My boost is not consistent, whats the problem?

[kmf4i]

I have to questions. First off, I am running the stock T25 turbo, with a 1g BOV, and RRE UICP. My car boost's about 15 psi, initially, then as the rpm's rise it falls down to 12-13 psi. From my understanding that's normal for that turbo to fall off. But, when I shift from 2nd-3rd, or 3rd-4th the boost jumps up to about 18 psi initially, then it falls back down. What cause's this? Should I take action to fix it, or consider it a godsend to give me a little help when I hit the next gear?

 

[griff]

How long does it take for it to start dropping from 18lbs?

Do you have a boost controller?

 

[marcmsj]

sounds like boost spike to me

 

[kmf4i]

It jumps up to 18 psi as soon as it spools back up, then it falls back down immidiately. I would say it takes about 1 second to fall back down.

 

[CanadianTSi]

That's boost spike, nothing really to worry about.

 

[kmf4i]

What causes it to do that?

 

[mdctalon]

1.) bad boost controllers (don't know if you have one, if you do is it Manual or electronic?)
2.) No boost controller at all.
3.) long boost source or wastegate activation hoses

 

[kmf4i]

I am pretty sure it doesn't have any boost controller, I bought it pretty much this way. The only things I have put on are an injen hard intake pipe, and filter, and 3" cat'back exhaust. I was thinking about buying a mbc from slowboysm are those anygood? Also, if I don't have a boost controller how is it possible for the boost to be increased? I am running around 15psi, it doesn't boost that high stock does it?