It doesnt work like that. You want a low end pipe for a low end engine and a high end pipe....... Now either pipe is good for the 8 port. Irun one of each on 2 of my buggies, both have 8 port race engines.One I use on tight tracks and the other for the tracks with long straights. If cash is a problem then the Ofna pipe is for you, but as there are no longer any Ofna distibutors in the UK this will be a problem and as you'll have to import it, it will cost more than the rossi.