Mountune Fiesta MRX Turbo

[antarctica24]

This is the upgraded wg that will fit. I'm 99.9% sure. 12-14 psi. The 14 setting should be spot on.
http://m.ebay.com/itm/Garrett-Inter...%3A1c0705c315e0aa19f5b3b8a6ffff1561%7Ciid%3A8

Help me out here. Everyone is so worked up about the waste gate, but the datalogs Im getting dont show that the wastegate is having any issues up to 27lbs. What is it that you are trying to accomplish with a wastegate with a stiffer spring on this turbo?

 

[1azst]

He's at 100% wgdc. A stronger spring will allow for more boost. I'd like to see it.

 

[jeff]

Help me out here. Everyone is so worked up about the waste gate, but the datalogs Im getting dont show that the wastegate is having any issues up to 27lbs. What is it that you are trying to accomplish with a wastegate with a stiffer spring on this turbo?

He's at 100% wgdc. A stronger spring will allow for more boost. I'd like to see it.

That's why I asked what the waste gate duty cycle is at. The next question is, though, what is the safe psi to run on this turbo? If it's not built to hold a higher psi then upgrading the wastegate could cause reliability problems if you than plan to tune for more boost.

 

[Turboman17]

That's why I asked what the waste gate duty cycle is at. The next question is, though, what is the safe psi to run on this turbo? If it's not built to hold a higher psi then upgrading the wastegate could cause reliability problems if you than plan to tune for more boost.

Yep this guy gets it! Overspeed, backpressure (too much axial loads), temperature spikes and surge all come to mind. But if we don't have atleast one test mule, then we will never know!

 

[jeff]

Yep this guy gets it! Overspeed, backpressure (too much axial loads), temperature spikes and surge all come to mind. But if we don't have atleast one test mule, then we will never know!

Question for you good man, if the wastegate duty cycle is at, let's say, 98%, opposed to, let's say, 50%, aside from having no more room to add boost does that also mean it is running less efficiently or poorly?

 

[re-rx7]

Help me out here. Everyone is so worked up about the waste gate, but the datalogs Im getting dont show that the wastegate is having any issues up to 27lbs. What is it that you are trying to accomplish with a wastegate with a stiffer spring on this turbo?

It doesnt hold 27. It gets 27psi and then fades. A stiffer gate will help hold boost.

He's at 100% wgdc. A stronger spring will allow for more boost. I'd like to see it.

Exactly

Yep this guy gets it! Overspeed, backpressure (too much axial loads), temperature spikes and surge all come to mind. But if we don't have atleast one test mule, then we will never know!

We have spoken alot on the subject. We feel there may be a lil left in the MRX tank.

 

[Turboman17]

Question for you good man, if the wastegate duty cycle is at, let's say, 98%, opposed to, let's say, 50%, aside from having no more room to add boost does that also mean it is running less efficiently or poorly?

Just had a revelation that I have been looking at this on a small scope and incorrectly! We really don't know exactly what the wastegate is doing since we can't measure the wastegate angle or stroke that is being achieved at the target boost pressure. What the wastegate duty cycle is actually referencing is the Boost Control Solenoid. So at 0% WDC <----- The control solenoid is letting no boost/vacuum through to the wastegate, allowing it to do its job and stay closed. At %100 WDC <------ the solenoid is effectively fully open allowing full boost/vacuum through to the wastegate telling it to open.

Now what we don't know is at between %0-100 of WDC, what the actual actuator is doing. Now an actuators movement is normally measured in degree of angle (how much lift/opening the wastegate flapper valve has opened) or stroke distance of the rod. I conferred with a colleague who does tuning and knows engine management systems for OEM's really well and what he says is that most tunes on factory vehicles react the same way. You will have a boost spike then it will taper off and show a %90-100 Wastegate duty cycle to allow the wastegate to do its job depending on certain factors, but mainly for reliability and emissions reasons. Unless we use an electronic wastegate actuator, we cannot monitor stroke of the rod or degrees of opening at certain duty cycles and engine load/RPM.

Now the question that we all want to know, is if by adding wastegate pre-load or going to a stiffer wastegate, can we product more USEABLE PSI/Lbs Min of airflow out of this turbo, or is it at its cap. This question will only be solved by adding a different wastegate and trying to command and tune for higher boost pressures.

