Rovertech 2.0

was hoping if someone knows why my turbo only maxin out at 8 psi when it was running 13 psi i cheaked the pipes they seem fine and the dump vale has gone very quiet when driving the tubo kicks in but never feels like its putting much power in as it never feels faster through the rev range ??

Only thing i can think off is boost pipe leak or damaged intercooler. Is it producing alot of black smoke on full throttle.

Failing the above could the turbo be on its way out or the boost controller.

leeking dump valve if its a diaphragm type

ive looked at pipes so was thinking turbo also would a broken dump valve course boost problems ?

Yes as that would end up being an escape route for the air.
If you can undo the alen key bolts on your dumpvalve making sure you keep hold of it before the spring shoots it all apart. Once you've removed the bolts seperate the two halfs keeping hold of the spring ang check the diaphram (flat plate that the spring sits in) if that's ok the check the condition of the spring. Replace any worn or damaged parts put back together and try again

also might be worth checking the actuator,try blowing down the pipe to it, there should be restistance,but it sounds like the dv
lisa x

thanks ill try blowing down the pipe and see. sounds like to much hassle taking the dv apart ill just buy an new one lol im lazy like that

skivvey220turbo wrote:thanks ill try blowing down the pipe and see. sounds like to much hassle taking the dv apart ill just buy an new one lol im lazy like that

taking the dv apart is pretty quick and simple
lisa x

Surley you can undo 3 tiny bolts dude!
If you do get a new one give me a pm and ill have your old one off ya

lol i know i done it anyway and it all seems fine and i blew down the pipe and got resistens so..... ????? bloody car will be the end off me

What's your boost pipes like? Check them for any holes even tiny pin pric holes can cause problems

If you have a mechanical boost controller, unscrew and remove and clean inside and the ball bearing.
Common cause of low boost mate.

also check and make sure no boost pipes are collapsing. Make sure they are nice and firm and not really squashy and soft.

My money is still on the dumpvalve, if the crack/pin hole is on the lip/edge, you'll still get resistance when blowing down the pipe.

Blowing down boost pipes/vac pipes never works.

You will struggle to blow even a couple of psi, never mind anywhere near 12 ish.

If your getting 8 psi boost, then you would need to blow more than 8 psi to find the leak , unless your superman you need to use a foot pump !

It works for for a properly split diaphragm, but if there was an imperfection as Mark suggests that stop it sealing shut it probably wouldn't. Checking the line holds vacuum might be a better test than blowing down it, but yeah, a source of compressed air and some means of measuring leak-off would be better.

well i've got a new dv on the way me had one spare so just waiting for that then were see. pipes are fine they've been looked at many times. thinking more internal like the turbo. any ideas what the standard boost is on the t16 ? so i got an idea what to be aiming for ? donno if it helps but listing to the car i could hear a high pitch noise coming from around the turbo area nothing loud or mager but just an idea.

random fact just found out i got the first eva 220 turbo on the road in the uk reg k405 ahp

Standard T25 hits 11.7 psi from engine speed of around 2.5k rpm.

You can hear a high pitched noise. Presumably this is with engine at idle. If so then that sounds to me like air escaping from somewhere, which would only be due to a loose hose or manifold connection or a hole in a pipe.