tune for 660 ice

modsrx

Active member
Joined
Oct 15, 2006
Messages
3,444
Age
50
Location
canada,qc
im a little lost on clutching on ice on this one ........did try both 8bu and 89a-10 ....out of the line i can't keep the rpm down to 8500-8300....its always shoot at 8900-8800 and it stay there .....if i add weight to tip it kill the rpm but at 400 feet ....gear 21-39...shave track and 196 chisel ...did try different some multi helix and straight always the same ...sled hook pretty good ...14.5 to 1 compression and fuel to go with it ......should i try to run taller gear to load the motor more ............
 

You want it to come out at 81-8200 off the line then steady climb from there to 84-8500 across the line. I would load the middle more and leave the tip. If it still over revs load the tip untill it does'nt. I like 21-39 gearing. And a 52-42 helix with green spring at 70. 8bu-00 I assume. If you can find one a Maxx white spring.
 
660

You want it to come out at 81-8200 off the line then steady climb from there to 84-8500 across the line. I would load the middle more and leave the tip. If it still over revs load the tip untill it does'nt. I like 21-39 gearing. And a 52-42 helix with green spring at 70. 8bu-00 I assume. If you can find one a Maxx white spring.

89-A weight to 58 grams,
hauck orange
engagement should be between 52 and 5500 rpms
47/41
silver at 80 depending on the drivers weight
3/4" transfer
rear suspension rear spring at 2" again depending on drivers weight
rear suspension front spring at 1 1/2 "
if your drag racing go to 20/40 or deeper
 
modsrx: try it to see how it works for you, There are many different combos for the perfect clutching, this has worked very well for my teammate when he was running drag races, I am not going to argue with anyone on this, It's what worked for us and we did very well, everyone has a socalled (PERFECT) combo, The only thing I can say is try them all and see what works best for your sled, thats the nice part about this website, you can get a ballpark idea on how to get close, then it's TEST TEST TEST, and to me thats the fun part, remember write EVERYTHING down and only change one thing at a time, if you change two things and it goes faster then you will wonder which one of the two things made it faster. have fun!! RJ21
 
modsrx: try it to see how it works for you, There are many different combos for the perfect clutching, this has worked very well for my teammate when he was running drag races, I am not going to argue with anyone on this, It's what worked for us and we did very well, everyone has a socalled (PERFECT) combo, The only thing I can say is try them all and see what works best for your sled, thats the nice part about this website, you can get a ballpark idea on how to get close, then it's TEST TEST TEST, and to me thats the fun part, remember write EVERYTHING down and only change one thing at a time, if you change two things and it goes faster then you will wonder which one of the two things made it faster. have fun!! RJ21



thnx ..i will for sure ... i wasnt sure why the rpm didnt want to go down out of the line ...i guess the middle hole wasnt load enough ;)!
 
mod, go to 21-40 for 660, look at it this way over rev a good thing, that means motor making power. tune your primary. add weight to your weights. 4.5 in both holes if your useing 8bu 3:16 (yammie tony)
 
mod, go to 21-40 for 660, look at it this way over rev a good thing, that means motor making power. tune your primary. add weight to your weights. 4.5 in both holes if your useing 8bu 3:16 (yammie tony)

im sure it does..i was just not able to bring down those dammm rpm out of the line ....will load the middle hole .......can load the 8bu tip it kill the rpm at 400 feet ...
 
mod, go to 21-40 for 660, look at it this way over rev a good thing, that means motor making power. tune your primary. add weight to your weights. 4.5 in both holes if your useing 8bu 3:16 (yammie tony)
You might want to load more weight in the 8bu's, right now I have 7 grams in each hole in my 800 Vmax 4 and still need 2 more grams in the tips but have no more hardware left, ( I know not the same sled ) so I'd try and load those weights up and let that engine grunt to the finish line that's what these engines like

Had good luck with a bender 51/45 in my srx but lost another stator so it will get a overhaul this summer and get ready for tar
 
Last edited:
I love it! Year 'round snowmobile racing! What kind of power do those V-max 4's have? I always wanted one but seem way harder to come by then a srx. Were they faster then srx's stock? I was in the v-max 4 section and the thread with the pics, I was on there forever. Those helix's listed by YAMMIEGOD3:16, those are for 660' with the low start? I noticed he did not list anything above 50. So say 1000', you would generally want something a little steeper because you have more room to accelerate? Sorry, not trying to hijack, just was wondering. Is there a pic of the 95 v-max 800 on here? I'll have to go look, no i'll be on there all night.
 
Last edited:
Be careful using a spring with a high preload to get engagement rpms. You might be better off trying a spring that gets you to say 5000rpm then cut notches to get your rpm higher. Too high spring pressure at the start can cause belt slip and hurt your 60ft times. 3 sled lengths at the end is only about 1/10 of a second or 1 or less in the first 60ft.
 


Back
Top