Question , does the mapping improve performance ?
Allen

Yes!

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"Show me the Mini!"

Definitely!
For example, the original curve in a Cooper S dizzy is nowhere near correct for 98 unleaded fuel.
Even more so if running a sportier cam.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Hi Allen

A good map will improve your performance, BUT you need to know what you want first. The black box users, ( megajolt stealth etc) and the programmable users ( CSI and 123) will be able to share the key parts of the curves that work for them. If you are planning to tinker yourself, i would just make sure your dizzy cam isnt too wide ( say 11 or 13 but not 15 dizzy degrees)and know what the vacuum is doing ( if you have one).

Just as an example, , , go to the CSI ignition website and nose around in the technical info area. Here are some of their curves http://www.csi-ignition.nl/bestanden/mi ... curves.pdf


As an example of the important bits of the curve ---------Below I am now talking about timing light degrees

Static 10degrees
Rapid rise , so i am at 22degrees at 2000rpm
More gradual to be all in ( maximum advance 30degrees) at anywhere above 4000rpm

I have a 1310 cc mild road motor ( 260 camshaft) with an early non vacuum CSI dizzy and find curves 11 and 13 work pretty well. I am not worried by maximum advance at 32 because i rarely if ever get up to 6000rpm.
IMO a number of these curves ( and those in the 123) are unsuitable mainly because they are too slow to advance.

When i change something on that motor ( eg different carbs), i use the curves and an AFR to 'optimise' - but apart from that i use one curve.... you only need one , but it needs to be the right one

Hi,before I offer my opinion I will do a disclaimer , so you can decide whether my answer is biased as I make and sell performance ignition systems with long duration spark,
Yes, the correct map for your engine will improve performance. The problems are that most people have no idea of the map they need, and being able to work out which one is correct from the dozens on offer and then precisely determining performance changes , its terribly hard. It may be fun to play, but getting it wrong can be tough on engine life.
Many distributors with mechanical advance will have a curve thats suitable, BUT they do not have a good enough spark to properly burn ULP. This includes many of the expensive distributors, beautifully made but again lacking quality spark. Generally road minis do not have efficient hi temperture combustion chambers , and need a big fat spark at the correct time and the best thing I have seen is a longer duration spark of approx 20 degrees of crankshaft duration.
I see from many posts of what users of adjustable systems set their timing at, there is an extreme reluctance to give them enough base timing, probably based on the 2 or 3 degrees that bmc often used. 10 degrees base timing is not enough. Cheers Lindsay Siebler

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1959 Austin A40 Farina fun car
1965 Mk1 Cooper S restored
1970 Colt 1100F SS restored
2014 Mitsubishi Imiev fully electric daily driver
1948 Allard M coupe Olds 215 v8 project
1971 Twin cam Escort ex Uk championship winning rally car project

Nailed it!

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"Show me the Mini!"