that exhaust reminds me about this one i saw on ebay:
[link]http://cgi.ebay.co.uk/HPI-rs4-3-Evo-dual-exhaust-Anodized-Green-20hp_W0QQitemZ6053311856QQcategoryZ19168QQrdZ1QQcm dZViewItem[/link]
it used to say it gave 20hp+ but he edited it after i emailed him