ok, im running a built motor, with compression around 12.3 :1 , and i was tuned for pump gas about 5-6 months ago.. drove the car every once and a while, and noticed it was making a tapping sound, under harder acceleration, only in low rpm's. once it hit maybe 4500 it stopped, so i didnt think anything of it. until yesterday, i was just messing around at my friends house, and came across a bottle of NOS octane booster. the race kind. i just wanted to see if it did anything at all, so i threw it in. took the car for a test drive, and the tapping stopped. so i think it was pinging this whole time after the tune. so my question is, do you think it would be ok to use a bottle of this octane booster every time i fill up? or drive 25 miles and pay 7.00 a gallon to pump 100 octane( because 91 is the highest we get here in CA)... and do you think it would be harmful to my motor to use octane booster all the time?

 

Add toluene.

 

Or reduce your timing below 4500 RPM.

 

I agree with Don. Fix the actual problem. Toluene should be a band aid fix for now tho.

 

how would this effect my tune tho? if i were to back it off a couple of degrees

oops..edit: its me, 4LugR, just under arts name. lol my bad

 

Take the timing out where it is detonating, not rest of the map. If you cannot do that go to the paint store and get some tolulene and figure out the ratio for your engine.

 

A det can setup can be very usefull for listening for detonation. I would suggest datalogging at the same time and have a friend ride with you to note where in the range detonation occurs. Change your timing in that area until you no longer hear detonation. You can also check the condition of your plugs to read for detonation...mild detonation appears as black pepper speckles on the porcelain of the plugs, and is caused by the rings shifting around.