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Imagem do site do "Darkside" com uma estimativa do que esperar num motor TDI (1.9 ou 2.0 L ???)
Teóricamente num motor 2.2L o turbo irá, com a reprogramação certa, alcançar a pressão Máxima (Full Boost) mais cedo, provavelmente às 2200 RPMs?
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Possivel confirmação, como previamente pensado, que a válvula de vácuo existente para a wastegate do turbo de origem, também tem a capacidade de atuar a geometria váriavel do gtb1756vk pois as carrinhas sprinter com OM611, têm a mesma válvula e vêm com um VNT de origem (gt1852v):
"The VNT is controlled by the same gizmo as the waste-gated turbo.
It is how the VNT turbo is controlled on the sprinter.
Sure some people will tell you you need an electronic controller, but this is not true.
Check out the Sprinters with the OM611 engines, and probably the OM612 too, and you will find the same gizmo controlling the turbo's VNT mechanism.
Of course the maps/tables in the ECU that control the boost controller are different for VNT and waste-gated turbos.
They are referred to as the N75 maps.
I have copied the maps off the sprinter, compared them to the C220, and tuned the Vito ECU to suit.
It is not recommended to modify these maps as they are calibrated for the turbo/engine pairing.
My Vito wasn't running very strong until I retuned the N75 map to suit the VNT. Now it does. 🤓"
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Aparentemente, mesmo que por pouco, este mapa da compressora de um gt2056V pode ser minimamente utilizado como base para o gtb1756vk:
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"2,0 bar at 2000rpm is no problem with this turbo in higher gears, but the question is how fast it spools not how early. Much is in the tune and the adjustment of the turbo."
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"GTB1756VK at 26-28psi is very good, at lower pressure you have better efficiency."
"the trick is to spool it fast without surge. Surge is the limitation I would say"
Quanto melhor a performance em baixas rotações, pior vão ser os EMPs (traduzindo, pressão dos gases de escape no coletor).
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"I wouldn't worry about surge too much the turbo will be pretty well cut for the engine displacement" - Xman turbos (pessoa à qual foi comprada o turbo já convertido a vácuo.
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"you do the guideline is the ECU map which is requesting certain boost,
you rise the boost and fueling in order to create more power
and then you see if the turbo is responding correctly to the requests and if you can't manage it using the VNT map then you have to look into adjusting the VNT physically (stop-screw) " - Xman turbos
Embora, penso que, juntamente com este método, devia ter um sensor de EMP's para ver o ponto em que o ajuste deixa de melhorar a performance e começa simplesmente a aumentar a pressão no coletor de escape (ou seja, já saiu da zona de eficiência e deve-se obter o melhor ajuste entre performance e EMP's).
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"On my GTB1756, with Race520s, I spool it up quickly enough to have 13 lbs (0.88 Bar) at ~1850. At full bore, 400 RPM later, I'm at 32 psi (2.17 Bar) . Currently I hold a sustained 29 psi until 4300 RPM. " - 1.9 TDI
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"Interesting factoid: under low mass-flow conditions (like at low rpm) turbos need to pressurize the exhaust in order to spin the turbine and drive the compressor in the absence of mass flow. So, in order to drive the compressor, exhaust manifold pressure has to increase, and this requires the VNT vanes be slammed shut (think of a reverse throttle on the exhaust instead of the intake and you are on the right track.)
The bigger turbines/compressors, are more efficient at higher mass flow rates. For instance, efficient at high RPM when you are going for the peak power numbers in the dyno or drag racing. However, the tradeoff is: at low rpm and higher Pressure Ratio, the compressors are WAAAY off the efficiency island, meaning you need EVEN MORE drive pressure in the exhaust manifold to spin them fast enough to "make the boost". This means high VNT angles, which is an exhaust restriction!
this is a classic turbo tradeoff, just in a slightly different way. Big compressors "surge" (stall) at low mass flow and high PR. Little guys choke at high mass flow. (We can see some onset of surge -compressor stall-in fixuntilbroke's video.) The Variable nozzle in the VNT extends the Map width "bandwidth" range somewhat but there's always that mass vs pressure tradeoff. There is no way around map width unless with well-matched compounds.
You can "make" all the "boost" you want, but if the exhaust is blocked, all you get is a bunch or air being pressurised and piling up with nowhere to go. Intake pressure is fighting exhaust pressure, and you see this is in the high EGT. "
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"I have made some PD130 cars with that turbo and they run 1.9b 2500/4200rpm and till today zero problems, that turbo makes around 240bhp on Pd130 engines" (pd130 -> 1.9L)
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Tentativa de traçar a curva no mapa do gt2056, parece bater certo com o que tenho ouvido/visto, comparei também com o mapa do gt2052 de origem e parece confirmar que estou no caminho certo
Olhando para mapa do gt2052, parece-me confirmar pois apresenta a limitação no topo do mapa que o gtb1756vk resolve (pois sempre ouvi que o gtb1756vk faria maior potência nas altas rotações, ou seja, não tem a mesma limitação no topo das ilhas como se pode ver na do gt2052)
Tudo continua, porém, experimental, e apenas uma tentativa de correlação dos factos e teorias.
