My Impressions of the Apexi AVC-R Electronic Boost Controller
Originally Posted by danielwebb
interesting I guess the light weight flywheel causes less load. Sub zero are you on test pipes or cats?
Originally Posted by danielwebb
anyone know if the utec supports this type of tuning? I'm assuming that if the emanage supports it the utec does as well
Originally Posted by GurgenPB
DanielWebb
I have a lot of experience with 5AT and FI.
The spike between gears... get used to it. That is NEVER EVER gonna go away due the very nature of gear shifts... you are at WOT at redline right before the shift, the shift lowers the RPM in a matter of 0.2-0.4 seconds, and slows the incoming stream of air by 20-30% percent due to the drop in RPM/flow. It's impossible to lower the pressure by the boost controller since the phenomemon happens in the reverse direction, from the engine back to the turbos (upstream pressure wave)...and there is nothing a pre-turbo pressure regulator (i.e. boost controller) can do.
I have a lot of experience with 5AT and FI.
The spike between gears... get used to it. That is NEVER EVER gonna go away due the very nature of gear shifts... you are at WOT at redline right before the shift, the shift lowers the RPM in a matter of 0.2-0.4 seconds, and slows the incoming stream of air by 20-30% percent due to the drop in RPM/flow. It's impossible to lower the pressure by the boost controller since the phenomemon happens in the reverse direction, from the engine back to the turbos (upstream pressure wave)...and there is nothing a pre-turbo pressure regulator (i.e. boost controller) can do.
Too bad about the UTEC not supporting this. The EU one actually worked really well, I had it setup to do just that.
No, the BOV can't help in this case, as the BOV works on the principle of pressure differential across the diaphragm...which is why it's connected to the manifold (post-TB)...so that when the TB closes, the pressure in the manifold falls rapidly, while the pressure in the pre-TB piping (at the BOV) rises rapidly...that pressure differential opens the diaphragm...sneeze!
In this case, he is WOT during shifts, so no pressure differential to hank the diaphragm open (as the plenum is still pressurized).
Originally Posted by rcdash
Won't a BOV help in this situation?
In this case, he is WOT during shifts, so no pressure differential to hank the diaphragm open (as the plenum is still pressurized).
Originally Posted by rcdash
hmmm.... so you'd need something to differentiate a pressure change pre-turbo to intake manifold. I take it a BOV couldn't be plumbed in this way?
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wow this thing keeps looking more an more difficult the more i get into it. So I got the peak values close to what i wanted them to and as I was driving today I started to pay attention to the actual boost level not just the peak. While doing this I reallized that it was falling from .53 bar to like .48 between 4k-5k rpm. So I started using the rpm dependent duty cycle setting and got third gear pretty stable. But then when I went and started doing 4th gear it was all F ucked up. This thing is insane. Can anyone make any recommendations on someone who i can just take this thing to and pay them to tune it?
Originally Posted by GurgenPB
Yep this is exactly how they are plumbed.. that's what that vacuum tube is for that goes from your manifold to the top side of the diaphragm on teh bOV.
Ahh i see....
That's definitely not a normal application, and I don't think it could control a spike in boost that's 0.2 seconds long and really has only a 0.1 long significantly high amplitude. I just don't think the diaphragm can open that quickly.
That's definitely not a normal application, and I don't think it could control a spike in boost that's 0.2 seconds long and really has only a 0.1 long significantly high amplitude. I just don't think the diaphragm can open that quickly.
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so gurgen... My car was tuned up to 9 psi but is running at 7.5 (or at least i'm trying to stabilize it there) The spikes generally go right to 9psi on the 2-3 and 3-4 shifts. Do you think this is ok?
I used to run a stock boosted car, I would never see boost in first gear there's no load on the motor and not enough flow, second I would generally get up to full boost and so on.
But I dont know why you would expect to see boost with first of all a rear mounted setup and with a decent sized turbo like you have it just wont happen.
I havent read the whole post but are you running a bov? If not then those spikes your seeing might just be pressure waves from when you shift. When you shift the turbo is still pushing air and that closing of the throttle body creates a wave that travels back to the turbo. You can disregard that if your boost gauge tap is after the throttle body on the engine side not in the piping.
But I dont know why you would expect to see boost with first of all a rear mounted setup and with a decent sized turbo like you have it just wont happen.
I havent read the whole post but are you running a bov? If not then those spikes your seeing might just be pressure waves from when you shift. When you shift the turbo is still pushing air and that closing of the throttle body creates a wave that travels back to the turbo. You can disregard that if your boost gauge tap is after the throttle body on the engine side not in the piping.
Last edited by gNaRKiLL; Jul 27, 2007 at 04:27 PM.
Originally Posted by danielwebb
so gurgen... My car was tuned up to 9 psi but is running at 7.5 (or at least i'm trying to stabilize it there) The spikes generally go right to 9psi on the 2-3 and 3-4 shifts. Do you think this is ok?
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yeah hopefully 3'rd time is going to be the chgarm on valve body upgrades for me. Do you think with the quicker shifts from the SGP valve body the spike will be less?
Originally Posted by gNaRKiLL
I used to run a stock boosted car, I would never see boost in first gear there's no load on the motor and not enough flow, second I would generally get up to full boost and so on.
But I dont know why you would expect to see boost with first of all a rear mounted setup and with a decent sized turbo like you have it just wont happen.
I havent read the whole post but are you running a bov? If not then those spikes your seeing might just be pressure waves from when you shift. When you shift the turbo is still pushing air and that closing of the throttle body creates a wave that travels back to the turbo. You can disregard that if your boost gauge tap is after the throttle body on the engine side not in the piping.
But I dont know why you would expect to see boost with first of all a rear mounted setup and with a decent sized turbo like you have it just wont happen.
I havent read the whole post but are you running a bov? If not then those spikes your seeing might just be pressure waves from when you shift. When you shift the turbo is still pushing air and that closing of the throttle body creates a wave that travels back to the turbo. You can disregard that if your boost gauge tap is after the throttle body on the engine side not in the piping.
I envy those SRT/STI that can make their BOV open even from a standstill. Oh, the OP has an Auto so he don't lift to shift.
Even with the quicker shifts a valve body provides, the rpms are still going to drop down resulting in engine braking and a pressure wave, so I'm not certain if it will help with the boost spikes Daniel. Maybe Gurgen will have a better idea as he has had a lot of experience with all sorts of transmission upgrades.
Last edited by rcdash; Jul 28, 2007 at 08:09 AM.
I don't know that anyone else can do anything - not sure what you mean...
I personally will have a built block and a fully built tranny, so I'm not too worried about boost spikes as long as the tune (which is MAP based) accomodates it...
I personally will have a built block and a fully built tranny, so I'm not too worried about boost spikes as long as the tune (which is MAP based) accomodates it...