Anyone ever had and or tuned this engine before? Still trying to work out some of the bugs with this thing in my MRX4. After some high end tuning as it suggest I still tend to get that PPPRRRRAAHHAARRAHHHAARRAHHH noise as if the clutch is engaging incorrectly or something to do with tuning. I will work this out in the meantime for Wednesday if its nice out, but if anyone had experience with this engine please post tips. I got it for a good price after hearing it's got quite a lot of power and hoping that I don't have to end up selling it for the OS .21 RZV or an RB .21.