Boost psi peak with Cobb AP?
#1
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Boost psi peak with Cobb AP?
I'm using a stage 2 Cobb map that runs and feels smooth but I'm slightly worried about over boosting. I have been using the baro minus absolute pressure to measure the boost with the AP. I'm not sure how accurate a method it is but I occasionally get a 27.5 psi peak. The ECU isn't throwing any codes but I was wondering if this is unsafe. Most of the time it's hitting at 25.5 psi but there is an occasional spike.
What is an acceptable peak boost with the mods I have listed. I have the boost pill removed as well.
Thanks!
What is an acceptable peak boost with the mods I have listed. I have the boost pill removed as well.
Thanks!
#2
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You need to download the newish firmware for you AP. That way you wont have to do any of that math you are using to find out your boost pressure. Just monitor relative pressure.
I have been having the same issue with my AP. Im running the AEM S2 map on 93 oct and hit spikes of up to 28-29 psi. Cobb needs to come out with a map that raises the wastegate duty cycles to help the people that are over boosting. I think this is a pretty common occurrence and with the weather getting cooler in my area the condition has been getting worse.
I have been having the same issue with my AP. Im running the AEM S2 map on 93 oct and hit spikes of up to 28-29 psi. Cobb needs to come out with a map that raises the wastegate duty cycles to help the people that are over boosting. I think this is a pretty common occurrence and with the weather getting cooler in my area the condition has been getting worse.
#4
I'm using a stage 2 Cobb map that runs and feels smooth but I'm slightly worried about over boosting. I have been using the baro minus absolute pressure to measure the boost with the AP. I'm not sure how accurate a method it is but I occasionally get a 27.5 psi peak. The ECU isn't throwing any codes but I was wondering if this is unsafe. Most of the time it's hitting at 25.5 psi but there is an occasional spike.
What is an acceptable peak boost with the mods I have listed. I have the boost pill removed as well.
Thanks!
What is an acceptable peak boost with the mods I have listed. I have the boost pill removed as well.
Thanks!
#5
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Perhaps it is the colder weather. I hadn't taken that into consideration. If I wanted to bring the peak boost down a hair would you guys recommend tweaking the waste gate duty cycle or the Boost Control offset value?
I really don't mind how the car is performing at all. It's really smooth all the way around and the power is great. My concern was whether the occasional spike was dangerous.
Thanks for the replies!
I really don't mind how the car is performing at all. It's really smooth all the way around and the power is great. My concern was whether the occasional spike was dangerous.
Thanks for the replies!
#6
Perhaps it is the colder weather. I hadn't taken that into consideration. If I wanted to bring the peak boost down a hair would you guys recommend tweaking the waste gate duty cycle or the Boost Control offset value?
I really don't mind how the car is performing at all. It's really smooth all the way around and the power is great. My concern was whether the occasional spike was dangerous.
Thanks for the replies!
I really don't mind how the car is performing at all. It's really smooth all the way around and the power is great. My concern was whether the occasional spike was dangerous.
Thanks for the replies!
Last edited by WickedWhite2008; Oct 7, 2009 at 06:05 PM.
#7
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The good thing about occasional boost spikes is that they are quick and harmless. If you were peaking 29psi and holding it to 5500 before the taper, then I'd say you should lower the Boost Control Offset. If it's a quick spike that drops to around 26psi right away, I wouldn't even worry about it, especially if there isn't any knock. You can lower the duty cycles right in the area of the spike if it'll give you some peace of mind.
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#8
The good thing about occasional boost spikes is that they are quick and harmless. If you were peaking 29psi and holding it to 5500 before the taper, then I'd say you should lower the Boost Control Offset. If it's a quick spike that drops to around 26psi right away, I wouldn't even worry about it, especially if there isn't any knock. You can lower the duty cycles right in the area of the spike if it'll give you some peace of mind.
+1
#9
I’ve been running the Stage 1 Map for 6 months now. I’ve seen 25-26psi regularly. But lately with the cold I’ve seen 29psi. It’s just a spike then goes down, but freaks me out. It’s never during a 3k-7k WOT though, seems to be when I’m rolling in 3rd/4th and WOT around 4Kish. Any one ever had a issue after the years?
#10
I’ve been running the Stage 1 Map for 6 months now. I’ve seen 25-26psi regularly. But lately with the cold I’ve seen 29psi. It’s just a spike then goes down, but freaks me out. It’s never during a 3k-7k WOT though, seems to be when I’m rolling in 3rd/4th and WOT around 4Kish. Any one ever had a issue after the years?
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bmxhotsauce (Jan 23, 2020)
#12
You need to download the newish firmware for you AP. That way you wont have to do any of that math you are using to find out your boost pressure. Just monitor relative pressure.
I have been having the same issue with my AP. Im running the AEM S2 map on 93 oct and hit spikes of up to 28-29 psi. Cobb needs to come out with a map that raises the wastegate duty cycles to help the people that are over boosting. I think this is a pretty common occurrence and with the weather getting cooler in my area the condition has been getting worse.
I have been having the same issue with my AP. Im running the AEM S2 map on 93 oct and hit spikes of up to 28-29 psi. Cobb needs to come out with a map that raises the wastegate duty cycles to help the people that are over boosting. I think this is a pretty common occurrence and with the weather getting cooler in my area the condition has been getting worse.
on pump gas you guys should not be seeing 27-29PSI if so thats really bad. most E85 cars see that with no issues on the stock turbo.
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