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Oct 12, 2010 | 08:27 AM

jrr

Thread Starter

Cruiser

Joined: Feb 2010

Posts: 198

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From: Vero Beach, FL

Map question

Just browsing PC-V maps for a Heritage and noticed that the tables for the two cylinders tend to be different, sometimes quite different. Can someone explain why this is done - what is the advantage of having different tables for each cylinder?

Thanks

Oct 12, 2010 | 09:36 AM

Lonewolf176

Stellar HDF Member

Joined: Sep 2007

Posts: 2,459

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From: Vancouver Island B.C.

Each cylinder has different fuel requirements. Usually due to short intake tract and different bends in the exhaust.

Oct 12, 2010 | 09:40 AM

Mr. Wizard

Club Member

Joined: Aug 2007

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From: N. Atlanta Burbs

No two cylinders are the same, they breath and exhaust differently depending on the exhaust set up. This is a simple explanation why they run separate volumetric efficiencies so they need separate fuel tables. Running in the advanced mode instead of the basic mode is the way to go.

Oct 12, 2010 | 09:41 AM

Mr. Wizard

Club Member

Joined: Aug 2007

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From: N. Atlanta Burbs

Damn Wolfy.. you beat me by ( ) that much.

Oct 12, 2010 | 11:46 AM

mkguitar

Extreme HDF Member

Joined: Sep 2010

Posts: 14,744

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From: Phoenix '53, '88, '09 Big Twins

and the rear tends to runs hotter ( air flow blocked by front cylinder)- so the rear is likely to need to be richer- or have timing less advanced to prevent pinging.

MK