I just purchased a lukey to use for my centre however i accidentally purchased a 6" which is too large]
my problem is the only high flow 4" round mufflers i can find a non-brand or similar cheap products.
anyone here have any experience with non-brand mufflers.

I got a $50 full size stainless rear muffler for my 2ng gen and have been happy enough.

For my 3rd gen I then bought 2 rear Mufflers and a long centre resonator quite cheaply and they have been good (X-racing was the company I think).

The other item I bought was a shorter centre resonator from somewhere else but it cracked staight thru the inlet pipe to muffler join after a month or 2.


I've seen 4" Magnaflows before, otherwise as above I have found the x-racing stuff very good.

Magnaflow 4" body in satin stainless 2.5" Inlet/Outlet
http://www.magnaflow.com/02product/shopexd.asp?zone=main&id=10351

Same but in polished stainless
http://www.magnaflow.com/02product/shopexd.asp?zone=main&id=10590

Magnaflow have an excellent reputation. I run magnaflow on my car. Only prob is that they are not the cheapest option though you can try Amazon or even motors.eBay as they pop up regularly there. These would be ex USA usually via USPS (approx 2 weeks to your door) even with postage cost it usually works out cheaper than buying from a local retailer in OZ - which is a shame :-(

Otherwise X-Force is a brand that several users here have on theirs and have received good reports. I'm a bit suprised that you can't find a 4" round resonator from Lukey. I checked their website but their links are stuffed :-S. Being that the centre muffler is mearly a resonator (or hotdog) these are very common so give Lukey a call and ask them for the part number for this to suit a magna sports with 2.5" pipe (Don't get the glasspack as they are cheap & the glass packing will burn out in 2 or 3 years).