del_orson

What is the best vacuum source for my waste gate. I was going to go to the port on my turbo housing.

97hb

Using the port on the compressor housing, no problems here.

Tchleung

Same with me. right off the compreossr housing. nice and simple...

del_orson

thanxs alot guys, ill do that

boosted420a

you can also use any other vacum line, I have read a guy picked up 20 WHP by switching his wastegate line from the turbine housing to the intake manifold.

SSBPGSR

maybe he picked up 20 more HP because he had some boost creep and upped the boost a little by using a terrible vacuum source.

Dunc

Hey SSBPGSR, why do you say that intake manifold is a bad source for the wastegate...I'm not trying to sound like a newb, just curious if there is acutal reason behind it. That's where mine is currently plumbed to, but don't worry I <U>am</U> re-routing it to the compressor side as soon as I get the chance. I think it is actually causing my wastegate to open prematurely at 10psi

BlueShadow

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dunc &raquo;</TD></TR><TR><TD CLASS="quote">Hey SSBPGSR, why do you say that intake manifold is a bad source for the wastegate...I'm not trying to sound like a newb, just curious if there is acutal reason behind it.</TD></TR></TABLE>

I'm trying to remember exactly how it works, but basicially the difference between going with the compressor and IM is that one makes the WG open slower/faster and as a result you end up spiking or not boosting all the way.

I believe the compressor causes you to boost slightly lower, because you never actually reach your target boost pressure. But your WG will have good response time, your boost will rise faster, but it wont be as high.

Now if you hook up your WG to the IM then you'll reach full boost, but your WG also reacts slower. Anyways. I think it has to do with WG reaction times, how responsive the WG is and wether you are above or below your desired boost level.

I'd go into it more but it's time for me to go to bed.

Dunc

That makes sense, I hope that is why my damn wastegate opens at 10 instead of at 14. That 4psi difference is alot of lost acceleration.

oxSLEEPERxo

from the wastegate to the compressor, wouldn't the rubber line will melt by the high heat that surrounds it? so you will have to get a steel braided line right?

Dunc

I dunno...I've seen alot of rubber hoses attached to the compressor side without any problems. I would just make sure it is out of the way of any direct heat sources

RyanEJ8

I run my Tial 38mm wastegate and Greddy EBC off of the intake manifold with no boost creep or spiking problems.

vtec-adykt

speaking of compressor vacuum sources, is it real necessary that you use teflon tape on the threads or will it cause a major performance difference? also, do all the vacuum t's have to be "ziptie" tight?

SOHC_MShue

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SSBPGSR &raquo;</TD></TR><TR><TD CLASS="quote">maybe he picked up 20 more HP because he had some boost creep and upped the boost a little by using a terrible vacuum source. </TD></TR></TABLE>
how is the intake manifold a terrible vacuum source? My boost was much more inconsistent using the compressor nipple. You want your wastegate to be reading pressure after the intercooler because usually there is at least a 1psi drop across the intercooler. If you want to boost what your wastegate is actually set for then run the line to the intake manifold.

Dunc

I dunno, I can't make my mind up....I can see both sides, but now I am on the side of: I don't see how it is possible that the WG would open at 10 instead of 14psi simply by being T-ed off the MAP going to the intake manifold.

PrettyLude

i have mine ran off the IM and no problems here

W O T

You also have to count in the PSI drop when the air passes through the intercooler

Im sure thats a major reason

Dunc

screw the intercooler then....no one really needs them right? hahaha j/k

W O T

Does that not make sence though, Taking the reading off of the intake mani would give you and actual PSI level that youre motor is going to see, but would it cause that little bit of lag form the time it takes to get form the compressor housing to the turbo....

Ill be using a Joep MBC

I dunno, I dont even get it

SOHC_MShue

i have been having trouble with my boost going up to 10psi where I want it and then dropping back to 8psi towards redline. This is with a small wrx turbo and a 38mm wastegate. I tried hooking it up to the compressor to see if anything changed, but it just made the problem worse. Now it would only go up to about 9psi and drop back around 7.

3RdT

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">i have been having trouble with my boost going up to 10psi where I want it and then dropping back to 8psi towards redline. This is with a small wrx turbo and a 38mm wastegate. I tried hooking it up to the compressor to see if anything changed, but it just made the problem worse. Now it would only go up to about 9psi and drop back around 7. </TD></TR></TABLE>

wrx turbos r known to drop in psi in high rpms. i kno cuz my suby is like that until i got a solid response wastegate. holds boost til redline.

vtec-adykt

anyone have an answer for this question?

SOHC_MShue

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 3RdT &raquo;</TD></TR><TR><TD CLASS="quote">wrx turbos r known to drop in psi in high rpms. i kno cuz my suby is like that until i got a solid response wastegate. holds boost til redline.</TD></TR></TABLE>
well i shouldn't have the problem because I have an external 38mm wastegate. When I ran off of the internal gate my actuator was messed up and it took forever for me to spool...like full boost not until 5k rpms. However It would hold 10psi to redline. In the winter months it would spike to 12psi though

DRAGLS

Ok, using the compressor as a vaccum source opens the wastgate sooner, using the mani as a source opens the gate later and also decreases some lag from opening the gate later.