School me on stock wastegate operation, oddjob, CW, Sid etc
03-12-2014, 01:32 AM
#16
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Spring rate is with no boost what so ever going to the wastegate diaphragm.
That means with the line connected directly you will get half the amount of boost.
What are you confused about.
That's why the cycling valve runs on a set duty cycle. If it was feeding boost directly to the wastegate, you will see at least half the amount of boost pressure. NOT WASTEGATE SPRING PRESSURE.
If you clam the line. not allowing boost to enter the wastegate. the backpressure will now force the valve to open allowing the turbo reach a certain boost level. As in the original thread. the OP was getting 15psi which is about right for his issue.
That means with the line connected directly you will get half the amount of boost.
What are you confused about.
That's why the cycling valve runs on a set duty cycle. If it was feeding boost directly to the wastegate, you will see at least half the amount of boost pressure. NOT WASTEGATE SPRING PRESSURE.
If you clam the line. not allowing boost to enter the wastegate. the backpressure will now force the valve to open allowing the turbo reach a certain boost level. As in the original thread. the OP was getting 15psi which is about right for his issue.
03-12-2014, 01:37 AM
#18
In order to visualize how the stock wastegate works its important to know that it opens 'outward'. It does no act like an exhaust valve, the boost pressure is on the back side of the valve. All aftermarket wastegate open in the other direction - the boost pressure hits the face of the valve.
If you clamp, disconnect or get a good sized hole in the wastegate control line you will get as much boost as your turbo can produce.I believe the aftermarket wastegates are made this way so that they don't need a large diameter exhaust pipe (for valve clearance on the stock wastegate). The exhaust pipe on a Tial can be the same diameter as the valve head.
One small error on M944 post - the 38mm Tial can have many different valve springs inside it - if you run the boost control line unregulated the opening pressure of the wastegate will be dependent on the wastegate spring.
If you clamp, disconnect or get a good sized hole in the wastegate control line you will get as much boost as your turbo can produce.I believe the aftermarket wastegates are made this way so that they don't need a large diameter exhaust pipe (for valve clearance on the stock wastegate). The exhaust pipe on a Tial can be the same diameter as the valve head.
One small error on M944 post - the 38mm Tial can have many different valve springs inside it - if you run the boost control line unregulated the opening pressure of the wastegate will be dependent on the wastegate spring.
03-12-2014, 01:43 AM
#19
The exhaust pressure in the crossover only aids the valve in opening because it opens in the same direction that the exhaust is trying to excape., it does not open the valve without boost pressure forcing on the diaphram.
03-12-2014, 01:54 AM
#22
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you realise his not talking about a factory gate. but an aftermarket gate?
If the wastegate could stay closed during spool up, you think people wouldn't change to an aftermarket dual port gate?
See thread: Stock vs dualport gate.
https://rennlist.com/forums/944-turb...yno-chart.html
If you clamp, disconnect or get a good sized hole in the wastegate control line you will get as much boost as your turbo can produce.I believe the aftermarket wastegates are made this way so that they don't need a large diameter exhaust pipe (for valve clearance on the stock wastegate). The exhaust pipe on a Tial can be the same diameter as the valve head.
See thread: Stock vs dualport gate.
https://rennlist.com/forums/944-turb...yno-chart.html
03-12-2014, 01:58 AM
#23
dude reguardless of if your using a tial, LR, or stock if you pitch the feed line you WILL over boost the car. likewise if you send a direct line to the feed side of the wg it will boost at the spring rate.
btw, many racers utilize the stock or clubgate wastegate using mbc to choke the wg of air, raising boost, which holds the gate closed longer. Your arguing is relentless and a waste of everyones time. your wrong. people opt to upgrade wastegates because the stock one is 27 years old now, likely to fail
btw, many racers utilize the stock or clubgate wastegate using mbc to choke the wg of air, raising boost, which holds the gate closed longer. Your arguing is relentless and a waste of everyones time. your wrong. people opt to upgrade wastegates because the stock one is 27 years old now, likely to fail
03-12-2014, 02:06 AM
#24
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First I am talking about a stock wastegate, second oveboost in a stock car with stock klr chip occurs around 12psi.
On a car with a mbc and aftermarket klr chip this setting is bypassed and boost is set directly by the mbc, the amount of boost you can run is defined by your chips setup.
Going back to the stock wastegate, is a fact that;
#1 the valve does not open against the exhaust back pressure
#2 back pressure which can reach as high or higher than 20psi will push the valve out allowing the wastegate to bleed boost
The stock wastegate spring resistance is about 11.5 psi
It’s a fact that stock wastegates start to bleed around 7 psi, this will not occur in a tial since the valve is designed to open against the back pressure.
Assuming that you are using a aftermarket chip and mbc and set your mbc to lets say 21psi, maybe a fresh low miles stock wastegate will probably reach 18-19 before the back pressure pushes the valve wide open, a tired stock WG will generate max 15-16 psi, but the turbo will be working much harder than a similar setup using a tial, you can see the effects of this wastegate anomaly in choppy dyno graphs.
