1 bar loop

I keep noticing that mine will boost to 0.9 then at around 4.75k go up to the 1 bar then at higher rpm say 6.25k reduce back to 0.9 is there more to it than just the 1 bar loop just wondering if this sounds like its has been nistuned or some other mapping has been done as the previous owner didnt mention it had been done but I know yours pete does that and yours is nistuned??

Mine goes up to about 1.15bar but drops off to 0.8, here is my boost graph:


You still on original wastegate Rich? Mine has a forge one fitted with the blue spring.

RED 17 psi (spool up) - 20 psi (running pressure) our product code FMAS049R.
BLUE 14 psi (spool up) - 18 psi (running pressure) our product code FMAS049B.
YELLOW 9 psi (spool up) - 15 psi (running pressure) our product code FMAS049Y.
GREEN 5 psi (spool up) - 10 psi (running pressure) our product code FMAS049G.

If by wastegate you mean BOV it has a forge one on it

Wastegate is the bit thats bolted to the side of the turbo its the block side of the turbo rich its the bit with a rod and round diaphram at the top if that makes sense.

Sorry i meant original actuator As Leighton says, the wastegate is the flap on the exhaust housing which is controlled by the actuator; the thing with the diaphragm. (check my 1st post)

You need the restricor in the boost hose that comes off the plenum, it has a green band on it if I remember correctly.
If you haven't got that hose on the. The 1bar loop won't work rite.

Nistune or any other ecu mod won't control boost! It's the boost controllers that control the boost, ecu's provide the right fueling via the maps on them.

Ok cheers for info guys, I presume its the original actuator but I havent checked all I know is it has a forge BOV and if I get time this weekend I shall check that its all plumbed in correctly

You can always check if you feel its not right by pinching the vac line if it changes then you know its leaking or not.

Well I'v checked and it still has standard wastegate and a bcu boost controller which isnt used as its not plugged in

Why is it not plugged in? is the boost soleniod all still present for it or not?

In all honesty Leighton I havent a clue whats there and what isnt it was presented to me by the twat who had it before me in current form so I dont have a clue on any of it tbf could do with someone who knows what is what having a look and telling me what I have/havent got

Well its relatively simple boost controller in the car should have a vac pipe and couple of cables from the back that goes to the soleniod under the bonnet plus earth and live then under the bonnet you should have pipe from the plenum to the soleniond then the other one goes to the actuator i do believe quite simple really it varies for different models but basics are the same mate. Always google your model theres lots of online manuals