Clamped boost line wont go over 15psi MODIFIED CAR
03-11-2014, 04:57 AM
#61
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when the stock klr determines an over boost condition it does two things, a fuel shut off (often refered to feeling like someone putting on the brakes) and the cycling valve is sent the signal to direct all the pressure to the wastegate fulling opening the valve, bypassing as much exhaust to the turbo as possible. no fuel, no exhaust spinning the turbo, no over boost.
this is exactly why when you upgrade to a mbc you remove this feature in the klr by use of aftermarket chips so your car can boost higher without getting the fuel cutoff and you are able to delete the cycling valve and run a line straight to the wg using a mbc to choke the feed supply, keeping the wg closed longer raising boost.
this is exactly why when you upgrade to a mbc you remove this feature in the klr by use of aftermarket chips so your car can boost higher without getting the fuel cutoff and you are able to delete the cycling valve and run a line straight to the wg using a mbc to choke the feed supply, keeping the wg closed longer raising boost.
03-11-2014, 05:06 AM
#62
more contradictions
You just got done saying the boost pressure opens the valve, now you saying boost pressure keeps it closed.
if your saying that the absence of boost on the line keeps it closed then your agreeing with me......lol a closed wastegate raises boost. therefore sending more pressure opens it sooner lowering boost.
but is not the higher boost preset that keeps the wastegate valve close but the absence of boost on the line
if your saying that the absence of boost on the line keeps it closed then your agreeing with me......lol a closed wastegate raises boost. therefore sending more pressure opens it sooner lowering boost.
03-11-2014, 05:12 AM
#63
but is not the higher boost preset that keeps the wastegate valve close but the absence of boost on the line, once the set boost is reached the mbc opens pushing the valve wide open, the wastegate would have been bleeding pressure along this time, making the turbo work harder to keep the desired boost level, that would not happen on the tial since the pressure is again the valve, (keeps valve shout) your theory is true on a tial or sipnase wastegate since the boost pressure is opposite direction in contrast to the stock wastegate valve
a shut wastgate is over boost and a open one is under boost at the spring pressure. so sending a line from the j pipe directly to the wg will cause under boost, and a restricted line(clamped) will cause over boost.
03-11-2014, 05:18 AM
#64
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okay, there is always boost pressure inside the crossover to wastegate tie pipe, that pressure is pushing the valve down(open) the other vacuum line on top of the wg has pressure only when the mbc opens at that time and pushes the valve open at the desired mbc setting. The fact that you can reach higher pressure by pinching the vacuum line on top of the wastegate doesn't mean that the valve stays closed it's actually bleeding and once the mechanical resistance 10.5 psi is reached it closes and opens if you have a big turbo it will build boost giving you the feeling that the valve is closed but in reality it will be a series of surges giving you the impression that boost is raising steady.
03-11-2014, 05:22 AM
#65
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I have been trying to explain that to you, NO NO NO in the 951 wastegate the boos pressure inside the crossover/ tie pipe does NOT pushes against the valve but in the SAME direction the valve opens
03-11-2014, 05:28 AM
#66
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And i'm also sure i said the boost works in the same direction as the exhaust back pressure.
03-11-2014, 05:31 AM
#67
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03-11-2014, 05:31 AM
#68
okay, there is always boost pressure inside the crossover to wastegate tie pipe, that pressure is pushing the valve down(open) the other vacuum line on top of the wg has pressure only when the mbc opens at that time and pushes the valve open at the desired mbc setting. The fact that you can reach higher pressure by pinching the vacuum line on top of the wastegate doesn't mean that the valve stays closed it's actually bleeding and once the mechanical resistance 10.5 psi is reached it closes and opens if you have a big turbo it will build boost giving you the feeling that the valve is closed but in reality it will be a series of surges giving you the impression that boost is raising steady.
