Boost leak...

[philpemberton94]

Just installed a manual boost controller yesterday, took it out for a spin and made 20 psi (was running 16 standard) and it seems gutless, wound the mbc right out and it now only boosts to about 14 and i have moved my boost gauge to the actuator line from the boost compensator, i think its a boost leak on that actuator line but dont understand how it can be slower for that?

[mr_fish]

Just installed a manual boost controller yesterday, took it out for a spin and made 20 psi (was running 16 standard) and it seems gutless, wound the mbc right out and it now only boosts to about 14 and i have moved my boost gauge to the actuator line from the boost compensator, i think its a boost leak on that actuator line but dont understand how it can be slower for that?

Wind it in for more boost

[philpemberton94]

Yes i know but without the boost controller it was peaking at 16 psi so even with it wound out it should be making that as that is what the wastegate is set to, i had 20 psi at first but its slower than it was, hence why i wound it out to check if there was a leak, but if its leaking from the from the actuator line, surely it wouldnt slow it down that much, i could do 70 in 3rd before at 16psi and when it was at 20 it was struggling to do 60 thats what has baffled me

[toseland]

if your boost guage is reading appropriately, it should acurately demonstrate the boost in the entire system from the turbo to the cylinder itself, if there is a boost leak, it would leak pressure from the whole system, hence hte boost guage would show this as a drop in pressure.

as you rightly said, regardless of where the boost valve is set to, the absolute minimum it will boost to is wherever the wastegate spring is set to.. above this it simply does not let any pressure to teh actuator until the desired - pre valve- pressure is exceeded.

you are correct about teh amount of boost leak, the actuator line would leak a small amount of boost. HOWEVER if this is after the controller then there would be problems with it overboosting (the valve would only let say 20psi through, if 8 or so of this was leaking off from the line, then the wastegate may fail to open until enough pressure was pushed through to compensate for the leak)


check your seals on each end of the line.. what diameter hose did you install the boost controller with?

put the boost guage back on the intercooler to pump line, this will give the best place for a reading.

break out a spray bottle with a solution of water and washing up liquid in it, spray it sparingly on all of the hose joints from turbo up, give it a rev with the pump there and look for bubbles (doesnt need to be stupid revs)

did you turn up the fueling? without extra fuel, boost is pretty pointless.. no point having 40psi without enough fuel to utilise the extra oxygen.


Is the intercooler clean? if not, clean it, heatsoak is a nasty thing, above about 18psi, if driven hard, the intercooler will get hotter and the density of the aircharge will fall significantly, which counteracts the benefit of having the turbo turned up further.

if the intercooler is clean, think about upgading it for the above reason.

[philpemberton94]

Will have a look at all the piping tonight, the fuel has been turned up hence the 16 psi it was producing, but it may need a bit more once ive sorted the suspected leak

[philpemberton94]

I replaced to boost compensator pipe with some silicone which was i bit to small so stretched and snapped still a slight leak of about 1 psi haha, i suspect it is the d seal on the inlet

[toseland]

most likely tbh, that seems to be a suspect for most boost leaks..