VNT or Twin Scroll
Turbo Mini Forums

On 7th Oct, 2014 Paul S said:
Thanks Gary,

Funny how ebay.com throws up different search results from ebay.co.uk although all UK based

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

I am an eBay ninja

In the 13's at last!.. Just

Ok then find me a cheap genuine K04-15 Gary :)

If something is worth doing, it's worth doing half of.

There's only cheap Chinese and expensive genuine ones availAble at the moment.

In the 13's at last!.. Just

That's what I found.

If something is worth doing, it's worth doing half of.

Well, I'm going to buy a Chinese GT1749v.

I figure that there is just as much risk buying a "good condition" second hand genuine Garrett.

Minimal miles at low boost is all that we are planning on this car.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Be interesting to see how it goes.

If something is worth doing, it's worth doing half of.

lots and lots of gt45 chinese turbo's being used in american cars nowadays ,no blow ups to speak of .just flush out any swarf .

i tuned a 16v 206 with a180 quid ebay gt2871 , worked very well.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

For what it's worth, like Denis, I rebuilt the GT1752V on my Mondeo 3-4 years ago using cheap (so presumably chinese) eBay parts, turbine wheel/shaft, compressor wheel, bearing/seals etc. also just relying on their individual factory balance and some 25k miles later it's still fine.

I think nowadays "chinese junk" is a myth or, at the very best, a thing of the dim and distant past.

Schrödinger's cat - so which one am I ???

Thanks for the positives guys.

Now all we need to do is sort out the control.

I assume that the simple starting point will be to connect boost pressure to the actuator and see what happens.

Will it open the nozzle ring as boost builds? and then modulate?

What happens when it can open no further, or will it never get to that point?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

What vehicle was it meant for ?

I'm only familiar with the diesel fitments and the ones I've worked on and/or seen with diaphragm type actuators are vacuum actuators controlled by solenoid valves (operated by the ECU) using vacuum from the main vacuum pump (which primarily powers the brake servo).

All the newer ones use a servo motor (again operated by the ECU) which is where a few people are going on the MS-E forums (I think Jean has included a servo option on the IOx now and I'm not sure if the MS3x has it anyway).

If it has a pressure operated actuator I guess it should do as you say depending on the spring loading inside the actuator.

Schrödinger's cat - so which one am I ???

Lots of them are vacum actuated, so you might need to swap actuators,

what I always got with just an actuator was boost building through the rev range, I would say the best route would be set the boost to somthing, it'll probably gain 5 psi through the rev range, and just use an MS output to map the boost to what you want.

if you try to do anything fancy with the actuator it normally results in a boost spike as it comes on boost.

oh and with mine open all the way it dosent make much boost at all, say 3-4 psi, but mine is big.

This is the variant that I'm currently favouring:

http://www.ebay.co.uk/itm/271568997977?_tr...K%3AMEBIDX%3AIT

Sounds like an actuator swap is in order. Running off boost rather than vacuum and pushing from the other direction rather then pulling.

I can map the duty cycle of a PWM output against boost vs rpm to control a fast acting solenoid with the MS3 if necessary.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

The fact the vane operating lever is up against the physical stop in the photo does certainly suggest it has a vacuum actuator fitted.

So, yes, it will need reversing.

The "Amal" solenoid valves were the weapon of choice back in the 90's for PWM control. There is probably something a LOT better around nowadays.

I do quite like the idea of a servo motor though....

Schrödinger's cat - so which one am I ???

Servo motor directly controlled by the ECU would be far better.

Trying to find a suitable motor is somewhat challenging.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I'm sure Joe was one of them on the MS-E forums questioning this a while ago ...

Joe, please chime in if I'm wrong.

If I'm wrong it was someone with a similar name....

The servos that people have mentioned are RC model servos, the bigger ones obviously.

They are a stepper motor but have an H bridge (I think that's the right words) circuit built in to read PWM.

Have a look on Jean's forum, I'm sure the details are there.

Schrödinger's cat - so which one am I ???

You are correct. I just found Joe's post on the MS forum.

I've just been looking at the Honeywell rotary electronic actuator commonly used by Ford, BMW, Mercedes etc. on the GT1749 amongst others.

http://www.ebay.co.uk/itm/mondeo-tdci-elec...=item46299d271c

Seems an ideal candidate if we can work out how to talk to it.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Found this relating to the Garrett controller:

http://www.superturbodiesel.com/std/Thread...08-412-actuator

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

LOL

dont forget that I did have a play with an RC servo, looks like it should work directly off the MS with the right settings.

Ive got a heavy duty RC servo you can have a play with if you like.

New chinese GT1749V for £160. Worth a punt eh?

Here it is pictured next to a GT1752S:




Nice and compact when compared with the 52.

This is going to be used on our budget port injection setup:

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=571531

Just need to get my hands on the Garrett electronic actuator and do some tests with the ECU.

Edited by Paul S on 14th Oct, 2014.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Are you planning on dismantling it to have a look see?

If something is worth doing, it's worth doing half of.

Too right. It will need a bit of a swivel and some fabrication of a mount for the electronic actuator. I'll be surprised if it does not come apart in the process

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Very good, also I do hope you shined my GT1752 up as much as the one in that picture! lol

If something is worth doing, it's worth doing half of.

Looking for flange drawings for the GT1749V and found this:



Cracking compressor for a 998, let's hope the turbine side can be made to work with nice low inlet pressures and we will be well away

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."