Damn APEX AVC-R!!!!
26 May 2001, 11:40 PM
#1
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Seems like everyone is having problems with this EBC.
Can someone please help figure out what have I done wrong? I set my boost level to 1.15bar, but it overshoots to 1.25-1.30 at gear changes.... I tried lovering the "start duty" but then it woudn't hit the tagret boost level... I also tried playing with "FB Speed"... it doesn't work. Now I start doubting if I connected the solenoid correctly. One of the port coonects to turbo outlet and another one to the actuator, right? Or is it a "bleed" type (like the OEM one)?
I also found my car to be jerky on gear changes, so I changed my HKS SQV blow off valve to standard and noticed a huge improvement.
Nick
Can someone please help figure out what have I done wrong? I set my boost level to 1.15bar, but it overshoots to 1.25-1.30 at gear changes.... I tried lovering the "start duty" but then it woudn't hit the tagret boost level... I also tried playing with "FB Speed"... it doesn't work. Now I start doubting if I connected the solenoid correctly. One of the port coonects to turbo outlet and another one to the actuator, right? Or is it a "bleed" type (like the OEM one)?
I also found my car to be jerky on gear changes, so I changed my HKS SQV blow off valve to standard and noticed a huge improvement.
Nick
27 May 2001, 04:29 AM
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hi gevor.
this is not a start duty problem if your start duty is set to zero you should be getting the boost target you set and no more
but....
lower the duty on the avc-r ( duty not start duty)if set to high then you will get higher boost.
this is not a start duty problem if your start duty is set to zero you should be getting the boost target you set and no more
but....
lower the duty on the avc-r ( duty not start duty)if set to high then you will get higher boost.
27 May 2001, 06:31 AM
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Hi Gevor,
What do you mean it overshoots AT GEAR CHANGES? What kind of base duty cycle are you using? Typically, 70+/- is a good figure to start with for 1.15 bar. If it overboosts, lower the duty. Raise it if you can't hit 1.15 bar. Once it stabilises around target boost, the unit will change the Dty to *** and self-learn will begin.
I suggest you re-initialise the whole unit, set in the correct parameters (engine cyl, throttle voltage etc), do the learn-gear ratios and kickstart self-learning again. Also, make sure your self-learning is not turned off. F/B speed changes the reaction time of the AVC-R. If you set it too high (e.g. 9), your boost will start to oscillate badly (overboost..underboost..overboost...) because the frequency at which boost is checked and regulated is much longer. If you set it too low, boost response might be sluggish. The trick is to choose the highest possible F/B speed for each gear without oscillation occurring. Typically, you use a higher F/B speed for the first couple of gears.
As for connections, it's NO port from compressor and COM port to actuator. Leave the NC port open to atmosphere.
Don't despair dude. I've set up quite a number of AVC-Rs before and they've always worked beautifully. Write back if you still have problems.
What do you mean it overshoots AT GEAR CHANGES? What kind of base duty cycle are you using? Typically, 70+/- is a good figure to start with for 1.15 bar. If it overboosts, lower the duty. Raise it if you can't hit 1.15 bar. Once it stabilises around target boost, the unit will change the Dty to *** and self-learn will begin.
I suggest you re-initialise the whole unit, set in the correct parameters (engine cyl, throttle voltage etc), do the learn-gear ratios and kickstart self-learning again. Also, make sure your self-learning is not turned off. F/B speed changes the reaction time of the AVC-R. If you set it too high (e.g. 9), your boost will start to oscillate badly (overboost..underboost..overboost...) because the frequency at which boost is checked and regulated is much longer. If you set it too low, boost response might be sluggish. The trick is to choose the highest possible F/B speed for each gear without oscillation occurring. Typically, you use a higher F/B speed for the first couple of gears.
As for connections, it's NO port from compressor and COM port to actuator. Leave the NC port open to atmosphere.
Don't despair dude. I've set up quite a number of AVC-Rs before and they've always worked beautifully. Write back if you still have problems.
