Hi My HKS 50mm racing wastegate used to have a .5 bar spring, and with my AVC-R turned off I would boost to about 1.2 bar. I thought the wastegate might need rebuilt, so I did. The smallest spring I could get was a .7 bar. Now I have to take my foot out by 5000 or 6000 rpm when the boost gets over 1.0, the wastegate has barely begun to open, and the boost creep has no intension of slowing down when I do... On my first run after I rebuilt it I hit 1.4 bar before I realized what was going on...

Do you think A) my turbo is too big for this wastegate or B) the AVC-R solenoid is broken thus keeping the wastegate shut until the motor just overpowers it?
~Jeremy

 

Easy way to find out, bypass the boost control and take a direct line from you're turbo outlet or plenum to you're waste gate.....If it opens, then you have a problem with the Boost control, If it does the same then you're WG is sticking or has a leak in the diaphram.

The way to check this is to hook up some compressed air (at low pressure) and lisen to the WG "click" open as you apply the pressue. If it does this then it is fine.

And the third step is if you still have overboost with a low spring in the WG (and it's working correctly) then you're pipes going to the WG are too restrictive and are not alowing all of the "by pass" to be bled of hence the increasing boost.

Generaly a 50mm gate is more than enough for a 13B street port with small rear a/r (0.8 odd) T04 running up to 700BHP to control boost pressure so long as the WG pipes (from the exhaust manifold to the WG) are designed correctly.

 

The diaphram is brand new. I had a steel manifold on before and now the XS manifold, they both yield the same results. I'll try bypassing the AVC-R, thanks You mean apply the compressed air to which vacuum hose? Keep in mind this TA51 compressor is the size of a dinner plate... ~J

 

It could be the size of a fat chicks anus ! ...It realy does not matter !

A T100 running at just over 1 bar will not overpower a 50mm WG, The compressor is not in it's MEGA range at this pressure ratio.

It is more a sign of the WG not working (opening) or the piping to the WG being too restrictive.

It sounds like the boost control to me.

To test the WG apply compressed air (@15psi) to the hose that goes to the WG, you should hear it open with a sharp "tap" noise.

good luck

 

Do you know the purpose of having the vacuum hose going to the side and to the top of the wastegate?

Does the screw on the top of the wastegate that is not attached to anything other than to plug the hole have a function?

 

Make sure the AVC-R solenoid is hooked up properly. I just installed mine and had to move one of the fittings to a different hole to get it setup properly. With the solenoid off, you should be able to blow into the nipple that the line to the top of the wastegate is connected to and have air come out one of the other holes. You can always just disconnect the hose that goes to the top of the wastegate, too, to see if that is what is causing your high boost. It may also be a problem if the pressure line is venting -- blow through that nipple to make sure you aren't losing pressure. The nipples on the solenoid should be on opposite sides, rather than adjacent sides (as it comes from A'PEXi). The manifold pressure should connect to the nipple on the end closest to where the wires come out, and the wastegate top port should connect to the nipple on the opposite side.

The line to the side of the wastegate should always get the full manifold pressure.

-Max

 

Today I connected the manifold directly to the wastegate and left the top vented. Still overboosts. Maybe I got the wrong spring? I doubt it, because I hooked up a pump and we heard it click open at 10 psi. I have the XS manifold that other people have said they do not have a problem with the runners being too small. Maybe the vacuum hose has issues. It comes from under the manifold somewhere... Will all the vaccum hose nipples on the manifold have equal (enough) pressure???
~Jeremy

 

 

That turbo is the same size as mine, more or less... what is it?

 

no way it's near the same
lol

It would not clear the frame

 

Mine has a 3" inlet and looks like that. If the inlet on yours is bigger than that then yes yours is bigger, and i just got the right proportions and wrong size...

 

Kabooski: is that a t100? that thing is a monster!!!

 

what did you change to -8 line? i must be confused because i can't think of anything to use that size hose on down there.

 

SOLVED! After lots of vacuum testing today, I found out that the nipple the line to the wastegate was connected to is bad.... No signal! I re did things and she runs STRONG

 

The thread is interesting, BUT a "FAT CHICKS ANUS" that is nasty!! Must be some of our Canadian girls down there in the land of OZ.

 

Eww... I thought Canadian girls were hot!?!?