Small vacuum line is a much better way to solve the problem. MUCH better. Simpler, cheaper, less failure points, less BS, etc. Get the smallest vacuum hose Autozone sells. That's what I'm running. Also they sell some tiny *** hard plastic tubing in a roll that works great too, just have to use small hose to hook it to things. But a smaller ID hose is a much better solution than adding filters/ restrictors, etc.

 

Wel ding tip!

 

y8s- what are you using to control boost? Your boost is stupid flat. Mine kinda goes up and down 3-4kPa during any given pull. Probably doesn't matter.

Also- any reason to use a restrictor w/ a big line vs. a small line? I ran a big line and had poor map values at idle. Smaller line fixed it.

 

can you give me a pic of what you're talking about please?

 

something like this

 

I have my wastegate vac-line on my compressor housing...should I move it somewhere better like the brake booster line, or intake plenum?

On my other cars I ran it off the intake plenum with a profec-b and never had this problem.

 

boostcontrol



...

the external wastegate doesn't hurt either. incidentally, I have a 3.8psi wastegate spring and run just shy of 10 lbs of boooooost.

 

PS I tee the vac lines all over the place. my boost gauge, MAP signal, and BOV I think are all on the same line. nice huh?

 

I'm running an external gate too. Is yours a dual port and is it plumbed that way? Or is is it just manifold>MBC>side port?

Also, if you have a 3.8 PSI spring, you'd about have to be using both ports else you'd overcome the waste gate before 10 PSI.

 

it's a dual port and I am using only the top port (TiAL). turbo>mbc>top port.

and since the diaphragm that holds the WG closed is more area than the port the exh gas passes through, it doesn't overwhelm the spring. at least at this boost level.

 

That is one weird way to plumb a EWG. Any time I've read that the boost controller goes to the top, they had the side port referenced to manifold pressure. Still not sure I see any advantage to doing it your way.

 

you dont see any advantage except that ruler flat boost line

it may not be the right way, but it works damn well.

 

Your way the wastegate will start to creep open before you reach target boost. That's what I don't like about it. But yeah that explains why it's so damn flat.

 

just realized I meant the SIDE port, not the top. the top is open. ewps.

photographic evidence!

 

Ah, yes. That's how it's usually done. That's how mine is setup. From my research on it though, the most ideal setup for maximum spool and boost control is to reference the top port to manifold, then use your MBC as it's installed to adjust the boost. And to use a spring that's close to your target boost. Tight spring + top port referenced to manifold = that bitch is shut till the MBC says open.