EddScott

Read on SNet somewhere about getting more boost by winding in the actuator?

Can anyone elaborate on this and explain how its done etc...

Ta.

jjones

winding in the actuator is a hit and miss method of increasing boost. basically the actuator arm for the wastegate gets activated when a certain boost level is reached. the arm opens the wastegate in the turbo that allows the exhaust gas to bypass the turbine blades and take the easier route straight down the down pipe. this has the effect of capping the boost pressure. by winding the arm you can increase/decrease the amount of boost pressure that is needed to effectivle move the wastegate flap.

do a search for dawes device, which is a bleed valve type device that bleeds some of the pressure off from reaching the wastegate actuator therefore causing the car to reach higher boost before the wastgate is opened.

also if you are messing with boost levels it is highly recommened to buy a boost gauge so you can see what is going on. it is also worth searching to see what boost levels are safe for your engine and current mods.

ByByR1

If this is true why dont Subaru do it anyway?.
Is it safe?
What's the benefits?
Cheers.

EddScott

So hows it done? I've got things like KLink and guages etc.

jjones

the actuator rod that runs to the wastegate (on most cars) is threaded. there is a lock nut to hold it in postition in normal use. you slacken the luck nut and rotate the rod to alter its length. shortening the arm will increase boost (i think).

you really need to adjust the arm slowly and check the results on the boost gauge.

if you fiddle with this bear in mind that you can easily blow your engine by increasing the boost too much.

EddScott

Currently the cars max PSI is about 16 running a TEK2. Was thinkning of increasing to perhaps 18 which I think is max for a TD04. I'll watch the AFR and KLink so if anything goes fishy I'll put it back again. I'll mark it up first just in case.

jjones

if you are reaching the limits of the turbo the air charge temps will probably be raising rapidly which may well negate most of the effects of increasing the boost pressure.

Jolley

Yes you can (as explained above). I employed exactly the same technique on a R5 GTT, and although it did up the boost, it was not as consistent as I would have liked. The problem is that the diaphragm in the actuator is under more pressure than it is designed to cope with, and because it it working beyond its limit it is more likely to be inconsistent or potentially split. You would get exactly the same effect (but without stressing the actuator) by fitting a bleed valve (not recommended again, unless you can monitor it properly) or a dawes device.

The only advantage is that it is a very stealth (read "insurance friendly") technique. Yet it has the potential to blow up your engine!

EddScott

Something tells me one must leave well alone then!