I have a 2004 proxr800 and was thinking of putting that slp air horn kit on.It is the one for around 40.00 bucks.I was told you have to rejett for this.I gutted the box and already dropped my mains down 2 sizes.Stock were 450's and I put in 430's.Does this mean if I put that kit on I should put it back to 450's?Would it be to much air with the airbox gutted and the kit?If I buy this will it be a noticeable diff?Thanks

99.9% of all the owner that have installed the slp airbox kit have found they needed to jet leaner about 1 size ..... so if your into running on edge 420 are where you want to be , Dont think I would do any 1/2 mile blast with that jetting at sealevel or extream cold >IMHO.... maybe even 1000' may even be to close , I would start at 440 and see what your plugs and wash tell you.... Any other mods? my 700 with a pipe, airbox kit reeds and a head is slightly rich with 440 mains at 500+' with a tempaflow.

I have to agree with xc-mark. I'm running the same mods as him and my jetting is the same as his and I'm at 750 ft above sealevel and it still seems slightly rich.

doubtful you'll notice MUCH difference, but, i think it runs better than the gutted box (the stock box runs better than gutted imho)... the air horn smooths the flow of air into the box better with less turbulence, but again, from the seat of the pants it is doubtful you'd feel it, but that doesn't mean it wouldn't be there... from the dyno's i've seen the slp kit is worth a couple hp, for 40 bucks i think it is worth it...

One of the main benifits is it help keep the intake charge cooler as it seals out underhood heat much better than stock. Well worth it.

i don't really buy that as a reason considering all the vents in the hood and the amount of air flowing under the hood when you are traveling more than 10mph...

The SLP kit seals off the air box from under hood heat. The oem seal allows the heated air to get into the air box thus reducing air density. Yes, the hood vents are there to help keep the air flowing. But you don't want the hot air to flow into the air box. This is the main benifit of the kit. That is how the kit gives a HP increase on a dyno. :frech32:

like i said, my oem airbox had a thick round foam ring that sealed as good as the slp one did anyway... and as i said, once moving under hood temps just aren't an issue... ask anyone that runs a tempa-flow or atacc... they warm up while sitting still and lean out your mixture, but once you are moving they cool back down and are fine, usually only takes about 50yds at most to ensure cool air flowing into the airbox...

slp purports this to be a benefit, in the real world though it just isn't though... nice for marketing... the real benefit of this is because of increased airflow that does not create airbox turbulence, the added hp is not because of cold air... just my .02 :beerchug:

i have been running my 800 htg twins with box gutted and two flow rites. should i get the slp intake kit?

I would say yes but be ready to make some carb changes to correct a off idle flat spot and poss rich on the main jet.

I have a question for ya. I have read every topic on the SLP kit for modded and not modded sleds and would like comments on what I was thinking of. 2002 xc 700 stock pipe, slightly modded resonator, 480 mains from 500 -was thinking of: installing slp horn , not gutting, opening up intake under dash and installing pre-filters.

To me this would be in line with most of the info you guys have given, any comments appreciated.

I hope I didn't hijack. :div20: Thinksno

thinksno : I dont think leaving the air horns in will give you any bennifit.... Poss adding a third air horn would help. If it where me I would take the shelf out, its really easy on your 2001/2002 air box run the pre filters like your going to do and just some minor tuneing to fix the flat spot . You really dont notice much noise with a gutted airbox if your not running a stock exhaust.

thanks! :div20:

will the airhorn help with snow ingestion? if so should you also get the prefilter or is it not needed?