EricMichael
New member
I added the slp pipes to my 02 viper at the end of last season. The sled had bender pipes before and already had the rear heat exchanger and the headgasket along with the 51/45 helix. I changed the jetting to slp's specs and loved the pipes. It had the single pipe when i bought it because the bender pipes were taking off. My question is, in the fall I plan on running 500ft on the grass..I'll jet to slp's specs for the temp. but how far should the helix be wound and should I gear the sled?Thanks for the help!
Eric
Eric
Eric
You can go way lean, (for more power) since your only running 500'. I run 150's at sea level, and 148.8's at 1200' of elevation. Then I like to adjust the needles rich, so when you slam the throttle wide open, there isn't a lean bog. I usually run my needles in the #4 position.
For gearing at 500' I've had good results with 20-39. As for the secondary spring, I like to run it as loose as possible without sucking the belt. This allow's for quick up shift's. This is where testing comes in, start out with the spring fairly tight, say at 90 then make a pass. Then start backing it off 10 degree's for each pass. When you get to the point where rpm's are ok at the start, but fall off a short distance off the line then slowly climb back up, (sucking the belt) you have gone to far. At that point you would want to tighten the sec back up untill it no longer suck's the belt.
Always tune the shift rpm's with primary clutch. When tuning rpms (primary), I like to keep throwing more mass in the primary weight's untill I reach the point where the motor wont take anymore, and falls out of the power band. Then back off the weight amount untill she's back in the sweet spot.
This requires a far amount of testing, but's it's the only way to know for sure that you have the most aggressive clutching for your sled/conditions.
You can go way lean, (for more power) since your only running 500'. I run 150's at sea level, and 148.8's at 1200' of elevation. Then I like to adjust the needles rich, so when you slam the throttle wide open, there isn't a lean bog. I usually run my needles in the #4 position.
For gearing at 500' I've had good results with 20-39. As for the secondary spring, I like to run it as loose as possible without sucking the belt. This allow's for quick up shift's. This is where testing comes in, start out with the spring fairly tight, say at 90 then make a pass. Then start backing it off 10 degree's for each pass. When you get to the point where rpm's are ok at the start, but fall off a short distance off the line then slowly climb back up, (sucking the belt) you have gone to far. At that point you would want to tighten the sec back up untill it no longer suck's the belt.
Always tune the shift rpm's with primary clutch. When tuning rpms (primary), I like to keep throwing more mass in the primary weight's untill I reach the point where the motor wont take anymore, and falls out of the power band. Then back off the weight amount untill she's back in the sweet spot.
This requires a far amount of testing, but's it's the only way to know for sure that you have the most aggressive clutching for your sled/conditions.
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EricMichael
New member
Thanks for the info, although i'm still unsure about starting at 90 degrees, Would that be 3-3 or 2-6 something like that?? Also for the 500ft, where would I want my rear suspension and transfer rods set at?Thanks again
Eric
Eric
90 degrees would be hole nr 3 in the secondery and hole 6 in the helix.. add the numbers and you get degrees!!! 3-3 is 60 degrees!
60-70 or 80 is normal for drag, depending on spring and helix.. good luck!
60-70 or 80 is normal for drag, depending on spring and helix.. good luck!
EricMichael
New member
Thanks, thats easy enough to figure out now!
Yes, 90 is a little tight, and I use it only as a starting point during testing. To find out if my sec spring is sacked, or if the helix is to steep. I figure if it sucks the belt at 90 degree's, then there's definetly something out of whack!
Most of the time I run 60 or 70 degree's depending traction conditions.
As for the rear suspension, becuase there is so much more traction on grass. You can set it up fairly tight, (close up the gap on the transfer rod's, tighten up the limiter strap's) so there is less movement to rob horsepower and ET. If your running in short track classes, I believe the rules still allow you suck down the suspension to 2 inches of travel. The idea is to carry the ski's only a couple inches. Big wheelies look impressive, but cost horsepower, and loose time.
Most of the time I run 60 or 70 degree's depending traction conditions.
As for the rear suspension, becuase there is so much more traction on grass. You can set it up fairly tight, (close up the gap on the transfer rod's, tighten up the limiter strap's) so there is less movement to rob horsepower and ET. If your running in short track classes, I believe the rules still allow you suck down the suspension to 2 inches of travel. The idea is to carry the ski's only a couple inches. Big wheelies look impressive, but cost horsepower, and loose time.
EricMichael
New member
Anyone know where a good place to get 20-39 gearing and chain new?The gearing does require a new chain right?? Also is a 51-45 helix ok for 500ft grass or is it to steep?Thanks again
Eric
Eric
you can use the stock chain with 20-39. You must use HYVO gears with the stock chain though.
51-45 should work fine for the grass.
Anyone of the perfered vendor's on this site should be able to get ya the parts for a reasonable price.
51-45 should work fine for the grass.
Anyone of the perfered vendor's on this site should be able to get ya the parts for a reasonable price.