Set me straight on Helix angles

Update....so the weights i got are not 8BU-00 but 8DN-00 so i am not sure what to do with those weights....

I also got a brand new Advantedge 51/47, used bender 49/45 and what looks like a stock 45deg helix thats been cut

I didn't have time to really tear into the primary but i did try the Advantedge 51/47 with a red sec spring at 90deg and it seems to really have brought down my RPMs....the river wasn't in the greatest of shape but out of the hole it engages at 3800 then to 8200ish down to 7900ish then to 8300ish.....seems to pull really hard, trenches the river hard pack for like 300ft!, had it up to 95mph but the river wasn't very hard packed and a pretty rough, I would also run out of straights between corners..... i am really surprised how much the RPMs came down to be actually below whats needed.....so i am going to try the same helix but with the green spring at 60deg and see if i can be bang on.
 
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BOX UP THOSE 8DN-00. THATS EXACTLY WHAT I WOULD DO TO. A LITTLE SURPRISED, YOU SAW BIG DROP LIKE THAT , WOW!!!. I BET SNOW CONDITION'S HELPED THAT TO. SHOULD BE ALMOST THERE. 3:16 (yammie tony)
 
From what i read in past post those Advantege helixs are have a more agressive cut than they show......i will make the change on sec spring and see what's the numbers are......wouldn't loose snow conditions add RPMs
 
That adavatnage will act more like a 56-50.The way they cut them they are very agressive thats why it's common knowledge to stay with the same brand helix when tuning.
 
HARD TO SAY, IF IT WAS WET SNOW OR DEEP,THAT WOULD FOR SURE PULL YA DOWN, ROCK HARD SNOW PACK IS BEST. 51/47 GOOD CAM. 3:16 (yammie tony)
 
Well, were forcasted to get more snow this week so hopefully our local trails will finally get a decent base to ride and see what my sled's going to do. It's kinda nice dealing with a under rev for a change after years of over reving. LOL!
 
Holy crap it's been awhile. Haven't done much riding after being away and then really sick for over a week. Anyway i did try the green at 60, 70 and then 80deg with 51/47 and did get up to 8500, still engages at 3800 then 8200 out of the hole, drops to 7900 then climbs to 8500 on top end. Got it up to just under 99mph (GPS) on the same stretch i was getting 95 before. For fun i took out dad's stock 2008 Apex Ltx and got just over 101mph on the same stretch. So what do you guys think? I think for a longtracked 136 and longtravel'd front and back 2000 SRX that's pretty respectable against a 2008 Apex LTX 136.
 
Another little update went out again with same set up ran up to 100.8mph(GPS). But i noticed i am still just under 8500rpms at wot. Using the same stretch of river to stay consistent on my testing. I have a few primary shims in the tool box so i am going to try one to fine tune the www primary spring i am using. I also picked up digital scale so when i have the prmary off I am going to check to see what my loaded with 4.5g & 5.0g 8DN-20's really weigh.

I haven't been riding the SRX much since i have my dad's 2008 40th Apex Ltx on loan for this winter. That thing is a blast to ride! But i plan on taking the old SRX out this Sunday for a full day of riding so hopefully the trails are dialed in, especially the old railway line trail to Elk Lake. :twisted:
James
 
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ReaperSRX said:
Holy crap it's been awhile. Haven't done much riding after being away and then really sick for over a week. Anyway i did try the green at 60, 70 and then 80deg with 51/47 and did get up to 8500, still engages at 3800 then 8200 out of the hole, drops to 7900 then climbs to 8500 on top end. Got it up to just under 99mph (GPS) on the same stretch i was getting 95 before. For fun i took out dad's stock 2008 Apex Ltx and got just over 101mph on the same stretch. So what do you guys think? I think for a longtracked 136 and longtravel'd front and back 2000 SRX that's pretty respectable against a 2008 Apex LTX 136.
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I know sideshowbob has the 02 SRX stretched and long traveled and he showed us on his GPS at hitting 112 or 120 on the speedo..so probably room for improvement,but I say that is pretty good for your sled.I am not getting much better on my SRX,stock skid and all.
 
ReaperSRX said:
Holy crap it's been awhile. Haven't done much riding after being away and then really sick for over a week. Anyway i did try the green at 60, 70 and then 80deg with 51/47 and did get up to 8500, still engages at 3800 then 8200 out of the hole, drops to 7900 then climbs to 8500 on top end. Got it up to just under 99mph (GPS) on the same stretch i was getting 95 before. For fun i took out dad's stock 2008 Apex Ltx and got just over 101mph on the same stretch. So what do you guys think? I think for a longtracked 136 and longtravel'd front and back 2000 SRX that's pretty respectable against a 2008 Apex LTX 136.
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rpm are not set properly ...should pull like 8400 then go to 8500 on snow if u trail ride ......could load more if u do ice radar run ;)!
 
I forgot to update this threat. I ended up using the 8dn-00 with 4.5g and 4.5g w/aluminum washer, www spring, advantedge 51/47 helix, green sec spring at 70deg, with newly studded ripsaw w/108 studs and managed to 111mph on a icy road at about 1500 feet, that was in late in 2014, now sorry to say I'm selling the old SRX as I picked up a 2008 Apex LTX GT with only 3500kms, going to miss the old girl, 13yrs and over 19,000kms of fun!
December 2014 249.jpg
 
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Fyi

ReaperSRX said:
I have spent too much time online last night because i still can't seem to get it into my thick skull which way to go on helix choice to lower my over rev problems.
So.....if i am currently running a 53/47 helix with a green spring at 60deg and my initial launch rpms are fine but my peak rpms are 9000.....d
o i look for a helix with lower angles? 50/37, 52/44 etc.
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Quote:
Do NOT change the secondary clutch to adjust engine rpm.
I’ve seen too many people increase the pre-tension on their secondary to bring up their engine rpm, myself included.
You are shooting yourself in the foot !!!!
It decreases the efficiency of transmission of power to the track while adversely affecting the ability of the secondary to keep the shift curve flat.
Once you have your rpm where you want it, you next job is to get it to shift out the way you want.
That’s the job of the secondary.
The combination of spring and helix is what determines this.
Multi-angle is what I prefer.
The secondary spring directly equates to side-force on the belt.
The idea is that the more side-force you have on the belt, the less efficient it is because of belt drag.
Yamaha Secondary pre-tension (wind) should be around 16-24 ft lbs.
What I try to do is get to the minimum side-force possible without slipping the belt in the secondary.
Too much side-force and the clutch will back-shift too fast and put you in too low of a ratio and over rev when you stab the throttle out of a corner.
Too little and it won’t back-shift fast enough and it will react sluggishly (bog) and you’ll loose rpm climbing hills or trying to maintain high speeds.

// Tom Hartman ( CEO and owner of: http://www.hartmaninc.com/ )
 
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