SLP vs Big Bore
- Thread starter boots1031
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Re: SLP stage 3 vs 860/858 big bore
I am in the same boat, leaning towards a "Modified" Stage III, and some other goodies. The cost of the 858 or 860 per HP gain is not worth it in my mind. By the time you have all the goodies on your not that much cheaper then a turbo, and substantially less HP.
I am in the same boat, leaning towards a "Modified" Stage III, and some other goodies. The cost of the 858 or 860 per HP gain is not worth it in my mind. By the time you have all the goodies on your not that much cheaper then a turbo, and substantially less HP.
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Re: SLP stage 3 vs 860/858 big bore
And the plus side to doing the stage 3 is that you dont have to purchase everything all at once or you can mix and match; get a clutch kit from lets say mds, the rktek head, then have the rest from SLP or whatever combination you want.
And the plus side to doing the stage 3 is that you dont have to purchase everything all at once or you can mix and match; get a clutch kit from lets say mds, the rktek head, then have the rest from SLP or whatever combination you want.
Jesse_01
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Big bore with pipe and can 
Jesse_01
Active VIP Member
I am still on the fence about going with a kit. I have had really good luck having a stock sled this last half of the season. First half was a mod sled nightmare.
If I get a snow bike as a second ride I will go terra alps kit. Price decent, he's in BC and I can get stuff over night from him. I hate waiting weeks to get ch!t out of the states if I am broke down.
If I get a snow bike as a second ride I will go terra alps kit. Price decent, he's in BC and I can get stuff over night from him. I hate waiting weeks to get ch!t out of the states if I am broke down.
Ya I know what ya mean, Its just hard for myself to justify ~$6000 for maybe 30HP when I can do a turbo for not much $$ more and double the HP. I like the RK Tek drop in kit and High compression head, heard good things, then couple it with a SLP pipe and PCV or BD controller (basically a Stage 3 system). Should be a fun set up and reliable.
dragonweld28
Supporting Vendor
I would go with the fix kit from the dragons. My cousin had his pro blow up and is now running the PMS fix kit with a SLP pipe set and PCV. Its is a whole new sled, pulls really hard, idles better and just sounds like the engine is working the way it was intended. And to give you an idea of how well these polaris mechanics put the engine together, the piston that was still good had 11 thousands of clearance. Then new PMS kit went in at 5 thousands. not sure how to spell that. Anyway, If you add a high comppression head to this combination i would be real fast. And this would probably be the cheapest route, and would make the motor super reliable.
9fingerracing
New member
A RKTEK 858 kit runs appx 2500$ for probly 25+/- HP. Stock pipe, RKT head, bored nikked jugs, new pistons, BD box. Silber Kit runs 4500$. BD 6500$. Not really apples to apples but not just a little more money either. The RKT kit is sposed to be running pretty spot on with very little tuning to dial in. I know a guy w/ a BD turbo that hasnt touched a button all year. From what I hear the 858 is equal to or better HP over the SLP stage 4.
Jesse_01
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I believe the terra alps kit is $2200. Head, exchange cylinder, pistons, tuner.
9fingerracing
New member
I do not know anyone with a 858 kit but have been researching them for myself. Kelsey designed the kit to be run with the stock pipe. He wont give a definate answer on HP but I would guess at least 20 hp if not as much as 25. Hard to say. From the reviews I've read off of snowest most people running them are very happy with them. The kit is 2150 with rkt head cover or 2050$ with machined polaris sleeper head cover. I figure 400ish for a BD control box.
From rkt website...
But, just for grins... Let's add the 7.5% more displacement ALONE into the equation..
So 60cc/800cc = 7.5% more volume
So at 150HP(Stock HP) x 7.5% = 11.25 So, the cc's alone CAN/MAY add 11HP or so..
Now if you include the new head for 7-8 hp and porting in cylinders and change in transfer port height I think low 20's HP gain is a conservative estimate
From rkt website...
But, just for grins... Let's add the 7.5% more displacement ALONE into the equation..
So 60cc/800cc = 7.5% more volume
So at 150HP(Stock HP) x 7.5% = 11.25 So, the cc's alone CAN/MAY add 11HP or so..
Now if you include the new head for 7-8 hp and porting in cylinders and change in transfer port height I think low 20's HP gain is a conservative estimate
Jesse_01
Active VIP Member
To bad the pro isn't 150hp stock. I think more like 13-15hp increase at the track with big bore.
Jesse_01
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Better off to lose the extra 20-30lbs that a lot of people carry around lol.
sledneck_03
Active VIP Member
I was thinking a rk tek head with slp pipe and power commander for $1500.
12-15 hp
12-15 hp
Jesse_01
Active VIP Member
No way your getting 12-15hp out of that.
Should be close after clutching is set up and add a high flow intake.
Jesse_01
Active VIP Member
I will believe it when i seen a non biased dyno results with before and after. I am just sceptical thats all.
With the High comp head your going to hold higher HP number at elevation. But exactly what the gains will be I am not sure. Everyone I have talked to with just a rk drop in kit said it was a really noticable difference in throttle response and mid range. so add a pipe and controller, better air flow and set up the clutching right, should be a fun sled. By no means anything near a big bore or a turbo.
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