Why does my setup seem to be wearing out Boost Controllers?
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So when I first got my setup aI had a manual boost controller that only lasted me a few weeks until it started not being able to even remotely control the boost spike between gears on my 5AT. So I switched out to a different manual boost controller and that worked fine for a while but wasn't as precise as I would've liked it to be in managin the boost so I switched out to the Apexi AVCR like a month or two ago. I got everything dialed in as good as i possibly could and it was keeping everything in order and my boost was spiking from like .53 to .63 bar (7.5 to 9psi) between shifts which I got used to. Then all of a sudden the other day it started to do what the first MBC did and was spiking to like .66 or .67 bar between shifts and under the same settings was overboosting to like.56 in third and fourth gear sometimes. So basically I had to reconfigure it again and drop the duty cycle from like 42% down to like 38% just to get it to not overshoot the boost but when i shift it is still going way over what I am comfortable with. What could be causing this? Any input would be greatly appreciated.
Thanks,
D. Webb
Thanks,
D. Webb
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small changes in atmospheric conditions can require adjustment of any boost controller if you care about 100% consistency. Running a wierd turbo/wastegate setup like the rear mount you have isnt going to help with consistency either. The best controller is the latest HKS EVC, I would recommend that, and then at least you know you are doing everything you can do in the boost controller department to keep things consistent..
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I've don't think changes in the atmosphere over the past week though would be causing me to have to lower my duty cycle by lik 4-5% and I also don't think it would be causing me to overboost so muych more while shifting. As far as the HKS vs. Apexi boost controllers goes, I've read a lot about it and they are the two top units on the market. The HKS just happens to be more popular with the 350z crowd presumably for the looks. It's deffinitely debateable which one is actually better.
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I've used on my cars in the past the Greddy Profec-B or Profec-e01 with great success. AVC-R is a huge PITA to get nailed down right. BTW, you aren't "wearing down" the boost controller.
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I didn't say thats what is happening. It just seems like that's whats happening. I actually have no idea whats going on. It was stable for about a month and then just went haywire
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Originally Posted by Sharif@Forged
I have yet to see a spike out of the HKS boost controller. But let me ask you, are you seeing a spike, even with the boost controller off?
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Originally Posted by Sharif@Forged
I have yet to see a spike out of the HKS boost controller. But let me ask you, are you seeing a spike, even with the boost controller off?
Are you saying you haven't seen any spikes between shifts on a 5AT with the EVC? I was under the impression from some other owners of 5AT's that this was inevitable to a certain extent... If thats they case I'll buy one tomorrow. Keep in mind its not spiking really when I run all the way through one gear just when I shift and keep it floored.
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This is what GurgenPB told me and he seemed to have some experience dealing with it.
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.
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Originally Posted by danielwebb
This is what GurgenPB told me and he seemed to have some experience dealing with it.
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Originally Posted by Alberto
Just wanted to add Blitz SBC-iD is a top tier EBC...good luck with your issues.
I've thought about that one because it is compact and a little cheaper than the other two.
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Originally Posted by merlin3
the avcr is a top notch boost controller, I doubt that's your problem as I'm running one on my 300 with no problems.
do you have the gear learn mode on or off?
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I've lowered the target boost to .45 bar (6.4psi) and turned the duty cycle up to 52% and that has got things back in line a little more. I also raised the feedback speeds in each gear except 1 and 2. wierd thing is happening now though. I'm still having a boost spike between 2nd and 3rd of like 1.5 psi but the boost spike between 3 and 4 which used to be similar is now almost nothing. what could be causing this?