Bleed valve help! gear changing probs?

[Cool Hand Luke]

After fixing the pinging problem on my car (fuel filter ), i installed the bleed valve but its causing a few problems. The main problem is that when i shift gears, it only comes back with 5 or 6psi of boost. If i shut the throttle for a few secs and boot it again, it will work normally... Why is it doing this? The only thing that i could see that i could have mucked up is the bleed valve in the wrong direction but i have the air flow going from the turbo to the actuator in the same direction as the arrow on the valve.

The other question is when setting the boost, i set it for max of 13psi but almost instantly drops back to 12 (wastegate opening?), and then as it reaches higher revs drops back again to around 11 or 10 which that part i know is an std rb20 turbo thing.

Do i set it so it spikes at 15psi but drops back to 14? or set it so that it never goes above 14 and drops back to whatever?

EDIT: - It seems like its the wastegate not shutting quick enough. If it doesnt open its fine, but when it reaches max boost it wont build up much boost for a fair bit after. I had to use a slightly smaller hose than what was standard because it wouldnt fit on the bleed valve, the fittings on the turbo for the hose are bigger than on the valve, would that be much of a problem? It is a single stage turbosmart valve

[Cool Hand Luke]

Anyone have any ideas?? Please

[51jay]

Possibly when you take your foot off to change gear and boost drops there is some residual pressure in the line from bleed valve to wastegate which slows the closing of the gate. We got around this by installing a one way check valve from between the bleed and wastegate to the line into the bleed.

A good explanation of this can be found in Julian Edgar's articles Audi's Do It Yourself Boost Control Parts 1 and 2 a search of Autospeed on line magazine will find these easily enough.

I've installed this system on my R33 and it works fine. With high flowed VL body turbo I have 7psi boost at 2600revs on half throttle and full boost at 3300 15psi virtually nil lag between gears and boost holds all the way to8000revs!!!