Gt2359v

[HDIkyle]

On a 2.1 running 25psi ish peak boost but not coming on boost until 2.5k revs. Now looking at the actuator( if its called that on a vnt) it sits afew mm off the stop screw. Is this right. Stop screw is about 3/4 turns out. Watching dum duke video it looks a lot in the same place but should the actuator be sitting on this when not running? Surely it should come on boost much earlier even my td04 came in before this.

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I have tryd to move the screw in abit more so less threads are showing on the arm side. But its stuck so had to leave it how it is for time been

[todd1983]

This is the turbo fitted to the bmw 330D, so coming on boost at circa 2.5k probably not too far off the mark. On the 3ltr 6 pot it hits full boost around there.

Ignore me, I miss read the title, it's 2259 on 330d

[Ruan]

Yeah it should be touching it the stop screw - but be extra careful, you can f*ck stuff up real bad if the stop screw is put in too far, high EMPs etc... If it's not been adjusted you're probably OK.

Is the actuator bracket bent?!

[HDIkyle]

Well when I got the turbo the stop screw was not in so I put one off the old turbo dum dums engine. I don't look bent I will get some photos up and check it.

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What are emps? Exhaust manifold pressure? Had a google but didn't seem to find a clear explanation

[Chris_90]

Well when I got the turbo the stop screw was not in so I put one off the old turbo dum dums engine. I don't look bent I will get some photos up and check it.

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What are emps? Exhaust manifold pressure? Had a google but didn't seem to find a clear explanation

Exhaust manifold pressure, when the vanes are shut make it only has a small place for the exhaust gases to go around, because there's not much room for them to flow round the hot side, it creates pressure in the pipe/manifold running up to it, you wanna get a emp gauge really with the vnt so you can see what's happening then you can play with the adjustment see if you can get it to spool lower down with out loads of back pressure.

[silverzx]

What gauges have people radged on then?

[mr_fish]

I used this, was only meant to be temporary but just left it bolted to the dash.

Lash up Gauge

[silverzx]

I used this, was only meant to be temporary but just left it bolted to the dash.

Lash up Gauge

Whats the max yours reads to? Thanked.

[mr_fish]

Just looked on my ebay items

63mm Hydraulic Pressure Gauge Rear Entry 0-60 PSI

It's a bit 'in-you-face' but meh makes you keep an eye on it.

[Dum-Dum]

Yes it should sit on the stop screw. If you tighten up the actuator arm a little so it sits on the stop with no boost and it'll come on boost earlier.

If that still isn't boosting early enough you can let the stop screw out by a quarter or half a turn at a time.

As Ruan says don't have the stop screw too far out, a quarter turn makes a HUGE difference to where that turbo comes on boost but I had it running so the turbo was well on boost by 2000rpm.

[Ruan]

But you need to have your ears open - too much and you'll run into surge and you can say goodbye to the turbo very quickly!

[zx_volcane]

Ideally, leave the stop screw as standard for now

adjust the actuator to pull the vnt lever all the way to the stopscrew at 0psi boost

Fit an exhaust manifold pressure gauge - take a feed from the exhaust manifold somewhere before the turbo.

Monitor the relation between the emp whilst the turbo is spooling.

I think on the older gen 1 vnt you can expect to see up to 2x emp to inlet pressure ratio on spool - then ideally as close to 1:1 ratio as you can get when you hit target boost.

Maybe 1.5x emp over inlet pressure once target boost is made will be ok, but the further you let the ratio go up the more pressure you're putting on the turbo to make the requested pressure ratio.

What you really want to avoid is pinning a 60psi emp gauge on spool and having a high ratio of inlet to exhaust pressure ratio when on boost.

Just as bad is having surge on boost / throttle. So if the vnt comes in too early it tries to push more air through the head than it will flow and it surges back through the turbo - this is bad news for the turbo. Irrc on a standard head with something like a 2256v surge was around 25psi at 2k revs, but it will be heavily dependant on the turbo and its surge line. You could have a huge turbo that would surge trying to make 5psi at 4k revs becasue it is trying to shift so much air.



TLDR - get an emp gauge on and go from there

[HDIkyle]

This is no boost engine off

[zx_volcane]

Yeah you need to adjust the length of the actuator rod to pull the lever down to the stop screw - looks like you can adjust the actuator rod length with the knurled adjuster you can just about make out on the right side of your photo

careful if that stop screw has been messed with, and perhaps err on the side of caution in pulling it all the way down.

[HDIkyle]

[Dum-Dum]

I'd probably wind the stop screw in a turn to be on the very safe side and then undo the lock nut and wind the actuator arm so the VNT arm so it sits on the stop screw.

[HDIkyle]

Ye will do. Does the pic work its not showing here

[nominous]

Yep works fine.

[HDIkyle]

Got a feeling its stuck open. I can see the part of the arm that moves as its clean with a dirt line where it obviously sits closed. But I cannot budge it at all manually.

[Ruan]

Has someone had the turbo apart since?

Looks like it's been put back together wrong.

[HDIkyle]

Not apart. I took it off to put a stop screw in. Unbolted bracket moved it round then put it back

[Chairchild]

ping off the arm, and see if you can move it - should flap about with ease

[HDIkyle]

The flap moves fine just the actuator that don't

[Ruan]

Ah just the actuator rod is too short then, just undo the locknut and wind down the thumbscrew on the arm and you should be good to go.

[Dum-Dum]

give the actuator a good pump in and out either by hand or with a bike pump. at a full 25psi its got quite a bit of movement.

Kyle the offer is still there that If I am ever up by you or your down here I will give you a hand setting it up 100% again



If you take the clip off the actuator and then the actuator arm off can you move the vane leaver all the way to the stop? If so shorten the actuator arm a little bit.
If the vane lever itself doesn't go any nearer the stop then either something inside the turbo is stopping the vanes moving or the exhaust housing has moved relative to the CHRA somehow

[HDIkyle]

Ye the arm moves both ways fully to stop so I must have moved the arm when I had it off. Just not getting much time to mess with it atm