Overboost issue

[tydon]

v3/4 converted GTB legacy

so ive sort of fixed half the issue its intermittent now.

On full throttle it will spike up to 20psi mayb more my gauage will only read 20 and it will then boost cut.

sometimes is will boost solid 16psi and not spike.

Ive tried 3 other boost solenoids and none made a differnce ive double checked wiring and everything is where it should be.

i swaped A3 and A19 on Plug B137

ive run wastegate pressure from turbo nipple to gate actuator with no problems.

[Rosssub]

Get a cheap MBC or try a bigger restrictor pill. What size pill are you using?

[tydon]

using a pill out of the black box lol not sure what size it is my expierence with MBC are that you either run wastegate pressure or freeboost never worked for me

[Rosssub]

0.8mm from hose #2. Going up to a 1.0mm pill would probably sort it, will give about 14psi. Pill part numbers in here:

http://www.perth-wrx.com/vb/mechanicals/48287-restrictor-pill-what-why-you-need.html

I'm using one of these cheapo's, works perfectly:

http://clubsub.org.nz/forum/showthread.php?43004-Rosssub-s-Single-Turbo-Conversion/page16

[tydon]

howmuch boost you running and how have you got it setup?

[Rosssub]

Reading that restrictor pill thread, the JDM version 3/4 WRX uses a 0.9mm pill.

http://www.perth-wrx.com/vb/mechanicals/48287-restrictor-pill-what-why-you-need.html

[tydon]

hmm mayb my pills blocked or twisted apparently can cause overboosting

[Rosssub]

 Rosssub said:

Reading that restrictor pill thread, the JDM version 3/4 WRX uses a 0.9mm pill.

http://www.perth-wrx.com/vb/mechanicals/48287-restrictor-pill-what-why-you-need.html

I'm currently running 1bar/14.5psi. Set up copying this turbosmart install:

http://www.turbosmartusa.com/wp-content/uploads/2011/12/Incabin.pdf

Page 16 of my conversion:

http://clubsub.org.nz/forum/showthread.php?43004-Rosssub-s-Single-Turbo-Conversion/page16

[tydon]

did u leave restrictor pil in? and how far can u wind your boost upto?

[tydon]

not that i wanna run ridiculous amounts just curious

[Rosssub]

No, restrictor pill comes out. The MBC has it's own restrictor built in. I could turn it up to free boost if I wanted.

I turned it up 3 clicks this morning and spent the day at a solid 18psi (14.5 before). It has about 15 more clicks to full.

[tydon]

Ohh lol did you take spring and ball out if the t piece?

Edited August 4, 2014 by tydon

[Rosssub]

 tydon said:

Ohh lol did you take spring and ball out if the t piece?

Yes. It would boost spike big time with them in.

[tydon]

ok strangely issue has fixed itseld and no longer oveboosts it boosts solid 16psi and sometimes spikes to 18

[Rosssub]

Your restrictor pill might of been partially blocked (now clear), or the solenoid had some gunk in it. I'd still get a MBC or try a 0.9mm restrictor.