hello all, just thought i would let peeps now that after getting a reconditioned turbo for my 03 plate focus tdci it at first would not boost until you was doing around 60 mph , i then found out after sending it back to gap turbo, in Birmingham http://www.gap-turbos.com/index.html that it was there fault and he told me it was some thing to do with the vnt http://www.honeywell.com/sites/portal?s ... s&theme=P1 now the point aim making here is that only garret can set up the vnt,s on the turbo and all the turbo shops relay or just guessing !! i believe there is a machine thats just come out from turbo technics (thanks guzzler) that can set vnt turbo,s up but unless the turbo shops have one they will just set the vnt,s to what they think, now ive spoke to my turbo shop who say what ive just said is correct and that he has got a machine from turbo technics on order at a massive cost but ive also herd that turbo technics might just keep this machine to themselves..it would make sense... after putting my second turbo on it is better but now were near as good as my oem one set up by garret this is cus its absolutely critical that the vains or set up absolutely perfect just for that model car.... Ive also de-cat,d my focus and that has made a difference to the power you can now here the turbo spining up and down from the exhaust

andy

 

 

Do you have another turbo to take measurements from? That would get you in the ballpark.
Wasn't the vane actuator just taken off complete and then refitted, it should cause any issues unless someone has adjusted it on removal.
You sure it not an boost soleniod/valve problem or amm?

 

ive spoken to the guy who sets them up from the turbo shop and he says he goes out and buys oem ones and gets the set up from them but its just not good enough.. its as near as but its so critical it has to be blob on mate garret will tell you that, and garret only want to sell you a brand new one thats why this machine has been made by i think turbo technics..

 

Well it aint rocket science mate, it wouldn't take long to get it right from a ballpark settings. Its no different to setting a normal wastegate really.

 

really
it works in completly the oppiste way, the actuator is not set by boost pressure, it is set by the amount of air that flows through the turbine end of the turbo!

 

Rs1 have you not read up on vnt turbo,s and how they work? thats why ive posted garrets web site.. its absolutely critical

 

I didnt say it was EXACTLY the same but its not like its a million mile away.
The differance bewtween the way they operate is fundamentally the same be it bypassing or redirecting exhaust gas and both are operated via actuation that has pressure/vac assistance.
If you set the base position of the vnt correct there is no other adjustment needed that isn't controlled by the ecu of which you have no input in(on oe chipset).

 

blob on pal, thats the whole ides of vnt, to get power from very low revs unlike a normal turbo

 

So what prevents it from making too much boost?

 

With a normal turbo theres plenty of room for error in actuator setting without it causing a problem as the actuator normally has a wide working range, ie; starts to open at .4 bar, fully open at 1.2 bar, the boost control solenoid with help a lot with this.
with a vnt turbo if its not set correctly it will be really flat low down or hit overboost to early (often putting the car into limp mode)

 

it still has a actuater on and mine is set at 1.2 bar but from 04 onwards the actuator is electronic and i would of thought will be controlled by the ecu

 

I asume that its that actuator that rs1 was refering to then as being basically the same as on a normal turbo car that was my understanding too.

 

Chip, there set at closed position, they use a vacuum actuator, its sits open (rod fully extended) when you start the car the vacuum pulls the actuator in to give the turbo maximum boost position from low down the rev range, as the boost increases the vacuum becomes pressure & pushes the actuator out again, thus starting to close the veins to lower the amount of exhaust gas passed onto the turbine wheel to prevent overspeeding/boosting.

 

Dude if youve read up on vnt turbo's i assume you also read up on "normal" and you can't be unaware of how similar that is to a conventional setup.
Like i said it aint rocket surgery.

 

RS1, Agreed, what Guzzler is saying is basically the same in terms of boost control operation as a normal setup.

This is also the same as my own understanding of how it works

 

if you read what i put then you will see that i said that work the opposite way round, yes they both use an actuator but in a totally different way, not something i've read up on but experiance

1 works on vacuum, 1 on pressure, ie; opposite
1 bleeds air out of the turbine housing, 1 directs air onto the turbine wheel.......

now perhaps you should go do some 'reading up' or maybe look at a vnt turbo compared to a normal one

 

But you just said:

If I was to describe how a normal actuator works I would say:
Surely thats pretty fucking similar by anyone's standards?

 

Chip if you looked at a vnt turbo you would know what i mean

example, if there so much the same in the way they work, why can't they be repaired like a normal turbo?
Why did Morto have to rebuild his engine because the turbo company told him the turbo was not at fault.... easy to set up a 'normal' turbo

some 'normal' turbos use vacuum actuators, there still fuck all like a vnt.

according to Garrett who make the turbos they can't be rebuilt/recalibrated, the turbo companys say they can't recalibrate them, they basically take a shot in the dark with the settings.

a normal turbo has all the exhaust gas passing over the turbine wheel, a vnt's gas is determined by the veins......

 

so what your saying is that there the same then Mr guzzler !!!!!

 

get bent ya hillbilly

 

sorry didn't mean to offend ya cunt

 

Guzzler, RS1 was talking about the fact that the boost is controlled in the same manner, so for example standard engine management should still be able to operate with a VNT from a boost control point of view.

He wasnt saying the internals as the same, as obviously they arent.

 

pmsl

 

he was on about the setup of the boost/wastegate, if your at central day i'll try to bring a cut-a-way vnt turbo.

 

Yes he was on about how you setup the ecu to control the actuator used to control boost, which is the thing that he is saying is basically the same on the two types (ie it gets longer to give you less spool as the boost rises).

Im not at central day, but ive already seen VNT turbo's in bits anyway, thanks for the offer though

 

can i have a cut away turbo for my car please

 

Chip re read the post, he said it could be a solenoid problem, he also said

Its no different to setting a normal wastegate really.