Don’t confuse a boost spike, with sustained boost, by pinching the line yes it may show you 21psi momentarily that’s the mistake of idiots that pinch the line, when they see the spike and believe that the stock wastegate will hold 20psi to redline Nize used to think like that, but the reality is that the STOCK wastegate valve will be pushed open eventually by the back pressure.
Lets assume the following
I have chips mapped for 21psi
I have a stock wastegate and a mbc connected to the intercooler pipe
I pinch the line what I would see is a sudden spike OF BOOST but since my chips are mapped to 21psi I continue to press the gas, what I would see is a series of spikes but the stock wastegate will never hold 21 psi to redline, the back pressure will push the valve out.
The point that I was trying to make was in the thread where the guy pinched the line and he was seeing no more than 15psi, first he is not hitting any overboost because he has aftermarket chips, second his wastegate spring has taken a dump and the valve opens fully by 15psi, probably a very tired wastegate spring.
I done this 10 years ago is documented not only with graphs but videos on this forum, I am not the only one, many have done it, I don’t copy stuff from clarks and paste, I tell you from first hand experience.
You want to see the threads and graphs, dig it your self for a moment I thought you were nize he was not only banned by was an idiot of the first kind.
On a car with a mbc and aftermarket klr chip this setting is bypassed and boost is set directly by the mbc, the amount of boost you can run is defined by your chips setup.
Going back to the stock wastegate, is a fact that;
#1 the valve does not open against the exhaust back pressure
#2 back pressure which can reach as high or higher than 20psi will push the valve out allowing the wastegate to bleed boost
The stock wastegate spring resistance is about 11.5 psi
It’s a fact that stock wastegates start to bleed around 7 psi, this will not occur in a tial since the valve is designed to open against the back pressure.
Assuming that you are using a aftermarket chip and mbc and set your mbc to lets say 21psi, maybe a fresh low miles stock wastegate will probably reach 18-19 before the back pressure pushes the valve wide open, a tired stock WG will generate max 15-16 psi, but the turbo will be working much harder than a similar setup using a tial, you can see the effects of this wastegate anomaly in choppy dyno graphs.
Don’t confuse a boost spike, with sustained boost, by pinching the line yes it may show you 21psi momentarily that’s the mistake of idiots that pinch the line, when they see the spike and believe that the stock wastegate will hold 20psi to redline Nize used to think like that, but the reality is that the STOCK wastegate valve will be pushed open eventually by the back pressure.
Lets assume the following
I have chips mapped for 21psi
I have a stock wastegate and a mbc connected to the intercooler pipe
I pinch the line what I would see is a sudden spike OF BOOST but since my chips are mapped to 21psi I continue to press the gas, what I would see is a series of spikes but the stock wastegate will never hold 21 psi to redline, the back pressure will push the valve out.
The point that I was trying to make was in the thread where the guy pinched the line and he was seeing no more than 15psi, first he is not hitting any overboost because he has aftermarket chips, second his wastegate spring has taken a dump and the valve opens fully by 15psi, probably a very tired wastegate spring.
I done this 10 years ago is documented not only with graphs but videos on this forum, I am not the only one, many have done it, I don’t copy stuff from clarks and paste, I tell you from first hand experience.
You want to see the threads and graphs, dig it your self for a moment I thought you were nize he was not only banned by was an idiot of the first kind.
03-12-2014, 02:14 AM
#25
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First I am talking about a stock wastegate, second oveboost in a stock car with stock klr chip occurs around 12psi.
On a car with a mbc and aftermarket klr chip this setting is bypassed and boost is set directly by the mbc, the amount of boost you can run is defined by your chips setup.
Going back to the stock wastegate, is a fact that;
#1 the valve does not open against the exhaust back pressure
#2 back pressure which can reach as high or higher than 20psi will push the valve out allowing the wastegate to bleed boost
The stock wastegate spring resistance is about 11.5 psi
It’s a fact that stock wastegates start to bleed around 7 psi, this will not occur in a tial since the valve is designed to open against the back pressure.
Assuming that you are using a aftermarket chip and mbc and set your mbc to lets say 21psi, maybe a fresh low miles stock wastegate will probably reach 18-19 before the back pressure pushes the valve wide open, a tired stock WG will generate max 15-16 psi, but the turbo will be working much harder than a similar setup using a tial, you can see the effects of this wastegate anomaly in choppy dyno graphs.
Don’t confuse a boost spike, with sustained boost, by pinching the line yes it may show you 21psi momentarily that’s the mistake of idiots that pinch the line, when they see the spike and believe that the stock wastegate will hold 20psi to redline Nize used to think like that, but the reality is that the STOCK wastegate valve will be pushed open eventually by the back pressure.
