Wastegate boost pressure relief from opening dump pipe?

[marleyskater420]

Lets say I have stock exhaust,WG-but its adjustable, and a Qboost controller. I have a 3" THDP with a dumppipe and a stock exhaust system.

How much boost does opening the dump relieve?

Example..when the dump is closed I have 14-15psi of pressure, when I open the dump the boost soars over 20psi...how much of a boost increase happens when the dumppipe is open?

With the dump open,the turbo spools awesome, but with it closed its a dog. I have the WG set real loose, and the Qboost kinda around 15 or so.

Im searching for the best HP here and no worries of overboost.

Should I A.)Adjust the boost w/ the dump open,since the turbo spools awesome. OR B.)Play with the dump closed and adjust the stock WG a little tighter,so spoolup is much better,and then play w/ boost from there.

Which will net me more HP? And how much more boost does opening the DP give me?

 

[TurboTR]

Sounds like you have a problem with the catback exh; did a mechanic leave a shop rag in the pipe opening there when the TH stuff went on, or?

TurboTR

 

[87GNcospg]

what kind of turbo do you have?
with the dump open my car spools slower. not a huge difference but i can feel the difference. less backpressure in the exhaust means slower spool time but more top end (i think ) . sounds like your muffler is clogged or something. what does your car sound like with the dump closed?

 

[marleyskater420]

Originally posted by 87GNcospg
what kind of turbo do you have?
with the dump open my car spools slower. not a huge difference but i can feel the difference. less backpressure in the exhaust means slower spool time but more top end (i think ) . sounds like your muffler is clogged or something. what does your car sound like with the dump closed?

quiet...not much louder than stock,if louder at all.

The boost SOARS and spools SO fast with the dump open.

I installed the DP myself,and theres no cat on the car...any ideas?

 

[Fuelie600]

Exhaust restriction. Collapsed muffler internals possibly, or just a poor flowing exhaust. What are you running for a system? Brian