External boost control.................... issue again

[greeneyegi]

yrs ago when i first started with this turbo stuff i had a post about boost creep and other boost issues.i thought i knew it all about this part of tuning.i totally understand the mechanics of boost control...this is why im stumped.

i have a bison 6262,with erics sd2 chip and a 39mm wastegate and a rjc controller,3"dp.
everything used to work great.
all the sudden i cant control boost.30 psi.my wastegate dosnt leak,ive got a handheld vacuum/boost pump.and everything opens way before 17lbs.
i can watch the valve on the pipe move open and stay open.but it shoots to 30 and i get out of it.i can control it with the gas pedal.

2 questions...1.can i remove timing from the sd2 chip,so i dont brake something during wot,
and 2 what am i missing?

 

[SHADOWII]

?1-I believe the instructions say "yes".
?2- Have you checked the diaphragm for cracks, etc? Have you cable tied all of your hose connections for safety?

 

[Phoneguy]

Stock waste gate hole ? Did you port the waste gate hole ? Stock size puck ? Remove the rjc controller and see what your boost does.

Bryan

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[forcefed3.8's]

Where do you have the line hooked up on the wastegate? The port on the base of the wastegate opens the gate, the one on the top will apply pressure to hold it closed.

 

[Phoneguy]

I assumed you had an internal gate....now that I am on my computer I can see you sig. Is your DP a GN1 performance by chance? If so you will need to open up the wastegate hole on the flange. The hole is much too small !!! Did Bison open up the hole on the exhaust housing?

Bryan

 

[psycho6cyl]

X2 if it's a gn1 but never having the problem and them having it seems strange. What was changed?

 

[greeneyegi]

I assumed you had an internal gate....now that I am on my computer I can see you sig. Is your DP a GN1 performance by chance? If so you will need to open up the wastegate hole on the flange. The hole is much too small !!! Did Bison open up the hole on the exhaust housing?

Bryan

yes its a gn1..with a pw39mm wastegate....no i dont think he opened it.im probably gonna send back to have opened and also open the pipe also.

Where do you have the line hooked up on the wastegate? The port on the base of the wastegate opens the gate, the one on the top will apply pressure to hold it closed.

yeah ive got it hooked up correct....i learned when i first got the car it had a deltagate with the manual adjuster under the hood.....that will learn you real fast how these wastegate systems work

X2 if it's a gn1 but never having the problem and them having it seems strange. What was changed?

i had no problems with the cheetah stg3 turbo @25#

 

[greeneyegi]

i can only find on the sd2 to advance the timing.
oh and i also rebuilt the motor with ported and polished heads with roller everything.

 

[Phoneguy]

You are flowing way too much through the little hole in the downpipe wastegate flange...that flange is pretty thick, not going to be any fun opening that up !!!
Have Bison open up your turbo, as soon as both of those are done please post back with the results.

Bryan

 

[greeneyegi]

You are flowing way too much through the little hole in the downpipe wastegate flange...that flange is pretty thick, not going to be any fun opening that up !!!
Have Bison open up your turbo, as soon as both of those are done please post back with the results.

Bryan

machine shop to open the dp?or just drill it to a certain size?

 

[Phoneguy]

If you have a friend at a machine shop, go for it. Otherwise You may be able to get a Unibit and a corded drill to work. I would highly advise against using a battery drill as it will get taxed heavily. It will take some time to do this, make sure you wash the pipe out thoroughly to get the metal shavings out of it before reinstalling. While you are at it I would also look at the main exhaust hole on that pipe too...There is probably a 1/4" overlap of the flange , if so , open that up too

Bryan

 

[greeneyegi]

If you have a friend at a machine shop, go for it. Otherwise You may be able to get a Unibit and a corded drill to work. I would highly advise against using a battery drill as it will get taxed heavily. It will take some time to do this, make sure you wash the pipe out thoroughly to get the metal shavings out of it before reinstalling. While you are at it I would also look at the main exhaust hole on that pipe too...There is probably a 1/4" overlap of the flange , if so , open that up too

Bryan

good info thanks

 

[T What?]

How'd this turn out. I'm having the same issue. Took the wastegate apart today and cleaned everything up on the puck. Was very dirty and stuck shut. Thought that'd fix it. However at half throttle I get instant boost to 25-30lbs. I'm going to take it all apart again and sand down the puck shaft and port the exhaust port on my turbo. Hoping this fixes it.

 

[greeneyegi]

How'd this turn out. I'm having the same issue. Took the wastegate apart today and cleaned everything up on the puck. Was very dirty and stuck shut. Thought that'd fix it. However at half throttle I get instant boost to 25-30lbs. I'm going to take it all apart again and sand down the puck shaft and port the exhaust port on my turbo. Hoping this fixes it.

worked perfectly!my boost issues are no more.opened up the hole on the turbo and laso port matched the downpipe also while i was their.i can turn boost up and down no problem now.