Okay for some reason when I stand on the loud pedal, my boost will hit 9PSI, and then creep up to 10 in the course of a few seconds then it JUMPS to 15! Sometimes even 20! I dont' hear any pinging (But I don't hold it at boost, I try to regulate it with the throttle to around 10) but I guess the two things I'm curious about:

 

1) What the $*$*@# is going on? Is it the boost control solenoid that I read about while poking through Alldata at school? (Nothing much about it but that it was used at high altitude)

 

2) Fuel cut? Shouldnt' my fuel cut hit at 9.5 psi? I can sustain it at 12psi (about as high as I will hold it for more than a few seconds) and no sign of a fuel cut, but MAN does she pull...

my 2 cents from owning a more then a couple turbo cars... depending on how your driving it... some cars will experience a boost spike when you let off the go pedal under moderate to high boost situations due to the throttle plate closing and the pressure hitting a wall so to speak.. but if it does it while under constant pressure on the pedal something may be interfering with the operation of the wastegate either something blocking the valve in the exhaust or it being stuck or leaky. as far as i can tell the subaru uses the wastegate only for boost control. hope this helps

 

 

Rllywgn

89 Toyota supra Turbo

88 Subaru Gl-10 sedan

ft4x4-lsd-5spd-turbo-picking it up today!

hose from the compression housing or to the wastgate may have a hole in it or may not be connected tight, make sure hoses are not holy and make sure you have clamps on all of them.

 

add my $0.02 now you have $0.04

hose from the compression housing or to the wastgate may have a hole in it or may not be connected tight, make sure hoses are not holy and make sure you have clamps on all of them.

 

add my $0.02 now you have $0.04

 

Hmm is Andrew's homade boost controller working anymore (a couple pinholes in the wastegate line). My thought was possibly the spring on the wastegate is getting a little worn...

Hmm is Andrew's homade boost controller working anymore (a couple pinholes in the wastegate line). My thought was possibly the spring on the wastegate is getting a little worn...

 

Pinholes in the wastegate line? I would say thats a good start....I was also thinking wastegate spring... big boost is bad...you hear my motor run? heh

after some flow increasing mods my stock waste gate could not dump enough exhaust to slow down the turbo. This would cause overboosting as you have described we had a thread on it long ago. after swaping to the TD04 the problem is completely gone. but now I run 15psi sometimes just because I want to:D. Fuel cut has not been a problem for the most part. no pinging but It probably wont last as long this way.

Here's a page written by a friend for internal WG turbo's. I don't know how much room there is on the wastegate flapper on the VF7 but it should help.

 

You can also cut the actuator rod in half, thread both sides, and use a coupling nut to adjust the base pressure of the flapper. Helps accomodate a weak/old spring.

 

http://www.fwdmopar.com/sites/dennis/wgateport.html

15 PSI huh....whats the problem with that????

15 PSI huh....whats the problem with that????

Yeah thats what I told him. It makes this awesome turbo whooshing sound when it hits 15psi. Makes a lot of people look especially the ones in the car... Makes me go YEAH!

I guess as long as the turbo wooshing noise doesn't turn into rattling and a cloud of smoke, I'll be okay.. I really need to put my intercooler on, and my BOV...and my 5th injector...

...and a TD04...and a header...and alchol injection....and an intercooler sprayer.....and a electronic boost adjuster.

Hey Hondasucks, does your car normally run 9.5psi of boost? If so, that is higher than normal. It should be running between 7 & 8psi of boost. I know it has been cold in Wyoming lately. That would cause the boost to increase slightly as the air is more dense, but I don't think that it would be at 15psi, or even 20psi for that matter.

 

1)The first thing that comes to mind would be a sticky wastegate actuator. 2) A hole in the vacuum line to the wastegate. 3) If you are running a manual boost controller, it needs to be re-adjusted, or even removed if you aren't running any sort of intercooler. Personally, I wouldn't bump up the boost until the car has an intercooler and recirculating BPV on it, but that is just me. Your turbo certainly won't last very long if you are pushing 15psi and no BPV. And your engine won't last long either if the boost keeps going to 15psi and above with no fuel mods and intercooler. I hope this helps.

 

Patrick