Top end MPH on 17 SW.

[KnappAttack]

14.5 rollers 35/39 reverse helix pink secondary spring at 6/3 runs 110gps in around 1000 feet with 1.5" track, with the black orange at 80 clutches were cool but rpm kept dropping on the top end could only get 105, maybe a straight 35 helix would work

I dont mean the primary rollers, what secondary rollers are you running? I assume this is on a stock tune and secondary rollers. So if your running stock rollers that could be too much pressure for these rollers on a stock tune. The Hi-Torque rollers make for less side pressure than any other roller out there. The stock rollers are crunchy and stick hard after just a bit of use and make for added side pressure on the drill press scale.

The B/O has way more pressure down low vs the stock pink spring. And I'm not sure why Yamaha is installing the 35/39 in these sleds stock anyway, because they can't hold the RPM up top like a 35 does, but putting in the 35 would help all around. IMO the 35/39 reverse helix is really messed up.

I found the same on my stock 2023 this week riding it stock. Pulls like 9100 even 9300 and falls down to 8650 or so in 36F weather. It needs the old 2017 clutch setup in it, not the messed up 35/39 revers helix. Maybe it will pull it in colder weather, but it sure doesn't in warmer weather. And it doesn't have enough spring down low with the stock pink either, it will not backshift worth a crap, the belt wont shift down, if you get back in the throttle, you can hear the belt squealing trying to get a grip on the clutches. You can't wrap the pink any tighter because it will coil bind hard. The Pink is the wrong spring to have in there along with the 35/39.

 

[1nc 2000]

I dont mean the primary rollers, what secondary rollers are you running? I assume this is on a stock tune and secondary rollers. So if your running stock rollers that could be too much pressure for these rollers on a stock tune. The B/O has way more pressure down low vs the stock pink spring. And I'm not sure why Yamaha is installing the 35/39 in these sleds stock anyway, because they can't hold the RPM up top like a 35 does, but putting in the 35 would help all around. IMO the 35/39 reverse helix is really messed up. I found the same on my stock 2023 this week riding it stock. Pulls like 9100 and falls down to 8650 or so in 36F weather. It needs the old 2017 clutch setup in it, not the messed up 35/39 revers helix. Maybe it will pull it in colder weather, but it sure doesn't in warmer weather. And it doesn't have enough spring down low with the stock pink either, it will not backshift worth a crap, the belt wont ship down, get back in the throttle and you can hear the belt squealing trying to get a grip on the clutches. Can't wrap the pink tighter because it will coil bind pretty hard. The Pink is the wrong spring to have in there along with the 35/39.

The rpm drop was there on my 17 before it was tuned with the stock 35 helix and clutching.
I believe it was from factory tune and intake temps.
Once tuned with Hurricane tune bundle never seen this rpm drop ever even with the 8jp belt.

 

[KnappAttack]

The rpm drop was there on my 17 before it was tuned with the stock 35 helix and clutching.
I believe it was from factory tune and intake temps.
Once tuned with Hurricane tune bundle never seen this rpm drop ever even with the 8jp belt.

My 17 when stock never dropped RPM like that. Ever. Even with the intercooler plugged with snow.

 

[1nc 2000]

The rpm drop was inconsistent for me some times it would run 8800 rpm and other times 8400 rpm.
I sure am happy not to have that issue anymore since tuned.

 

[Snowaddict]

I dont mean the primary rollers, what secondary rollers are you running? I assume this is on a stock tune and secondary rollers. So if your running stock rollers that could be too much pressure for these rollers on a stock tune. The Hi-Torque rollers make for less side pressure than any other roller out there. The stock rollers are crunchy and stick hard after just a bit of use and make for added side pressure on the drill press scale.

The B/O has way more pressure down low vs the stock pink spring. And I'm not sure why Yamaha is installing the 35/39 in these sleds stock anyway, because they can't hold the RPM up top like a 35 does, but putting in the 35 would help all around. IMO the 35/39 reverse helix is really messed up.

I found the same on my stock 2023 this week riding it stock. Pulls like 9100 even 9300 and falls down to 8650 or so in 36F weather. It needs the old 2017 clutch setup in it, not the messed up 35/39 revers helix. Maybe it will pull it in colder weather, but it sure doesn't in warmer weather. And it doesn't have enough spring down low with the stock pink either, it will not backshift worth a crap, the belt wont shift down, if you get back in the throttle, you can hear the belt squealing trying to get a grip on the clutches. You can't wrap the pink any tighter because it will coil bind hard. The Pink is the wrong spring to have in there along with the 35/39.

Yamaha is putting in a 35/39 as helix from the factory now? I have a '17 and believe the stock was a straight 35. When these things first came out one of the first recommendations were to go to a 35/39. I was originally told one of the best clutch set ups was this helix with Thunder Products orange primary and secondary, along with Heavy Hitters weights. I tried the orange TP secondary, but the clutches ran too hot. So, I went back to the stock secondary (just with tighter wrap.) The rest is still the same. Oh and I got TP rollers right away too. Clutches run cool now.

 

[Fords4life]

Yamaha is putting in a 35/39 as helix from the factory now? I have a '17 and believe the stock was a straight 35. When these things first came out one of the first recommendations were to go to a 35/39. I was originally told one of the best clutch set ups was this helix with Thunder Products orange primary and secondary, along with Heavy Hitters weights. I tried the orange TP secondary, but the clutches ran too hot. So, I went back to the stock secondary (just with tighter wrap.) The rest is still the same. Oh and I got TP rollers right away too. Clutches run cool now.

