
GTSBoy
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Everything posted by GTSBoy
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A GT-V would be a fine daily. Not fast, and no point in trying to make one fast. Well, that used to be true, but perhaps if the only nice R34 you can find is an NA, then the "sell it and buy a turbo instead" advice we used to give becomes out of date.
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Anybody affected by the M1 minefield this morning?
GTSBoy replied to PranK's topic in General Automotive Discussion
HAL 9000 The Butlerian Jihad Mother & Ash Skynet The Matrix Ex Machina And now..... The AIs are taking our tyres. -
Mistakes were made, my R34 Story
GTSBoy replied to Kinkstaah's topic in Members Cars, Project Overhauls & Restorations
That's true for things that are treating the input as a "temperature" input, ie that are interested in measuring the resistance of the sensor. But in the case of Greg's MPVI3, he's just measuring a voltage. Voltages are measured with a high impedance input, so no significant current flows, so they have almost no effect on the circuit being measured. It is exactly the same as probing the sensor's terminal with a multimeter set to DC volts. -
At first I thought these were knock offs....
GTSBoy replied to PranK's topic in General Automotive Discussion
AIs new frontier is as "personal shopper" for people too lazy to do their own research. You should try to get one of these AIs to purchase some of these "Pirellys". Would seem like an Inception moment. -
One Headlight isn't working - Driver Side Fuse Keeps blowing
GTSBoy replied to kevboost7's topic in General Maintenance
That would be the better outcome. The one where the car is burning to the ground while also being broken down in the dark of a wet rainy night is also possible. -
Anybody affected by the M1 minefield this morning?
GTSBoy replied to PranK's topic in General Automotive Discussion
Yeah, it's f**ked up. The boss of the trucking co might be in a world of hurt saying "it's all our fault" and that their insurance company will cover everyone's damages. I think his insurance co might object to him accepting liability out in the open like that, and things might start to suck for him from some point in the next day or 2. -
Welcome. We're all grumpy old men (and a few grumpy old women) who are slowly coming to hate these cars. Any of the newer owners who have joined in the last few years are rapidly catching up with us as they realise they have bought a basket case and that parts are getting difficult to find. Just be realistic about your goals. You'll need a fat stack of cash to buy an R34 GTR, and you'd be far better off using that to buy absolutely anything else (ie, shares, a house, scratchy tickets) unless that fat stack of cash is only ~10% of the actual fat stack of cash that you have. You'll never want to drive an R34 GTR on the street if you have fear of it getting destroyed. That's more or less true of the 33s and 32s also. Most of the RWD cars have been drifted backwards into power poles. No-one knows what they are worth these days because they are not changing hands. My car has notionally been down to <$10k value at some point and was probably sellable for $40-$50k in the height of COVID stupidity, but I have no idea what it's really worth now. It's irreplaceable anyway, because... where would I find one to replace it? Being realistic means either paying a lot of cash for a really really clean example that you will only drive on sunny Sundays, or buying one to daily that you will not want to be really really clean, for the same fears of destruction that applies to the GTR. I daily mine and some people think I'm crazy. But....to me it's just a car that I bought last century with the express purpose of driving it as my daily. The silliness that has happened since doesn't affect my original purpose. I have well and truly amortised the initial purchase cost and most (probably all) of the subsequent modification costs. But I don't think I could go out and buy one now to daily.
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Another little story of weird shit happening
GTSBoy replied to GTSBoy's topic in Engines & Forced Induction
I'm thinking that this is such a small part of the problem that you could easily forego the vac pump and just achieve 90% of what you need, which is keeping the gate open when off boost. It's not as if there are not already techniques to keep a gate fully closed under boost. After all, you have boost. Just use a wastegate actuator that will allow you to apply the boost on the appropriate side, just like every external gate out there. -
Mistakes were made, my R34 Story
GTSBoy replied to Kinkstaah's topic in Members Cars, Project Overhauls & Restorations
I said "Matlab clone". I could throw one onto one of my linux VMs. Probably only take 10 or 20 hours to sort out the dependencies, relearn how to use it, etc etc. -
At first I thought these were knock offs....
