can anyone confirm why when i took off the vacuum from my wastegate that was connected to the turbo, the car now boosts more than 4psi?

my buddy said it could be a bad wastegate, the wastegate im running is a turbonetics evolution with 7lbs spring (white color spring). the vacuum line was connected to the wg to turbo, and currently no boost controller is hooked up.

 

the wastegate will never open with no boost reference. put the line back on.

 

but do you know if its cuz of the wastegate is bad?

 

no, its cause your not supposed to remove the vacuum line from the wastegate.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike1114 &raquo;</TD></TR><TR><TD CLASS="quote">no, its cause your not supposed to remove the vacuum line from the wastegate.</TD></TR></TABLE>

the point is the fact that originally im only boosting 4psi its supposed to go up to 7psi, after i take off the vac line it goes up past 4psi

 

Maybe double check some simple stuff, like what are you using to read boost pressure (gauge, map sensor data log, etc.)? Are you sure its accurate if its just a gauge?

Have you tried taking the vac reference from the intake manifold for the wastegate instead of the turbo to see if that has any effect on boost?

Also maybe a dumb question but are you sure that you just dont have that much of a pressure drop through the intercooler and charge piping? Some intercoolers have been know to have a pressure drop across them, or maybe a leaking BOV or something.

Just some ideas.

 

yeah at first i was thinking maybe the bov was leaking, but i double checked everything for leaks, and there was none, so finally my buddy told me to try testing out the wastegate by taking off the vac line, from there boost was able to go up, im reading boost from a boost gauge right now. Im gonna think about trying to hook up the vac line from the wg to the manifold and try it out

 

Taking the vacuum line off will of course make you overboost , the wastegate is looking for a reference for boost. When you puyll the vacuum line it will stay closed and you will overboost. The reason why you only get 4psi instead of 7psi with the vacuum line on could be many things, depends on where you are getting your vacuum soirce from before or after the intercooler. If you are getting vacuum from the turbo by the time it gets through the IC and piping and to the intake manifold you may lose 1-3 psi, if you switch it to the intake manifold you will now get the boost at the intake manifold as opposed to the turbo since it is before the IC. This is of course works as long as your boost guage is hooked up at the intake manifold also. A

Your boost gauge also could be off by 1-2 psi . Things to look at

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostfed.com &raquo;</TD></TR><TR><TD CLASS="quote">Taking the vacuum line off will of course make you overboost , the wastegate is looking for a reference for boost. When you puyll the vacuum line it will stay closed and you will overboost. The reason why you only get 4psi instead of 7psi with the vacuum line on could be many things, depends on where you are getting your vacuum soirce from before or after the intercooler. If you are getting vacuum from the turbo by the time it gets through the IC and piping and to the intake manifold you may lose 1-3 psi, if you switch it to the intake manifold you will now get the boost at the intake manifold as opposed to the turbo since it is before the IC. This is of course works as long as your boost guage is hooked up at the intake manifold also. A

Your boost gauge also could be off by 1-2 psi . Things to look at</TD></TR></TABLE>

ok this would make sense, i will try this and let you guys know. Right now the boost gauge is Tee'd off with my bov and hooked up on the intake manifold, so ill try hooking up the wastegate to the manifold and see what happens from there

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by H22TurboNos &raquo;</TD></TR><TR><TD CLASS="quote">

ok this would make sense, i will try this and let you guys know. Right now the boost gauge is Tee'd off with my bov and hooked up on the intake manifold, so ill try hooking up the wastegate to the manifold and see what happens from there</TD></TR></TABLE>


WHEW! I am glad you understood my RAMBLING POST. Let us know how it works out. Also what boost guage do you have, I have seen alot of boost gauges and alot are not centered on the zero some are in vacuum when not on so of course they will be off too. Can you read boost in the Crome?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostfed.com &raquo;</TD></TR><TR><TD CLASS="quote">


WHEW! I am glad you understood my RAMBLING POST. Let us know how it works out. Also what boost guage do you have, I have seen alot of boost gauges and alot are not centered on the zero some are in vacuum when not on so of course they will be off too. Can you read boost in the Crome?</TD></TR></TABLE>

im just using this megan racing boost gauge, when it started to go around 9-10psi the gauge was shaking, but then again my whole car was shaking

 

EWWW I saw your other thread, you are tuning with no wideband? Please get a wideband and tune it unless you have VAST KNOWLEDGE Of tuning and can read your plugs very well and really really know what you are doing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostfed.com &raquo;</TD></TR><TR><TD CLASS="quote">EWWW I saw your other thread, you are tuning with no wideband? Please get a wideband and tune it unless you have VAST KNOWLEDGE Of tuning and can read your plugs very well and really really know what you are doing. </TD></TR></TABLE>

i tuned it at church's last week

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by H22TurboNos &raquo;</TD></TR><TR><TD CLASS="quote">

i tuned it at church's last week</TD></TR></TABLE>


OK, with a wideband of course?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostfed.com &raquo;</TD></TR><TR><TD CLASS="quote">


OK, with a wideband of course?</TD></TR></TABLE>

yeah

 

off topic! update you site terry!

 

alrite updates: so i finally got a chance to try putting the vac hose to the back of the manifold, no change and so the only thing i can try now is maybe a new 7psi spring, if that still doesnt work im gonna have to conclude its a faulty wastegate

 

My car was doing the same thing. i tried everything under the sun. including switching to another wastegate and got the same results. so i pulled the reference line off the WG and finaly built more than 3-4 psi. Built a boost leak tester and had no leaks. At this point i had a turboxs MBC and threw that on and tuned it into 10 psi. Hits full 10-11psi at 3900-4100 and goes strong. My fix was a MBC. Good luck

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by a1320honda &raquo;</TD></TR><TR><TD CLASS="quote">My car was doing the same thing. i tried everything under the sun. including switching to another wastegate and got the same results. so i pulled the reference line off the WG and finaly built more than 3-4 psi. Built a boost leak tester and had no leaks. At this point i had a turboxs MBC and threw that on and tuned it into 10 psi. Hits full 10-11psi at 3900-4100 and goes strong. My fix was a MBC. Good luck</TD></TR></TABLE>

i actually tried a mbc, it was only going up to 8psi, it shouldve gone at least to 10psi, but without the mbc i should be hitting minimum 7psi with that wastegate, which isnt doing so. But thanks for the input on your situation

 

it was the spring, i guess when i checked the spring it turned white but the spring originally couldve been blue and faded, bought a 9psi spring and it boosts up to 9lbs now