Triumphrat

sweatmachine · 05-25-2006

Can anyone explain what ignition advance does, like with the ignition box that's for sale on various sites?

My (mis)understanding of it is an earlier spark, but how does this help? Is it a hotter spark? How does it make more power?

Thanks!

Jimi_X · 05-25-2006

OK,...I'll try.
When the air/fuel mixture explodes, it does so at reasonably fixed rate,...BUT...(here is where it gets tricky), the parts, are spinning faster and faster as revs increase. Therefore the spark must be introduced earlier, in the stroke to get the maximum power from the air/fuel mixture. There are many other things that can have an influence on the rate of advance or "curve" of your spark advance, such as the overall flow or breathing of your motor. I believe some of the boxes you mention with a modified curve have a higher maximum rpm before the limiter as well.
Hope this helps. It's basic, but gets you on the right track.
Tony

357Bob · 05-25-2006

Sounds right to me. You can't speed up the combustion. Just set it burning sooner with advance.
(Okay. Before someone says something. By using lower octane fuel [which burns quicker] you can get a knock caused by the burning flame front compressing the remainder of the mixture & causing it to ignite too soon) That would speed up combustion. Sort of.
Also lower octane fuel DOES burn faster. Hence less timing needed.
(Did he say "hence"?)

eagle · 05-26-2006

So ... following on from 357Bob - if you live in or take your bike to a place that doesn't have high octane petrol (gas!) you wouldn't want to be using an ignition advancer. As the ones for the Triumph are 'plug 'n' play' it's easy to unplug the advancer unit and reconnect the original. Prolly need to do it on the Mexican border.... or in the UK the Welsh border (only joking!)