio signals and need different pre-amp treatment. Despite all that.....it is immaterial here. The ECU is not trying to play the knock noises into the cabin for you to hear. It is quite capable of listening for knock noises at the microphone signal level. There may well be a small pre-amp stage in the ECU to make the signal larger, but I wouldn't expect it. THERE IS NO POWER TO THE KNOCK SENSOR. No. No. No. As posted by Ben, again, the knock sensor is not a 5V sensor that simply changes its resistance with whatever it is measuring. It is not. Therefore your continued pushing of that line that your 2.4V means something shows that you have not understood what you have been told over and over again. Have a looooooooong look at the graphic posted by RICE again. Note the midpoint of the waveform is at ZERO volts. Zero. There should be no DC bias on the knock sensor. What have you done to your car? No. You are just bashing out meaningless terms now. No. They are not in code. They will be in hardware. No, I did not contradict myself. The ECU DOES NOT ADD TIMING TO THE BASE 15° to get you the mythical 30° that you claim your engine idles at. That is the point I have made, more than once, about your incorrect claim. The other things I have said about the ECU using timing to attempt to control idle speed AS A MATTER OF LAST RESORT are all true. I will not reiterate all that typing. You are doing my head in as it is. No. No. No. Take an early one, like an RB20. The wax pellet valve is a separate device, lodged under the inlet manifold. It is the AUXILIARY AIR VALVE and it is responsible for opening up a big air leak to give a cold start high idle. The idle control valve is on the back end of the plenum and is controlled by the ECU. Take a later one, like a NEO. The wax pellet valve is integrated into the IACV and does the same job as it does on the RB20. Open when cold, closed when warm. This is why the NEO has a coolant feed to the IACV on the back end of the plenum. It feeds cold or warm (or hot) water to the wax pellet to allow it to sense the engine temperature directly. The stepper motor controlled valve is still under the control of the ECU for normal idle control. I am pretty sure that Nissan will have abandoned such old fashioned shit by now and not be using wax pellet valves at all. They will do everything with the IACV, like every other manufacturer does. We can't comment on what you may have done to your car. That's because you have butchered the system. I believe the word you are looking for in all your usages so far is "respectfully". Not respectively, which has a completely different meaning. /thread, please mods.

No. Frequency is a property of an alternating voltage that is completely independent of the peak to peak voltage of the signal. Using DC voltmeter, you should see zero volts average. If you have a DC voltmeter that can respond very very very fast, then you may see it flicking back and forth from + to -, but this is hugely unlikely, and almost certainly not going to happen on any multimeter that you can afford. Audi signals are at far too high a frequency to see with an AC voltmeter. You need a CRO. If you have a CRO (or something that can sample as fast as a CRO, like the ECU that RICE would have logged his signal with) then you can see the waveform. Capacitors are high pass filters. They block low frequencies (The point at which they start "filtering" depends on the capacitance value). Chokes (inductors) are low pass filters. They block high frequencies, and again, the frequency at which they start filtering depends on the value of the inductance. You can assemble these together into circuits that will do gentle filter slopes of 6dB/octave, all the way to really aggressive slopes like 24 dB/octave, and you can combine a low pass and a high pass to either cut a notch out of a signal (allow everything above and below, but not in the notch to pass) or to create a bandpass filter (only allowing the signal between the lower and upper limits to pass through). You keep saying you are seeing the frequency "displayed". Are you using a frequency meter? If you are using a voltmeter, you are not reading frequency, as I have said previously. Absolutely sure. There is ONE sound that an RB makes when it pings. (OK, it actualy probably makes a few different sounds, but there's realy only going to be one that the ECU needs to look for). Nissan's engineers will not have wasted time trying to make the ECU able to learn what a new, different knock sound might be. They did not intend for anyone to be hacking the ECU and doing anything to it, or the engine. You can definitely trust me on that. No OEM engineer ever wants the buyer to be able to do that. (Ask me how I know....) No. Not it is not. The idle valve is in fact a stepper motor controlled variable orifice** that opens and closes at the ECU's direction to let more or less air flow to the engine to control the idle speed. The manual needle valve adjustment is actually not intended to be used except to set the absolute minimum amount of air that will flow to the engine when the stepper motor is completely closed. **There's actually a few different types across all the years of Nissan doing this stuff. But theyall work much the same in the end. And no, as I have said before, while the AFM signal may go up and down as total airflow varies around idle, the ECU does precisely NOTHING with that value, because it does not use it at idle. The idle map is essentially a 1-D map, unlike the main load vs. speed maps for running off idle. If the ECU can keep the O2 sensor working properly at idle, then the ECU will in fact use it to run the engine in closed loop mixture control at idle. You can see this by watching the O2 sensor voltage flip either side of 0.5V. If, however, the O2 sensor is cold, or old and slow, the ECU will instead just run the engine off the idle map without using the O2 sensor. It doesn't. If you have an air leak, or have passion fingered the manual idle adjustment, then the ECU will use delta control to try to bring the idle back down. It will retard timing to bring the engine speed down. As you can imagine, this is actually not a disireable state of affairs, it is desperation on the ECU's part. Low timing at idle is not good for anything, from exhaust temperatures, to emissions. I have personally seen my Neo's ECU run only 2-3° of TOTAL ADVANCE BTDC, when my IACV was filthy and stuck too far open. The ECU was able to get the idle down to ~700rpm, which was still above the 650rpm target value which is set in the ECU. And here's the best thing you didn't know. With Nistune, you can actually go in there and change that value. That is truly how you adjust the idle speed. Mine is now set to 600 rpm. If the idle is too low and the ECU can't get the IACV to bring it up, then it can and will add some advance to try to increase the engine speed. But it can't add anywhere near as much timing as it is able to remove, because running too much advance at idle is stupid. Low compression motors are easy to idle. They are the exact opposite of "lumpy". As to the limit of advance, see above, even though it has nothing to do with this part of your question. I'm afraid that, from what you have been saying, it was quite evident that you did not know much, if anything, about some fairly basic electrical/electronic concepts. So it really sounded like you needed basic instruction on how things like microphones work. As I have had to explain things like caps and chokes as filters, I remain convinced of that. You have in fact stated a number of "facts" about the ECU and the idle speed control systems that are in fact quite wrong. So don't try to squirm out from that. Beliefs play no part in this. OK. If you actually promise to understand what I have said, and you also promise to use the correct terminology. If I have misunderstood anything that you have written, then so has everybody else that has taken you on. The reason for that is not us.

