to date I have dyno tested somewhere in the range of 100 different tuned pipes...pretty much everything I can get my hands on I will test...... overall the Novarossi 9886 is the king of pipes on almost every single engine I have tested....the very odd time another pipe edges it out or comes close, but for 98% of nitro big blocks that 9886 is the pipe you want .. It has fantastic power across the entire powerband, bottom, mid and top.....it is not just a top end pipe, far from it...At one time it was a very popular pipe for racing but EFFRA created a 3 chamber pipe rule about 10 years ago and 9886 become obsolete...But the reality is its a great all around pipe , mix and match with different manifolds to alter its personality and its pretty much a guaranteed good to go pipe on every big block money can buy bar none..... The Dynamite 086 is fairly close and the OFNA 086 is something else completely............ The Nova 9853 is 98% the same pipe, on some dyno tests the graphs were spot on identical and on some other engines the 9886 slightly outperformed it........ I know on the ground the 9886 tends to have a little more peak then the 9853, or at least the exhaust note sounds like it has..............