Bad wastegate?

[hex]

Hi, Im pretty new to the DSM world I bought a 98 eclipse GST and have been adding parts slowly. I ran in to a problem that i just cant figure out. The car is acting as if a have a boost leak, at WOT I first over boost then drop 7 to 8psi only to build it back up and drop again. I've made the bosst tester and fix all the boost leaks. I even managed to hunt down the throtle shaft seals. I also took off (completely) the wastegate and added pressure to the bottom nipple. the valve opens but tons of air rushed past the valve in to the exhaust... seems like when the valve opens all the way it startes to close then it kind of opens again. Are wastegates ment to leak boost? is this normal? if it is what else could cause boost spikes then under boost.
mods:
20g turbo
tial wastegate
550 injectors
walbro pump
frontmount
greedy bov
SAFC
AVCR
272 cams

 

[All_Boost16G]

Do you have the right spring in your wastegate? Or what spring do you have in your wastegate, also what PSI are you trying to run.

 

[e85_4g63]

sounds like the diaphram got a hole in it

 

[srumel]

^^bingo

 

[mindset]

Hi, Im pretty new to the DSM world I bought a 98 eclipse GST and have been adding parts slowly. I ran in to a problem that i just cant figure out. The car is acting as if a have a boost leak, at WOT I first over boost then drop 7 to 8psi only to build it back up and drop again. I've made the bosst tester and fix all the boost leaks. I even managed to hunt down the throtle shaft seals. I also took off (completely) the wastegate and added pressure to the bottom nipple. the valve opens but tons of air rushed past the valve in to the exhaust... seems like when the valve opens all the way it startes to close then it kind of opens again. Are wastegates ment to leak boost? is this normal? if it is what else could cause boost spikes then under boost.
mods:
20g turbo
tial wastegate
550 injectors
walbro pump
frontmount
greedy bov
SAFC
AVCR
272 cams

To answer that question, yes, they are, they control the amount of exhaust flow that goes through to turbo to prevent going over your specified boost setting.

 

[BoredDSM]

You do have a greddy BOV which leads me to believe it is most likely leaking. A leaking blow off valve can cause a drop in boost and you have one that is known for doing it. Tial makes good products and I doubt it would leak unless you have something setup incorrectly. This is all going out of assumption though which is a bad thing. First I would pull the blow off valve off and see if the diaphragm is in good condition and there are no leaks and tears. Easy way to check is if you do a boost leak test and see if any air is coming out of the BOV.

 

[mindset]

You do have a greddy BOV which leads me to believe it is most likely leaking. A leaking blow off valve can cause a drop in boost and you have one that is known for doing it. Tial makes good products and I doubt it would leak unless you have something setup incorrectly. This is all going out of assumption though which is a bad thing. First I would pull the blow off valve off and see if the diaphragm is in good condition and there are no leaks and tears. Easy way to check is if you do a boost leak test and see if any air is coming out of the BOV.

He already did a boost leak test. Good idea though. Do a second boost leak test JUST to be sure.

 

[hex]

I have a ten pound spring on the wastegate. I had the car set to 1.00 bar, but since this over boost problem started it gets as high as 1.4 bar. I first thought I some how set the Avcr wrong but even after seting to .30 it still gets up to 1.1. Also when this started it was just spiking hard but then it when from over boosting to under boost and back.
To give you and example lets say Im in 2nd gear 3200rpms. I punch the gas and I get a good size lag till about 4200rpm when the car sits me back. That power only last till around 5200 to 5500 rpm range and insidently thats when the spike hits. around 5200 to 5500 rpm going up I lose power and my gauge drops from 1.1 to .60 or less, holds for a bit and starts shoot up as Im about to shift. Now the funny thing is I can almost swear I can hear Air escaping from some where but Ive test the system at 25psi dont hear anything. Ive also swapped the soleniod from my boost controll with my friends but nothing changed. .
As far as the BOV how do i know if its leaking while im driving. When I ran the test I put about 25psi in too the engine. The Bov wasnt leaking, I also disconnected the hose from the nipple of the bov and attached a tire compressor set to 5psi and it held all the air, set to 10psi and held got all the way to 20psi with out the bov leaking from the top nipple or diaphram. Is there a better way of testing the BOV?
My main concern right now if the wastegate. Ive heard that they shouldnt leak and boost (thrw the bottom nipple down the valve in to the exhaust). I dont have an extra waste gate so i cant test by changing them out and a new one will run me 300.00 so im not in a hurry to buy one and not being the problem.
e85 mention possible hole in the diaphram is there any way to test or check that part it self?
I going to run a 3rd boost check tonight to see if I can find anything else.
any input will be appreciated and tried... please let me know if youhave any ideas

Oh sorry I have a tial wastegate..

THX