Lunch_Box
Active VIP Member
You're running an Evo stage 4 tune correct? Any reason you didn't go with Thunder Products primary and secondary clutching? I was able to get mid 70mph track speeds last season after fine tuning.
2018 Yamaha Sidewinder MTX 162 Build
- Thread starter Xmrider163
- Start date
- Thread starter
- #222
Xmrider163
Active VIP Member
I have it and I wanted easier tuning and a different profile which was recommended by a few experienced folks on here. The Dalton QA’s are nice and simple.
Thunder Products Setup I Ran:
Orange dalton primary spring 28-132
Orange/black secondary spring 114.4
Heavy Hitter Flyweights @ 68G’s
Dalton 33/35 Helix @ 70%
I’ll be directly comparing the new setup to old side by side this trip coming up aswell. One of my riding buddies has the exact same sled with exact same setup I ran last season. Hoping for a noticeable improvement and setup geared more towards climbing.
- Thread starter
- #223
Xmrider163
Active VIP Member
Well the Dalton QA70 with 39Helix and EPI purple spring pulled really well a noticeable difference for sure. Still have some fine tuning to do and a second setup to try with the QA70’s. 70++ mph hard to look down when she’s pulling like that. Rpm is finally off Rev limiter and sitting 8800-9000 range.
I did find 1 of my primary clutch rollers seized so I changed all 3 out. Easy to change but pricey $52/each last minute before leaving to revy.
My secondary rollers were free n clear of binding and all 3 were touching my helix.
Both clutches after riding around and pulling a few hills were equally warm. Almost too hot to hold my hand.
I did find 1 of my primary clutch rollers seized so I changed all 3 out. Easy to change but pricey $52/each last minute before leaving to revy.
My secondary rollers were free n clear of binding and all 3 were touching my helix.
Both clutches after riding around and pulling a few hills were equally warm. Almost too hot to hold my hand.
- Thread starter
- #224
Xmrider163
Active VIP Member
I’ll be adding these secondary rollers in for the next trip
- Thread starter
- #225
Xmrider163
Active VIP Member
My next issue from early season sledding...... wonder if I will learn next season.... start a little later. Season #1 was chaincase not very fun time OCT 30th and now Season #2 I found the weak spot in stock Rails...... Nov 29th. Season #3 will be December next year......
Iceage Bomber Rails will be going in as soon as they show up. Stuck with 162” to keep the sled fun.
Iceage Bomber Rails will be going in as soon as they show up. Stuck with 162” to keep the sled fun.
canuck5
Active VIP Member
Are you using the base weight only? Just curious what weight you found to keep rpm in said range.
- Thread starter
- #227
Xmrider163
Active VIP Member
I’m waiting until next trip to see a more accurate weight number with more snow, bigger pulls. I’m gonna guess 71-73G’s with the 39Helix. It pulled base weight easily. But I don’t think there is a whole lot left for adding. Snow conditions will matter.
2nd setup I will be trying is add weight to primary 73-76G’s with the EPI Purple Spring and the 35Helix.
See which one I prefer. Waiting for a deep snow day.
canuck5
Active VIP Member
Steeper the helix the quicker the belt should drop down into full shift in secondary keeping rpm down right wouldn’t you need less weight in primary on shallow helix? What is the stock mtx helix angle?
- Thread starter
- #229
Xmrider163
Active VIP Member
Stock Helix is 35.
First trip out I ran QA62’s @69.4G’s(full) and ran out of adjustment with the 33/35helix and banged rev limiter quickly so I’ll add primary weight to the QA70’s to bring it down to 8800-9000 range and start fine tuning from there. I’m gonna just use the stock 35Helix not the multi angle.
Steeper helix loads the engine similar to heavy primary weight? Similar effects I believe.
So a shallower helix will require a larger primary weight to load engine. If I’m understanding it correctly.
The upshift/backshift will be different aswell between the setups.
- Thread starter
- #230
Xmrider163
Active VIP Member
I’m still waiting on a copy of Aaen Clutching handbook to help me understand it more. If anyone has a copy they can email me PDF file. That would be awesome.
