Little help here guys.

Setup: Full race mani, 44mm Vband, B18c, Hondata, AVC-R.

Problem: Overboosting like crazy. Not boost spiking. Just instantly over boosts. I had the .9 bar spring and it would instantly rev to my hondata boost cut at 17psi. Put the .5 bar spring in there and it still sees 15psi. I inspected the diaphragm and it is not torn, ripped, pinched, etc. I put air into the side port of the wastegate and it takes approx. 15psi to get the .5 bar spring to move. No air is leaking out of the top of the wastegate when I plumb air into the side port. I have the AVC-R off and it over boosts. I turn the AVC-R on and set it to .20bar and it overboosts. I removed the AVC-R and plumbed it straight to the intake manifold and it still over boosts. I have checked all my vac lines and there are no leaks, etc. I have noticed a small exhaust leak inbetween the mating of the manifold and wastegate. See pics.

<FONT COLOR="red">***UPDATED***...8/31/04 3pm.....Feeling that my air compressor psi gauge probably had some error in it, I installed a mechanical boost gauge to check. The .5 bar spring starts to open at 10psi gauge pressure....Exactly where it should. So I do not think that it is the wastegate not working properly. Thanks to Boosted Hybrid and St00pid and the help of Tial, I have come to the conclusion that there is not enough flow coming out of that manifold/wastegate setup to get it to open at the lower psi. I will see tomorrow if it will equalize around the 15psi pressure with the .5 bar spring. **** </FONT>

<FONT COLOR="blue">PROBLEM IDed:

Because of the large turbine wheel, there simple is not enough flow coming out of the wastegate port on the manifold for the wastegate to open at the proper level. If the wastegate port coming off the manifold was at say a 20 degree downward angle, then possibly, the gases would be forced into the wastegate port and it would open at a lower psi level. For example, I ported the wastegate tube and fire ring on the wastegate and was able to get the boost to equalize from 15psi unported to 13psi using a .5 bar spring. </FONT>



Modified by Blown90hatcH at 12:03 AM 2/9/2005

 

Change the spring in the wastegate for another

 

sounds like the gate is bad. you have eliminated everything else

 

You could easily overboost if that AVC-R is not tuned correctly. What do you have the spring duty cycle set at? and what gain?

 

He said he unhooked the AVCR and ran it straight to the IM off the spring and still overboosted. He also has already said he swapped springs.

I would point to a WG or vacuum issue as well....if youre sure the WG is tapped to a solid source, then Id point to the WG itself since when you put in a lower spring, it peaks at 15 rather than 17...at least youve identified a variable that makes a difference.

 

I swapped springs already.

.5 bar went to 15psi. .9 bar was still climbing when it hit my boost cut. I know that the wastegate is opening. When I took it to the intake manifold on the .9 bar it will overboosts. I have the side port right now plumbed to the compressor side of the turbo.

 

what size line are you useing? is it minum of 6mm

 

The ID of the line is larger than the barb nipples that come with the gate. I had this setup on my HKS 50mm wastegate and 30psi with no problems. I could try a larger ID vacuum hose I guess.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Blown90hatcH &raquo;</TD></TR><TR><TD CLASS="quote">I put air into the side port of the wastegate and it takes approx. 15psi to get the .5 bar spring to move</TD></TR></TABLE>
that right there tells me something isnt right with the wastegate, unless Im mis-interpreting things...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tinker219 &raquo;</TD></TR><TR><TD CLASS="quote">
that right there tells me something isnt right with the wastegate, unless Im mis-interpreting things...</TD></TR></TABLE>

Granted this is gauge pressure, without the help of the exhaust gases, but that is correct. Something is not right. The .9 bar springs needs about 23psi before it starts to open.

 

Hey Jason,

What is the nipple on the side of the WG hooked up to? Try Hooking the side up to the IM and take off the line that goes to the top of the WG. Then see how much you boost.

