Why does my Boost fall?

[euro2fast4u]

report back your findings

[Jaxx_]

That could work, i already have most of the stuff to do the leak test, so i might do that. But i would bet that its a shit waste gate as well, i will prob switch to external right away. Should i just weld the internal shut?

or you could preload it to a very high amount so that you can still have the extra room if your external can't do the work.

But I would just wire it shut as long as it's sealing properly. No need to weld it. Even better: replace the exhaust housing with no wastegate. ;)

if your boost is fading after a few seconds, likely a wastegate and boost control issue. If you see it fall off even more near redline, it's for sure a wastegate issue. Seriously, just pull the wastegate vac line and go for a drive. take it real easy getting up to 50mph and put it in 3rd/4th gear. roll into the throttle and watch your boost gauge. do a few pulls for consistency. Drive carefully home and re-connect your wastegate line. don't even think about going WOT unless you are in a tall gear and low RPMs. but always ALWAYS roll into the throttle and not stomp on it. It's a simple troubleshooting test. I daily drive a turbo car and I've had 2 more. my E30 is my first non-turbo car.(and I have a turbo in my room to fix that)

[Lrutts]

could just be the shit internal wastegate. Unplug the wastegate's line and really slowly roll into the throttle to see if there's a leak. If you can boost 8psi and you're not losing boost, your internal wastegate sucks, just like all internal wastegates. And this way you don't need to worry about pressure testing.

That could work, i already have most of the stuff to do the leak test, so i might do that. But i would bet that its a shit waste gate as well, i will prob switch to external right away. Should i just weld the internal shut?

[Jaxx_]

i feel like that just sounds like a bad plan. why not take the time and do a boost leak test. i still think its just too small of a turbo.

because it takes 5 seconds and free vs many trips to a hardware store and a few bucks...

It's perfectly safe as long as you're sensible. and that also gives you an idea of boost fade.

[euro2fast4u]

i feel like that just sounds like a bad plan. why not take the time and do a boost leak test. i still think its just too small of a turbo.

[Jaxx_]

could just be the shit internal wastegate. Unplug the wastegate's line and really slowly roll into the throttle to see if there's a leak. If you can boost 8psi and you're not losing boost, your internal wastegate sucks, just like all internal wastegates. And this way you don't need to worry about pressure testing.

[euro2fast4u]

what size ebay turbo?

[Lrutts]

8psi, ebay turbo

[einstein57]

Whats yor wastegate supposed to be set to?

[Lrutts]

Are you able to hear any faint rattling during boost?

No it sounds fine, i can't even hear a wine or anything like that. I went to home depot to get the stuff i need to make a home made boost leak test kit, they had nothing.....

[ak-]

Are you able to hear any faint rattling during boost?

[sweet6e30]

classic boost leak

[Toadleg]

On my car i switched to an external waste gate and that seemed to help with boost spike also

[Toadleg]

Try and get it to hold 15lb for as long as possible you will get some leak by in the head

[Toadleg]

On one of my cars I take the intake off the turbo and attach to that With whatever works for you size intake. For me it was a 2 inch mission band with pvc cap and thread in a schrader valve. Get a compressor and pump it up and you will hear the leaks or spray soapy water on pipes and bubbles will appear. You will have to cap off a couple lines that will just leak air I dont know your set up mine is one of those turbo neons.