aWeX

Hi

Boost:
I`ve just picked up my "new" 03 STI, and I`m a little worried about the amount of boost it runs. The engine is completely stock, including stock filter and exhaust. The Defi\STI-gauge shows a peak boost of 1.4 bar in the higher gears (from 3rd and onwards), before it settles at 1-1.1 bar at around 7000 rpms. On such a new car, this must surely be too much?

Does the STI use a ECU-controlled boost controller, or does it rely on the WG to control the boost? The defi boost-gauge is connected with a T-piece between the WG and the turbo. The vacuum line from the WG to the turbo looks fine. There is nothing else connected to WG that could possibly affect the boost pressure.

Could anyone tell me how much boost the j-spec STI runs when it`s completely stock?

DCCD:
The DCCD-display in the dash is set at Auto, and it stays that way no matter how much i try to adjust the dial in the centre console. What could be the reason for this?

The car has done 24.000km`s since new, and is in no way molested and abused. I`m going to try and solve these problems tomorrow, so any pointers in the right direction would be great.

Regards
Trond, Norway

Normski

Do a search on here to find out the standard boost levels for your car, it's bound to have come up many times before. The boost figures you are seeing look about normal to me.

The DCCD on your car has two modes, auto and manual. There is a switch on the dash to move between the two modes. Only when it's set to manual will the thumb wheel next to the handbrake have any effect.

aWeX

Hi, and thanks for replying.

About the boost figures, I tried to search several times, but didn`t find any relevant answers. I guess I`ll have to try harder then The norwegian STi has some kind of boost sensor that triggers the fuelcut at 1.3 bar, but this doesn`t occur on my car. The peak function on the defi boost-gauge shows boost levels near 1.5 bar.

There`s no button to switch between auto and manual, I found out that I should have one of these after making the last post. I didn`t actually think that my car had the DCCD-A function, just the ordinary manual DCCD - well, that`s an added bonus i guess. Near the handbrake lever, there`s a open hole where a switch should have been. After removing the plastic trim around the handbrake, i also found a blue plug that wasn`t connected anywhere. The length of the cable indicates that the plug should be fitted to a switch in the missing hole.
You can se switch I`m talking about on this pic, just above the handbrake:

AvalancheS8

The ECU controls the boost via a solenoid valve that will be mounted on the RH suspension turret (LH as you look from the front). The hose from the turbo to the WG will have a T in it connecting a hose that heads over to a cylindrical solenoid on the suspension turret. The valve will have at least one other hose connected to it. If the turbo was connected straight to the WG you would typically only be seeing about 0.5 bar boost.

As far as the peak boost pressure and the fuel cut, the fuel cut only cuts in if the boost stays over the limit for a couple of seconds, so peaking above the fuel cut might not trigger it.

DPat

aWeX,
I have the same car as you and get exactly the same boost readings you indicate.
I have a knocklink and see nothing wrong there (1 green on when on full chat)

Bob has this excellent thread on mods here:
http://bbs.scoobynet.co.uk/showthread.php?t=283364

DPat

aWeX

I`m pretty sure that there`s no boost solenoid connected to my turbo, but I will check this again tomorrow.

DPat

I think you'll find it is or you wouldn't be getting the figures in your OP, just 0.5ish

DPat