Phil

Andy Wornell had a Hayward and Scott on his 500 if I remember correctly, I remember thinking it was expensive compared with the likes of Mongoose etc but it was also designed to be a certain diameter and flow and also for noise purposes so he didn't get black flagged on track, this is from memory as it was a long time ago when he had it done - Lynne or Andy would be the best people to advise if you dont get anywhere on here.

HTH