Tomei makes one for around $300+ I believe, but I think depending on what app its going onto, you could use I think the Q45 one for alot cheaper. I believe I read somewhere that Enthaply posted that the stock TB's(SR's that is)can handle up to around 400-500whp). Someone was wanted to change theirs out on this board or another one and I remember reading something to that effect. Plus I think to get the full effect, you would have to port match the tb to the manifold or something of that matter.