Just thought I'd pass this on to the group in case nobody has happened on these. They are designed for exhaust systems, but looking at the photos, I would say they provide the next best thing to a spun aluminum toroid. 9" OD, and 3" ID with a secondary (?) diameter of 3". These are SS, so that makes it easier to tack a mounting plate in the middle of the toroid. http://www.ebay.com/itm/Mandrel-Bend-Donut-3-0-3-0in-3in-3-00-3-Exhaust-Intake-Stainless-Steel-Ubend-/350977132953?hash=item51b7de0999:g:hk0AAOSwQJ5URqpO&vxp=mtr Terry This email and any attachments are for the sole use of the intended recipient(s) and may contain confidential information. If you receive this email in error, please notify the sender, delete the original and all copies of the email and destroy any other hard copies of it. _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla