Bleed Valves Rant
#41
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On some cars bleed valves work very well, and are cheap.
I fitted a plastic fish tank bleed valve to my Volvo turbo estate. £1.89
Does the job perfectly.
Every application is different though, but as long as the w/g is sized well for the engine, then a simple bleed valve can be very good.
If people out there think they are shite and useless.....it must be because they dont understand how they should be used.
I fitted a plastic fish tank bleed valve to my Volvo turbo estate. £1.89
Does the job perfectly.
Every application is different though, but as long as the w/g is sized well for the engine, then a simple bleed valve can be very good.
If people out there think they are shite and useless.....it must be because they dont understand how they should be used.
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think the problem is that people blame the bleed valve for the engine melting
when the problem is that it wasnt made idiot proof
so any fuckwit can make their car go like fuck just with a couple little turns(not for long)
when the problem is that it wasnt made idiot proof
so any fuckwit can make their car go like fuck just with a couple little turns(not for long)
#43
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Correct.
Do you guys twiddle your fuel pressure regs too?
They do remove the ecu's ability to lower boost if you actually replace your boost control valve with one instead of fitting it in adition to it, but they are no more dangerous than an amal valve providing:
1) You use a quality one like this:
2) You set it safely, which usually means letting a tuner set it.
Do you guys twiddle your fuel pressure regs too?
They do remove the ecu's ability to lower boost if you actually replace your boost control valve with one instead of fitting it in adition to it, but they are no more dangerous than an amal valve providing:
1) You use a quality one like this:
2) You set it safely, which usually means letting a tuner set it.
Martin
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I had one on my escort cossie when it was converted to big turbo for 2 years it was never touched once set & never gave any bother boost was the same all the time went perfect , infact its one of the best cars ive had for boost with amal valves etc ive always had bother , air injectors sometimes the boost was funny not always the same bleed valve was ok.
#50
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amal valves can fail,bleed valve is not electrical so the only thing that can happen is that it is turned somehow,so get a lockable one.
i fail to see how its any different from a massively expensive electric boost control module that you can also play about with and potentially melt your engine,funny that never gets mentioned though.
i fail to see how its any different from a massively expensive electric boost control module that you can also play about with and potentially melt your engine,funny that never gets mentioned though.
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From what I've heard (feel free to correct me if I'm wrong here)
Bleed valves can be used and are safe....as long as the car is mapped to it's maximum safe level of boost. i.e you can raise and lower the boost as you see fit (for weather conditions, daily driving etc) but only to the maximum safe limit for your engine.
Bleed valves can be used and are safe....as long as the car is mapped to it's maximum safe level of boost. i.e you can raise and lower the boost as you see fit (for weather conditions, daily driving etc) but only to the maximum safe limit for your engine.
#52
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i love the bleed valves are wank topics, nothing wrong with them in essence.
even an electronic boost controller is a bleed valve (air to air are not the same), it's about allowing a small percentage of boost to not make it to the actuator, therefore reducing force acting against the actuator spring.
if your not an idiot, then you'll only open it up enough so it raises the boost safely enough without spiking/surging too much in a safe environment.
even an electronic boost controller can knacker an engine if someone sets it too high, so no worse than a bleed valve.
the only benefit to an EBC is that you can have various settings and still keep the valve close to the turbo so not increasing the pipe length and therefore keep spikes to a minimum and reducing chance of pipe splits that could occur on longer runs.
even an electronic boost controller is a bleed valve (air to air are not the same), it's about allowing a small percentage of boost to not make it to the actuator, therefore reducing force acting against the actuator spring.
if your not an idiot, then you'll only open it up enough so it raises the boost safely enough without spiking/surging too much in a safe environment.
even an electronic boost controller can knacker an engine if someone sets it too high, so no worse than a bleed valve.
the only benefit to an EBC is that you can have various settings and still keep the valve close to the turbo so not increasing the pipe length and therefore keep spikes to a minimum and reducing chance of pipe splits that could occur on longer runs.
#54
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The other can be a totally adjustable air bleed at any rpm, boost level, throttle, road speed....whatever way you want to map it.
Ultimately they are both simply air leaks. But it can be a little more complicated than that
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just saying how it can be done
was done to my car by ava a few years ago
but opinions vary on whether they are reputable or not lol
was done to my car by ava a few years ago
but opinions vary on whether they are reputable or not lol
#58
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My bleed valve was fitted by a tuner as my Amal valve was not working properly. The car was then set up by the tuner and has run spot on for the last 4 years and 12k miles and I've never been tempted to up the boost. I can't see what the fuss is about.
#59
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Might beg the question, why fit air injectors ?
What cant you see is different ? One is a simple adjustable orifice to bleed air, regardless of anything else.
The other can be a totally adjustable air bleed at any rpm, boost level, throttle, road speed....whatever way you want to map it.
