UnhuZ

Hello guys.

I come to you asking for help as i have this setup for some time now and i havenīt been able to reach a solution.
The problem is working with external wastegate. I have a Trust 50mm external WG and i canīt find anywhere how to correctly work with it.
I have searched long hours on foruns and google and found a lot of diferent ways to use them but anywhere i was able to fully understand it.
My issue is: this external wg is working because i leave it without any vac tube plugged and the turbo pressure is but at about 0,7bar.
If i plug any vac tube to each one of the possible 2 locations (underside of wg and top) i only see about 0,4-0,5bar pressure.
I have looked at many schematics of ext. wg. and noticed that everyone plugs the uderside of it to a press. source but i do it and have only 0,5bar boost.
Also on the top i have a screw that i can turn but that doesnīt seem to affect anything.

I send a ugly drawing of it to better explain what i mean.
Can someone pls help me out?

the setup is:

91 edm crx vt
fully built b16a1
os geiken double plate clutch
t4 turbo
trust 50mm ext wastegate
hks 40mm bov
600hp ic
450ccīs for now
tuning with bre/ostrich
d2 suspension system
big brakes

Thanks!

UnhuZ

n2o_2k

What's the size of the spring inside the wastegate? fyi 0.4 = 5.88 psi and 0.5=7.35 psi . You might be limited to the size of the spring inside, if you need more boost, you'll need a boost control.

idiot-stick

Take it apart and see how it works.

UnhuZ

Well i donīt know but i can tell is:

- if i just leave the wastegate alone without any vac hose it does 0,7bar top from 4500/4700 to 8000.
- i donīt know if you can see in the pics but i have a "strange" valve on the front of the intake mainfold that looks to have 2 diafragms and on the top one a vac connection (this engine is jdm and the valve seems stock). I tried conecting the buttom port of wg to there and now the turbo does 1bar!!!

The engine is built and electronics are good to about 1bar (12psi is the limit by now - waiting for 3bar map sensor) so iīm not very scared, problem is understanding why i canīt control boost. Today later iīll try to use the top screw to see if it changes anything.

Pls help me!

sohcpwr

i hope you didnt build the engine/turbo kit if you dont know how to work your wastegate.

the top port should be for electronic boost control. the bottom one is the one you wanna hook vac up to, and the screw on the top should be for preload adjustment on the spring. screw in = more boost

*** if you leave it totally unplugged, your wastegate should stay shut and put all the exhaust through the turbo, causing massive boost pressure. If this doesnt happen, something is wrong with either your gate, or your turbo

UnhuZ

This is my first external wastegate.... sorry for looking so stupid on this... :P

I donīt understand why i canīt reaise boost in any other way rather than hooking up the vac source to that strange valve on intake mainfold.
If i plug it to any press source wb pressure drops 0,1bar.
Do you guys ever seen the intake mainfold valve i talk about?
The wastegate was a oportunity buy and i plan putting down large hp numbers so i thought it would be a nice buy.
Iīm looking for a boost controller but i also start to think why doesnīt the WG act like others?

I shure miss something.... strange is that pluged to that valve it raises boost like crazy.

Any ideias?

Thanks so far!

sohcpwr

no, ive never heard of this "valve" you speak of. Do you have a better pic of it? IF the gate is totally unhooked to vacuum, the turbo should make its maximum boost (like 35+ since you probably have a t3/t4)

hondalover

If you look at the front of the intake header you see a valve that i never seen before.

hondalover

HEre is a pic of the valve, the best i can so far.
On the middle of the intake you see this "double" valve.
Any idea?