I don't have FAST installed on my PC, and I don't have a suitable VIN to make it easy(er) to search. You could use FAST yourself. You could also do a directed google search on these forums because I am sure I have seen any number of threads about that pressure switch over the last 20 years.

Oh, FFS! A small piece of plastic inside the cylinder is less than no threat to the engine or the turbo. That is why I gave that perfectly sound advice. You cannot use epoxy to fix something that is running even 10 psi inside it, let alone the possibly hundreds of psi that you could expect in a hydraulic circuit. There is a crack in the plastic, there is oil on the crack. No glue is going to want to hold onto it properly anyway, let alone with that much force working against it.

Let's go back to basics again. The knock sensor is a microphone. It is picking up ALL the noise that the engine makes. OK, not all of it. Because it is a piezo sensor it won't be sensitive to low frequencies. As does any microphone, it generates an AC voltage representing the amplitude and frequency of the noises it is picking up. Hit it with a single pure tone and you will get a single sine wave at the same frequency as that tone. Make it quiet, then the max + & - voltages you will see will be not so far from zero volts. Make it loud and you will get higher + & - voltages out of it. Hit it with a broad spectrum noise made up of lots of different frequencies and and at different amplitudes and what you will see coming out of the knock sensor will be a complicated waveform with the higher frequencies causing the waveforms of the lower frequencies to be all muddied up, laid on top of each other, interfering because of being out of phase or in phase, etc etc. Somewhere in that messy waveform is the information the ECU is looking for. That info is either 1) There is a knock sound, or 2) There is no knock sound. The way the ECU finds it is to put that signal into the notch filter that I originally described quiet a number of posts ago, then after filtering out all the wrong frequency information, it passes it onto a discriminator circuit. Now, I don't know what the discriminator circuit in these ECUs actually is. It is very likely to be a Fourier Transform, which is relatively trivial to do in digital electronics, but these ECUs are quite old, so they may have used something more crude. Anyway, whatever it is, when it ses a waveform that looks like knock, it registers a knock. Get too many in a row and it will pull timing. Now, I would guess that the reason you see the voltage change when idling on E85, and keep in mind that if you are measuring it with a multimeter, you probably should not be seeing a steady DC voltage unless the knock sensor circuit is somehow being held above zero volts, is that engines actually do run more quietly on E85. It has a much softer burn rate than pure hydrocarbons do. The knock sensor will just be hearing less noise overall. It should also almost never hear any knock at all when under load because even when engines have too much advance on E85 they seldom make the same noises as when knocking on petrol. And, as I have said before, you ECU should not be trying to change the timing at idle. The idle map is a steady 15°, unless it cannot maintain the idle speed using the IACV alone. Any other variation in timing that you see is just jitter.

