sti 360

iTrader: (1)

hello
if i drill me restrictor out bigger than the standard 2mm ,say 2.1mm,2.2mm in diameter will it up the boost slightly ,also ive read that if i adjust me actuator arm by turning it that it can give some more boost,

as it would not cost anything to do is any of the above worth doing

thanks matt

Graz

AFAIK none of the above will increase boost significantly. They will however effect how boost is controlled. Tightening the actuator will increase the pressure at which the waste gate opens (typically around 0.5bar) and therefore make the boost control more agressive.

Best bet for a cheap boost increase is to get a manual boost controller such as a Dawes device (about £40). Make sure you know what you are doing though.

mulf

I assume this is what you are talking about

http://www.wrxlinks.com/forum/forum.asp?FORUM_ID=3

see the threads on 3/16th mod and 3/16th mod problem.
If it helps my final conclusion was it isn't worth bothering with

[Davey]

Unplug the hose from the actuator and plug it up with a screw

She'll boost a bit higher then

gotmashed

well you can get a bleed valve but you will still need a fcd and even then you wont get much more than a fw psi with out blowing somthing up from lack of fuel

p1mark

drilling the restrictor out will decrease the boost, not raise it.

would not advise it anyway - a bit iffy just upping boost without fueling/ignition etc to match.

sti 360

iTrader: (1)

i have uprated fuel pump but on a standard reg,not looking for a massive improvement,have a sti 2 ,read on scott t post that a pre 96 you have to make restrictor bigger,
thanks matt

[Davey]

The Fuel pump could be providing a gazzillion bar the injectors only have a certain duty cycle and limit.. plus as you say your standard fuel reg will only allow a certain pressure the rest goes back to the tank. So this wont help fueling issues at higher boost..

Do you have a standard exhaust system? Go for a de-cat down pipe and you'll find the turbo spools up much faster and will create a little more boost at full chat..

sti 360

iTrader: (1)

yeah have a full decat good arent they

New_scooby_04

iTrader: (4)

My advice would be don't do any mods to the Impreza on the cheap; get it done properly to enjoy optimal and reliable gains. I wouldn't be trying to directly manipulate boost without corresponding alterations to ignition and fueling parameters.

If you must fiddle at least get the AFR checked out and have someone with DET cans listen to the car.

Ns04

sti 360

iTrader: (1)

right then ill stop trying to fiddle with it ,as i have a bust leg and am getting bored,
thanks for the advice