boost leak test questation

[valjo]

hi!

i have some problems with mine boost leak. i have changed all hoses (samcos) and also i have checked all small hoses on the back of the IM, all ok.
well the problem/questation is; how long must hoses hold pressure? i could pump them to about 2 bars but then boost start falling down...
is it possible that boost leak at pistons rings? or any other sugestions?
thanks!
valjo

[Knight Rider S4]

You have blocked off oil breather on the MAF pipe..........have you changed over the throttle intake pipe?

[S2central.net]

You need to block off the TB hose to prevent air getting into manifold - it will blow past open valves and leak past cylinder rings.

Also be aware that when pressurising from MAF hose that you can push air past the oil seal in the turbo as the MAF hose never sees pressure in normal operation.

PAul

[valjo]

hi!
thanks for all answers!
@knight: sure i blocked oil breather
@s2central.net: yes i read posts about leaking turbo and i am aware of those leaks
well i replaced all small hoses too, test hoses again like you said paul, plug boost gauge and get about 1.35-1.4
em i only get 1 bar in first gear, is it ok?

samcos and homefries

[A80Avant]

yes 1st gear is always lower,around 1bar.only changes if you change the wastegate spring

[valjo]

yes 1st gear is always lower,around 1bar.only changes if you change the wastegate spring

em what if i screwed wg screw a little more? will it help geting more boost in 1 gear?

[A80Avant]

yes but it is not recommended....

[valjo]

yes but it is not recommended....

why?

[A80Avant]

more stress on the valves.At least that is what i have heard.if you have stronger cylinder head internals though,that is another thing!!!

[S2central.net]

You cant get max boost in 1st gear as the engine doesn't generate enough load for long enough to get to those boost levels.

Messing with the WG spring can give you a little increase (or big increase if you fit stiffer springs). BUT - the reason you have to be careful is that the WG spring defines the level of mechanical boost for 'safety modes'. Stock, this is about 0.4bar... You can verify that by dissing the WGFV.

By all means you can try stiffening the spring - the ECU will adapt to changes in that within limits - but I have NOT tested to limit of stock spring.

Stiffer WG decreases WG creep and gives quicker spool times, but you must respect the safety issue so that if your ECU is trying to play safe-mode you don't want the ability to have silly mechanical boost levels potentially causing you engine damage when the ECU is trying to back off boost in software.

If 0.4bar is factory safe mode, and 0.8bar is max boost at redline under load for K24 then you can use that as reference point for maximum mechanical boost - I wouldn't go above that... Nor do I know if the homefries can adapt to it... You can try - maybe go for 0.6bar WG mechanical boost 1st - that is good comprimise for me and I think the ECU will adapt to that OK. Let me know...


PAul

[valjo]

many thanks for that explanation paul!

You can try - maybe go for 0.6bar WG mechanical boost 1st - that is good comprimise for me and I think the ECU will adapt to that OK. Let me know...

PAul

Could you advised where should i buy good spring, because i do not want to buy some crap?