So to answer your question Jeff, it all depends on how wastegate duty cycle is measured and in this situation, it really wont have a negative and or positive performance affect commanding so much wastegate duty cycle. All it is telling us is that on their tunes, the tuner (who ever it is) has requested to make no more boost at that current point in RPM, Engine load, throttle input. Now why they haven't requested anymore boost is the question and my assumption is that it is because through tuning the found the point at where they have demanded more boost and either no more boost was made, or most boost was made and no more power was made.

So still-the only option on the MRX is to change wastegates and see if more usable boost can be made or not.

 

[re-rx7]

Just had a revelation that I have been looking at this on a small scope and incorrectly! We really don't know exactly what the wastegate is doing since we can't measure the wastegate angle or stroke that is being achieved at the target boost pressure. What the wastegate duty cycle is actually referencing is the Boost Control Solenoid. So at 0% WDC <----- The control solenoid is letting no boost/vacuum through to the wastegate, allowing it to do its job and stay closed. At %100 WDC <------ the solenoid is effectively fully open allowing full boost/vacuum through to the wastegate telling it to open.

Now what we don't know is at between %0-100 of WDC, what the actual actuator is doing. Now and actuators movement is normally measured in degree of angle (how much lift/opening the wastegate flapper valve has opened) or stroke distance of the rod. I conferred with a colleague who does tuning and know engine management systems for OEM's really well and what he says is that most tunes on factory vehicles react the same way. You will have a boost spike then it will taper off and show a %90-100 Wastegate duty cycle to allow the wastegate to do its job depending on certain factors, but mainly for reliability and emissions reasons. Unless we use an electronic wastegate actuator, we cannot monitor stroke of the rod or degrees of opening at certain duty cycles and engine load/RPM.

Now the question is that we all want to know, is if by adding wastegate pre-load or going to a stiffer wastegate, can we product more USEABLE PSI/Lbs Min of airflow out of this turbo, or is it at its cap. This question will only be solved by adding a different wastegate and trying to command and tune for higher boost pressures.

So to answer your question Jeff, it all depends on how wastegate duty cycle is measured and in this situation, it really wont have a negative and or positive performance affect commanding so much wastegate duty cycle. All it is telling us is that on their tunes, the tuner (who ever it is) has requested to make no more boost at that current point in RPM, Engine load, throttle input. Now why they haven't requested anymore boost is the question and my assumption is that it is because through tuning the found the point at where they have demanded more boost and either no more boost was made, or most boost was made and no more power was made.

So still-the only option on the MRX is to change wastegates and see if more usable boost can be made or not.

Im ordering a 12-14 psi gate today. Should be here mid week next week. Id like for the turbo to hold 24-25 through the band instead of falling to 20-21. I can hit 26psi but from there it gradually falls. What I want is a consistent hold. Whether there is power by doing this is the unknown. I dont think my turbo was pre loaded from Mountune. So I know for sure i didnt do it.

 

[M-Sport fan]

That's why I asked what the waste gate duty cycle is at. The next question is, though, what is the safe psi to run on this turbo? If it's not built to hold a higher psi then upgrading the wastegate could cause reliability problems if you than plan to tune for more boost.

...or if you plan on holding onto this car with THIS kit on it, for longer than most on here ever will (like well past 75K miles)

 

[re-rx7]

Just had a revelation that I have been looking at this on a small scope and incorrectly! We really don't know exactly what the wastegate is doing since we can't measure the wastegate angle or stroke that is being achieved at the target boost pressure. What the wastegate duty cycle is actually referencing is the Boost Control Solenoid. So at 0% WDC <----- The control solenoid is letting no boost/vacuum through to the wastegate, allowing it to do its job and stay closed. At %100 WDC <------ the solenoid is effectively fully open allowing full boost/vacuum through to the wastegate telling it to open.
.

Backwards, At 100% the solenoid is letting all air through trying to keep it shut not open. At 0% it is not letting any air through letting the WG operate on spring pressure. Basically, the wg is getting forced open no matter what since its not strong enough to hold the door shut.

 

[Turboman17]

Backwards, At 100% the solenoid is letting all air through trying to keep it shut not open. At 0% it is not letting any air through letting the WG operate on spring pressure. Basically, the wg is getting forced open no matter what since its not strong enough to hold the door shut.

