I have a ’97 XC 600 with Starting Line pipes and need to get more performance..What else can I do? I’m looking to run against a 670 MXZ. My clutching is O.K. and I’m running a stock airbox. Can I remove the foam? If I can, what changes should be made to the jetting, if anything?
Butch St. Peter
You should be in pretty good shape in terms of peak hp with the SLP pipes. They allow the monoblock 600 Fuji spin up to 9000-9200 rpm and produce about 125 horsepower, which should be very competitive compared to the 116 or so HP that a typical 670 produces. Where the 670 will stomp on you is on the bottom end and midrange, and there’s not much you can do about that. Depending on what kind of running you’re doing, a gearing change may be in order since you’ve changed the power of the engine so drastically (hopefully you’ve already done this). Removing the foam will allow the engine to breath easier, and would require more fuel (bigger jets). Perhaps a better option is to install one of the high flow airboxes (that SLP has likely performed extensive testing with and can supply jetting specs) that will give you even more. The heads on the ’97 XC are already very similar to the SLP heads, so there may not be much to gain here. Short of going to a “big bore” kit, about all you have left is some “manicuring” of the system. Translation – there’s not much left to get out of it.