Lets assume the following
I have chips mapped for 21psi
I have a stock wastegate and a mbc connected to the intercooler pipe
I pinch the line what I would see is a sudden spike OF BOOST but since my chips are mapped to 21psi I continue to press the gas, what I would see is a series of spikes but the stock wastegate will never hold 21 psi to redline, the back pressure will push the valve out.
The point that I was trying to make was in the thread where the guy pinched the line and he was seeing no more than 15psi, first he is not hitting any overboost because he has aftermarket chips, second his wastegate spring has taken a dump and the valve opens fully by 15psi, probably a very tired wastegate spring.
I done this 10 years ago is documented not only with graphs but videos on this forum, I am not the only one, many have done it, I don’t copy stuff from clarks and paste, I tell you from first hand experience.
You want to see the threads and graphs, dig it your self for a moment I thought you were nize he was not only banned by was an idiot of the first kind.
On a car with a mbc and aftermarket klr chip this setting is bypassed and boost is set directly by the mbc, the amount of boost you can run is defined by your chips setup.
Going back to the stock wastegate, is a fact that;
#1 the valve does not open against the exhaust back pressure
#2 back pressure which can reach as high or higher than 20psi will push the valve out allowing the wastegate to bleed boost
The stock wastegate spring resistance is about 11.5 psi
It’s a fact that stock wastegates start to bleed around 7 psi, this will not occur in a tial since the valve is designed to open against the back pressure.
Assuming that you are using a aftermarket chip and mbc and set your mbc to lets say 21psi, maybe a fresh low miles stock wastegate will probably reach 18-19 before the back pressure pushes the valve wide open, a tired stock WG will generate max 15-16 psi, but the turbo will be working much harder than a similar setup using a tial, you can see the effects of this wastegate anomaly in choppy dyno graphs.
Don’t confuse a boost spike, with sustained boost, by pinching the line yes it may show you 21psi momentarily that’s the mistake of idiots that pinch the line, when they see the spike and believe that the stock wastegate will hold 20psi to redline Nize used to think like that, but the reality is that the STOCK wastegate valve will be pushed open eventually by the back pressure.
Lets assume the following
I have chips mapped for 21psi
I have a stock wastegate and a mbc connected to the intercooler pipe
I pinch the line what I would see is a sudden spike OF BOOST but since my chips are mapped to 21psi I continue to press the gas, what I would see is a series of spikes but the stock wastegate will never hold 21 psi to redline, the back pressure will push the valve out.
The point that I was trying to make was in the thread where the guy pinched the line and he was seeing no more than 15psi, first he is not hitting any overboost because he has aftermarket chips, second his wastegate spring has taken a dump and the valve opens fully by 15psi, probably a very tired wastegate spring.
I done this 10 years ago is documented not only with graphs but videos on this forum, I am not the only one, many have done it, I don’t copy stuff from clarks and paste, I tell you from first hand experience.
You want to see the threads and graphs, dig it your self for a moment I thought you were nize he was not only banned by was an idiot of the first kind.
I know i said it clear in the original thread. But if he doesn't understand this. Well. who knows.
Boost spiking and boosting are 2 different things.
03-12-2014, 02:14 AM
#26
most after market chips completely remove boost protection not raise it.
if you clamp the feed line you will max out the turbo. period. unless your still running the factory chips then you will get the fuel cutt off and boost protection via the cycling valve
Ive personally tested these on the bench, in multiple cars. and chris even confirmed this, take it or leave it.
if you clamp the feed line you will max out the turbo. period. unless your still running the factory chips then you will get the fuel cutt off and boost protection via the cycling valve
Ive personally tested these on the bench, in multiple cars. and chris even confirmed this, take it or leave it.
03-12-2014, 02:15 AM
#27
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you realise his not talking about a factory gate. but an aftermarket gate?
If the wastegate could stay closed during spool up, you think people wouldn't change to an aftermarket dual port gate?
See thread: Stock vs dualport gate.
https://rennlist.com/forums/944-turb...yno-chart.html
If the wastegate could stay closed during spool up, you think people wouldn't change to an aftermarket dual port gate?
See thread: Stock vs dualport gate.
https://rennlist.com/forums/944-turb...yno-chart.html
more of my cars
tuning a k26-6 with ape chips and afpr and mbc
03-12-2014, 02:16 AM
#28
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and by the way Nize welcome back
my thread where i compared a shimmed wastegate to a 38mm tial
https://rennlist.com/forums/944-turb...yno-chart.html
and your thread nize
https://rennlist.com/forums/944-turb...-graphs-3.html
my thread where i compared a shimmed wastegate to a 38mm tial
https://rennlist.com/forums/944-turb...yno-chart.html
and your thread nize
https://rennlist.com/forums/944-turb...-graphs-3.html
03-12-2014, 02:19 AM
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After reading this thread and the other one that I started I don't understand something. If clamping the line should make the turbo boost with zero control say to even 50psi (exaggerating) why is it that when i clamp mine i can floor it through the entire powerband and have it hit a maximum of only 15psi?