i have an HP racing cannon see it at their website www.hpracing.com--- it is just like the greddy evo-- sounds like it too--- i had to get an N1 when i went turbo-- this has a 2.5" inlet and 5" tip--- make offer
The comptech sounds good.
Nice low tone, quiet at cruising speed.
Check around the site, you should be able to find some positive posts on the comptech.
Let me know if you would like some pics or if you have any other q's.