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GTSBoy

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  1. Phase change is a wonderful thing. Can apply it to your water as well as your refrigerant. There are some orders of magnitude difference between the latent heat of melting of water and the specific heat capacity. The crude form of this is the ice box. The possible form includes the ability to refreeze the ice, thus reducing the mass of water needed to achieve the goal. Example at the opposite end of the thermodynamic spectrum. A friend's company is using molten silicon to store heat. Originally it was intended to store heat created by passing excess electricity (solar, wind, etc) through radiant heater elements, but the idea has expanded to allow it to be fed from other forms of excess heat. Biogas from landfill, for example, burnt and the heat transferred directly to the storage medium. You can input heat into the storage medium from one side and extract heat from the other side simultaneously. Generate power, or use the (very high grade) heat off the extraction side as you will. Anyway, the point to be made is that a unit the size of a couple of shipping containers can hold the energy contained in MANY of the lithium battery shipping containers in a typical lithium grid battery. The energy density available in phase change storage is....large.
  2. Just dealing with that separately.... that's all obvious and at the simpler end of what we're talking about. I do P1V1 = P2V2 calcs in my head every day. Standing at the pitot traverse point in a stack converting the raw velocity I've just measured into a volume flow rate in Normal cubic metres per hour, to within a typical accuracy of 5%. By the way, the definition of Normal conditions is 0°C and 101.325 kPa, in case you were wondering, or confused by all the American websites that would like you to think that 15 or 20 °C (or, shudder, 60 or 70 °F) is Normal.
  3. Didn't say that you were going to make the same power increase at the crank as the heat pump leverage gave you in terms of cooling from the input mechanical power. Did say, unequivocally, that heat pumos DO yield multiple times the cooling/heating effect as the mechanical power put into them. Did say then that you would yield a substantial amount of cooling power to remove heat from intake air as a consequence of using that mechanical power to run the heat pump. Did say that, say, 12kW of heat removed from ~500HP worth of air could pull 60°C worth of heat out of the air. Did suggest that a 60°C colder charge would make a substantial power increase over running the same amount of air hot. Denser air is obvious. Timing advance increase is obvious. Did then suggest that if it only took 3kW of engine power to run that heat pump, it seems very f**king likely indeed that you would yield a lot more than 3kW extra power. If you couldn't, then there is no way that the intercooler would have every taken off, because.....that's what they do. We're talking about 3kW as a breakeven point here. Did suggest that you wouldn't bother for another 3kW (ie, zero benefit). Did suggest that you'd need some sizeable multiple of that to justify the weight and complexity. But....look back at the intercooler example. Did adding an intercooler to a typical turbo engine yield about a 10% increase? I'd suggest that most of them did. Hell, people are looking for multiple % increases just from using better intercoolers in place of an existing intercooler. Did also suggest that the time to use the heat pump would be when NOT demanding all the power that the engine can make transmitted to the tyres. Use the unused capacity to bank some cold, then use that when WOT. Cannot see how this is so hard for people to follow. By the way, my degree includes 4 years of thermodynamics. My career includes 25 years of thermodynamics. It's difficult to suggest that I don't know what I'm talking about.
  4. Little bits of sharp/abrasive plastic just slough off them. They should only be used when you're going to scrub down with solvent/water afterwards.
  5. No there wasn't. Not hen it came out of the packaging, anyway. They scored it and didn't notice.
  6. Definite potential cause of problems. Get rid of it. You don't need it. There is Nistune in the world. Yes. Well. Do.... again, because, obvious reasons. Your ECU hates you for having it VTA. This could be what is driving the boost drop, because the stock boost pressure is about 5 psi (on the spring) and the solenoid bleeds it up to about 7.
  7. They should just reconsider how hard they make it for ICE to meet emissions targets in a market environment where ICE is getting killed off in favour of EV for various other reasons anyway. No reason to use emissions as a lever when there are plenty of other levers, and no reason to make emissions limits really tight when the number of ICE vehicles will fall, which will have a much bigger effect than trimming the last 1% off the NOx/CO/HC emissions.
  8. Hard to see how that is true. It's not as if the turbine stops the flow and it's not as if the engine (should) be getting thrashed until it is a little warm anyway, so the turbine shouldn't even extract much/any energy from the exhaust, apart from that required to heat up the housing. If heating up the housing is critical cf the heating rate of the catalyst, then....f**k! The biggest benefit to the OEM in the immediate post cold start period might be just to enforce "no boost for you" until the engine is warm enough for it.
  9. I took the intercooler part of the question to be a distraction, but Ben is almost certainly on the money.
  10. Any larger turbo worth using will flow more at at "low boost" than the stock turbo does wound all the way up to "turbine flies off". You can't really go past the airflow available from the stock turbo at 10 psi without the stock ECU starting to get upset, and at 11-12 psi it will really be pissed off. I wouldn't contemplate a highflow on a stock ECU without Nistuning it to get around all that.
  11. You doing this on the stock ECU? Don't.
  12. Johnny bangs on about hall sensors aimed at the back of the wheel studs.
  13. It's not a "flammable fuel", therefore it is not covered by the wording of the regulation.
  14. Purge of what? Oil? Asbestos? Flammable gases? Covid?
  15. No. You'll have to make something. But if you're going to do work to change too totally different coils....why use nasty old coils when you can buy good new tech coils like R35s?
