Anyone tried these turbo boost adjusters??

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Post Reply
London luke
Posts: 59
Joined: 07 Nov 2005, 01:06
Location:
My Cars:

Anyone tried these turbo boost adjusters??

Post by London luke »

http://cgi.ebay.co.uk/POWERTEK-BOOST-CO ... dZViewItem

use to have a similer device on my Subaru.It was good.
Sir Clive

Post by Sir Clive »

How do these things work? I assume it bleeds some air away from the wastegate actuator to produce the effects of a lower boost pressure and thus delay activation.
Completely useless on a turbo diesel unless you increase the fuelling as well. Pumping more air in by itself ain't gonna make it go any faster :lol:
Stewart(oily)
Posts: 893
Joined: 07 Oct 2005, 16:31
Location: North Wales
My Cars: Citroens since 1990, BX Diesel, GTI, TZD with 1.9 TD running extra boost before it was fashionable!, ZX Volcane TD, S2 Xantia break 1.9TD, Xantia HDI 110, currently zipping about in a C2 Diesel. C2 died from the dreaded worm, C3 Picasso HDI Exclusive, the adventure continues.
x 31

Post by Stewart(oily) »

I have one fitted to the hooligan BX, I extended the lines so its accessible from under the bonnet but when I built up the turbo/wastegate the actuator pushrod adjustment ended up with me having 15 psi compared to the standard 13 psi that my old turbo was giving me, i then did just the first increment in the on boost fuelling and maximum fuelling (Bosch pump) and the increased power has proved sufficient to stop me from tampering any further for the time being, note they only fit the Garrett turbochargers if your turbo is KKK then theres nowhere for it to go.
Stewart
BXs since 1993 built 1.9 TZD turbo, got a S2 Xantia estate, brilliant car! 2013, Xantia HDI LX 110 2000 new car with 122,000, l C2 HDI Rusty rocket, C3 Picasso HDI new to me.
NiSk
Posts: 1422
Joined: 24 Jan 2002, 20:11
Location: Sweden
My Cars:
x 1

Post by NiSk »

It depends on were you fit it. If you fit to the wastegate line, the above is true. However, if you fit it to the line going from the intercooler to the injection pump, it will have an effect, even on a diesel. (the ECU registers a lower pressure in the intercooer than it is expecting and increases both boost and fuelling).

However, a rather difficult device to adjust accurately without a precision boost gauge and I think you might have trouble with the MOT smoke test as well.

//NiSk
jeremy
Posts: 3959
Joined: 20 Oct 2002, 16:00
Location: Hampshire, UK
My Cars:
x 2

Post by jeremy »

It doesn't work - how can it. Turbos pump and provide boost. The output is limited by a wastegate in many installations - this simply spills excessive air and can be adjusted to increase boost. This is a small valve on the end of a bit of thin tube. Open the valve - and you can only LOOSE boosted air - admittedly not much as the tube is too small.

Same is true for both diesel and petrol. Some engines are designed to run at higher boost than others (Citroen CT 2 liter for example of a low boost engine)

Someone now tell me I'm wrong
jeremy
Sir Clive

Post by Sir Clive »

Oh, I absolutely agree that on an ECU equipped car, you will be able to fool the system to some extent. However, on a mechanical injection you have to do as Stewart says if you want some extra gee-gees. Just adding the device by itself won't help.
Stewart(oily)
Posts: 893
Joined: 07 Oct 2005, 16:31
Location: North Wales
My Cars: Citroens since 1990, BX Diesel, GTI, TZD with 1.9 TD running extra boost before it was fashionable!, ZX Volcane TD, S2 Xantia break 1.9TD, Xantia HDI 110, currently zipping about in a C2 Diesel. C2 died from the dreaded worm, C3 Picasso HDI Exclusive, the adventure continues.
x 31

Post by Stewart(oily) »

Jeremy I see why you dont think it works, the device sits in line between the turbo and the wastegate actuator, It actually restricts airflow to the wastegate actator, therefore the actuator does not see the 13psi it needs to open and let the gas go down the pipe, so it carries on letting the gas spin the turbine. this effectively increases the amount of boost before the wastegate opens, and is far easier to adjust under the bonnet than under the car.
Stewart
BXs since 1993 built 1.9 TZD turbo, got a S2 Xantia estate, brilliant car! 2013, Xantia HDI LX 110 2000 new car with 122,000, l C2 HDI Rusty rocket, C3 Picasso HDI new to me.
Senor Pat
Posts: 5
Joined: 19 Oct 2005, 18:17
Location: El Escorial Spain
My Cars:

Post by Senor Pat »

I have fitted one to my activa 2 litre turbo and even though I don't understand the mechanics the car flies now from 3000 rpm onwards.
It pulls really strong especially from 70 mph.
It has actually improved fuel consumption as well.!!
It gave me about 30 extra ,horses but as mentioned has to be adjusted with a boost gauge. :lol:
" Iam the way the truth and the life" Jesus
London luke
Posts: 59
Joined: 07 Nov 2005, 01:06
Location:
My Cars:

Post by London luke »

Senor Pat

Did you notice any difference at lower speeds etc?? I am looking for a performance increase I can use !
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Post by Mandrake »

jeremy wrote:It doesn't work - how can it. Turbos pump and provide boost. The output is limited by a wastegate in many installations - this simply spills excessive air and can be adjusted to increase boost. This is a small valve on the end of a bit of thin tube. Open the valve - and you can only LOOSE boosted air - admittedly not much as the tube is too small.

