Just seeing if anybody has bothered with these while staying naturally aspirated. There seems to be quite a difference in price among some of the brands, with Summit being the cheapest, then Msd , and Granatelli being the most money at roughly $500. Are they worth the money?
There's a big debate going on about GMS COP's on another board right now. Basically, the only dyno proof being provided by GMS shows 6 to 7 HP, while they advertise 12 HP on a NA car. And you know that with dynos you can be off 10 or more HP just between runs. But basically, any time anyone makes GMS an offer to test them out and give a non-biased opinion/third party dyno, they refuse. They say their products and the amount sold should speak for itself.
On a NA car, I don't think there's much to be gained. A few HP maybe. However, they do burn fuel more efficiently, so they're probably better for the engine. Less unburnt gas.