Carb Tuning

[mikey]

Following the carb tuning bit in the post on local dyno I have managed to change the log files into a Jpeg format.

As I mentioned before out of the box application is way too rich and loses you power and fuel consumption. The first image shows the next step up from out of thye box on the Barry Grant I am trying to sort out. This utilised a change in Idle feed restrictor and Idle air bleeds it made a major improvement over the sub 12:1 A/F Ratio out of the box.

Next stage was increasing the Idle air bleeds to intrroduce more air into the mixture whilst still on the idle and cruise system. As you can see a major improvement

Final slide is by increasing further the Idle air bleeds further. Tickover around 14.5 and up to 3000 RPM the mixture has reall leaned out nicely. The difference on the road is staggering and a much smoother cruise witha very radical cam has been achieved.

I am only just at the tip of the iceberg and I have no doubt that final tuning will be done on the rig but I hope you can see the major benefits that can be had including I would think 10% at least improvement in Fuel consumption.

Obviously you really need a tuneable carb such as the Holley or Barry Grant preferably with removable air bleeds, IFR's etc but they are not that expensive nowadays and the benefits on a well tuned motor are there to be had.

A quick edit - slide 1 and two are the wrong way around but you get the drift

Mike