Not to say your wrong, but the wastegate being used on the MRX is a single top side port. Which normally means that pressure is being used to force down the diaphragm which is connected to the rod and open the wastegate. So to understand correctly, you are saying the solenoid being used on our cars is a (3 or 4 port) vacuum operated unit? Which is creating vacuum on the diaphram and inside the canister to keep it closed? Which I have seen before, I am just verifying that is how our system works. I have not looked that deeply into the stock setup.

Back in the day you never saw vacuum operated systems, only pressure controlled except on race cars that would use a 2 port wastegates.

 

[re-rx7]

Not to say your wrong, but the wastegate being used on the MRX is a single top side port. Which normally means that pressure is being used to force down the diaphragm which is connected to the rod and open the wastegate. So to understand correctly, you are saying the solenoid being used on our cars is a (3 or 4 port) vacuum operated unit? Which is creating vacuum on the diaphram and inside the canister to keep it closed? Which I have seen before, I am just verifying that is how our system works. I have not looked that deeply into the stock setup.

Back in the day you never saw vacuum operated systems, only pressure controlled except on race cars that would use a 2 port wastegates.

The turbo on my car is off right now. At 100% WGDC there just isnt anything else to keep the door shut. Thats with the WGDC wide open. Yes, our cars use a 3port solenoid system. It uses the "boost" pressure to put pressure on the diaphram from the top to keep it shut.

 

[antarctica24]

Just had a revelation that I have been looking at this on a small scope and incorrectly! We really don't know exactly what the wastegate is doing since we can't measure the wastegate angle or stroke that is being achieved at the target boost pressure. What the wastegate duty cycle is actually referencing is the Boost Control Solenoid. So at 0% WDC <----- The control solenoid is letting no boost/vacuum through to the wastegate, allowing it to do its job and stay closed. At %100 WDC <------ the solenoid is effectively fully open allowing full boost/vacuum through to the wastegate telling it to open.

Now what we don't know is at between %0-100 of WDC, what the actual actuator is doing. Now an actuators movement is normally measured in degree of angle (how much lift/opening the wastegate flapper valve has opened) or stroke distance of the rod. I conferred with a colleague who does tuning and knows engine management systems for OEM's really well and what he says is that most tunes on factory vehicles react the same way. You will have a boost spike then it will taper off and show a %90-100 Wastegate duty cycle to allow the wastegate to do its job depending on certain factors, but mainly for reliability and emissions reasons. Unless we use an electronic wastegate actuator, we cannot monitor stroke of the rod or degrees of opening at certain duty cycles and engine load/RPM.

Now the question that we all want to know, is if by adding wastegate pre-load or going to a stiffer wastegate, can we product more USEABLE PSI/Lbs Min of airflow out of this turbo, or is it at its cap. This question will only be solved by adding a different wastegate and trying to command and tune for higher boost pressures.

So to answer your question Jeff, it all depends on how wastegate duty cycle is measured and in this situation, it really wont have a negative and or positive performance affect commanding so much wastegate duty cycle. All it is telling us is that on their tunes, the tuner (who ever it is) has requested to make no more boost at that current point in RPM, Engine load, throttle input. Now why they haven't requested anymore boost is the question and my assumption is that it is because through tuning the found the point at where they have demanded more boost and either no more boost was made, or most boost was made and no more power was made.

So still-the only option on the MRX is to change wastegates and see if more usable boost can be made or not.

I can speak non intelligently on this. My tuner tells me it is a fuel and octane issue. You can make all the boost in the world but if you don't have the fuel or octane to match it your asking for trouble. From my experience is high hp vehicles, boost is a restriction. The key is to make the engine more efficient so you can make the same power on less boost. There are limits here that have not been explored. Normally on a turbo motor, you don't get rod failure because of boost because the rod is always under a load. It's when the rod suddenly comes off a load that causes it to break. However there are other components to take into consideration like crankcase pressure, piston rings and blow by, structural integrity on the bottom end normally fixed by reinforcement of at the oil pan among other issues. On 93 octane this motor is probably good to about 29psi maybe, stock and anything more you are probably asking for catastrophic failure and my guess not all engines are created equal in this regards. Meaning their are probably variances from year to year. That I hit 26.99psi then drop to 22 when I hit 6.5k in a space of 2500 rpm which happens between 4K and 6.5 which happens in probably a second maybe 1.5 seconds. You all act like we're talking about an eternity that the car is loosing boost. Forgive me but this conversation just sounds like a fairytale.
Your hunting for a great white giraffe in the Indian Ocean on planet mars. Even if your racing on a circle track it doesn't sound like a big deal.

