GTSBoy

That might be your mental model, but an engine that has the rpm jumping up and down and all the control actions that the ECU thinks it has to perform in order to repair that shitty condition will very likely result in an increase in fuel consumption. Not to mention all the other negative consequences of unstable combustion, which includes incomplete combustion which can lead to both sooting (and hence carbon build up in places where you don't want it) and cylinder wall washing. But then that's why engineers design engines, and not everyone else.

When faced with the same thing I recently(ish) bought Hertz C 165 6.5" 210 Watts Cento Series Component Woofer - Pair from Frankies Auto Electrics. I only bought the woofers because I was reusing some crossovers and tweeters that would work real well with them, but the full kit wouldn't have cost a lot more. They are very good speakers for the price.

I strongly suspect that unless you have the ear of the engineers at Garrett, or equivalent - ie you're running an important race team in an important race series - then you're probably not "designing" these things from first principles. You're probably running on trial and error. It's still a time-tested approach to exploring new ground, even if the ground is not completely new. If someone else owns all the maps and won't share, you have to make your own! I'm sure there are people who are sufficiently clever in a few orthogonal directions who could start with what's known, and via good gut engineering, or small step trial and error, or throwing a lot of random shit at the wall to see what sticks, or big bold concepts, could get to the answer(s) as to what works. As such, I'd suggest you'd be looking to see if you could leach information from any rally race teams that had to run under some old restrictor rules where they bought or learnt the lessons, and could pass on much of it because it's no longer relevant to their competition. There might be some of those in Oz. Maybe also in NZ.

^^ Yes. Essentially. With respect to what happens to compressor maps. Even without a restrictor, the choke limit on any compressor inlet is the sonic velocity. Obviously you can't and don't exceed ~300m/s in the inlet. Importantly, even without a restrictor, air going that fast is already at significantly reduced static pressure (this is because you gain dynamic pressure at the expense of static pressure - they have to add up to the presure you started with, which is only 101.325 kPa at sea level on an ISO standard day). The dynamic pressure associated with the velocity is many tens of kPa, and you only have ~100 kPa available at atmospheric pressure. So the air density goes down. I think that standard compressor maps effectively take this inlet velocity static P drop into consideration anyway. After all, they are tested in an actual compressor housing, with an actual inlet throat. With a restrictor, you will choke** the flow in the restrictor and then the air expands back into the volume between the restrictor throat and the impeller inlet face, leading to the reduced static pressure that you would expect. This reduction in static pressure and density is on top of the existing drop in static pressure resulting from the high air velocity. Shit starts to get weird and you have to keep your wits about you when talking about this stuff, because now the "vacuum" caused by the restrictor means the air is at a lower density, which means its sonic velocity is higher than it was at normal/standard density and the amount of dynamic pressure associated with velocity is on a different slope than it used to be. All very complicated, and I'm not going to try to straighten it out in my head sufficiently to make sense of it. Anyway, what it means is that you actually a dedicated compressor map for the inlet pressure condition that you have to run at. You can't easily use the standard comp map and just look to higher pressure ratios (to account for the vacuum in the inlet). This is because the relationship between mass flow and pressure ratio will also be changing, so where the choke line is, where the speed lines and efficiency lines are, will all move around. You'd need to do the work that generated the standard comp map again, with a restrictor in place, to create a map that you can trust. ** The reduction in static pressure caused by the restrictor occurs even without reaching the choke point. A restrictor is just that, a restrictor. It causes a pressure drop, and some of that pressure drop is permanent and unrecoverable. That's how they work.

If I had 292° cams in my car I'd still be trying to tune the idle to be as smooth as possible. Choppy idle is not "cool". It is an indication that things are not working as well as they could. You can bet your bottom dollar that a race team engineer, running an engine with massive cams, is not trying to tune it to make the idle worse, even if it spends very little operational time at idle. It's not 1970 any more. We can control this shit better.

I suggest you get someone to listen for what is actually making that clicking sound after the cranking stops. Has it ever worked since it was converted to LHD?

That takes me back. A friend of mine use to make these for ALFAs back in the 90s. It's a method with a long history, and even represents the way some OEM LSDs were done. This is better than what my mate used to make because they have provided the wear plate to stop the wear being done on the LSD plate or the side gear. Saves having to put metal back onto gears if you get your hardnesses wrong! In short....what could go wrong? It seems like they've got a good design and manufacturing process.

Well, no. But, surely you don't need "settings". Surely the tuner knows what he would need to do to make it sound like shit.

