I’ve got the DS Jammer and I like it quite a lot. I haven’t measured the exact performance improvement yet (HP wise), but the engine definitely breathes and sounds better. I use it in conjunction with the 93 octane tune on the Predator 2 and there’s a noticeable increase in power and throttle response.
FWIW, don't waste your money. Put it toward something that will make more of a difference....like a good cat. back exhaust. The stock airbox flows more air than a relatively stock 5.7 engine is capable of processing. If you want a good, true CAI, add another inlet to the stock airbox that goes out to behind the grill and also install a high flow air filter element. On both of my somewhat modified 5.7's, I have SRT airboxes with extra ambient air inlets and Airaid high flow filters and they're more than adequate, even with about 125 more horsepower than stock....see signature.