 

[re-rx7]

I can speak non intelligently on this. My tuner tells me it is a fuel and octane issue. You can make all the boost in the world but if you don't have the fuel or octane to match it your asking for trouble. From my experience is high hp vehicles, boost is a restriction. The key is to make the engine more efficient so you can make the same power on less boost. There are limits here that have not been explored. Normally on a turbo motor, you don't get rod failure because of boost because the rod is always under a load. It's when the rod suddenly comes off a load that causes it to break. However there are other components to take into consideration like crankcase pressure, piston rings and blow by, structural integrity on the bottom end normally fixed by reinforcement of at the oil pan among other issues. On 93 octane this motor is probably good to about 29psi maybe, stock and anything more you are probably asking for catastrophic failure and my guess not all engines are created equal in this regards. Meaning their are probably variances from year to year. That I hit 26.99psi then drop to 22 when I hit 6.5k in a space of 2500 rpm which happens between 4K and 6.5 which happens in probably a second maybe 1.5 seconds. You all act like we're talking about an eternity that the car is loosing boost. Forgive me but this conversation just sounds like a fairytale.
Your hunting for a great white giraffe in the Indian Ocean on planet mars. Even if your racing on a circle track it doesn't sound like a big deal.

29 psi on 2860 is alot different than 29 psi on the stock turbo. CFM. Think of the power you are missing if that boost never dropped...if the turbo was capable. 4-6500 is the the meat of the band acting like you arent losing anything is asinine at best

 

[antarctica24]

29 psi on 2860 is alot different than 29 psi on the stock turbo. CFM. Think of the power you are missing if that boost never dropped...if the turbo was capable. 4-6500 is the the meat of the band acting like you arent losing anything is asinine at best

I think based on the design of this turbo your dreaming on 29psi at 2900rpm I don't care what kind of wg you put on it. The turbo has to have time to spool up and this housing is too big to make that pressure at that low rpm. Unless I'm missing something. My car feels really strong and feels that way all the way to redline. I'm not saying their aren't more powerful fiestas I'm saying it feels really strong. 29psi at 2900rpm I'd be willing to be you couldn't drive thiat car

 

[re-rx7]

I think based on the design of this turbo your dreaming on 29psi at 2900rpm I don't care what kind of wg you put on it. The turbo has to have time to spool up and this housing is too big to make that pressure at that low rpm. Unless I'm missing something. My car feels really strong and feels that way all the way to redline. I'm not saying their aren't more powerful fiestas I'm saying it feels really strong. 29psi at 2900rpm I'd be willing to be you couldn't drive thiat car

HUH? We are talking about the last 2500 rpm till redline?

 

[Sekred]

The turbo on my car is off right now. At 100% WGDC there just isnt anything else to keep the door shut. Thats with the WGDC wide open. Yes, our cars use a 3port solenoid system. It uses the "boost" pressure to put pressure on the diaphram from the top to keep it shut.

You have it nearly right but boost pressure forces on the actuator diaphragm to move the rod and open the wastegate flap. The solenoid is normally open meaning the boost signal flows from the compressor outlet to the actuator and is powered up to close so the boost signal is bleed off allowing the boost pressure to rise higher the actuator spring pressure. The normally open design is a fall safe meaning if the solenoid fails or we have a broken wire the actuator stills works.

 

[M-Sport fan]

HUH? We are talking about the last 2500 rpm till redline?

I believe that turbo model numbers are being mistaken for boost levels at low revs.
(WHY I cannot stand all of these many different various model numbers/names for the same exact snail! )

 

[antarctica24]

HUH? We are talking about the last 2500 rpm till redline?

I was having a moment sorry I get what your saying

 

[re-rx7]

You have it nearly right but boost pressure forces on the actuator diaphragm to move the rod and open the wastegate flap. The solenoid is normally open meaning the boost signal flows from the compressor outlet to the actuator and is powered up to close so the boost signal is bleed off allowing the boost pressure to rise higher the actuator spring pressure. The normally open design is a fall safe meaning if the solenoid fails or we have a broken wire the actuator stills works.

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