In my parts, 91 octane is the highest I can get. Wahts the highest CR i can safely run? I'm aiming for 12:5

 

I'd stick with 12:1 maybe....I'd rather be safe than sorry

 

depends on the parts, tuning, and assembly finish... higher than 12.5:1 has been done...

 

As long as you have a good timing map you should be fine...have you spoken with Lawrence at DynoSpot? When I was thinking about running that high of a compression ratio he stated that he has a couple of customers cars that are running that type of a compression in the area.
Austin

 

Yes, timing is very important. With that kind of compression, there are good chances for detonation using pump gas, unless like Austin said, you mod your timing maping, or use racing gas, which is out of the ecuation for a daily driver.

Edit: I'm almost sure that for your 91 octane in CA the closest to the compression limit is 11.1 to run safe with the stock maping (Before detonation occurs).


[Modified by '01ITR#950, 6:14 PM 3/3/2002]


[Modified by '01ITR#950, 6:16 PM 3/3/2002]