PA65 / pipe setup, ~10% nitro,  55~60 oz plane..
Will a 6 oz tank be big enough for the pattern ?

If I decided to go with a rear header/muffler setup instead,
does that change things relative to fuel consumption ?
 

Your better to put in a 7 oz tank, Yes you can restrict the motor down some and do the pattern on 6 oz with a muffler

Randy

PA65 / pipe setup, ~10% nitro,  55~60 oz plane..
Will a 6 oz tank be big enough for the pattern ?

If I decided to go with a rear header/muffler setup instead,
does that change things relative to fuel consumption ?
 

    My PA61 used 7.6-7.8 ounces depending on the temperature. That was a "hammer of Hades" sort of setup, incredible power.  David's 75 setup is significantly detuned for the 75 but he used one of my old 7.8 oz tanks for a while and was just getting through, just about like my 61. Some setups take as little as 6.5 - but 6 is just not enough.

   The fuel you use is pretty much proportional to the power you get - you can cut the fuel use by cutting the power. The difference in power between 6 and 7 ounces is very substantial and greatly overcomes the tiny extra weight. You can always make a tank as thick as you want, if space is a concern. Mine are all 6" long, but as much as 1 1/4" thick and 2 1/8 wide. I made one for Jim that put 8 ounces of fuel in 5 3/4". it was also tapered in 3 dimensions and almost 2" thick at the rear.

      Brett

    My PA61 used 7.6-7.8 ounces depending on the temperature. That was a "hammer of Hades" sort of setup, incredible power.  David's 75 setup is significantly detuned for the 75 but he used one of my old 7.8 oz tanks for a while and was just getting through, just about like my 61. Some setups take as little as 6.5 - but 6 is just not enough.

   
     

Thats alot of fuel!  Maybe you need to hang drop tanks on your Infinity to carry enough fuel for the mission!