27 May 2001, 08:56 AM
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I will try to initialize the unit, that's my last hope
The problem is that if I set the "Start Duty" to 0 I hit the target boost no problem, but I quickly change from 2nd to 3rd or rom 3rd to 4th the boost spikes to 1.30bar, I can even hear detonaion sound. If I lower the "Start Duty" the spikes are not that high but I can't hit the target boost.
Another queston - does anybody hit the target boost on 1st and 2nd gears? I don't and I think this is normal due to not enough load.
There's also another possible reason: I have and aftermarket center section (no cat, no resonator) and backbox, but the downpipe is still stock. Is it possible that the wastegate is not working properly because of that?
Cheers,
Nick
The problem is that if I set the "Start Duty" to 0 I hit the target boost no problem, but I quickly change from 2nd to 3rd or rom 3rd to 4th the boost spikes to 1.30bar, I can even hear detonaion sound. If I lower the "Start Duty" the spikes are not that high but I can't hit the target boost.
Another queston - does anybody hit the target boost on 1st and 2nd gears? I don't and I think this is normal due to not enough load.
There's also another possible reason: I have and aftermarket center section (no cat, no resonator) and backbox, but the downpipe is still stock. Is it possible that the wastegate is not working properly because of that?
Cheers,
Nick
27 May 2001, 11:46 AM
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Yo Gevor,
It takes a while (maybe half a tank of fuel of continuous thrashing) for the self-learn to adjust and stabilise the duty cycle curve. Bear in mind that you MUST get it to self-learn mode first before it can do that, otherwise it will use the same duty for the entire rev range, and this often results in overboost conditions. Also, it is important that you take the readings on your boost gauge as benchmark. It's not uncommon for the boost gauge and AVC-R to report different boost values. In such cases, ALWAYS trust your boost gauge. Never take the readings derived from the AVC-R pressure sensor as gospel. These should be calibrated against your boost gauge before tuning/self-learning by the way.
The self-learning works and adjusts the duty curve continuously, until you switch the feature off. Usually, it's harder to hit target boost in the first couple of gears due to a lack of load and/or too much backpressure (in the case of a car with stock exhaust for example), but this can be overcome by playing with the Start Duty. Take my MY94 for example, I have to use +10% for first gear and +3% for second gear, on top of the base duty, to hit 1 bar. Third, fourth and fifth will yield 1 bar without any Start Duty adjustment (+/- 0%). By the way, when I say 1 bar, I'm referring to 1 bar on my boost gauge. It'll show anything between 1.00 to 1.05 (in extreme cases it might even show 1.10) on the AVC-R. The AVC-R pressure sensor just isn't precise enough to give the correct reading, although for your case, the overboost does seem a bit too much.
Your exhaust modification should not have any impact at all on your wastegate. Your max boost might go up some, but the wastegate should still function the same way. It shouldn't affect the AVC-R at all unless your AVC-R was tuned before all the exhaust changes.
Best regards,
Jack
It takes a while (maybe half a tank of fuel of continuous thrashing) for the self-learn to adjust and stabilise the duty cycle curve. Bear in mind that you MUST get it to self-learn mode first before it can do that, otherwise it will use the same duty for the entire rev range, and this often results in overboost conditions. Also, it is important that you take the readings on your boost gauge as benchmark. It's not uncommon for the boost gauge and AVC-R to report different boost values. In such cases, ALWAYS trust your boost gauge. Never take the readings derived from the AVC-R pressure sensor as gospel. These should be calibrated against your boost gauge before tuning/self-learning by the way.
The self-learning works and adjusts the duty curve continuously, until you switch the feature off. Usually, it's harder to hit target boost in the first couple of gears due to a lack of load and/or too much backpressure (in the case of a car with stock exhaust for example), but this can be overcome by playing with the Start Duty. Take my MY94 for example, I have to use +10% for first gear and +3% for second gear, on top of the base duty, to hit 1 bar. Third, fourth and fifth will yield 1 bar without any Start Duty adjustment (+/- 0%). By the way, when I say 1 bar, I'm referring to 1 bar on my boost gauge. It'll show anything between 1.00 to 1.05 (in extreme cases it might even show 1.10) on the AVC-R. The AVC-R pressure sensor just isn't precise enough to give the correct reading, although for your case, the overboost does seem a bit too much.