BTW, you got mail

 

Another thing to note is that you cant use an EBC to lower teh boost more than the spring in the WG is good for. Also if these are brand new springs, they need broken in but I havent had one be off THAT much, usually only 1-2psi

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Full-Race Henry &raquo;</TD></TR><TR><TD CLASS="quote">Hey Jason,

What is the nipple on the side of the WG hooked up to? Try Hooking the side up to the IM and take off the line that goes to the top of the WG. Then see how much you boost.
</TD></TR></TABLE>

Yeah if you're not using the boost controller the top vac line should be disconnected, it is on mine

 

man i had the same problem,

turbonetics deltagate, 6psi spring in and mine was immediately hitting 12 psi...

i thought what a peice of **** this wastegate is...but guess what i found out?

it wasn't the wastegates fault it was the damn vac line going to the wastegates port
that ******* port gets so HOT..and the so called high heat rubber line was expanding and bleeding off pressure..

the only reason i found out was because i was changing my range rovers brake lines and i noticed that the parts that screws into the caliper looks like it was a perfect fit for the wastegate port...sure enough it was all the way down to the thread pitch...

as soon as i switched it went right back to 6psi and hasn't moved at all

the METAL line is routed from the wastegate port all the way to the back of the engine about 10in from the intake manifold a peice of high heat rubber completes the gap between the intake manifold and the metal line. zip tied at both ends...

someone should manufacture a kit to convert all wastegate vac line to metal ones

hope this helps

 

<FONT COLOR="red">****Updated above***. I will try the braided line for the wastegate vacuum lines.

Update cliff notes: Craftsman compressor gauge has some error. Possibly from bleeding off at the nipple, etc. I installed a boost gauge inline when I redid my tests and the wastegate is working properly.

Thanks to Boosted Hybrid and St00pid and the help of tial, it looks as though my manifold/wastegate does not flow enough with my turbo setup to open the wastegate at smaller boost levels. Cars rule. Thanks for your help H-T. This site is still bad a$$!</FONT>

 

mine did the same ****. i never worried about it though becuase it was pretty consistant. my theory to the prob was prob that the vac line to the WG was extremely long. if i woulda tapped it closer it prob woulda helped a bit.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by itr206 &raquo;</TD></TR><TR><TD CLASS="quote">mine did the same ****. i never worried about it though becuase it was pretty consistant. my theory to the prob was prob that the vac line to the WG was extremely long. if i woulda tapped it closer it prob woulda helped a bit. </TD></TR></TABLE>
My vac line is pretty short. Basically if the wastegate had some type of downward slope so that gases were aided in escaping, I probably would not have any issues with it.

 

any resolution to this yet?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cramerox &raquo;</TD></TR><TR><TD CLASS="quote">any resolution to this yet?</TD></TR></TABLE>

Because of the large turbine wheel, there simple is not enough flow coming out of the wastegate port on the manifold for the wastegate to open at the proper level. If the wastegate port coming off the manifold was at say a 20 degree downward angle, then possibly, the gases would be forced into the wastegate port and it would open at a lower psi level. For example, I ported the wastegate tube and fire ring on the wastegate and was able to get the boost to equalize from 15psi unported to 13psi using a .5 bar spring.

 

What manifold are you using?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by m R g S r &raquo;</TD></TR><TR><TD CLASS="quote">What manifold are you using?</TD></TR></TABLE>

Full Race

 

So this isn't fixable with the wastegate where it is now?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by m R g S r &raquo;</TD></TR><TR><TD CLASS="quote">So this isn't fixable with the wastegate where it is now?</TD></TR></TABLE>Not short of going to a larger wastegate...even though I have the 44mm on there now. The exhaust gases going into the turbine wheel don't want to stop and make a 90degree turn into the wastegate until 13psi with a .5 bar spring.

 

https://honda-tech.com/zerothread?id=913679

Scroll down mid way. Might help? I had similiar issue. Do you know if your WG is FULLY shut?


::EDIT:: NVM...Just saw your UPDATE post. -=P

 

Damn thats pretty crazy. What turbine wheel and compressor are you runnning?