inertiauk

I have fitted a second hand Greddy Profec A (fuzzy logic) Electronig boost controller to my 1997 UK turbo 2000 to increase the boost on my stock TD04.

I was advised that the standard ECU would handle the fueling because the turbo sucking in more air via the maf will tell the car to use more fuel and maintain the correct mixture, is this correct ?

I have the controller set to 1.0 Bar with its alarm (and boost kill after 2 seconds) at 1.1 Bar are these settings reasonably safe ?

The car pulls a lot stronger and it feels liek it has made a big differance, I have driven 100 miles and it seems stable, it holds boost at 1.0bar on the controllers readout and 14psi on my existing analogue boost controller, which seems about right to me..

When My mechanic fitted the boost controller, I noticed he left one of the connectors ont eh back of the boost coontroller open to the atmosphere. Its the back connector on its own (see this picture, not mine)
http://carphotos.cardomain.com/ride_...0008_large.jpg

Is this a release/vent port ? if so the fact that it releases to atmosphere is slightly messing up the fueling isnt it ? Shoudl this be hosed up to another connector just after the MAF which my mechanic has blanked off with a piece of pipe and a bolt ? so that the air goes back in the system ? or does it really not matter ?

If I shoudl hose it up do you know what is the correct diameter of hose to buy, ebay has many choices from 3mm, 4mm, 5mm, 6mmand 8mm of boost pipe.

On another subject my o2 sensor is a bit intermitant (firing a CEL and sometimes runs really rich) Will this cheap alternative be ok ?

http://cgi.ebay.co.uk/Subaru-Univers...item20affad088

Thanks.

Gigsy

It certainly looks like the bleed / vent port and should in theory connect back to the connector on the air intake... on the stock system, this port is the equivalent of the output from the boost control solenoid which IS connected back to the air intake.

Venting to the atmosphere means that less air is going through the combustion chamber than the MAF is telling the ECU there should be. It's possible that this could result in the engine running a little rich.

Having a dodgy O2 sensor certainly won't help your fueling as the ECU uses it to work out how much fuel it should be injecting when in closed loop fueling mode. The eBay O2 sensor will most likely be fine.

IIRC the hose should be 4mm internal diameter.

1 Bar / 14 psi target boost should be OK with the stock map... I wouldn't want to go any higher myself without a remap though I do know of people running 19 psi (1.3 Bar) with an EBC.

Gigsy

Essentially, yes... there's a more complicated answer but the stock map is quite tolerant so long as you don't totally abuse it.