Geo 100

I am jetted perfectly for sea-level and 70-80*.
I am going to go to 1000-1500' and will be 100+*.
Any formula for calculating the two.
My thoughts are droping one jet size, cuz the heat will
make it leaner but the alt. will make it richer.
10.5-1 550+hp Pfaff motor. I do mix race fuel with 92
Thanks GEO

DanB

You probably wont see too much diff at that alt change and temp, but a 1" smaller pitch prop may help some. If its not permanent dont worry

Dan

Geo 100

Thanks Dan, never thought of prop pitch.
I talked to Paul Pfaff and he agreed that not much difference,
he said its like picking fly crap out of the pepper, I wouldn't
notice any difference.
Thanks again
GEO

RumRunner

With that type of change in weather, and elevation you'll need to go down at least 2 jet sizes.

Krumbsnatcher

Who did you talk to at Pfaff? The old man himself or Gordy? Unless steve served you up information?

I buy alot of my custom rigging from Pfaff they are good people who make a great product.

Geo 100

Krumb, I talked to Paul, He's a family friend, and was one of my dads customers. Your are right, he does build a great product.
My motor was built in 1983 and has not had any major problems
except for the ones I have caused. I put over 400hrs/yr and each yr I make things fresh again. If I ever need any machining done
Paul will be the only one to do it cuz it would be done to perfection. Some of the motors he is building now have over
1200hp ad run on 87 oct. and live a long and trouble free life.
I here he is now doing service work no matter if it is his motors
or not.
GEO