DCAWD.com

Not long, but gives some interesting insight. Original URL

jblaine wrote:I can't tell you how many times I wish I had chart to post... showing MBT vs. ignition timing. Under load, there is no reason to ever to be running 2 degrees from knock when running 5 degrees from knock buys you a great amount of safety and costs you about 2ft-lbs of torque.

I wish more people understood that if you're roughly in the area of MBT, and on the safe side, leave your timing map alone.

(Not an attack on you, sean18337)

Element Tuning wrote:jblaine is correct, don't get greedy when it comes to ignition timing especially if you don't have a way to detect knock at insignificant levels. You only run as much ignition timing as you need. You don't need a dyno to tune your ignition curve as you will never reach MBT before blowing up your motor on anything less than VP C16.

Typically if your pump fuel ignition curve is optimal you'll need +2 to +4 degrees of ignition timing with the Hydramist. If your pump fuel ignition curve is not optimal such as if you were running a boost level that couldn't be tuned on pump fuel with out very low ignition timing then you might use +6 to +8 degrees more ignition timing.

You should treat tuning your Hydramist as if you had a basic race fuel (not VP C16).

If none of that makes sense, leave the timing, dial in the fuel, and increase the boost if the turbocharger is capable.

Thanks,
Phil
http://www.elementtuning.com

My guess is you posted that up for my benefit since I'm not all that afraid of advancing timing until a knock epsisode. Actually, I agree with the priciple that jblaine and Phil are exposing. Most folks follow the following tuning hiearchy: 1st get your AFRs set. 2nd set your boost where you want, while making sure your IDCs aren't in danger-land. 3rd add timing. That is the advantage of tuning on a dyno. You can see if adding timing is really adding power. As the engine reaches it's peak volumetric efficiency, the addition of timing will contribute diminishing amounts of power. For example; if adding an additional 4 degrees of timing between 6,200-6,800 RPMs netted only a small amount of power increase on the dyno than adding more is not likely to beneficial. And lets face it, I doubt any of us can tell the difference between a handful of whp and torque at the kind of power levels we run, so why not be safe and pull it back another 2-3 degrees to be safe?

Bench racing dude, bench racing. If you don't got the numbers you might as well have a blown engine.... wait that is the real world, oops