personally I thought the 9853, 2084..41005 and 41021 all performed poorly on the stock Bonito.... We run on high grip and these combo's made the engine feel very soft..From every bit of testing I have done with the Bonito it prefers to have the shortest manifold possible, especially if you are wanting it to make good power with lots of snap....The longer the manifold the lazier the engine feels and responds....

note. Lower traction conditions can make the engines react differently...How early and how hard the engines are put under load can change how different pipes react and feel to throttle input....

on our track conditions there is no other combo worth running but a 9886/41001/41019 on a stock or modified Bonito...this combo gives the best bottom end kick with the largest overall powerband... SO if you are running on higher traction I wouldn't be looking at a 2084 or a 9853 or a long manifold...maybe its great for slick tracks, but for anything like what we have those combos are not that good.....The very first time I tested a Bonito it was on a 2084/41005 and my first thoughts were that no wonder nobody likes these engines as it had no pop whatsoever. But as soon as a 86 and short manifold were put on the engine woke right up with all kinds of bottom end power and snap.... true story !