Shownomercy

iTrader: (1)

Boosted engine, 15psi, previous tune 10.5afr at wot, changed to 11.5afr. No other changes timing etc.

Any guesses on what that may net HP gain wise?

68Formula

In theory it's around 2%, but that's probably assuming timing was optimized for both. So if the timing along with the enrichment are conservative, then leaning it a little while keeping the timing the same would result in more.