Well, the main risk with going to a bigger fuel pump is losing control of pressure at idle or low load because the FPR isn't able to flow the juice. So, if you manage to see your normal 43ish psi when you expect to, and ~11 psi or so less than that at idle with the sense line connected, and it's not wandering too far away from 3bar + boost at the top end, then you can't really fault the stock FPR (or any other FPR) if it wanders around a little bit in between. The FPR is a mechanism after all, and it will have hysteresis and a mechanical response time, so dynamics will always result in some local non-linearity and under and overshoot behaviours. You could gather a lot of data from logging that would make your eyelashes curl looking at those details, but provided it hits the 3 main points (or really only 2 main points if you discount the sense line disconnected test point) at steady state, then the reg is doing what it is designed to do. With a low power RB, coming onto boost in the 2300 rpm range (actually probably worse than that, given that it was still a 20 when I did this), you can see the fuel pressure gauge go from reading 3 bar + low load vacuum (so, what? About 26 psi?) up to ~43 psi when the throttle is opened up full but no boost yet, and then a few psi creep in followed by the very rapid ramp up to 3 bar + boost, which in my case was probably 12 psi at the time, so 55ish on the gauge. All of that is fairly easy to follow even without being able to see the tacho, and happens slowly enough that what happens and when it happens either makes sense, or if it doesn't then it indicates a problem. And on a typical 6 bar gauge it all happens right around the top** of the dial. On a 10 bar gauge it's a little more compressed to between about 25-40% of full scale, but that's still quite readable. I'm used to doing pitot measurements in process ducts where I have to pinch the silicone tubes down to damp out wild 2 kPa fluctuations in total pressure while the dynamic pressure in only about 50 Pa or so. By comparison, measuring fuel pressure on a car is something I can do without even needing a coffee first! **And what I meant here was like at the 12 o'clock top, not full scale over on the lower RHS.

And a big troubleshooting tip is that any circuit that is still lighting up after you have removed the correct power supply for it (wire, fuse, etc) has a short to another circuit somewhere. Crossed wire, failed component perhaps. The R33 wiring diagrams are freely downloadable. They are almost certainly attached to a post on these very forums. Have a search.

What, you want to make it idle like it's a peripheral port rotary running a Microtech dial-an-ECU back in the early 90s? Why?

Don't need to log it. Stood next to the car holding the fuel pressure gauge in hand as it was run across the full load range. It sat where it was supposed to. Was 20+ years ago though....

255 should have been fine. Mine worked just fine (as in, fuel pressure is/was correct) with similar sized 040.

Turbo 400?

For subframe to chassis, the R32 GTR torques would have to be close enough. As also for most other fasteners in the undercarriage. Most of them are the same sizes in the same places.

Yes, I was going to say that because it's NA you can use either an NA box or a turbo box, and a turbo box is $4500 at worst, so call that done. Then you need the clutch pedal stuff as Robo said. Tailshaft and gearbox crossmember can be made from scratch if absolutely necessary....for a cost, of course. But you should be calling around the wreckers, surfing (ugh, shudder) monkeyplace, for the bits you need. You also need the manual side loom to save you having to find connectors and modify the auto side loom. Modding is possible (subject to obtaining the manual box's connectors), swapping the whole loom is easier. You'll also need to sort out the speed sender. You have to hope there's one in the box (if you buy it 2nd hand) but if you buy it new you'll need to get a sender too. And then, there might be some fun getting it to work with the auto's cluster, as there may or may not be some differences there. I'm no expert on auto 34s. Greg ( @Kinkstaah ) might be able to tell you something about that.

He did ask about Neo 25, which use shim, not hydros. Shitty 2nd class shim over buckets though. And.... No, with regular oil changes and not too aggressive cams, you should get a couple hundred thousand out of them without needing to shuffle/replace shims.

I must stipulate though, that I haven't been able to turn the boost up on my new highflow because the car was pinging and the ECU was going to panic mode, and it is quite possible that the 040 is low on pressure from great age and needs to be replaced. Maybe. Haven't had a chance to get it onto the dyno with the fuel pressure gauge etc etc, and so just dribbling it around on low low boost. So, likely Walbro replacement might be a different story. Shouldn't be, but might be. Only going to need a 255 (341? 342? Whatever they are), and I think they pull the circa same current as the 040.

My 040 is wired up to the FPCM. Was done at least 20 years ago when the stock pump died, and when the car was making barely more than stock power. Fuel pressure was fine at the low end and the high end back then. Has stayed that way through boost ups, 25 transplants, etc. And sure, the ECU has been tuned as a result of most of the big changes, but regardless, the FPCM has worked just fine running an 040. No meltdowns, no pressure problems, etc.

Perhaps useful to know where you are and whether NA or turbo.

If the car's already f**ked, then there's no point in trying not to f**k the car.

You should only use a 2 post lift under the sill jacking points if you have suitable adapters on the lift pads to touch the car ONLY only the surfaces either side of the pinchweld. Where the OEM jack would touch the car. Same as if using chassis stands there. So that would be either rubber, or preferably steel block with a slot in them. The chassis rails are not strong enough anywhere to carry the weight of the car. If you spread it out over a really large area with a block of wood....yeah, maybe. But that's not real secure. I'd be wanting to make an adapter of some sort that fit along and up the sides of the rails at least 5-10mm, to reduce the chance of it slipping sideways, and that adapter would want to be fastened to the lifting pad well, too. I've never seen anybody go that far though.

Whiteline 24mm bars are a bit too stiff, IMO. Certainly at the rear. I have 22 at the rear, 24 at the front, set to softest. Could probably survive with a 22 at the front also. I have had 24 at the rear, and it was too much, even set to the softest.

Similar to mine. More than desirable but (for 10+ years) impossible to get rid of. At least without replacing everything. Remember, It's not just what's in the diff that contributes to how much the axles will move. There's also the splines out at the hubs. Sum up all the little slops and hey add up into one great big shitty slop.

Neo turbo ECU will shit the bed without the boost sensor. Will need to wire in a resistor, or one of a couple of other options, as detailed at Nistune.