Last edited:
Lund
Active VIP Member
You have it backwards, shallow helix will make the weights act like they are heavier and steeper helix will make the weights act like they are lighter.
This is why i had mention at one time to reverse your multi angle, its backwards. It would be better if it was 35/33, so now in the upper end of your shift the shift rate will slow down but also the weight effect will increase(act like a heavier weight).
canuck5
Active VIP Member
I think of the clutching as a gear ratio right the steeper the helix the quicker you should get into higher gear and track speed the shallower the helix the lower the gear ratio longer. You start out in a low gear ratio belt in bottom of primary and top of secondary and end up at 1-1 when belt is at top of primary and bottom of secondary. So if you have a really steep helix it should shift fast into bottom of secondary pulling down rpm meaning lighter weights needed for peak rpm but I suppose a shallower helix rpm stays higher initially because your in a lower gear meaning more weight in primary needed. You agree with this Lund?
- Thread starter
- #233
Xmrider163
Active VIP Member
This is what I had thought. Steeper helix upshifts quicker requiring less weight because it pulls rpm down. My 35 helix seemed to need way more primary weight to control the rpm while climbing I was bout 600rpm to high so that’s roughly 3G’s of weight needed in the primary. Which is higher then what’s required right now running the 39Helix.
Lund
Active VIP Member
Same springs?
- Thread starter
- #235
Xmrider163
Active VIP Member
Same primary and secondary springs, same setting.
Lund
Active VIP Member
I'm thinking the reason your seeing these results is because of your power up EVO tune. (250hp) I keep forgetting your running a power up tune.
A steeper helix will require more HP to pull and shift out in comparison to the shallow helix that need's less HP to shift out. I think with the 35 your actually shifting out, BUT, out of the power curve of the engine, because the 35 is not loading the engine up so you end up hitting the rev limiter. Not loading the engine up will also translate to poor track speeds and lower HP out put.
The 39 though is actually loading the engine up enough that it stay's within its range(power curve, very important) by loading the engine it is now going to generate HP.
So basically with EVO's tune the 35 doesn't allow the engine to load before shifting out, while the 39 is enough to cause the engine to load up and stay within its curve during shift.
I don't believe this will work on a stock tune and that's why mine is setup so different then yours, my Winder will not shift out a 39 effectively, it doesn't have enough HP and torque and track speed would be poor.
Don't forget last season i generated 67mph hill climbing track speed and averaged 63-64mph all season long, you can only do that if you keep the shift speed and torque curve together. If one run's away from the other, it all falls apart, no track speed.
The 35 i believe might had been doing just that for you with your EVO.
Last edited:
- Thread starter
- #237
Xmrider163
Active VIP Member
Makes sense to me I know the intentions were to create track speed and with the 39 helix it definitely pulls much hard and is quite a bit faster up the climbs.
I thought with enough primary weight I could achieve this same “pull” with the 35 degree helix making it a bit more adjustable for changing snow conditions?
If I just simply ran the 35 degree and loaded the weight in the primary to lower engine rpm it wouldn’t work?
Aaen Clutch Tuning book is on route to help me learn the basics.
Lund
Active VIP Member
Yes, it can be done but only with a much more aggressive profile. (Flatter profile)
This will change the entire torque curve from the engine and shift ratio relation.
- Thread starter
- #239
Xmrider163
Active VIP Member
The Dalton QA70’s are much flatter then the Thunder Products I previously ran.
Are they not a flat enough profile? Daltons are in the middle.
canuck5
Active VIP Member
For a reference we used to run a straight 47 on nytros my understanding is roller tends to act about 6deg shallower than the button on the nytros. I am running the same tune as you and only difference from what you have said is that epi strong purple spring that’s why you needing 70+ grams is still surprising to me. I love the throttle response and pull of this sled at 64-65grams 9000-9200rpm that evo initially recommended but I’m not a climber so the top end track speed is not my priority we have also rode a lot in really deep snow so maybe loads change things a lot. If track speed is the ultimate I would think a steeper helix would be your ultimate gain and target your 8800 8900rpm
Similar threads