Download the R32 GTR service manual from your uncle Torrence. It is quite readily available. The whole ATESSA system is detailed from page CH-57 onwards. The black can is a pressure switch, as shown in this You can get the part number for it from google, or a Nissan FAST and you can buy them from Amayama, RHD Japan, et al. And don't use f**king epoxy to try to stick it together. It's a hydraulic system. The pressures inside are very large and will laugh hysterically at a patch of epoxy.

The voltage readings mean nothing useful. You would expect to see your ECU add precisely zero degrees beyond the baseline 15° that the engine actually idles at. There. That was both polite and correct.

For f**k's sake Slap. You cannot measure frequency with voltages. You just cannot. It is time for you to let the big boys carry on and go play with your pathetic ideas quietly by yourself. Almost all of those ideas have no place in the real world anymore, as we have no need to bandaid shitty solutions to problems that can be fixed by proper selection and adjustment of the correct equipment.

25 should be similar to 35.

No. Rice's pictured waveform is the AC audio signal produced by a SINGLE ping event (or a hammer strike if that's the way he generated the noise). You cannot make the measurements that you have with a simple voltmeter because it is the wrong tool and showing you numbers that have no meaning. Analogue tuning by signal bending is dead. It is not the 1990s any more.

On an RB25 Neo, there is only one code that involves a 7, which is 17. That's ABS/TCS fault. Wouldn't be TCS on a Stagea, so that would suggest ABS. But.....I can't see anything other than the 7 even flashes. For code 17, there should be 1x flash @ 0.6s duration, then a pause of a couple of seconds maybe, then 7 flashes at 0.3s. But yours is a VQ35, right? The fault codes are in 4 groups of flashes. So your video does not, in any way, conform to what is expected. Even "no fault" is 4 groups of ten flashes. Meaning 0000.

Essentially, yes. As to exactly which make&model of cat to use.....I'm not sure what the cool kids are running these days. MetalCat was cool for a while. I think it has been Venom more lately, but that could have changed.

Almost all dump pipes and cat backs assume the retention of a factory sized cat. Thought 1. 100 cell cats are useless as cats. Also not legal. You might as well have a punched out fake cat as waste money on a 100. Thought 2. 200 cell cats actually work. Not as well as a proper cat, but they actually do something. They are also not much more restrictive than a 100 cell cat. Thought 3. As you're only putting it on an RB20, you won't need to consider massive flow potential, so a 4" cat (rather than the more extreme 5" that people squeeze into RB25+ exhausts) will do the job. That's a 4" cat matrix with 3" or 3.5" flanges to suit your other exhaust parts. Thought 4. It is very common to have to buy a cat with no flanges and get them put on to make all this shit fit together.

Bride Lowmax copies with low rails. Doesn't matter exactly which Bride style - they are pretty much all available in Lowmax. JustJap on-line is a valid place to get them. I can't point you to anything in Bris, as I stay as far away from Bris as I can.

Ha! No, you don't want a discussion on how the ECU works. What you want is to either have us slavishly agree with your wrong opinion on how it works, or spoon feed you with 3rd party references to demonstrate why what we have said is correct. It's really not up to us to prove to you why you are wrong. You can ignore a strong concensus of people who have actually opened up and performed surgery on Nissan ECUs is you want. People who have replaced internal components, swapped processors and EEPROMs out for Nistune boards, soldered programmers in, fault found any number of reasons why a given ECU wasn't working, etc etc. Or you can be a dick. We actually don't care.

Don't get me wrong, I'm no pinko leftist who supports arbitrary taxes. I just love poking the ants' nest. But in all seriousness, spending luxury car tax money on a car is already a silly and unnecessary exercise, which I have never done and will never do, until and unless I get sufficiently wealthy that I do not even have to think about whether spending that much money on a massively depreciating purchase** is a sensible idea or not. And being of sound mind and body, I cannot imagine how anybody else can think that they should go out and spend that much money on a car unless they have already surpassed that threshold of wealth. If you are not sufficiently cashed up that the difference in cost caused by the tax doesn't even factor in, such that the tax does bother you, then you shouldn't be spending that much money on a car anyway. **note that I said "depreciating purchase" and not "depreciating asset". Already shows the mindset difference between me and the bleaters.

If you don't like what I post to you, please report my posts to the moderators.

Why would I go to the effort to google up "articles" that say the same things I learnt directly for myself over a period of 20 years? That is for you to do, now that you have been told that your understanding was wrong.