Monitoring cycling valve
02-15-2005, 12:30 PM
#1
Burning Brakes
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Monitoring cycling valve
I have a crackpot idea.
I think my cycling valve is playing up, occasionally opening when it shouldn't - sometimes I'll only be able to get 1.2bar.
One time when it was misbehaving, I put 12V across it, and it only switched sometimes.
Am I correct in assuming that it defaults (no voltage) to open - running boost straight to the wastegate - as a safety measure ?
If I replace the CV with a manual boost controller, could I re-wire the CV power to indicator lights - a green one for when it's hot (closed, boosting), and a red one for when it thinks I shouldn't be ?
From what I've read, the computer will sometimes limit your boost if something else goes wrong, and an MBC would remove that safeguard. Putting a light back in should give me an indication, right ?
I think my cycling valve is playing up, occasionally opening when it shouldn't - sometimes I'll only be able to get 1.2bar.
One time when it was misbehaving, I put 12V across it, and it only switched sometimes.
Am I correct in assuming that it defaults (no voltage) to open - running boost straight to the wastegate - as a safety measure ?
If I replace the CV with a manual boost controller, could I re-wire the CV power to indicator lights - a green one for when it's hot (closed, boosting), and a red one for when it thinks I shouldn't be ?
From what I've read, the computer will sometimes limit your boost if something else goes wrong, and an MBC would remove that safeguard. Putting a light back in should give me an indication, right ?
02-15-2005, 04:45 PM
#2
Pro
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AFAIK you are correct that the cycling valve defaults to low boost.
You can't connect an indicator light to it though. The KLR gives a pulse modulated signal to the valve, not an on/off signal. It's like the signal to the injectors, a longer pulse will give more flow. I'm not sure of the switching frequency but it is several periods per second. I may have heard the figure 10 Hz but I'm not sure.
Tomas
You can't connect an indicator light to it though. The KLR gives a pulse modulated signal to the valve, not an on/off signal. It's like the signal to the injectors, a longer pulse will give more flow. I'm not sure of the switching frequency but it is several periods per second. I may have heard the figure 10 Hz but I'm not sure.
Tomas
02-18-2005, 01:40 PM
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Burning Brakes
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OK, slightly different question. If I go into an overboost / fault condition, is there an idiot light that goes on, or is my only signal the fact that I can't boost over 1.2 bar ?
Do I lose any safety by replacing my intermittent CV with an MBC ?
Is an LBE suitable for use alone, or should I get a specific MBC ?
Do I lose any safety by replacing my intermittent CV with an MBC ?
Is an LBE suitable for use alone, or should I get a specific MBC ?
02-18-2005, 03:20 PM
#4
Three Wheelin'
The only way you know the engine is in an overboost condition is the car stops accelerating, similar to hitting the brakes. Of course the same thing will happen should the mixture go lean and the engine starts to knock.
If you switch from a CV to an MBC you need to dial in how much boost you get before the Waste Gate opens. Too much boost and things go BANG!
I have a ReliaBoost that is set at 15 psi, and with a Guru Chipset I get just under 2 BAR on the stock gage. The LBE is a similar device to the Reliaboost, while the AccuBoost MBC has an adjusting **** that is mounted in the cockpit.
If you switch from a CV to an MBC you need to dial in how much boost you get before the Waste Gate opens. Too much boost and things go BANG!
I have a ReliaBoost that is set at 15 psi, and with a Guru Chipset I get just under 2 BAR on the stock gage. The LBE is a similar device to the Reliaboost, while the AccuBoost MBC has an adjusting **** that is mounted in the cockpit.
02-18-2005, 03:27 PM
#5
Burning Brakes
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The only way you know the engine is in an overboost condition is the car stops accelerating, similar to hitting the brakes. Of course the same thing will happen should the mixture go lean and the engine starts to knock.
02-18-2005, 03:46 PM
#6
Three Wheelin'
Yep.
Part of the KLR's function is KNOCK contol. When the KLR hears knocking (ping, detonation) it automatically retards ignition timing to reduce power. There is also a "limp home mode" that severely limits engine power, and the DME has a pre-set Rev Limiter to keep the enigne from self destructing.
Part of the KLR's function is KNOCK contol. When the KLR hears knocking (ping, detonation) it automatically retards ignition timing to reduce power. There is also a "limp home mode" that severely limits engine power, and the DME has a pre-set Rev Limiter to keep the enigne from self destructing.