question on the "15% rule" with dyno differences

[FattyBoomBatty]

So, when I take 15% of 350(whp) it's 52.5. so I add those to get 402.5.

Then I take 15% of 402.5 and get 60.375, so 60 hp.

If I were to first dyno my car on a DD and get 350, then go straight to a Dynojet, I could expect about 402whp, yes?

But say I went first to a Dynojet and got 402whp, and thought, well, 15% less is 340, then went to a DD expecting to get 340, what would I get?


Also, two trains leave the station at the same time, one heading west, one heading east... just kidding.