Hi Ed -

After installing one of these distributors in a customer's car I was disappointed to find that no one at 123 would share any information on the various advance curves. Because we were working with a very custom engine, we were really hoping to avoid spending a half day at the dyno removing the distributor, selecting a different advance curve, reinstalling the distributor, and running the car as we sought the 'best' preset curve and then tailored the fuel to either optimize or mask the timing characteristics. It was frustrating that the adjustment could be made only with the distributor completely removed from the engine rather than in situ.

The best answer we could get from anyone was "start with the B20A curve." Compounding this was the fact that the preset curves in the distributor were based on the European market cars and not the US market cars (granted, there's probably a lot of crossover, but we were flying blind at best).

I understand there's now a programmable unit that plugs into a laptop. Does this newer version come with any kind of preprogrammed curve that will allow the user to run the engine and then tailor the advance curve, or would we be starting from scratch with something like a "no advance whatsoever" starting point? If there's no 'default' curve built in, is there any information available that might relate to a specific curve I'd want to start with, or can I order a distributor with a specific curve preprogrammed as a starting point and then tailor from there?

I ask because I've considered this for my B20 engine, which is fitted with a supercharger that produces between 0 and 13 psi boost depending on the pulley configuration. I'd need both vacuum and centrifugal advance as well as boost retard. But given the price point - about 3x what it costs to have an original Bosch dizzy rebuilt and curved to my specs - I'd need it to do more than the last one I worked with was able to deliver. And it'd need to do markedly more than the Bosch I'm currently using.

Any insight you have is most welcome.

Thanks,

Cameron
Rose City