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"...even on a GTB1756VK, 1.78 BAR boost at 4300 RPM (witch is the max at 4300 RPM), EMP = 2.7 BAR." - motor 1.9L TDI
Pelo que vi traçando no mapa do gt2056, o valor máximo às 4300 de um gtb1756vk ronda na casa dos ~1.65 bar para este motor 2.2L, o que não me parece horrivelmente longe do que foi lido, tendo em conta, claro, que este mapa não é exatamente o mesmo que de um gtb1756vk, e que existe sempre uma variância nos cálculos feitos com base em valores teóricos aproximados dos reais, portanto devem ser considerados apenas como referência teórica.
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Encontrado mapa de um gt2056vk, melhor aproximação possível do gtb1756vk.
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Curva traçada no mapa do gt2056vk com o mapa "ideal" no carro, utilizando esta ferramenta - http://www.turbos.borgwarner.com/go/IGCIIR) :
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"boost level increase has to be accompanied by fuelling / timing tweaks as well"
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gt2052S de origem -> 50 TRIM, compressora de ~52mm (exducer)
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"I've seen a lot of files where tuners set requested very high in hope of improving spool. This is the wrong way to go about it, though - all you do is make the PID controller go crazy because it cannot reach requested with sane parameters and tries to fully close the vanes, which doesn't let the engine breathe well enough and actually impairs spool but promotes surge/spikes.
Requested should not be too far above what can realistically be achieved - instead, modify the N75 map and fuelling to hit your boost target - and fit your boost target to the right of the surge line...it'll thank you."
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"General forum wisdom is EMP < 1.5 * Current Boost."
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"A embraiagem de um W202 C220 CDI aguenta um binário máximo na casa dos 400-450NM" - Contacto fornecido pelo cláudio da Merclasse.
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"Do vaglogs on MAF(with large enough housing that it isnt saturated all the way through 1500-5000rpm) and see how different vane positions affect the total airflow that goes through the engine. Then compare the results to your notes on boost vs. EMP that you surely took at the same time.
After you have searched and tested. And wasted alot of money and time. And probably thought you are going insane you might end up with something like this:
Boost is on the right and EMP on the left. This is done on 2.15l Diesel engine and the turbo reaches max boost at around 3k."
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Safe gtb1756vk boost example - "On 4,0L 1,0bar max, on 2,0L engine 2,0-2,1bar."
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"Yep it measure's exhaust manifold pressure - the pressure between cylinder head and turbocharger on the exhaust side, anyway.
You can use EMP measurements (alongside boost measurements) to try and indicate how well an engine is breathing. If you find exhaust pressures to be disproportionately higher, excusing some natural reasons for this, you can assume that the engine isn't breathing well.
The result is, in the best case, reduced engine efficiency and thus power, but there's other factors too. If your exhaust manifold pressure is high, then your engine has to work harder against it, which means a car with high emp putting 150bhp at the wheels, will actually be producing (but losing) more power than a low emp vehicle putting out 150bhp at the wheels. "
_________________________________________________________________________________
"I wouldn't worry about surge too much the turbo will be pretty well cut for the engine displacement" - Xman turbos (pessoa à qual foi comprada o turbo já convertido a vácuo.
_________________________________________________________________________________
"you do the guideline is the ECU map which is requesting certain boost,
you rise the boost and fueling in order to create more power
and then you see if the turbo is responding correctly to the requests and if you can't manage it using the VNT map then you have to look into adjusting the VNT physically (stop-screw) " - Xman turbos
Embora, penso que, juntamente com este método, devia ter um sensor de EMP's para ver o ponto em que o ajuste deixa de melhorar a performance e começa simplesmente a aumentar a pressão no coletor de escape (ou seja, já saiu da zona de eficiência e deve-se obter o melhor ajuste entre performance e EMP's).
_________________________________________________________________________________
"On my GTB1756, with Race520s, I spool it up quickly enough to have 13 lbs (0.88 Bar) at ~1850. At full bore, 400 RPM later, I'm at 32 psi (2.17 Bar) . Currently I hold a sustained 29 psi until 4300 RPM. " - 1.9 TDI
_________________________________________________________________________________
"Interesting factoid: under low mass-flow conditions (like at low rpm) turbos need to pressurize the exhaust in order to spin the turbine and drive the compressor in the absence of mass flow. So, in order to drive the compressor, exhaust manifold pressure has to increase, and this requires the VNT vanes be slammed shut (think of a reverse throttle on the exhaust instead of the intake and you are on the right track.)
