| Boost creep? - Click HERE for Original Thread |
| Mekanik22 |
| What is boost creep exactly and how can it be avoided? I have a rough idea of what it is, but I need to be filled in more. :) Thanks guys. |
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| Kris |
| Boost creep is when you have you boost set to a certain Psi and it starts to go past that as you continue to accelerate. Say you have your boost set to 15 Psi and you reach that by 4000 RPM, but by the time you hit red line you are at 17 Psi. That is boost creep. It can be avoided by going with an external waste gate, or an O2 dump if you are internally gated, bigger O2 housing. |
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| REFLUX |
Avoid boost creep by enlarging your wastegate (whether it is internal or external)
Remember, a boost controller w/ a tiny wastegate can NOT control boost creep.
It is purely dependent on the size of the wastegate & the psi it is set to let off boost at. |
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| PraxRX7 |
and remember that boost controllers CANNOT LOWER your boost.
They can only raise your boost by making the wastegate open less.
What ever your car boosts at without a boost controller, you won't be able to "set" it lower. |
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| Pro Drag |
quote:
Originally posted by REFLUX
Avoid boost creep by enlarging your wastegate (whether it is internal or external)
Remember, a boost controller w/ a tiny wastegate can NOT control boost creep.
Straight, simple correct advice.:bthumbup:
If the hole is too small on the wastegate, the path of least resistance will be through the turbine housing, which will spin the turbine wheel faster which will spin the compressor wheel faster, creating more boost than you want.
This is one of the few times in life when you WANT a bigger hole.
However, don't hog out you wastegate hole unless you are running into boost creep, especially on an internally wastegated turbo. The pressure acting on the larger flapper can cause it to open prematurely, adding unwanted lag. |
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| crazyrx7 |
quote:
Originally posted by PraxRX7
and remember that boost controllers CANNOT LOWER your boost.
They can only raise your boost by making the wastegate open less.
What ever your car boosts at without a boost controller, you won't be able to "set" it lower.
Actually your wrong on that. If you turn off the boost controller than you won't be able to boost past what ever your wastegate spring is set at e.g. my fd if I turn off the boost controller then you can't boost over 7psi; 10psi is stock. So yes I can turn down the boost lower than stock. Different cars have different wastegate springs.
R.K.:) |
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| Nightstalker |
quote:
Originally posted by Pro Drag
Straight, simple correct advice.:bthumbup:
If the hole is too small on the wastegate, the path of least resistance will be through the turbine housing, which will spin the turbine wheel faster which will spin the compressor wheel faster, creating more boost than you want.
This is one of the few times in life when you WANT a bigger hole.
However, don't hog out you wastegate hole unless you are running into boost creep, especially on an internally wastegated turbo. The pressure acting on the larger flapper can cause it to open prematurely, adding unwanted lag.
I noticed that the Sivic has the turbo's internal wastegate welded shut and a external one added, is this why you guys did that ? |
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| PraxRX7 |
quote:
Originally posted by crazyrx7
Actually your wrong on that. If you turn off the boost controller than you won't be able to boost past what ever your wastegate spring is set at e.g. my fd if I turn off the boost controller then you can't boost over 7psi; 10psi is stock. So yes I can turn down the boost lower than stock. Different cars have different wastegate springs.
R.K.:)
Either or, you can't turn it "down" past 7 then. |
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| crazyrx7 |
^^^Thats right. 7 psi is the lowest that I can go.
R.K. |
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