39/35 not 35/39, 35/39 is a reverse angle helix to fix the stock turbo lag.

 

[KnappAttack]

Yamaha is putting in a 35/39 as helix from the factory now? I have a '17 and believe the stock was a straight 35. When these things first came out one of the first recommendations were to go to a 35/39. I was originally told one of the best clutch set ups was this helix with Thunder Products orange primary and secondary, along with Heavy Hitters weights. I tried the orange TP secondary, but the clutches ran too hot. So, I went back to the stock secondary (just with tighter wrap.) The rest is still the same. Oh and I got TP rollers right away too. Clutches run cool now.

Yes, I believe they've run the 35/39 reverse angle helix in the winders since 2019. TP claimed to need it, but I've always found it to be completely backwards from what is needed. It may have worked well on the old EVO tune as that tune had no bottom end. I find my new stock sled to drop RPM in the topped with the backwards 35/39 helix, but it wont be staying stock for long.

I run a normal progressive helix in my 17 and its quicker working it down low and letting the RPM come up down track. 35 helix holds a nice straight shift. Reverse helix just slows a sleds ET if it has any power at all, I've never seen it help ETs ever myself. Also it typically takes more pinch in the secondary to hold the belt on the top end, so the last thing you want to do is back off on the top end pinch on the belt.

 

[74Nitro]

Yes, I believe they've run the 35/39 reverse angle helix in the winders since 2019. TP claimed to need it, but I've always found it to be completely backwards from what is needed. It may have worked well on the old EVO tune as that tune had no bottom end. I find my new stock sled to drop RPM in the topped with the backwards 35/39 helix, but it wont be staying stock for long.

I run a normal progressive helix in my 17 and its quicker working it down low and letting the RPM come up down track. 35 helix holds a nice straight shift. Reverse helix just slows a sleds ET if it has any power at all, I've never seen it help ETs ever myself. Also it typically takes more pinch in the secondary to hold the belt on the top end, so the last thing you want to do is back off on the top end pinch on the belt.

Would a 41/37 be an angle you prefer?

 

[KnappAttack]

Would a 41/37 be an angle you prefer?

Yes it would.

 

[twyztid]

I'm running 33/35 with the B/O Seemed mine ran hotter at 6-3 than at 6-2 also during back to back tests. Stock tune with new rollers in both clutches.
RPMs are down a bit with the XS belt (8600), but I haven't tried any weight changes yet.

I am running ALL TP parts and my clutches run just warm. The only part that gets near what I would call hot is the inner primary sheave (connected to the engine so it WILL get hotter). I am running a TD PowerTrail 275hp tune with 3" SQ exhaust & CAI and in 25-degree temps, my rpms go right to 8900-9000 and stay there. The fastest I have seen on the dreamometer on the trail so far is 119mph. There was more in the sled but I let off.

2012 Vector Primary clutch w/ overdrive cut
TP Heavy Hitter weights
TP Orange Primary Spring
TP Glide Washers
TP 14.5mm Primary Rollers
TP 33/35 Helix (likely a Dalton?)
TP Secondary Rollers
TP Orange Secondary Spring wrapped to 40
XS825 Belt

 

[sideshowBob]

There's many ways to skin a "Yamacat" when it comes to clutching but I have found that the conventional approach what worked on previous sleds I have clutched typically works on my tuned SW...the key here is "Tuned". The SS tunes make so much hp and torque from low rpm that there is no need to run #*$&@ backwards helixs.

 

[1nc 2000]

I am running ALL TP parts and my clutches run just warm. The only part that gets near what I would call hot is the inner primary sheave (connected to the engine so it WILL get hotter). I am running a TD PowerTrail 275hp tune with 3" SQ exhaust & CAI and in 25-degree temps, my rpms go right to 8900-9000 and stay there. The fastest I have seen on the dreamometer on the trail so far is 119mph. There was more in the sled but I let off.

2012 Vector Primary clutch w/ overdrive cut
TP Heavy Hitter weights
TP Orange Primary Spring
TP Glide Washers
TP 14.5mm Primary Rollers
TP 33/35 Helix (likely a Dalton?)
TP Secondary Rollers
TP Orange Secondary Spring wrapped to 40
XS825 Belt

What base gram weights do you have and how are they set up?

 

[scottt]

Went riding today,,155 miles.,,,mid 30s again and windy on the lake. Snow was a little tighter this time.Made like 6 top end runs back to back. Couldnt keep my hand on the primary or secondary for no more than 3-4 seconds. Im assuming it should be hot anyways after that. 122 speedo and 116 gps. Cross winds were so bad I had to abort a couple of runs.Sketchy.Honestly all my other sleds Ive had I just rode them and fixed them if they broke. This SW is the first sled Ive had that Ive messed with as far as HP and looking for top MPH. So when it comes to clutches,springs,weights,helixs,etc is all new to me ,,trying to learn with zero experience.

 

[twyztid]

What base gram weights do you have and how are they set up?

I am not sure what the base weight it but they are loaded to 76.3 grams (heavier than normal due to the Japan-model primary clutch).

 

[1nc 2000]

I am not sure what the base weight it but they are loaded to 76.3 grams (heavier than normal due to the Japan-model primary clutch).

View attachment 171983

Thank you. I run the nytro primary so your weight will be similar.