Not a proponent of the bassani 1d18rb, I don't like the way the rear head pipe wraps around the cam chest. I would think that it definitely hampers the velocity of the exhaust. I would think the style of the 1FXRB, 1FXR2B or the 12121J n 12122J would be a better performer all around.. Would like to see some numbers on the latter 2 if anyone has to post. Currently am running an RB....