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Uncle Uncle is offline
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Join Date: Dec 2008
Location: Newcastle Australia
Posts: 675
Yep. Below is from Brians site.


RPM control of the enrichment circuit has been developed in an effort to eliminate the absurdly rich mid-range condition exhibited by modified CIS Turbos. This condition is particularly noticeable on cars that are running a modified fuel distributor, aftermarket turbocharger, short-tube headers, 0.9+ bar of boost, and the Adjustable WUR. In order to have enough fuel for a proper 12.0 AFR at high RPM, the mid-range will typically be incredibly rich at the onset of boost. This is because the WUR enriches based upon boost pressure alone, regardless of engine speed.

The RPM Controlled Solenoid Valve (CSV) remedies this problem by allowing you to select when the enrichment circuit is enabled. This is achieved by swapping "chips" on the RPM controller. By controlling when the WUR receives its boost signal from the intake manifold, a much flatter Air/Fuel Ratio (AFR) curve can be achieved. This results in improved throttle response and more mid-range torque and horsepower. A side benefit is improved gas mileage and extended engine oil life, as the oil is no longer diluted with any fuel laden blow-by at the onset of boost.

The dyno chart below shows typical gains at only 0.9 bar of boost. The blue curve represents a dyno run with a precisely tuned Adjustable WUR. The red curve has the enrichment delayed until 4200 RPM. These runs were made back-to-back with no other changes between runs. You might be wondering what happened to DYNORUN_006. DYNORUN_006 was made with a 4400 RPM module installed which caused the AFR to peak at nearly 13.0 just before the enrichment was enabled. This was deemed to be too lean. A 4200 RPM module was installed and the car was re-run yielding the following results:
I've taken out the dyno graph as it was a little big.


Last edited by Uncle; 11-18-2014 at 01:34 PM..
Old 11-18-2014, 01:32 PM
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