Tuning Changes with Elevation Question

ben_beyer

Junior Member
Any guess as to how much engine tuning (I.E how far off the needles would be) would change from lets say 3000 ft. difference in elevation?

I'm looking at getting back into IMAC. The contests I would be able to make are about 3000 ft. less in elevation than where I currently fly.

So, are we talking increase by 1/2 of a turn of the needles or less or is there no real good estimation of how much it would need to be increased?
 

Tired Old Man

Staff member
There is no good, one size, fits all, amount, especially since both needles would need a slight tweak and different types of engines would require more or less of either needle depending on how they were done initially. Too many variables.
 
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BRUTUS

Plank Junky
Lifetime Supporter
Not to mention density altitude differences. I've flow here at 6K and competed in Vegas at 1500' and didn't touch the needles. Didn't feel a difference. But I don't try to eek every single RPM either.
 

red7fifty

BadAss Member
When I moved from sea level to 3000 ft, I leaned 1/16 a turn on both (top end was a little more fat than normal, so was the low end) But, engine was/is still breaking in.....so that has some to do with it.
 

Dean Bird

Lifetime Supporter
Not to mention density altitude differences. I've flow here at 6K and competed in Vegas at 1500' and didn't touch the needles. Didn't feel a difference. But I don't try to eek every single RPM either.
Agreed.

I fly at 1,500 feet. I haven't changed the needles when competing at sea level in California or over 5,000 feet at Mile Hi RC in Colorado.
 

ben_beyer

Junior Member
Good info guys!

I realize that experiences may vary by engine and set up but I was trying to get a feel of what to expect and I got it.
 

Tired Old Man

Staff member
Unless the density altitude changes a lot tuning changes minimally. Our type carbs do not self compensate for altitude but they have tremendous functional latitude.
 
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