Has anyone ever modified the dizzy to alter ignition curve

[OleVix]

or is it impossibe? Som dizzys with springs and bob weights can be altered...

[NZ fan]

The "stealth programmable ignition" does this and locks off the mechanical advance all together But still uses the original vacuum advance. http://www.accuspark.co.uk/Blackbox.htm. If they made one with a map sensor to do away with the vacuum advance unit as well I would be tempted. I feel big improvements could be made in the ignition department.

[Andy_mr2sc]

A bit more expensive which may defeat your objective but this:

http://www.aldonamethyst.co.uk

Looks a neat piece of kit. Locks off the vacuum advance completely which is the main reason for inaccuracies.

[Sardonicus]

Agree with the above it would take you an age and a Dyno to get an OK advance curve with the Lucas dizzy (it is do-able though) thing is there are cheaper options available nowadays to not warrant this agro

[gacksen]

currently have the tune version of the 123 ignition in the datsun. no problems so
far and fully free programable.

http://www.123ignition.nl/

[PH430]

+1

gacksen said:

currently have the tune version of the 123 ignition in the datsun. no problems so
far and fully free programable.

http://www.123ignition.nl/

[blitzracing]

A couple of us have been messing around with the Amethyst- but there where a few teething problems with the Lucas Amplifier set up. I supplied a spare dizzy to Aldon, and they now assured these simply needed a couple of resistors to allow the correct switching of the Amethyst with the stock Amp. Ive got the set up back now, but the car wont be on the road for a few months for testing. Generally on the setting up side, its very difficult to get the RV8 to actually knock with over advance, all that happens is the torque drops off, so you cant use your ear or knock detectors for accurate set up, it needs to be done on the rolling road where you can monitor the torque as you alter the timing. I dont see much point in fitting timing control with taking the vacuum into account electronically- after all you might squeeze an extra MPG or two out if you maximise the advance on light load and overrun. The 123 system is really nice, but its very costly at around £500- thats a significant figure towards a complete after market ECU with coil packs- The Amethyst comes in around £180 with full vacuum control and the Steath with just a basic 2d advance curve and mechanical vacuum advance comes in around £100.

Edited by blitzracing on Saturday 3rd January 18:33