Your exhaust modification should not have any impact at all on your wastegate. Your max boost might go up some, but the wastegate should still function the same way. It shouldn't affect the AVC-R at all unless your AVC-R was tuned before all the exhaust changes.
Best regards,
Jack
27 May 2001, 05:49 PM
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PERFECT THREAD!!! I was just about to post the same.....
I`ve had the AVC-R in my UK 00MY for about 3 months now.
Gevor,
I`ve had exactly the same problem as you!
On initial application to WOT and on gear shifting I get boost oscillation of upto 0.15 mm/hg!
My unit kicked into self-learn after I set it initialy but the problem has not got any better.
I have just checked connections - I tried fitting it as per the std. set-up ie connected NO port to T-piece in compressor-to-wastgate pipe. No joy. Unit did not work. Car hit about 7psi - ie limp home mode.
Then tried fitting as before - NO port to compressor but included the brass restrictor in the compressor pipe. This lowered the duty cycle setttings to get the same boost as before but oscillation was not affected. I would say this was to be expected as the restrictor acts as a time delay.
So back to origianl installation with the same problems....
Jack,
I have to disagree!! I think the AVCR supplied pressure sensor would be very accurate. More so then the majority of dial gauges in use. I also have another A-pillar gauge an this mirrors the AVC oscillation charateristic.
If you have seen the same type of oscillations on other AVCR installs on Scooby`s I would say that these oscilations in boost were REAL and happening.
why would I hit the fuel cut defender exactly as the AVC-R oscillates to 1.25mm/hg which happens to be the cut limit. ie the car is cutting at the correct pressure accordiing to the AVC-R.
This unfortunately leeds me to think that the the AVC-R is a nice head-unit but a crap controller, unless I need to play with the under/over duty cycle on the start duty screen. Once into the boost curve, boost is held to +/- 0.02mm/hg
I know that NITO (?) is running an HKS jobby (I think) and doesn`t seem to have reported the same problems....
Can anyone shed some light on all this????
I`ve had the AVC-R in my UK 00MY for about 3 months now.
Gevor,
I`ve had exactly the same problem as you!
On initial application to WOT and on gear shifting I get boost oscillation of upto 0.15 mm/hg!
My unit kicked into self-learn after I set it initialy but the problem has not got any better.
I have just checked connections - I tried fitting it as per the std. set-up ie connected NO port to T-piece in compressor-to-wastgate pipe. No joy. Unit did not work. Car hit about 7psi - ie limp home mode.
Then tried fitting as before - NO port to compressor but included the brass restrictor in the compressor pipe. This lowered the duty cycle setttings to get the same boost as before but oscillation was not affected. I would say this was to be expected as the restrictor acts as a time delay.
So back to origianl installation with the same problems....
Jack,
I have to disagree!! I think the AVCR supplied pressure sensor would be very accurate. More so then the majority of dial gauges in use. I also have another A-pillar gauge an this mirrors the AVC oscillation charateristic.
If you have seen the same type of oscillations on other AVCR installs on Scooby`s I would say that these oscilations in boost were REAL and happening.
why would I hit the fuel cut defender exactly as the AVC-R oscillates to 1.25mm/hg which happens to be the cut limit. ie the car is cutting at the correct pressure accordiing to the AVC-R.
This unfortunately leeds me to think that the the AVC-R is a nice head-unit but a crap controller, unless I need to play with the under/over duty cycle on the start duty screen. Once into the boost curve, boost is held to +/- 0.02mm/hg
I know that NITO (?) is running an HKS jobby (I think) and doesn`t seem to have reported the same problems....
Can anyone shed some light on all this????
27 May 2001, 08:22 PM
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Another wierd thing that proves that Jack is right about AVCR's pressure sensor being not correct: sometimes I get boost spikes up to 1.30bar and I the fuel cut doesn't kick in.
Once again, I want to say that I had this unit for around a month now, and I've played with all the settings, initializing the unit several times. I have no problem hitting the target boost (1.15bar) at WOT. The problem occurs only when shifting at redline - the boost jumps up to 1.20-1.25bar. I will try to change my downpipe and see if that helps.
