I just read that you can never reach max torque when dyno tuning ignition timing on pump gas (91 oct here in UT) without hitting detonation first.

Is there any point in dyno tuning ign. maps on pump gas then? Seems like you want to just add timing until you barely start to see knock and just pull a couple of degrees back out and call it good?

Can someone confirm this?

I understand that with race gases or ethanol this is a totally different story, right?

 

The answer really is "it depends." High compression, small cam engines might be hard to find mbt, especially with **** 91 pump gas.

I don't think it makes it irrelevant to dyno tune though, unless you have experience with a specific combo you'll want the data so you know if you're over the hump or not. And what about everything that's not on the wot line that's probably not knock limited? You'll still want to know where that is too, no?

 

Depends if your octane limited with your engine setup..

A stock engine will see MBT way before knock.
A high compression engine (or boosted) will start to "close the gap" between MBT and knock.
Go too high of compression (or boost) and you become octane limited, meaning your seeing knock BEFORE reaching MBT.

Race gas and Ethanol, let you put a lot more timing into it so you will reach MBT, before seeing any knock.

I can relate to this as my daily driver is supercharged and high compression 10.9:1 and about 10 lbs of boost. I see a little bit of knock in certain parts of the map, so I had to back timing down to as low as 9 degrees, just so it wouldn't knock on pump gas 93 octane.
I am octane limited and I know I cannot reach MBT with 93 octane, so for now I am about 1 degree below the knock threshold. GM has a pretty good knock retardation strategy so its not as dangerous as it may sound.

So, like SpAdam said, Depends on the setup.