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Discussion Starter · #1 ·
I have triple SLP pipes in there right now. I just finished rebuilding it this summer, i had to get it bored out .040 over. What can i do to either bring up my compression, get some more horse, i've tried EVERYTHING![V]
Any help would be very appreciated!
thanks guys!
 

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cut the heads, and run high octane. CLUTCH IT!!!! get the motor dynoed, so you know where it makes the power, and then clutch to that RPM. You will gain a tremendous amount of power to the ground.

loose some weight also, heh. You or the sled. each pound makes a difference.

-Dean
 

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i would leave compression alone, not every gas station has high quality gas, with high compression you will find out the hard way who gave you the bad tank. the average stock sled gets just over half the hp to the ground so you can spend money on the engine or work on getting more efficient with what you have, start with gearing and clutching, i would gear that sled down one on top and go up one on bottom for starters, then start clutching from there.
 

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Discussion Starter · #5 ·
so you recomend gearing a little more bottom end then play with clutching?
I was going to gear the top gear one size bigger and the bottom gear one size smaller for top end so i can get 115-120mphmaybe more. Then i would concentrate on the clutching so i can accelerate to that speed as fast as possible in a 1/4 mile - 1/2 mile. what do you guys think?
 

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If you gear up your sled for top end, you will definatly lose your torque off the line. Although it will depend greatly on the horsepower and torque of your engine. Many people forget about the torque of the engine, but it is as important as the horsepower, or maybe more important for acceleration. I've heard that torque is a measure of how fast you get to speed, and horsepower is what determines what the top speed is. So a sled with all the horsepower in the world will do little good if it has no torque to accelerate with. I'd say gear down, and if top speed is that important to you, buy an overdrive kit for your clutches when and if you purchase a performance clutch kit. these are available from places like hot seat performance.
 

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ur sled should hit 115mph on radar stock
 

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for most riding stock gearing is to high, did the shop bring the port hight back up after boring out the cylinder you might be losing a lot of power potential right there, a good polish job and port work would snap that sled up big time.
 

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how do you set your cluch? by changing the springs or the size of the cluch???
 

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you could go threw polaris or erlandson, they make a nice quality gear and chain set.
 

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if your port hight has been changed do to cylinder boring. the inexpensive fix is to raise the cylinders the proper amount with a base gasket that is thicker. this will also raise the height of the cylinder head. this area between the piston and the cylinder head dome (outside egde against cylinder wall) is referred to as squish. as a rule .090" is stock on most machines. you can go to .070 safely. you measure this with a piece of thick plumbing soldier. stick it in to the cylinder wall and take piston to top dead center. the engine will stop when it hits soldier. roll over past this point. compressing soldier. remove soldier and measure the amount of clearance. if you measure .100 you could remove .030 from cylinder head surface. this would give you higher port timing. increase compression ratio. consult polaris engine builder for safe specs. note you can also make squish measurement with stock gaskets. install thicker base gasket. measure squish and machine of what is needed to return to factory squish specs. also remember. less squish more compression. better fuel. hotter temps. use caution.
 

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the base gasket thing works, but the timing window stays the same if you bring the top port back up to stock highth you will have a bigger port window, letting you make a little better power and might raise the rpm a tiny bit, also just because you shim a jug up depending on the engine you might not need to bring the head back down, the cylinder pressure might stay the same, sounds wierd i know i had a hard time beleiving it myself and still question it sometimes.lol
 
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