I'm still learning as I go but, thanks anyway.but thanx FocusRacingAustrali...i see rep in your future
Don't change the octane unless you get a tune for it. Stock with just upgraded Stage2 is fine at 87. IMO, 89 is trash.
That's not the case at allYou really shouldn't need highe octane unless u up the compression
He can run 87 or 91 octane with these cams but, if he want abit extra peroformance in Hp and torque and little bit more mpg then he'll have to get a tune for 87 or 91 octane.You will be fine with 87. No need to get 91.Cams dont need a higher octane.
Your 98 octane is race fuel? our 98 octane is street fuel.more octane does not mean more hp, more octane is adding a stronger safety factor only. Ur 98 octane is not the same as 98 octane in the states. Do a search on it, I know it is explained. Ask Tom, the only reason you need to run higher octane is if you have higher compression or u advance ur ignition timing. Else, you can start to have carbon build up, or something like that, I know that was explained in a recent forum thread as well, I will see if I can pull it up!
the only reason you should be running high octane fuel is if you are FI or high NA compression. the higher the octane, the leaner you can run your car without risk of knock and other related lean issues. the leaner the mixture the more power (to an extent obviously). i will give an example.
assuming that you have some way to advance timing and you know how to tune.
say you are running an a/f ratio of 11.3 which is the knock threashold for your car so it is the leanest you can go and make the most power on 87, 91, whatever.
now throw in race gas and your car will still be running your same 11.3 a/f ratio but your car will be running like the a/f ratios are at 10.5. which means what, you can advance your timing, or in a boosted application you can turn up your boost and run an a/f ratio of say 12.0 or something like that and still be safe because of the higher octane.
hope this makes sense and helps a little can't really gather my thoughts right now cause i am busy here at work and got a little down time.