I have BC2's in my car right now on stock s/r's and I rev to 7400 all day long with a stock ECU. After 5300 they pull like a pull to redline on my stock cam gears. The low end is what sucks on them with stock cam gears and stock ECU. If you get some CS cam gears and a Calum ECU tuned, they will perform almost identical to S4's and the S3's would not touch them up top. Plus they idle like stock cam gears. You can't even tell a difference. Now if you adjust them with aftermarket cam gears, it is possible that they will idle like S4's once they are dailed in. I will find this out later on. The price increase is why people are not jumping on them like they use to.