  16. I'd make my first assumption that the rings did not bed in.
  17. No. Not true. The physical work put into the compressor is not converted into heat. It is converted into the transfer of heat from a cold location to a hot location. The heat comes from the environment around one of the heat exchangers and therefore violates no laws of thermodynamics. The work is sneaking the heat past what you think are the laws of thermodynamics because you're drawing your energy balance boundary too close to the heat pump. Quote from: https://www.eec.org.au/for-energy-users/technologies-2/heat-pumps I wasn't at all suggesting that a chiller would be good for NA applications. Boosted applications are obviously even more sensitive to IAT and are also able to create more IAT so it makes sense to consider chillers for boosted applications first. I rather explicitly said that they would have to be useful at times when you are not using 100% of the engine's available power (ie do not need all the available power, owing to traction limitations, braking into corners, etc etc) and therefore they would likely be useful in more applications than people would give them credit for, because most people only think about the WOT case. They are certainly used in drag racing in the pre-WOT time, for exactly that reason. There's no reason why they could not be similarly applied in circuit or rally or some other types of racing, provided there is enough time off WOT to gain some of that power gap. So, look at the math. If a car AC compressor takes about 3kW to drive, and can yield (conservatively) 4x that in cooling power, and you have air post intercooler (assuming a reasonable boosted application already) at say 50°C ....bugger it, let's say it's bad and you really need to think about a chiller, so.... 80°C, and you're making say 500 engine HP and using 350 cfm to do it. That 350 cfm is about 0.2 kg/s. Air spec heat capacity is about 1 kJ/kg.K (nice and easy). So, 12kW will decrease that air temperature by nearly 60°C. So, from 80°C to 22°C. ON A CONTINUOUS BASIS. So, even if the car AC comp's leverage is only 3:1, you still get like ~45°C drop. And if it's better, like 5, you get really cold air. On much more powerful engines, you would need a much bigger AC system. That's obvious. But at 500HP it already seems feasible with what's already lying around. The real question becomes, how much more power can you make from air that is 50+°C cooler in a 500HP engine? It only needs to be >5HP to be positive, but you wouldn't consider all the weight and complexity for almost no extra power. You probably wouldn't even consider it for ~10HP. But, if it were worth say, 10% of the 500HP base, then it's probably looking attractive. And with the detonation threshold at 80°C being pretty scary, that might actually be possible. It would be even better if the system were well managed and could run the compressor more when there is spare power available and bank it in cold coolant so that you can actually use even more cooling power than the system produces naturally for short periods. I think there's something in it and it just requires some dev work to make decisions about how big and how controlled and so on it needs to be.
  18. You broke a wire.
  19. It takes a few (like low single digits) horsepower to drive a car AC compressor. If you can gain more than that few HP back, it should be nett positive. It would seem like an interchiller should be able to be worth more than a handful of horsies. Most importantly, it should be run when the engine load is less than 100% (ie, when there is spare power available, going unused at the tyres, when whatever power is used to run the AC won't take away from thrust.
  20. You really should consider providing all relevant information at the beginning. Point 1....ECU. Not stock right? So....totally unlikely that anybody else's experience is likely to replicate whatever wiring f**kup was done that caused the HICAS to interfere with engine operation. Point 2. What do you mean "I do not have the standard HICAS CU"? If you have no HICAS CU, then how can you expect anything other than trouble with your HICAS? I mean - at least you'd hope the electric rear rack would lock up, but it could be quite weird. And the HICAS light shouldn't come on if there's no CU to make it come on....so what is that dashlight wired up to? And how is it that your power steering is still working if you have removed the HICAS CU?
  21. It might seem like it does, but it actually doesn't - by a long way. The beauty of compressor based phase change cooling/heating is that you leverage the mechanical/electrical power you put in, by a factor of (up to) about 5. Exact same as reverse cycle airconditioning for the house. When used as a heater, you put your 2kW worth of electrical power into it, and you get about 10kW worth of heating out of it. All courtesy of the remarkable ability of heat to want to flow downhill all the time.
  22. So, for anecdotal value, street driven R32 with <200rwkW, stock rear brake equipment and R34 310mm fronts. Intima SR pads on the front. I think I'm also using SRs on the rear, but it possible that I chose SSs to hopefully provide a little less rear brake power. RDA slotted and grooved (the current design and spec that come with the black passivation coating) front and rear. More than adequate for the street, and really good in all respects. Not a lot of dust, no noise, great performance. I have nothing against DBA rotors, but they are more expensive than the RDAs and I'm a tightarse and the RDAs are proven to be fine. I used to use Bendix Ultimates as a street pad, which is really just a default choice. They're fine, nothing special at all, but the Intimas seem to be much much better. No discussion of chosen braking system elements is complete without a master cylinder stopper (or equivalent things done to mechanically firm the pedal) and braided teflon lines.
  23. Standard torsional harmonics as per every straight 6. Toyota/Yamaha just do a much better job of other aspects of the fundamental engine balance and oil pump drive and harmonic balancer integration and so on than Nissan did. The RB is a bit of a grandfathers axe, having its roots back in the 60s.
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