Low humidity/High altitude/Hot Weather...... What to do?
 

Looking for some help here guys. Going to Vegas in September for the Nationals and the info i have is that beside the altitude (2000 plus feet), the air it's really really dry. From the experience you guys have in this situation, what sould be done to the engine to make it work properly? Normally with more altitute you should take a shim (0.10 mm)out to compensate. But in this case to me, the most important thing it's the humidity cause is really low.
Any help will be appreciated

The answer is clear, just remove .010mm shim and pay a look on the carb adjustment. Maybe you need to lean just a tad the LSN and the HSN.

You don't say which engine is an their size, but if you're running a 30% on a Nova .21 I would go to around 0.50 - 0.52mm of combustion chamber height (measure it with the crushed solder wire method). The same applies for a Ninja .21 engine.

You can go lower, but... you need to have guts and be ready for facing runtime problems, bitch carburetor adjustments (more critical) and maybe a rough but powerful engine.

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.

Thanks Corse. Anybody with experience in Vegas can post some info please?

The best place for help is the source/location... Give Rich Taylor a call at 4Aces/Team /Taylor Racing. Here's the web-link... http://www.4acesrcracing.net/Contact.aspx
I'm sure he can give you all the tuning tips you need to race in the Vegas Heat and altitude... :nod:

RC_Alan