I havent been able to find any good information on performance upgrades for a 2008 Sportsman 500EFI. I'm not looking for a big bore kit and a turbo, just something fairly simple that works. I would like to keep up with my dads '04(ish?) grizzly 660. So, what works? Thanks.

Mike

 

The upgrades I would start off with Is a performance clutch kit. But even that you really ain't gonna see a dramatic difference. Also you can put in a K and N air filter. There ain't that much you can do for the 2008 EFI sportsman.

 

Best you can do without spending huge $( getting a 800 or 850XP) is a clutch kit, K&N filter, and exhaust. You'll lose some top end with the clutch kit but it will roost on the low end!

 

Thanks for the info guys. Thats too bad there aren't many parts. Who makes a good clutch kit (colorado riding)? I dont care too much about top-end. As long as I can go about 40mph I'm good. Is there an exhaust that is quiet and makes power? The fart sound isn't desireable. Will I need more fuel to go with the added air? So, if I do the clutch kit, exhaust, and filter, should I be able to keep up with the griz?

Mike

 

Kolpin makes an exhaust that will reduce exhaust noise, but it won't increase HP... and may cost you some HP.

You're not going to see any difference with the K & N filter either... especially if you run the outerwear cover (and you should).

It sounds like the Grizz is getting you on the low end. The only thing that might help is a clutch kit or different clutch springs. Have a look at Dalton's site for clutch kit info.

 

I'll check out the dalton site. Are the UNI filters any better than k&n? The sound of the stock exhaust doesn't bother me, its the sound of some of the loud aftermarket ones that do. Didn't know if there was one available the was just slightly louder/deeper, that helped performance.

Mike

 

bump?

 

You can put the K&N on without issues. Won't see much(if any) gain but if you get some water in the airbox you won't be stuck with a soggy filter getting sucked in. EPI and Dalton makes nice clutch kits. Check out the Highlifter web site. Should be able to get one off eBay somewhat reasonable. As for an exhaust, I don't think there is much of anything out there that will give you more power without added noise.

 

did ur dealer put high altitude clutch weights in when they put it together, cuz my 500 eats a 660 up to top end but after that theres no replacement for displacement. should be 10 RH weights in the primary

 

Check this site out http://www.aaenperformance.com/Power500.asp they make 5 stage kits for the Fugi 500 motor.

Stock= 37.5 HP @ 6600 RPM and 32.9 Ft/Lbs @ 5400 RPM.

$250 Stage 1 = 40 HP @ 6600 RPM and Max torque increased to 33.7 Ft/Lbs @ 4800 RPM, 600 RPM lower than the stocker.

$559 Stage 2= 42 HP @ 6600 RPM and Max torque increased to 35 Ft/Lbs @ 5400 RPM

$871 Stage 3=44 HP @ 6800 RPM and a Max torque of 36.4 Ft/Lbs @ 5800 RPM.

$1056 Stage 4= The improvement is stronger bottom end and midrange torque. The Stage 4 Mods give you 45 HP @ 6600 RPM and 37.3 Ft/Lbs @ 5600 RPM. In comparison, a stock Polaris 700 Sportsman puts out 45 HP @ 6000 RPM.

$1388 Stage 5=47 HP @ 6800 RPM and Max torque is 38.3 Ft/Lbs @ 5600 RPM. This represents a 25% increase over stock.

Now of these kit have include performance 42mm TMX Carb carb, and is not a option with your throttle Body, but they would just have to change the mapping on the EFI I would guess or the EFI requires no different set up, They will tell you on the Phone.