The rear mini pipe set up will be less than 3 oz. All the ones I have bought have been set up with fairly high compression ratios so do not like much nitro and I run mine on 20% castor 75% METHANOL 5% NITRO. But they come with head shims and you can lower the compression ratio and run more nitro.

The supplied plug is good for running in but play around with others and you may see a RPM increase. Enya 3 works most of the time on 5% but you must fit a colder plug if running more nitro even with the head shimmed. Ground RPM figures are meaningless as it gets on the pipe in the air.

Here is a pic of my set up in a combat model.