boostedup

It only has one gate which for all intents and purposes was completely blocked off as the bolt was stopping the valve from opening, this netted another 3 psi. I agree that the wastegate was not the problem this was just the method to prove it.
the tuner has triple checked the BOV, I have to tread carefully here as I don't want to undermine him.
I'll ask how much ignition timing is in it. This set up is nothing risky or developmental it's all fairly off the shelf and tried and proven.
Forced performance suggested that possibly the ex housing might be to big but again, same set up as many others are running and would it not run out of puff before 43 psi?

boostedup

Ok so here's an update, the tuner whacked on an old gt42 this is a fairly old turbo running at t4 exhaust housing with a 1.02 rear, it ran 55 pounds of boost no problem at all on went just over 600 kilowatts basically did everything that turbo supposed to do.
Also also he said that it came on about 1800 revs faster.
boost control was all perfect everything worked the way it should so clearly there's a problem with the turbo which is brand new in the box, so either the exhaust ar is just too big and the engine can't spool it up or there's an actual problem with the turbo, any thoughts?

Evo8cy

Yes I know you only use one wastegate, I meant bov and wastegate when I said both gates. I also insist that even the 3psi you got was not due to the wastegate, but due to the different cam dialing combo which allowed for better V.E along with the tweaking of the maps. If the leak was that tiny small, it would allow you as I said to run 53+ psi. There was also no need to put that screw there, as if the wastegate was actually leaking, then the boost pressure would flactuate a lot especially up top, and boost would drop in the higher rev range by quite a significant margin. In general the behaviour of boost would highly indicate whether the wastegate was malfunctioning or not.


On post 26, I suggested changing the turbo to something else. After blocking off everything and if the problem persisted, then it should have been turbo change time.


Nevertheless, I am glad you guys got it sorted out. In regards to the turbo, it is not the exhaust housing size. The exhaust housing cm2 area and A/R affects peak power, the velocity,the speed of the exhaust gasses and in general the way exhaust gasses hit the wheel but it does not affect peak boost limit. Boost is the inability of your engine to absorb a certain amount of cfm in a certain way and timing, hence why increasing V.E affects boost greatly. The only way an exhaust housing would affect peak boost, but nothing that would not have been corrected with a stiffer spring and better boost control strategy, would be if the housing was too small for the setup and created a dynamic restriction in the form of backpressure thus pushing the gate to open up, something which would be very apparent in the way boost behaved and would also be shown in the logs.



Enjoy the progression and use of your setup.










Marios

boostedup

so we got to the bottom of the boost issue.
once the tuner had checked and double checked everything the only option was to start replacing things.
first thing to replace was the turbo, the tuner put in an old GTX42 he had lying around, went straight to 55PSI and made over 600kw no problem.
FP had advised that the exhaust housing may have been to big, tuner put the Xona back on, give it a small shot of NOS to spool the turbo up and it flew to bits.
FP are saying intercooler to small, to prove the point, the tuner pout a gen 2 turbo on, same AR ratio, at 55PSI with the same small NOS shot it made 985whp, 3psi pressure drop across intercooler.
clearly the engine or intake system has no issue.
awaiting FP to respond, interested to hear peoples thoughts here