GTSBoy replied to PranK's topic in General Automotive Discussion
If you ask just me you'll get 3 different answers. -
Mistakes were made, my R34 Story
GTSBoy replied to Kinkstaah's topic in Members Cars, Project Overhauls & Restorations
Do not ever trust ChatGPT with anything math related. They can't do math. They have no idea what it is. With enough data we can fit a decent equation in Excel, or if the available fits in Excel aren't good enough, a Matlab clone. -
At first I thought these were knock offs....
GTSBoy replied to PranK's topic in General Automotive Discussion
Not 10 out of 10 crap. But just so......disappointingly....bleh. Just didn't do anything well. Everything was bland. Didn't even have a long enough life to justify the ongoing daily disappointment. Although I was so happy to see them go that I'm glad they didn't last longer. -
At first I thought these were knock offs....
GTSBoy replied to PranK's topic in General Automotive Discussion
Not enough to make any difference at all. -
Yeah, they look good. I should try to fit them on mine. But being a GTSt, the guard shape probably doesn't suit properly.
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Mistakes were made, my R34 Story
GTSBoy replied to Kinkstaah's topic in Members Cars, Project Overhauls & Restorations
Nah, it's not a simple voltage divider. I'm not enough of an electronics guru to know how they make these circuits work. If I had a better idea of how the ECU's temperature measuring is done, I could then actually do as you want, which is turn that resistance chart into a voltage chart. But my approach has not worked. What I did was interpolate the sensor ohms values for the temperatures you listed, as you did not have any of them on a temperature ending in zero or 5. These are: °C ECU V sensor ohms (interpolated) 58 2.68 11.85 57 2.7 11.89 56 2.74 11.93 54 2.8 12.01 49 3.06 12.208 47 3.18 12.284 43 3.37 12.42 I then assumed 5V supply to the resister and calculated the voltage drop across the sensor for each of those, which is just 5 - the above voltages, and then calculated the current that must be flowing through the sensor. So you get: Values in sensor °C ECU V sensor ohms (interpolated) Supply volts Volt drop Current 58 2.68 11.85 5 2.32 0.195781 57 2.7 11.89 5 2.3 0.19344 56 2.74 11.93 5 2.26 0.189438 54 2.8 12.01 5 2.2 0.183181 49 3.06 12.208 5 1.94 0.158912 47 3.18 12.284 5 1.82 0.14816 43 3.37 12.42 5 1.63 0.13124 And then use that current and the ECU's sensed voltage (which must be the voltage drop across the in ECU resister is there is one) to calculate the resistance of that in ECU resistor. You get: Values in sensor Other resistor °C ECU V sensor ohms (interpolated) Supply volts Volt drop Current Volt Drop Resistance 58 2.68 11.85 5 2.32 0.195781 2.68 13.68879 57 2.7 11.89 5 2.3 0.19344 2.7 13.95783 56 2.74 11.93 5 2.26 0.189438 2.74 14.46381 54 2.8 12.01 5 2.2 0.183181 2.8 15.28545 49 3.06 12.208 5 1.94 0.158912 3.06 19.25592 47 3.18 12.284 5 1.82 0.14816 3.18 21.46325 43 3.37 12.42 5 1.63 0.13124 3.37 25.67816 And that's where it falls apart, because the resulting resistance would need to be the same for all of those temperatures, and it is not. So clearly the physical model is not correct. Anyway, you or someone else can use that information to go forward if someone has a better physical model. I can also show you how to interpolate for temperatures between those in the resistance chart. It's not fun because you've got to either do it like I did it for every 5°C range separately, or check to see if the slope remains constant over a wide range, then you can just work up a single formula. I'm just showing how to do it for a single 5° span. For the 58°C temperature, resistance = 11.77+2*(11.97-11.77)/5 The calc is a little arse backwards because the resistance is NTC (negative temperature coefficient), so the slope is negative, but I'm lazy, so I just treated 58 as if it was 2 degrees away from 60, not 3 degrees away from 55, and so on. -
Mistakes were made, my R34 Story
GTSBoy replied to Kinkstaah's topic in Members Cars, Project Overhauls & Restorations
Um.... This is not easy. I will have a fiddle with it, but make no promises. I think, given the explicit resistances vs temperature, and your ECU measured voltages, it should be possible to match them up. I will do that by assuming a 5V supply from ECU to sensor, find out how much current would have to flow to produce that voltage, then use that current as a .... nah f**k. That won't work. The supply voltage is fixed, but there's nothing to say that the ECU regulates the current too. Um... I dunno. I guess there's a voltage divider setup in the ECU. As in, there's another resistance between the ECU's sense terminal and ground. That way, as the sensor resistance changes, that's how they get a floating voltage that varies with the temperature, without having to control the current. Give me a minute or 3. -
Hmm. I had a good look (w/o searching, because I'm not logging in) and couldn't see it either. I distinctly recall the thread, not many weeks ago. It must have been removed or perhaps put into the back section. If it was in Off Topic you should at least have been able to search it up. So if I'm not hallucinating, it is fairly decently removed.