The bigger turbines/compressors, are more efficient at higher mass flow rates. For instance, efficient at high RPM when you are going for the peak power numbers in the dyno or drag racing. However, the tradeoff is: at low rpm and higher Pressure Ratio, the compressors are WAAAY off the efficiency island, meaning you need EVEN MORE drive pressure in the exhaust manifold to spin them fast enough to "make the boost". This means high VNT angles, which is an exhaust restriction!
this is a classic turbo tradeoff, just in a slightly different way. Big compressors "surge" (stall) at low mass flow and high PR. Little guys choke at high mass flow. (We can see some onset of surge -compressor stall-in fixuntilbroke's video.) The Variable nozzle in the VNT extends the Map width "bandwidth" range somewhat but there's always that mass vs pressure tradeoff. There is no way around map width unless with well-matched compounds.
You can "make" all the "boost" you want, but if the exhaust is blocked, all you get is a bunch or air being pressurised and piling up with nowhere to go. Intake pressure is fighting exhaust pressure, and you see this is in the high EGT. "
_________________________________________________________________________________
_________________________________________________________________________________
Tentativa de traçar a curva no mapa do gt2056, parece bater certo com o que tenho ouvido/visto, comparei também com o mapa do gt2052 de origem e parece confirmar que estou no caminho certo
Olhando para mapa do gt2052, parece-me confirmar pois apresenta a limitação no topo do mapa que o gtb1756vk resolve (pois sempre ouvi que o gtb1756vk faria maior potência nas altas rotações, ou seja, não tem a mesma limitação no topo das ilhas como se pode ver na do gt2052)
Tudo continua, porém, experimental, e apenas uma tentativa de correlação dos factos e teorias.
_________________________________________________________________________________
"...even on a GTB1756VK, 1.78 BAR boost at 4300 RPM (witch is the max at 4300 RPM), EMP = 2.7 BAR." - motor 1.9L TDI
Pelo que vi traçando no mapa do gt2056, o valor máximo às 4300 de um gtb1756vk ronda na casa dos ~1.65 bar para este motor 2.2L, o que não me parece horrivelmente longe do que foi lido, tendo em conta, claro, que este mapa não é exatamente o mesmo que de um gtb1756vk, e que existe sempre uma variância nos cálculos feitos com base em valores teóricos aproximados dos reais, portanto devem ser considerados apenas como referência teórica.
_________________________________________________________________________________
Encontrado mapa de um gt2056vk, melhor aproximação possível do gtb1756vk.
_________________________________________________________________________________
Curva traçada no mapa do gt2056vk com o mapa "ideal" no carro, utilizando esta ferramenta - http://www.turbos.borgwarner.com/go/IGCIIR) :
_________________________________________________________________________________
"boost level increase has to be accompanied by fuelling / timing tweaks as well"
_________________________________________________________________________________
gt2052S de origem -> 50 TRIM, compressora de ~52mm (exducer)
_________________________________________________________________________________
"I've seen a lot of files where tuners set requested very high in hope of improving spool. This is the wrong way to go about it, though - all you do is make the PID controller go crazy because it cannot reach requested with sane parameters and tries to fully close the vanes, which doesn't let the engine breathe well enough and actually impairs spool but promotes surge/spikes.
Requested should not be too far above what can realistically be achieved - instead, modify the N75 map and fuelling to hit your boost target - and fit your boost target to the right of the surge line...it'll thank you."
_________________________________________________________________________________
"General forum wisdom is EMP < 1.5 * Current Boost."
_________________________________________________________________________________
"A embraiagem de um W202 C220 CDI aguenta um binário máximo na casa dos 400-450NM" - Contacto fornecido pelo cláudio da Merclasse.
_________________________________________________________________________________
After you have searched and tested. And wasted alot of money and time. And probably thought you are going insane you might end up with something like this:
Boost is on the right and EMP on the left. This is done on 2.15l Diesel engine and the turbo reaches max boost at around 3k."
_________________________________________________________________________________
Safe gtb1756vk boost example - "On 4,0L 1,0bar max, on 2,0L engine 2,0-2,1bar."
_________________________________________________________________________________
"Yep it measure's exhaust manifold pressure - the pressure between cylinder head and turbocharger on the exhaust side, anyway.
You can use EMP measurements (alongside boost measurements) to try and indicate how well an engine is breathing. If you find exhaust pressures to be disproportionately higher, excusing some natural reasons for this, you can assume that the engine isn't breathing well.
The result is, in the best case, reduced engine efficiency and thus power, but there's other factors too. If your exhaust manifold pressure is high, then your engine has to work harder against it, which means a car with high emp putting 150bhp at the wheels, will actually be producing (but losing) more power than a low emp vehicle putting out 150bhp at the wheels. "
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