I have got half an idea why and would appreciate any tech input on these thoughts.
Background;
GTIR with 3071 and 34mm inlet restrictor. Closed loop control of boost working correctly 1.1 bar ish. Fuelling corrector (against revs) upping the fuel to suit the bigger turbo, crudely. Forge dump/vent valve opens on deceleration, to atmosphere. The airflow meter is in the standard position, before the turbo
Issue;
Does about 4mpg rallying, big lag after exiting chicanes. Going rich??????
What causes it;
I think every time I hit the brakes the dump/vent valve getting rid of all the compressed air that the airflow meter thinks is going into the engine.
Ideal solution;
Airflow meter downstream of the dump/vent valve? (ie blow thro) (hard to achieve, plumbing wise) OR get rid of
dump/vent valve
Proposed solution for discussion;
I'm going to fit a flow restrictor before the dump/vent valve, so only a small amount of air gets dumped to atmosphere. 1mm, 2mm, 3mm, 4mm, 5mm or something like that.
Hopefully it wont be so slow to re accelerate due to not having to build up new boost and not running stupid AFR's initially. Byproduct is a big saving in fuel. Risk is doing damage to the turbo (surge)
Anybody care to comment?
Jon
Background;
GTIR with 3071 and 34mm inlet restrictor. Closed loop control of boost working correctly 1.1 bar ish. Fuelling corrector (against revs) upping the fuel to suit the bigger turbo, crudely. Forge dump/vent valve opens on deceleration, to atmosphere. The airflow meter is in the standard position, before the turbo
Issue;
Does about 4mpg rallying, big lag after exiting chicanes. Going rich??????
What causes it;
I think every time I hit the brakes the dump/vent valve getting rid of all the compressed air that the airflow meter thinks is going into the engine.
Ideal solution;
Airflow meter downstream of the dump/vent valve? (ie blow thro) (hard to achieve, plumbing wise) OR get rid of
dump/vent valve
Proposed solution for discussion;
I'm going to fit a flow restrictor before the dump/vent valve, so only a small amount of air gets dumped to atmosphere. 1mm, 2mm, 3mm, 4mm, 5mm or something like that.
Hopefully it wont be so slow to re accelerate due to not having to build up new boost and not running stupid AFR's initially. Byproduct is a big saving in fuel. Risk is doing damage to the turbo (surge)
Anybody care to comment?
Jon