Ian

iTrader: (10)

it has got the one what came with the turbo, and when i brought it (from someone on here) i was told it was a andy f unit

when it was last mapped, the actuator arm had to be wound out so the car would hold boost longer from what i can remember.

what would be a better actuator to have?
here is a pic


any info ideas welcome

Ian

iTrader: (10)

bttt

Gman1976

Forge actuator on MHI turbos..Had one in my Evo V RS..Works very well.You just have to buy separate springs for different boost levels.I.e yellow,blue,green.The guys at Forge know what to deliver if you know how much boost you are going to run.

cheers.

Ian

iTrader: (10)

not a 100% sure, am running 1.5 bar at the mo

Ian

iTrader: (10)

bttt

Andy.F

That does not look like one of mine, can I see a side view ?

Andy

Ian

iTrader: (10)

sorry andy, my mistake, just had a re-look through my pm, and it was supplyed new and fitted to the car of the person i brought it off, by AS Performance, is it just the mornal run of the mill 20g? any info would be good

here is a couple more pics, any more info on the actuator?

Andy.F

Hmm yea could be after all, I have supplied Alyn with a few 20g turbos.

It was just the first pic that looked like the actuator was at an odd angle, the others look fine

Why do you consider you need an uprated actuator ?

Jolly Green Monster

iTrader: (4)

I presume boost is dropping off?

has the actuator arm been tightenned?

Simon

Ian

iTrader: (10)

from what i can remember, when it has the last map tweek, the actuator arm had to be wound out, as it wasnt making or holding boost on the avcr, after this was done, it held boost better, and frm what i recall it was mentioned that a up rated one may be needed in the future so it held boost for longer.

thanks
ian

Andy.F

My view is that if the std actuator spring is being overcome by high exhaust gas backpressure then there is a bigger or at least different problem to be sorted out.
If the turbo is having to be overworked to achieve boost then more actuator tension on the wastegate will only build more internal pressures, this results in a cylinder pressure higher than ideal for the power output achieved.
Usually when this sort of issue is encountered the best solution is to look at the breathing in/through and out of the engine as a whole and eliminate any restrictions. The result should be that your 'problem' will be controlling overboost and all on the same low pressure actuator !
You will end up with a lower stressed engine, running at lower EGT and making more power.

FWIW on my race car I run with the softest springs available in the wastegates (two 40mm wastegates 0.5 bar spring) and this easily achieves 2.5 bar of boost.

Ian

iTrader: (10)

i have got a aps caik (with new K&N filter on) and at the time a 3"bell mouth decat down pipe, and blitz nur spec system.

i have changed the blitz to a titanium system now, that is a true full 3" all the way, and have got a set of gt-spec headers to go on as well.

hopefully this will sort it out

thanks
ian

Ian

iTrader: (10)

evening bump

Andy.F

That setup sounds fine, the only issue may be if the turbo has been previously ported specifically to suit a 2.5 ?

Ian

iTrader: (10)

yes i think he had it on a 2.5

he never said it was any different

Andy.F

The higher gas flow in the midrange requires different porting on a 2.5 turbo, that may well be your issue with not being able to hold boost with it on a 2.0.

A different exhaust housing may be a better solution for you than a high pressure actuator.