 

I think you have missed the point of what he was saying mate.

Anyway I'll leave the two of you to discuss it mate, as I dont really care that much to be honest so now im leaving the office, I dont intend to spend any of my own time discussing it

 

Christ, where to start, i thinks Chips got the right idea in walking away from this,lol.

Guzzler youve completly missed my point mate. Either conventinal or vein turbo actuators can only set be shortening or lengthning the rod....yes? So what is so hard in morto shortening or lengthning his in order to set it correctly, he has to be capabale of loosening the lock nut and running the thread which ever way surly??
If he has a turbo that is working correctly or one that is off and hasn't been tampered with then that will serve as an excellent base setting if he measures/counts the threads and sets his to the same.....as engineering goes you simply can't be a million miles away like that or garrett would be in deep shit finacially with there herendously bad build tolernaces.
When garrett say the turbo's can't be rebuilt/recalibrated they are merely talking in terms of cost effective repair not that its impossible to actually repair.
Your not the only one who has has experience with vnt's dude.

 

that is what you said, what i was pointing out is that its a different set up & setting to a normal wastegate, i've seen them needing to be recalibrated because its about a mm out, its not just a case of adjusting the rod lengh, it also has a stop that needs to be correct, with a normal turbo theres room for some error, theres not with a vnt turbo.
you could get the correct rod lengh but still have problems with the stopper.

 

Its no different to setting a normal wastegate.....as in you run the threaded bar exactly as you do on the vnt actuator. How is that so hard to understand.
Its very basic mechanics/engineering.

 

if its no different then how come you don't need a special machine to set an actuator on a normal turbo
what your on about is the basic princaple of the actuator fitment, i think you need to see a vnt turbo being calibrated to understand, not just 'guessed' in some workshop.
i deal with quite a few people who have had a 'mechanic' with your kind of attitude give them back a car with poor performance or tell them its another problem, i see it most days.

i see your point about rod lengh but its not that straight forward, i know lots of people who have done it to vnt turbos but very few that work properly, its normally ok if its a turbo that is disasembled & put back together, but when things are moved about its a different story.

 

Mechanics with my attitude,lmao.
They need a "special" machine, whats so special about it then? The will run the unit with a set amount of drive and adjust the actuator so that it makes the required pressure, open/close the vein and set the stop, job done. Due to the tolernaces of each units parts they will not need to set each one, they'll probably do a QC every 1000 or so(maybe more) just to make sure those tolernaces are as they should be and a bad batch of maching/part supply/material isn't coming through the productuon line.
You obvioulsy dont see my point about the rod length as you would realise it is that straight forward. What do you think garrett would do if you sent it to them? They would adjust the rod length and set the stop, that all they can do there is no other base adjsutment.

 

i see your point about rod length but what i was pointing out is that its not 'just like setting a normal turbo' its set against the stop & pretty critical its right, i was going to get some pics of 1 being set but havn't got a camera with me at the mo.
every unit normally has a slight difference, we set every one when its reassembled, some are close but never spot on.

 

have a read of this... by garret

GarrettŽ VNT™ turbos are highly complex units, engineered and calibrated to meet the exacting performance parameters of automotive manufacturers.

The first requirement is to set the turbo's critical minimum flow vane position. This intricate process takes account of the large number of parts and extremely tight tolerances within the GarrettŽ VNT™ and involves using a highly accurate turbine flow bench to measure and compensate for any variation in gas flow through the vanes of the turbo.

Highly skilled technicians then set and lock the minimum flow position to suit the requirements of each individual application. It is only when the ‘minimum vane open' position is set that it is possible to calibrate the unit (to three decimal places), using four checkpoints to ensure correct operation.

Each of these steps is vital in ensuring the optimum performance of GarrettŽ VNT™ turbochargers. Indeed, these engineering complexities cannot be compromised – which is why Honeywell's official Aftermarket distributors are committed to supplying only new GarrettŽ VNT™ turbos that are quality assured and matched to the original OEM specification.

Any attempt at remanufacture, using substitute parts, is fraught with difficulty because of the turbo's technical complexities and can lead to potentially serious problems, such as:

* Conflict with the engine management system
* Low flow/pressure, causing poor response, poor overall performance and increased emissions

* Over-rich diesel fuel/air mix, causing excessively high temperatures, damaging both the turbo and the engine

* High flow/pressure, leading to the over-speeding of the turbo, wheel bursting and damage to turbo and engine
* Excessive boost pressure, causing physical engine damage

"GarrettŽ VNT™ turbos are highly complex and meticulously calibrated components renowned for their performance," says Ed Goodwin, Director, Independent Aftermarket Europe. "Our distributors are committed to safeguarding the interests of their customers by protecting the integrity of the technology – and will therefore supply only new replacement GarrettŽ VNT™ turbochargers."

 

Define critical, as a few posts up you say...

" i've seen them needing to be recalibrated because its about a mm out "

1mm in engineering terms if fucking massive mate.

If you can be arsed adjust and actuator on a conventional turbo by 1mm as so how un-critical it is to set them correctly.

 

chill ya pants mate and try and learn something.. tell ya what pal i will phone the guy who rebuilds these vnt turbo,s everyday , he sells around 10 a week and when i last talked to him he agreed with everything guzzler said

 

i've fitted & adjusted plenty of conventional actuators over the years thanks Also of late done a lot of work with vnt turbo's.
funny that my theory fits in with Morto's, his turbo company & Garrett's

maybe you should start making your own turbo's, you seem to know more than the rest of the world

 

ps, Morto, glad you got it sorted at last

i have a galaxy one coming with a similar situation, they've spent over 2k on it already