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911st 911st is offline
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Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
He was converting the Lambda heads to operate like a euro head.

The main reason these heads flow more it they are adjusted by the builder to do so. Thus, at every point along the arm travel they flow a given percentage of fuel, say 12%. Thus, if you set them correct at idle, they will be say 12% richer at cruse and 12% richer on full boost.

To compensate correctly for this change the WUR should be reconfigured so the arm will move said 12% less with changes in air flow.

This unfortunately this may limit the total amount of fuel delivered unless the control pressure it then lowered at higher rpm on boost like the Andial Fueler did.

The work around it to clamp the boost enrichment function on the WUR until later in the rpm range and try to adjust around idle and cruse AFR's.

Even without modifying the USA head there is more fuel to be had by 1) making sure you get full travel of the metering arm (reprofiled metering plate, Andial fueler, or lower CP/WUR) and or by taking over control of the Lambda valve with a different controller (Split Second w built in Oscillator).

In theory, a modified Lambda head that has the Lambda circuit manipulated should flow more than the modified Euro Head. However, not one that I am aware of has tryed this yet.
Old 04-18-2009, 07:46 AM
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