Unfortunately Estes A8-3s tend to run a little short of 3 seconds.....the NAR cert data says 2.25s. But so do Quest A6-4s - at 3.52s (for the Chinese motors). So the A6-4 sounds right (though it's thrust curve will yield a lower altitude flight).

__________________
Bernard Cawley
NAR 89040 L1 - Life Member
SAM 0061
AMA 42160
KG7AIE