I'm now running TBS XR-1 14/71 HH blower on my street / grudge car (3700+lbs) after seeing blower dyno comparison with the lb-20 and kobelco superman which the XR-1 not only made more boost it did so at lower INT. Temps and less parasitic loss. I also spoke with tommy keeter at KPE after he got some engine dyno results and he claimed he was very impressed, he said it not only made killer power at low OD. But very cool intake temps, There is a video of him making 2400+ hp with a 24 deg. Headed BBC with an lb-20 roots. I asked him how he thought the XR-1 stacked up against the lb-20 and he said the XR-1 would run circles around it, I don't have a lot of data yet on my car but so far I've seen 32lbs boost at 7800 rpm with only 21% OD on my 555 and I will give updates at a later date. You can take this for what it's worth but I just wanna say for only $8000 where are you gonna get an all billet blower with that kind of performance.