Quote:
Originally Posted by HemiCharger
x2 -- my tune is spot on to Shell V Power 93 anything else and it wants to spark knock under certain loads. That is what I had it tuned on and that is what she likes. No other fuel is quite as good as it but it is all around me right now. I will hit you up on pm. Yeah I definitely do not want to screw around with it too much thansk
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Please define this spark knock.... To me that is another word for detenation, but is that what your meaning by it? Or are you getting blow out? Do you see signs of detenation on your plugs? What is making you think you have detenation? Is it audible? Or are you feeling something (shouldnt be able to do unless its severe) or is your hand commander or whatever saying you have it? Either way, shell is great gas but you are tuned on the ragged edge if you have detenation with all other brands of fuel, but your power numbers do not reflect a tune on the ragged edge.
There is something else I have seen that seems to be pretty common in this thread that I as a tuner dont like to see. People tuning off of knock sensors. They are not 100% reliable. They are great for putting a little fear in you, such as if you just filled up with fuel and you see your knock % raise then that fuel might be bad. However they do miss allot of legit knock and they pick up on allot of phantom knock. There are many different tools and methods for listening to knock. My suggestion to anyone doing their own tuning (especially if you incest on doing some street tuning) would be to run an overly safe timing map and start out rich on your fuel map taking fuel out as needed. Get your afr's smooth and in check and then hit the dyno. If your tuning on pump gas I would recomend a listening device of some sort. If your on a detenation resistant fuel you still really need to just pay attention to the tq curve (as you need to on any fuel). Watching the tq curve is major. If it goes down in a spot and then back up you should lower the timing there to see if it goes back up. If it goes down you might need more timing. It can also be caused by other things too. Like on the graph I posted of my run you see the tq drop off at 6300 and come back up around 6900, I did not overlay my boost on that graph I posted but if I were to add that you would see that the boost spiked up about 1 psi at 6900 giving it an odd curve. That is acceptible because there was most likely allot of back pressure at that point and the internal gate can only do so much.
My point is dont take knock sensor reading with a grain of salt if your getting them, but dont rely on them and dont expect them to work when its most important. Please do not base your tune off of a knock sensor.