BTW, when I changed my center section and the backbox the boost started oscillating badly (from 0.6-1.15)... so I still think/hope that the problem is in my DP
Cheers,
Nick
Once again, I want to say that I had this unit for around a month now, and I've played with all the settings, initializing the unit several times. I have no problem hitting the target boost (1.15bar) at WOT. The problem occurs only when shifting at redline - the boost jumps up to 1.20-1.25bar. I will try to change my downpipe and see if that helps.
BTW, when I changed my center section and the backbox the boost started oscillating badly (from 0.6-1.15)... so I still think/hope that the problem is in my DP
Cheers,
Nick
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29 May 2001, 06:44 PM
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Hi Guys,
I'm not saying the pressure sensor will cause the readings to go haywire, just that it's always better IMHO to benchmark your boost against a more reliable measurement mechanism, i.e. a good boost gauge. It's more a fail safe measure in case either decides to screw up.
More checks:
1. Is your original solenoid disconnected? Disconnected as in it has to be there, but it shouldn't be taking any readings and it shouldn't be bleeding to any part of the system anymore. Seal the pipe-back into the airbox if you're still using the airbox.
2. Where did you plumb the pressure sensor into? One good place would be the same spot where you plumb your boost gauge to, e.g. manifold.
3. Did you use the original hoses supplied? The solenoid is VERY sensitive to varying hose sizes. Using too large diameter hoses will almost guarantee unstable boost. Happened to me previously when I was using the old AVC-R (2 generations ago). To confirm this, put in a restrictor or a one-way flow control valve and see if the oscillation is reduced.
4. Check the <<Car Select>> settings and confirm them with the <<Sensor Check>> readings somewhere inside the nest of etc functions, especially the TPS voltage. Strangely, it's reversed on my MY94.
More suggestions:
Try lowering the FB speed and see if it alleviates your oscillation problem. I'm using 5/4/3/3/3 if it's any help, but on another friend's JDM WRX, I had to pull it all the way back to 2/1/1/1/1 for optimum stability. Usually, oscillations problems are either hose-size related or due to this.
BTW, if you're getting 7 psi or 0.5 bar, it means the AVC-R is not performing boost control at all. The standard actuator spring is tensioned at this pressure.
I've heard both good and bad stories on just about every EBC in the market. Most of the time, it's just a bad connection or a bad setting or in some very rare cases bad luck cos of bad parts....
I'm not saying the pressure sensor will cause the readings to go haywire, just that it's always better IMHO to benchmark your boost against a more reliable measurement mechanism, i.e. a good boost gauge. It's more a fail safe measure in case either decides to screw up.
More checks:
1. Is your original solenoid disconnected? Disconnected as in it has to be there, but it shouldn't be taking any readings and it shouldn't be bleeding to any part of the system anymore. Seal the pipe-back into the airbox if you're still using the airbox.
2. Where did you plumb the pressure sensor into? One good place would be the same spot where you plumb your boost gauge to, e.g. manifold.
3. Did you use the original hoses supplied? The solenoid is VERY sensitive to varying hose sizes. Using too large diameter hoses will almost guarantee unstable boost. Happened to me previously when I was using the old AVC-R (2 generations ago). To confirm this, put in a restrictor or a one-way flow control valve and see if the oscillation is reduced.
4. Check the <<Car Select>> settings and confirm them with the <<Sensor Check>> readings somewhere inside the nest of etc functions, especially the TPS voltage. Strangely, it's reversed on my MY94.
More suggestions:
Try lowering the FB speed and see if it alleviates your oscillation problem. I'm using 5/4/3/3/3 if it's any help, but on another friend's JDM WRX, I had to pull it all the way back to 2/1/1/1/1 for optimum stability. Usually, oscillations problems are either hose-size related or due to this.
BTW, if you're getting 7 psi or 0.5 bar, it means the AVC-R is not performing boost control at all. The standard actuator spring is tensioned at this pressure.
I've heard both good and bad stories on just about every EBC in the market. Most of the time, it's just a bad connection or a bad setting or in some very rare cases bad luck cos of bad parts....
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