seishuku
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« Reply #45 on: August 19, 2016, 10:19:47 AM »
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Perhaps the terminology is different, coming from Megasquirt and other aftermarket engine controls, they refer to overrun as occuring on decel (foot off pedal).
Also I wasn't saying lean out in the power band (where you would lose power), I mean at cruising.
No, I dont have exact experience with this exact engine, I did dabble a bit with my AWN 4.2 when I had it... Otherwise, most of my tuning comes from Nissan 4 cylinder engines.
At any rate, it's no reason to get bent out of shape about, chill.
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bitmap
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« Reply #46 on: August 20, 2016, 11:27:55 PM »
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This is not a diesel with retarded soi for NoX. On Gasoline the only thing you can do is very slightly lean out the target AFR, but this has to be done as an ASM hack, which the OP will never get done. The fuel efficiency difference is max 1%, if that. I will also challenge you any time on that 14% claim. You are not going to make 14% more fuel efficiency by closing the EGR and bumping SOI in the "loft". Not even close. On 1-2 spots on the map maybe, but your car spends <1% of time in those spots.
You can challenge me all you want but my numbers don't lie  I can regularly achieve 60MPG(US) tanks without really trying and once I tried really hard and got 69MPG tank with my TDI which also develops 205hp and 450Nm when floored. My car is extensively modified for maximum efficiency and those 14% I mentioned came from just ECU tuning and bulk of the modificaion lies in the boost control not SOI or EGR. Only thing that stayed stock in the boost department were PID parameters and everything else I had to write from scratch. EGR and SOI control were a walk in the park after that |
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nubcake
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« Reply #47 on: August 21, 2016, 02:30:48 AM »
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You can challenge me all you want but my numbers don't lie I can regularly achieve 60MPG(US) tanks without really trying and once I tried really hard and got 69MPG tank with my TDI which also develops 205hp and 450Nm when floored. My car is extensively modified for maximum efficiency and those 14% I mentioned came from just ECU tuning and bulk of the modificaion lies in the boost control not SOI or EGR. Only thing that stayed stock in the boost department were PID parameters and everything else I had to write from scratch. EGR and SOI control were a walk in the park after that You do realize that we're talking about petrol NA engine and you're quoting TDI differences, do you? |
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bitmap
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« Reply #48 on: August 21, 2016, 03:43:56 AM »
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Yes I know I'm off topic.
prj "challenged" the possibility of achieving 14% better FE on my stinky TDI just by recalibrating ECU so I just wanted to clarify how I did "the impossible".
Also, you lot clearly don't understand how part load engine behaviour is supposed to work saying that leaning out part throttle lambda won't effect fuel economy much because engine will make less power as a result of that.
In a cruising situation, on a throttled engine you actually want to make least amount of power for a given throttle opening so that when not much power is required, throttle is open as much as possible, therefore intake manifold pressure is as close to atmospheric as possible, therefore engine is running more efficiently while making less power than it possibly could if tuned "properly".
This stuff is not very intuitive so I understand why a lot of people might think that factory tune can't be improved upon in this area but when emission regulations are involved, there ALWAYS is a room for improvement. Especially if the engine has continuously variable valve timing and/or external EGR system (which I don't know if this V8 has any of that).
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« Last Edit: August 21, 2016, 03:46:55 AM by bitmap »
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vwaudiguy
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« Reply #49 on: August 21, 2016, 12:27:35 PM »
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Yes I know I'm off topic.
prj "challenged" the possibility of achieving 14% better FE on my stinky TDI just by recalibrating ECU so I just wanted to clarify how I did "the impossible".
Also, you lot clearly don't understand how part load engine behaviour is supposed to work saying that leaning out part throttle lambda won't effect fuel economy much because engine will make less power as a result of that.
In a cruising situation, on a throttled engine you actually want to make least amount of power for a given throttle opening so that when not much power is required, throttle is open as much as possible, therefore intake manifold pressure is as close to atmospheric as possible, therefore engine is running more efficiently while making less power than it possibly could if tuned "properly".
This stuff is not very intuitive so I understand why a lot of people might think that factory tune can't be improved upon in this area but when emission regulations are involved, there ALWAYS is a room for improvement. Especially if the engine has continuously variable valve timing and/or external EGR system (which I don't know if this V8 has any of that).
Wow. Just wow. |
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"If you have a chinese turbo, that you are worried is going to blow up when you floor it, then LOL."
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k0mpresd
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« Reply #50 on: August 21, 2016, 04:08:19 PM »
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Wow. Just wow.
you have to appreciate the confidence in that post. |
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hopsis
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« Reply #51 on: August 21, 2016, 11:21:33 PM »
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Yeah, I have four of these N/A petrol V8 engines so You can understand fuel efficiency means the world to me. I'm getting the ebay resistor chip for my MAF sensor. Seller tells me it will reduce fuel consumption by 10%. I went and bought ten so that should amount to 100% of fuel savings.
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bitmap
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« Reply #52 on: August 21, 2016, 11:44:54 PM »
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It's Ok guys, I'm used to people thinking I'm a complete idiot. I even had a big car magazine in my country test my car and they verified all my claims but people still think I'm full of shit and that I paid them off to write that article even though I'm not trying to sell anything  |
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nyet
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« Reply #53 on: August 21, 2016, 11:55:12 PM »
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Hint: the 4.2 isn't a TDI
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ME7.1 tuning guideECUx PlotME7Sum checksumTrim heatmap toolPlease do not ask me for tunes. I'm here to help people make their own. Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
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bitmap
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« Reply #54 on: August 22, 2016, 01:09:37 AM »
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I know, no hints necessary.
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prj
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« Reply #55 on: August 22, 2016, 02:36:18 AM »
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In a cruising situation, on a throttled engine you actually want to make least amount of power for a given throttle opening so that when not much power is required, throttle is open as much as possible, therefore intake manifold pressure is as close to atmospheric as possible, therefore engine is running more efficiently while making less power than it possibly could if tuned "properly". I think you need to read a book about internal combustion engines. This made me lol. As for TDI, you would need to show fuel/hp at each operating point on dyno, otherwise it is just talk. |
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« Last Edit: August 22, 2016, 02:56:30 AM by prj »
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turbojohan
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« Reply #56 on: August 22, 2016, 02:53:26 AM »
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You can get some better fuel economy on better fuel and bit of mapping, but better fuel will cost more...
Better try get economy from tires, tire pressure and allignment... or buy a diesel :-)
Johan
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prj
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« Reply #57 on: August 22, 2016, 02:57:02 AM »
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You can get some better fuel economy on better fuel and bit of mapping, but better fuel will cost more...
Better try get economy from tires, tire pressure and allignment... or buy a diesel :-)
Johan
Don't forget the driver's right foot  |
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hopsis
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« Reply #59 on: August 22, 2016, 11:21:16 PM »
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Can someone please point out how tuning a turbocharged diesel engine is relevant to mapping a BFM engine? All this is borderline interesting but in the end completely pointless.
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