Same is true for both diesel and petrol. Some engines are designed to run at higher boost than others (Citroen CT 2 liter for example of a low boost engine)

Someone now tell me I'm wrong
You are wrong :wink: although I can see how you might think it could be like that.

What you're overlooking is the relative sizes of the pipes, and the effects of pressure drop under load on small pipes.

The boost output from a turbo is usually in a large manifold pipe, lets say 30mm in diameter, however the waste gate controller is usually tapped off that pipe using a longish length of rather small diameter pipe - for the sake of argument lets say its 150mm long, and about 3mm in diameter.

Now if you were to fit a pressure bleed valve to the main mainfold pipe then you're right - any drop in pressure that the waste gate controller detected would be equal to the actual boost pressure drop, so it would boost it back to where you were before and you'd be back to square one. (Assuming the turbo had enough oomph to provide the extra boost to overcome the leakage)

However wastegate bleed valves are fitted at the wastegate controller end of the long skinny pipe, not at the manifold end. Because of the long skinny pipe it only takes a small amount of bleed off from that valve to cause a big drop in pressure as registered by the waste gate controller, however due to the long skinny pipe back to the main mainfold, the actual mainfold pressure will hardly drop at all.

Therefore there is a net increase in boost pressure as the wastegate controller tries to get the pressure it measures back to normal.

If the pipe from the mainfold to the wastegate controller is too big in diameter, this approach won't work very well, so I would say (without having seen inside any) that a commercially made manual boost controller valve would be a combination of a series restrictor and a parallel bleedoff valve - that way it would work effectively regardless of the size of the sensing pipe.

Edit: re-reading your post I think you might be misunderstanding the wastegate operation itself. The small sensing pipe that is tapped off the mainfold is not where pressure is bled from when the wastegate opens, its simply a pressure sense line which operatates a small pressure diaphram like a dashpot, but it is a dead end which air can't leak out past. (Before modifying with a manual boost controller that is)

That diaphram then pushes the actual waste gate, which can be either a flapper valve inside the turbo housing itself which allows exhaust to bypass the rotors - like my old Daihatsu Charade, or if you're a noisy boy racer type, it can be an external dump valve connected to the main mainfold pipe.

Regards,
Simon
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
Senor Pat
Posts: 5
Joined: 19 Oct 2005, 18:17
Location: El Escorial Spain
My Cars:

Post by Senor Pat »

London Luke.
I said it goes really well past 70 mph as this corresponds to 3000 rpm in 5th.
Obviously power comes in strong from thenon in any gear ,3 rd especially is very strong.
It didn't give me any low down grunt but for 25 quid and 30 mins fitting can't go wrong can you?
" Iam the way the truth and the life" Jesus
Stewart(oily)
Posts: 893
Joined: 07 Oct 2005, 16:31
Location: North Wales
My Cars: Citroens since 1990, BX Diesel, GTI, TZD with 1.9 TD running extra boost before it was fashionable!, ZX Volcane TD, S2 Xantia break 1.9TD, Xantia HDI 110, currently zipping about in a C2 Diesel. C2 died from the dreaded worm, C3 Picasso HDI Exclusive, the adventure continues.
x 31

Post by Stewart(oily) »

If you are fitting it to a TD Xantia along with a boost gauge and suitable adjustments to fuelling then the benefits can be felt from the moment you pull away, this is the nearest thing to a free lunch that I can think of :D :D :D
Stewart
BXs since 1993 built 1.9 TZD turbo, got a S2 Xantia estate, brilliant car! 2013, Xantia HDI LX 110 2000 new car with 122,000, l C2 HDI Rusty rocket, C3 Picasso HDI new to me.
RichG
Posts: 173
Joined: 27 Oct 2002, 01:36
Location: Manchester
My Cars:

Post by RichG »

Stewart - Perhaps I am being a bit thick here (not unknown) but I fail to see how such a device could help at low revs. As I understand it the waste gate is not progressive but is either open or closed. Consensus on this forum is that the best way to test the maximum boost is to drive the car, foot to the floor, up hill in third gear. I have done this with a boost gauge attached and got a max reading of 1 barg. If this device just delays the waste gate operating until a higher pressure then surely it will only affect the upper part of the rev range at high loads? The lower range where the waste gate is normally shut should not be affected.

Richard
1998 Xantia 1.9TD Estate (Sold - replaced with Skoda Octavia (sorry))
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Post by Mandrake »

RichG wrote:Stewart - Perhaps I am being a bit thick here (not unknown) but I fail to see how such a device could help at low revs. As I understand it the waste gate is not progressive but is either open or closed.
Most modern waste gates are progressive, even the one in my 1984 Daihatsu Charade was :) In that case it was nothing more than a pivoting flapper valve opening a bypass port in the exhaust section, operated by a dashpot type diaphram.
Consensus on this forum is that the best way to test the maximum boost is to drive the car, foot to the floor, up hill in third gear. I have done this with a boost gauge attached and got a max reading of 1 barg. If this device just delays the waste gate operating until a higher pressure then surely it will only affect the upper part of the rev range at high loads? The lower range where the waste gate is normally shut should not be affected.

Richard
It's not clear from your post whether you're talking about 1 bar boost on a modified or unmodified turbo ? At what RPM did you first reach maximum boost ?

Turbo boost is related not only to RPM but also volumetric throughput which is affected by throttle opening, so what rev range it improves with a MBC will be highly dependant on the characteristics of the turbo...

Regards,
Simon
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
London luke
Posts: 59
Joined: 07 Nov 2005, 01:06
Location:
My Cars:

Post by London luke »

My God... some very well informed members on this forum. I am tempted to buy one and get it set up... But am trying to get a better result at lower speeds and revs.
Post Reply