More clutching!

[chunkysoup]

So i finally finished my sled! Took it out for a few pulls down the trail! Man this thing pulls like a cat on a screen door! Only problem is that with the spring i have, the sled is engaging at around 4500 and peaks at around 8200. i know i want to bring the rpms down. the spring is a slp green/silver rated at 160-300. what spring pressure would you go with to get around 7800 with 11-72 weights? and can i engage at 4500 without having any issues?
Thanks
Jason

 

[BIGGDAWG]

So i finally finished my sled! Took it out for a few pulls down the trail! Man this thing pulls like a cat on a screen door! Only problem is that with the spring i have, the sled is engaging at around 4500 and peaks at around 8200. i know i want to bring the rpms down. the spring is a slp green/silver rated at 160-300. what spring pressure would you go with to get around 7800 with 11-72 weights? and can i engage at 4500 without having any issues?
Thanks
Jason

it is better on the 900's to engauge 3800-4000.What weights do you have in it now and what altitude? i can get you close i think

 

[chunkysoup]

it is better on the 900's to engauge 3800-4000.What weights do you have in it now and what altitude? i can get you close i think

Im running 11-72 billet weights. Im right around 850-1000ft. I was looking at running the slp blue/red spring. it is rated at 140-320. that should bring my engagement down around 4000 i think and then bring the peak down to around 7800 rpm. What do u think?

 

[BIGGDAWG]

Im running 11-72 billet weights. Im right around 850-1000ft. I was looking at running the slp blue/red spring. it is rated at 140-320. that should bring my engagement down around 4000 i think and then bring the peak down to around 7800 rpm. What do u think?

my brother runs 11-72 here at home it is a 1000 feet and runs the green pink spring 120/340 has around 3900-4100 engaugement and turns 7800-8000. his is a stock 900 with cpi pipe so the 140/320 will be close i think

 

[GKR]

The lower initial rate will bring your engagement down but the higher finishing rate will take your top end up. I would suggest something in the range of 130-280 or similar. The other option is to go to heavier weights

 

[chunkysoup]

So i took it out and test drove it again just to make sure about the engagement and peak rpms. Green/silver slp spring (160-300). It engages right around 4200 and peaks at 8100. I called slp and asked what they would recommend and the guy was an A$$. He told me i had to run heavier weights. When i asked him if running a lighter spring would work he said that no one makes a spring with final pressure less than 300. Y would i want to buy $100 weights when i can buy a $20 spring? I hung up the phone and called epi and ordered a PS-4 black spring (145-280). I hope this works.

 

[chunkysoup]

So i rode this weekend and besides the cooling problem i found that my sled is still running to many rpms with the new spring. I am using 11-72 weights with a 145-280 spring. Now the engagement is right at 4000 but the peak rpm is 8050 which only came down about 50 rpm with 20 psi less pressure. do you think i can run a lighter spring yet or should i really get the heavier weights?

 

[BIGGDAWG]

what are you running in the secondary? helix spring?

i would try 11-74 or 10-76 and see what you get. these 9's light a lot f weight.

 

[chunkysoup]

im running a 66-44-.46 helix with a red pink spring. i want to stay away from spending too much. thats y i got the lighter spring but if i have to i guess i will get the weights.

 

[BIGGDAWG]

do you still have the stock red/black spring? it is a little softer on top and will let the secondary shift a little faster pulling the rpms down a bit.

 

[chunkysoup]

yeah i still have it. i will give that a try and see what happens. thanks!