I've been breaking-in a Forster .35 for a flying buddy who wants to try OTS with a period engine.
I thought someone might be curious as to how they perform, at least on the bench.
Their preference for a wet-2 seems confirmed as on-the-edge 4-stroke is around 9000 rpm and it picks up only ~700 rpm on rotation.
I've run different fuel mixes and prop sizes with these peak results:
0/75/25
9-6 APC 12.4K
10-6 APC 11.5K
10/62/28
9-4 APC 13.6K
9-6 APC 12.7K
10-4 Zinger 11.7K
13.5/61.5/25
9-6 APC 12.8K
It seems happiest with the 9-6 on 10% @ ~10.2K, going to 11.2K on rotation, but seems quite content with no nitro.
I must say it has a distinctive 4-cycle growl, which I suspect would attract attention at a contest.
Terry
Added:
I have another, of unknown history, which is down only 100-200 rpm with some of the same combinations, and also does well with no nitro.