Can anyone tell me what compression ratio can be run using 98 Octian fuel? In an A15.

11:1 is probably close to the limit.

What is it standard. Any idea how much horse power would be acheivable with that sort of compression?

recently i built a pretty hot a15 with a a12 GX head big port and valve mods double valve springs modified the cobustion chambers inexed spark plugs also flat top pistons large valve reliefs and a 10 cc dish shot peined & polished rods big cam makes power between 3 & 8 thousand rpm running on 98 ron fuel bp or mobil the most timing i can have to stop detination is 5 degrees and 24 total at 4200 rpm i cant fuel up just any ware its a pain becos every time i get crap fuel bp or mobil i blow a head gaskit so far iv done 5000 ks and blown 3 head gaskits not to mention the damage to my big end bearings!!!! its all good but awsome peformance with twin 40"s it revs off the tach past 8 close to 9g doggy down low just dun drive slow!!!!!!!!!!

jack ass i am forgot to say i run 11 to 1 comp and only 98 +ron fuel

I have tried with 11.6:1 on one of my A14/A15 engines but that didn

11 to 1 is slightly to high for todays fuel 10 1/2 bout it. my datto bit doggy down low becos of retardard timing to stop detonation