03-11-2014, 05:38 AM
#70
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For one i hope theres not boost pressure in your crossover, mine uses exhaust lol. and second, if you want to argue that the valve slightly opens thats fine, but dont contradict yourself in the same post. your saying the exhaust pressure is causing the valve to bleed open, then adding pressure to the diaphram will cause surging (opening and closing). if the boost pressure helps open the valve and the exhaust pressure is only building as the car reaches higher rpms then your theory is trashed because if exhaust pressure can open the wastegate and the pressure is only getting stronger are rpms get higher and boost pressure is being used to open the valve then the valve would open more. lowering boost
In fact. There is pressure in the crossover. More then what is measured in your manifold. I stated this before too.
It can range from 1.1:1 ratio to 1.5:1 ratio. ideally you want 1:1 but that's very hard to achieve. most cars will be 1.25:1.
That means most turbo cars will have 10 psi going through the manifold and 12.5psi in their exhaust manifold or crossover pipe in a 944 turbo.
That pressure opens the wastegate.
Can i be more clear?
03-11-2014, 05:42 AM
#71
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For one i hope theres not boost pressure in your crossover, mine uses exhaust lol. and second, if you want to argue that the valve slightly opens thats fine, but dont contradict yourself in the same post. your saying the exhaust pressure is causing the valve to bleed open, then adding pressure to the diaphram will cause surging (opening and closing). if the boost pressure helps open the valve and the exhaust pressure is only building as the car reaches higher rpms then your theory is trashed because if exhaust pressure can open the wastegate and the pressure is only getting stronger are rpms get higher and boost pressure is being used to open the valve then the valve would open more. lowering boost
I can explain it in spanish much more clearly.
03-11-2014, 05:43 AM
#72
In fact. There is pressure in the crossover. More then what is measured in your manifold. I stated this before too.
It can range from 1.1:1 ratio to 1.5:1 ratio. ideally you want 1:1 but that's very hard to achieve. most cars will be 1.25:1.
That means most turbo cars will have 10 psi going through the manifold and 12.5psi in their exhaust manifold or crossover pipe in a 944 turbo.
That pressure opens the wastegate.
Can i be more clear?
It can range from 1.1:1 ratio to 1.5:1 ratio. ideally you want 1:1 but that's very hard to achieve. most cars will be 1.25:1.
That means most turbo cars will have 10 psi going through the manifold and 12.5psi in their exhaust manifold or crossover pipe in a 944 turbo.
That pressure opens the wastegate.
Can i be more clear?
03-11-2014, 05:47 AM
#73
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Mate, your english is fine. I'm pretty sure your first few posts explaining how it works makes sense. to the point you need to repeat yourself you sometimes muddle things up. Including the frustration from this guy not paying any attention!!
03-11-2014, 05:47 AM
#74
Yeah I meant to say back pressure, no boost pressure you have to understand that english is not my first language and when you were playing with dolls I was already driving 944's, I know how it works maybe I have hard time explain it.
I dont need to prove im right because i know i am. ive done the in field testing. if you dont believe me your welcome to try. run a line from the j pipe to the supply side of the wastegate. this send the most pressure to the wastegate opening it at the springs pressure. if you clamp that line the wastegate, even with the slight bleed from exhaust pressure, doesnt open enough to relieve the pressure causing the turbo to over boost.
03-11-2014, 05:49 AM
#75
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In fact. There is pressure in the crossover. More then what is measured in your manifold. I stated this before too.
It can range from 1.1:1 ratio to 1.5:1 ratio. ideally you want 1:1 but that's very hard to achieve. most cars will be 1.25:1.
That means most turbo cars will have 10 psi going through the manifold and 12.5psi in their exhaust manifold or crossover pipe in a 944 turbo.
That pressure opens the wastegate.
Can i be more clear?
It can range from 1.1:1 ratio to 1.5:1 ratio. ideally you want 1:1 but that's very hard to achieve. most cars will be 1.25:1.
That means most turbo cars will have 10 psi going through the manifold and 12.5psi in their exhaust manifold or crossover pipe in a 944 turbo.
That pressure opens the wastegate.
Can i be more clear?