Ultimately they are both simply air leaks. But it can be a little more complicated than that
What cant you see is different ? One is a simple adjustable orifice to bleed air, regardless of anything else.
The other can be a totally adjustable air bleed at any rpm, boost level, throttle, road speed....whatever way you want to map it.
Ultimately they are both simply air leaks. But it can be a little more complicated than that
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Sorry, I never stated why I hate them...
1) too easy to adjust. These are rarely properly set and sealed so cannot be adjusted.
2) Most are cable tied to a boost hose or left dangling in the engine bay .... utter bodge IMO.
3) Unstable boost levels depending on ambient air temperature due to the thermal expansion of brass.
(plastic AMAL valves are less suseptable![Wink](https://passionford.com/forum/images/smilies/icon_wink.gif)
4) I just really hate them !! lol
1) too easy to adjust. These are rarely properly set and sealed so cannot be adjusted.
2) Most are cable tied to a boost hose or left dangling in the engine bay .... utter bodge IMO.
3) Unstable boost levels depending on ambient air temperature due to the thermal expansion of brass.
(plastic AMAL valves are less suseptable
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4) I just really hate them !! lol
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Sorry, I never stated why I hate them...
1) too easy to adjust. These are rarely properly set and sealed so cannot be adjusted.
2) Most are cable tied to a boost hose or left dangling in the engine bay .... utter bodge IMO.
3) Unstable boost levels depending on ambient air temperature due to the thermal expansion of brass.
(plastic AMAL valves are less suseptable![Wink](https://passionford.com/forum/images/smilies/icon_wink.gif)
4) I just really hate them !! lol
1) too easy to adjust. These are rarely properly set and sealed so cannot be adjusted.
2) Most are cable tied to a boost hose or left dangling in the engine bay .... utter bodge IMO.
3) Unstable boost levels depending on ambient air temperature due to the thermal expansion of brass.
(plastic AMAL valves are less suseptable
![Wink](https://passionford.com/forum/images/smilies/icon_wink.gif)
4) I just really hate them !! lol
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no one has mentioned the fact that bleeding too much air off can damage the turbo as it has to spin faster to compensate for the loss of pressure on the compressor side, overspeeding can prematurely wear the turbo, not to mention the increase in back pressure required to make it spin faster, creating a loss in power at the same time
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Its true.. to a point !
Are you saying metal doesnt expand ? ...LOL
The air gap is very small and expansion does affect the amount of air passed.
Also, the temperature of the air will affect boost level as the denser it is, the less it will pass.
I will say that the variations will be small the majority of the time.
I suppose anything other than true closed loop boost control is pants and unsafe IMO !
Are you saying metal doesnt expand ? ...LOL
The air gap is very small and expansion does affect the amount of air passed.
Also, the temperature of the air will affect boost level as the denser it is, the less it will pass.
I will say that the variations will be small the majority of the time.
I suppose anything other than true closed loop boost control is pants and unsafe IMO !
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Its true.. to a point !
Are you saying metal doesnt expand ? ...LOL
The air gap is very small and expansion does affect the amount of air passed.
Also, the temperature of the air will affect boost level as the denser it is, the less it will pass.
I will say that the variations will be small the majority of the time.
I suppose anything other than true closed loop boost control is pants and unsafe IMO !
Are you saying metal doesnt expand ? ...LOL
The air gap is very small and expansion does affect the amount of air passed.
Also, the temperature of the air will affect boost level as the denser it is, the less it will pass.
I will say that the variations will be small the majority of the time.
I suppose anything other than true closed loop boost control is pants and unsafe IMO !
#67
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Yes it does, but also its usually in a linear fashion, along its length I believe.
The temperature issue will affect amal valves too of course, but Ford seem perfectly ok with it. LOL
For reference, what Simon the scaremonger is referring to as "Unstable boost levels " is instead of 20psi, you may indeed run 20.01psi instead due to thermal expansion and air density issues.
The temperature issue will affect amal valves too of course, but Ford seem perfectly ok with it. LOL
For reference, what Simon the scaremonger is referring to as "Unstable boost levels " is instead of 20psi, you may indeed run 20.01psi instead due to thermal expansion and air density issues.
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I find this thread mildly amusing as most of my mates have, or have had turbo cars with boost gauges, and when you ask them "what boost does it run?" they say "i dont know" or "not sure it goes up and down a lot" to which i normally answer oh i see.
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I have removed several brass type bleed valves to fit an amal type valve in place with simple on/off control and the stability issues dissapeared.
I thought all quality tuners hated them or removed them on sight given the chance
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#75
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You will probably find that those cars had too large a boost adjustment made to them by the bleed valve or were incorrectly fitted by someone. Amal valves score over the cheaper valves by their ability to be jetted which can aleviate some such problems. More expensive ones are also jetted.
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Mine is exactly the same as yours mate, was fitted when tuned before i got the car and i've never touched it.
Although i've always told myself im gonna get it back on an amal valve next time its set up