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Another little story of weird shit happening
GTSBoy replied to GTSBoy's topic in Engines & Forced Induction
Hi Tao. My dump was ground out to provide clearance over the used swing arc. But when the clip fell off, the flap was free to travel too far. Got stuck. That's all. There's decent preload too. You may remember that I asked for a low pressure actuator because I wasn't able to tune the car immediately, and a proper actuator probably would have left the car undriveable. Or at least barely safely driveable. But it hasn't been an obvious problem in terms of the gate blowing open under normal use. Well, maybe it has. The turbo is quite laggy compared to stock - so an actuator upgrade will be done first after the supporting mods are done and it's dyno'd to stop it pinging. Hopefully the gate has actually been lifting early. If it has, it has been necessary for me anyway, because as I said earlier in this thread, I had to back off the ramp allowed by the boost controller, to stop it pinging. I might have been in a bit of trouble if it hadn't been as slow to build boost as I have found it. In fact - given that I will get it onto the dyno soonish - I think I'll order an actuator from you pretty soon, so we've got it there if it is clear that there's no point continuing to try tuning with the low pressure one. -
At first I thought these were knock offs....
GTSBoy replied to PranK's topic in General Automotive Discussion
They are real good. Big central grooves, sticky compound. I have no fears in the wet. Except for the first couple of miles where you wouldn't count on them to have any warmth in them yet. -
Looks like the site: operator works for other domains on google, but not for PF. So either google is not indexing PF because PF finally pissed them off too much, or PF is blocking google. And....PF appears to be blocking all indexers. site: operator on bing returns lots of hits saying that they can't show info for the site.
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Meanwhile, I'm struggling to find the thread on PF. I'm trying to use the site:performanceforums.com operator in the google search and it returns no hits, regardless of the other search terms. Does it work for you?
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I refer you to a similar thread on PF.com recently (find it yourself, it's not too long ago). I think the general concensus is that they are cheap CCP crap with a "brand" name, and that thus the correct thing to do is buy NGK/Bosch/genuine/whatever is respectable and available. And no no-name CCP crap, which is possibly the same carp as the PAt stuff, or could be even worse.
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At first I thought these were knock offs....
GTSBoy replied to PranK's topic in General Automotive Discussion
Which tyre out of the 3 mentioned? -
Contains some of the same waxes that are in the Meg's gold wax anyway. Your car is white? Wax won't make it look "cloudy" enough to worry about it. Just put wax on it and decide if you think it looks cloudy. I would bet you couldn't tell. If you want to follow the paint shop's advice, then you'd be looking to ceramic coat the paint first. Then wax on top of that (although the ceramic coat purists would say that you don't need to wax on top of ceramic - I'm not in their camp). I am of the opinion that ceramic coat should only get put on top of paint that has recently been properly corrected by an expert, or thereafter as maintenance. But wax can be put on anything and keeps the nasties away from the paint and can either be removed easily enough, or comes off on its own over time - unlike the ceramic, which you can have a hard time knowing what condition it is in. Um, what? Fuel stain? On the rear bumper? Please explain.
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At first I thought these were knock offs....
GTSBoy replied to PranK's topic in General Automotive Discussion
I liked them too, but somehow they were not quite as good as the preceding RS3, and I vastly prefer the Yoko AD09s. Quieter, longer lived, more progressive, damn near as sticky. And they don't howl like the 'Kooks do when they're mostly worn.