Ignition advancing

[pajo99]

Have a question about ignition timing for people who know. I know basic principles and how it works but like to learn more.

Fj1100 and Fj1200 have ignition advancing 37° (maybe 35°). xjr 1200 has 50° B.T.D.C.
Late fj1200 and xjr1200 are basicly same engines. XJR beeing restricted in power compared to fj1200.

Why XJR has so much advance compared to fj is there something i'm not seeing?

Question is because I'm interested in buying dyna2000 foe my XJR and pickup is setup to go up to 45°...What am I loosing with 5°

Anyone who put Dyna200 and have modified engine with cams, carbs and exhaust (internaly engine not touched) what advancing you used.

I read somewhere here that Randy RPM while was racing with FJ put 39°

I understand that advancing is properly setup on dyno run and advanced enough so engine does not tick (detonations).

[Alf]

My experience with ignition advancers, if it could help

Factory made ignition advancers are 5º for 1100/1TX, 4º for 3CV/3XW. No detonation at all and reliability checked, 165.000 km with a 1100 and 250.000 and counting with my 1200 3CV, mainly sport riding and fast travelling alone