Originally Posted by
miker2209
Corse, thanks for your reply. It is a .21 Max. Theoretically speaking i am on the same page as you, but i keep hearing comments about how hard is to tune the engines there and i am sure the dry air (we are talking 15% humidity or maybe less) it's the main issue cause i have run at an altitute more or less like this one and no big problems. The report i have is that generally speaking, the people that have run there face big issues in order to have a consistant performance. It looks like the engine it's really sensitive, inconsistent and running on average hotter than in other places.
AFAIK... on the Toluca 1/8 worlds (the highest altitude where a 1/8 worlds has been done) almost all the official guys went with different combustion chambers. I don't have more information about this, but seemed that shape and size of the combustion chamber was severely reduced to overcome the very thin air there and trying to regain more power...
a 15% rel humidity is quite low... I never run an engine with such dry air (my lowest was 24% taken this value with an hygrometer). Maybe what you're experiencing is a very extreme example and the engines need further tunning just to have decent perf.