series mcrae no16

hi there , new to scoobynet. i own a impreza turbo on a n plate it is a uk model. i have had it for about 2 years, only mods are induction kit and exhaust. i have just bought a powertek boost controller off e- bay. has anybody had the pleasure of one of these, do they actually work??? more to the point could anybody out there tell me how to fit. or which pipes i am to splice in to ?? i would be much appretiated , thanks simon

series mcrae no16

can anybody help me out here? this is the manual under the bonnet boost controller which you place some where between waste actuater and some where else . could do with some help, please thanks

series mcrae no16

can anyone help out here??

TonyFlow

I would guess it will be similar to the dawes device, found here:
http://stefanostadal.homedns.org/car_mods_engine.htm

jaytc2003

iTrader: (1)

Is it an electronic controller or a manual one? If its manual then I will probably be able to help

series mcrae no16

yes it is a manual one , under the bonnet , can you help , and tell me which pipes i need to cut in to to fit? its a 95 uk turbo, if this helps. pictures would be good if you can. thanks

TonyFlow

Follow the Dawes one I posted, they all work on the same principles/pipes etc!

jaytc2003

iTrader: (1)

Tony, I have a manual controller on mine that was on the car when I got it, and mine is connected in a different way.
Mine is teed into the pipe that comes from the boost soelnoid into the actuator. Is this unusual?

TonyFlow

TBH, most people fit it as posted (as the Dawes manual states) - never seen it fitted the way you describe, but that is not to say that it will not work, although I would have thought some boost issues may occur as you have the solenoid controlling the boost feed to the MBC, instead of a clean boost feed to the MBC!

jaytc2003

iTrader: (1)

Tony, I will just check my facts, the boost solenoid is it on the o/side inner wing with I think about 3 pipes connected to it?

How does this actually work then? does it only allow air to the actuator//wastegate when it has a certain level of presure thus controlling the boost?

TonyFlow

Yes that is the boost solenoid - I would guess you have a 3 port, unlike the later 2 ports!

To my understanding (which is not anywhere near a lot of the chaps on here), the solenoid does work by allowing pressure to the wastegate, which opens at a set pressure (not sure what that is on a scoob, probably .5bar), and boost is controlled by allowing the pressure to the wastegate actuator or not! The idea in a MBC is that the valve does not let any pressure get to the wastegate actuator until the set boost level is reached (hence why they generally improve spool times and keep boost on strong). I am not sure how well that will work when plugged in via the boost solenoid -perhaps a more knowledgable person could iterate that - but if it were me, I would plug it in as per the manuals etc!

The basic premise is that the boost solenoid allows ECU control of boost - but byt fitting a MBC, you do not want the ecu to control boost, and as such, the solenoid should become redundant!

series mcrae no16

thanks for the replys , looking at the instructions, it says it should fit between the wastegate actuater and the boost source. the description for the dawes was for the later spec car. looking at my car the pipe from the wastegate does go back to the boost solenoid ( 3 port ) . so does this mean i just cut the pipe and place it there, then set to desired pressure using my boost gauge. seems simple enough. does anyone no the fuel cut pressure? i am currently running at 13 psi .

jaytc2003

iTrader: (1)

So if I get this correct my ecu is still controlling my boost? Should I just blank this connector off then that is connected to the mbc and connector it as per photos. Will the fuelling change though If I do it this way as surely with the boost solenoid in operation the ecu adjusts the fuelling to whatever presure it is reading.
With the MBC inline with this pipe as it is connected now, it is still reducing the presure getting to the wastegate as it is bleeding the air of or am I going down the wrong tracks here?

jaytc2003

iTrader: (1)

Thats how mine is connected, I have no running problems with it, but I am not sure if it is right now. I know mine isnt a dawes though but they all should work on the same principal.
Also I only seem to have the 1 feed at the wastegate. Mine is a TD05 turbo if that makes a difference

series mcrae no16

hi jaytc2003 what year car have you got? what pressure are you running? does it make any difference ? or have you never taken it off to see what it is like standard. it must be fitted in the right way, or you would have had running problems , surely

jaytc2003

iTrader: (1)

