straka

Lots of threads here concerning ECU tunes. The results are measured in both peak hp and maximum hp, with maximum hp being the greater number for the same tune. What do these terms refer to and how are they different?

spdracerut

Peak hp is how much peak hp the engine makes with a tune. Max hp gain is how much more than stock which can be at different parts of the rpm range of the tune. As an example, the peak gain may only be like 50hp and peak hp is typically near redline. But the max gain of a tune over stock could be 100hp at like 5000rpm because the time pushes way more boost in the midrange.

thesaintusa

If maximum HP is the highest number as you refer:

The maximum gains are the highest delta (difference from stock / earlier tune) (hp / tq) recorded., i.e. 40 hp and 50 tq gains, but at 4000 rpm for example, 250 hp and 300 tq ==> now makes 290 hp and 350 tq @ 4000 rpm.

The peak hp/tq numbers will be gains at peak numbers, i.e. originally makes 400 hp and 400 tq, @ 6800 rpm but now makes 420 hp and 430 tq, so peak gains of 20 hp an 30 tq @ 6800 rpm.

Sorry for not using a dyno plot, which make it much easier to understand.

In the threads regarding headers on the 991.1 there are gains of 30-50 hp/tq in the mid range, but up top they only gain 10-20 hp/tq.