Mine is a 1992 import or a MY93 as it is classed.
I am running less than 1 bar at the moment, I need to turn the boost up a little , It probably peaks at around about 12 - 13 psi (cant be more accurate as my gauge only measures it in bar) and then drops of to around I would say 10 psi so this is probably slightly less than standard. Still feels quick though.
I would have thought that if it wasnt connected correctly then it would cause running problems, but mine has always been fine in the short time that I have owned it apart from rough running originally but this was solved with a new set of plugs

TonyFlow

The standard way of fitting, would be to connect it directly from the turbo nipple, to the wastegate actuator nipple. The boost solenoid would not stay connected to the wastegate. (although you will need to keep it wired in to stop throwing a CEL). You would then blank off the pipes on the solenoid (thus bypassing ECU control of boost, and allowing the MBC to control it). This is the same for 2 or 3 port solenoids.
Jay, the way you have it fitted obviously works to allow 13psi of boost, but as mentioned, the recognised way of fitting is as described (bypassing the Boost solenoid) - as mentioned though, maybe one of the more techy guys can answer as to why yours is fitted in the way it is (and why/if it should/shouldn't cause any problems!)

series mcrae no16

thats two different theory's now, can someone shed some light on this, is it the same throughout the models or is it different from an early 95 to a different spec ( engine bay ) on a 99 model. where things look different. jays seems to work, but as tony said and looking at the dawes one they fit between the wastegate and the turbo nipple . but this was a discription for a 99 model.

jaytc2003

iTrader: (1)

Im just gonna check my car, cos as far as I can see I dont have anything liek the piping that is shown in the pictures showing how to install the dawes. I cant see a nipple on the turbo(seen many in my time ;-) ) only the wastegate so will post back in a few mins as just of to the car park to check.

jaytc2003

iTrader: (1)

right, just checked my car and I stand corrected there is a turbo nipple. Mine is connected but the pipe runs back to the boost solenoid!!
It is a 3 port solenoid. I have one pipe conncted into the induction side of things just after the maf, the top pipe on the solenoid goes to the wastegate (via the mbc) and the turbo nipple goes back to the solenoid.

TonyFlow

As it will (as standard) - to fit as per instructions, the turbo nipple is connected to the MBC, and the MBC to the wastegate actuator, the 3 port solenoid should then be blocked off!

Again, not sure on the implications of this, but that is not as per most other people fitment or the instructions etc! I can see why it would work fitted that way, but I would want as little hardware connected as possible, and the shortest pressure pipes possible, which should help control boost with more stability!

If it were me, I would connect as mentioned!

jaytc2003

iTrader: (1)

Will try this later, This means thought that I will have to blank off two pipes then that connect to the solenoid it this correct?

What about fuelling though, if the ecu isnt controlling the boost then will the fuelling be out?

TonyFlow

You could just connect the 2 ports on the solenoid together using spare pipe!

Fuelling relies on MAF voltage/RPM AFAIK, and you are not altering that, it will still run the same fuelling as the ECU is set to - this is why if you turn the boost up too high, you will be running lean.

jaytc2003

iTrader: (1)

Your a genius, good thinking

So is there any advantage though to doing this?

TonyFlow

In your situation, I could not say for sure, other than eliminating the extra pipe used to connect the solenoid etc. can only be a good thing, and may help boost response/stability. Also, as the boost solenoid is not actually controlling the boost, there really is no point in it being connected, it will just be subjecting it to oil vapours etc it doesn't need!

jaytc2003

iTrader: (1)

One more thing, If I am thinking correctly, by doing this it means that once I am up to maximum boost, it will then remain constant instead of it spiking and then dropping, so in theory I can set it up to run at 13psi and it will not tale of from this boost?

TonyFlow

Should be the case if the mbc is any good!
By eliminating the contrived installation you have, you may find if you have been having boost problems it may cure it (certainly will not make it worse anyways )!

Just make sure you set the boost in 5th, and adjust it slowly!

jaytc2003

iTrader: (1)

dont you worry about me adjusting it slowly Tony, learnt my lesson on an old nissan bluebird turbo that I had superchipped (basic bleed valve job) adjusted bit to much resulting in a fun rebuild!! Ahhh well, you live and learn!