Blown Belt

[newtron]

Just got back from a 25 mile test with the new 37/33 Dalton Helix and CAT rollers.

Stock Engine
Stock Secondary Spring
Stock Primary Spring and Weights
Wrapped 3&3
Temperature +2 Celcius

With the Stock helix and rollers my rpms were fine down low but would drop to 8500-8400 on a long pull on a packed RR bed. Tonight with the new helix and rollers the rpm was a little low on take off (Because of the steeper angle), but were good up top(8750-8850). The RR Bed was rough, packed/Sugary snow. I took it up to 107 GPS with no loss of rpm up top. Rpms were 8700-8800 throughout the longer pull

I then went to a plowed road to test if I lost any real top end. I managed to get 118 mph GPS with rpms around 8800-8900.

When I got home I checked the clutches for Black marks and Heat. The secondary was a bit warmer than the primary, but could leave my hands on both for as long as I wanted without a burning sensation. All rollers are still nice and snug to the helix!

The clutches are actually cleaner now than they were before I went for a ride. Only sign of slippage is at the very top of the primary. Could be binding in the secondary or the shallow finish angle on the new helix. Overall looks really good. I think a 35/33 helix would be better with the stock primary weights!!

Next I am going to test the same setup with the QAY66 Dalton weights. I'm hoping this will give me more bottom end and maintain good rpm up top with no slipping.

Will Keep everyone posted.

 

[helix]

sometimes when you get fully geared out you get a bit of black at the top of the shift on the primary because it loses some pinch on the belt when the bottom of the primary sheaves hit together.

sounds like pretty good speed for a warm night

 

[newtron]

sometimes when you get fully geared out you get a bit of black at the top of the shift on the primary because it loses some pinch on the belt when the bottom of the primary sheaves hit together.

sounds like pretty good speed for a warm night!

Ya its getting close to gearing out.

Seeing as you said this spring is close to the Pink spring found in the viper button secondary, do you think we can use the Red Secondary Spring that you offer for the yamaha Button secondary? It is longer and would reduce coil bind

 

[helix]

you could try it, but see the other topic about coil bind that i posted...it would never be as big of deal as it was in the viper because it is not the same secondary. maybe slightly though.
The YMR spring was widely used in those factory viper turbo kits and would not be close to coil bind at all, but we have some other springs in the works to test with as well.

I'll have some new secondary test data info soon.

 

[newtron]

you could try it, but see the other topic about coil bind that i posted...it would never be as big of deal as it was in the viper because it is not the same secondary. maybe slightly though.
The YMR spring was widely used in those factory viper turbo kits and would not be close to coil bind at all, but we have some other springs in the works to test with as well.

I'll have some new secondary test data info soon.

Good info, Thanks!

One more question. Will the profile of the QAY66 weights improve my bottom end versus the stock weights?

 

[bleedyamaha]

Just got back from a 25 mile test with the new 37/33 Dalton Helix and CAT rollers.

Stock Engine
Stock Secondary Spring
Stock Primary Spring and Weights
Wrapped 3&3
Temperature +2 Celcius

With the Stock helix and rollers my rpms were fine down low but would drop to 8500-8400 on a long pull on a packed RR bed. Tonight with the new helix and rollers the rpm was a little low on take off (Because of the steeper angle), but were good up top(8750-8850). The RR Bed was rough, packed/Sugary snow. I took it up to 107 GPS with no loss of rpm up top. Rpms were 8700-8800 throughout the longer pull

I then went to a plowed road to test if I lost any real top end. I managed to get 118 mph GPS with rpms around 8800-8900.

When I got home I checked the clutches for Black marks and Heat. The secondary was a bit warmer than the primary, but could leave my hands on both for as long as I wanted without a burning sensation. All rollers are still nice and snug to the helix!

The clutches are actually cleaner now than they were before I went for a ride. Only sign of slippage is at the very top of the primary. Could be binding in the secondary or the shallow finish angle on the new helix. Overall looks really good. I think a 35/33 helix would be better with the stock primary weights!!

Next I am going to test the same setup with the QAY66 Dalton weights. I'm hoping this will give me more bottom end and maintain good rpm up top with no slipping.

Will Keep everyone posted.

What was your top speed on GPS before you added helix ?

 

[newtron]

What was your top speed on GPS before you added helix ?

Didn't try the plowed road but on the RR bed it was 104. Rpms would drop off.

The new rollers could be contributing to the higher speed/rpms as well as the new Helix

 

[newtron]

I have reached 118 with the stock setup on ice/plowed road before. This wasn't really a problem. It was when I would get onto packed trail or loose snow where the rpms would drop on a long pull

 

[helix]

Good info, Thanks!

One more question. Will the profile of the QAY66 weights improve my bottom end versus the stock weights?

I expect so, TD recently did a lot of testing in boosted applications with QAY70 and ecotrail tunes...they claim huge increases with experienced track dyno operator, but also in plenty of field testing. they claim most improvement in bottom end. We have always sold a lot of the QAY/DTYA curve to boosted applications, in fact plenty of aftermarket clutches on skidoo turbos, big cats, etc and other brands use them in sets of 4 weights. Guys that do a lot of testing.

 

[newtron]

Thanks again.

Will post my results of the new weights once weather is better!

 

[NOS-PRO]

Received my new rollers and 37/33 today. Will install and let u guys know the results

With stock weights and springs I'm not sure why anyone would want a steeper angle on top end. My rpms drop up top which is telling me it's up shifting to quick up top.

Anyway I'll let u guys know how it goes!!

A lot of the turbo guys are running reverse angle helix's and slightly steeper on top because you want the engine to rev quick, build boost and once the turbo power comes on you want to put more power down to the track.

Just put a reverse angle helix on my turbo Viper and the skis pop up immediately and hangs them for however long you want. Before that was all kinds of angles and took 25 feet to get the skis up.

Videos to come after this weekend of testing

 

[NOS-PRO]

We've been machining secondary's for years for the same reason. But we're trying to find a solution with a different spring vs machining. Stay tuned.


Sent from my iPhone using Tapatalk

X2

 

[Kevin]

Are people blowing the 8DN belts too or just the stockers

 

[DMCTurbo]

Just got back from a 25 mile test with the new 37/33 Dalton Helix and CAT rollers.

Stock Engine
Stock Secondary Spring
Stock Primary Spring and Weights
Wrapped 3&3
Temperature +2 Celcius

With the Stock helix and rollers my rpms were fine down low but would drop to 8500-8400 on a long pull on a packed RR bed. Tonight with the new helix and rollers the rpm was a little low on take off (Because of the steeper angle), but were good up top(8750-8850). The RR Bed was rough, packed/Sugary snow. I took it up to 107 GPS with no loss of rpm up top. Rpms were 8700-8800 throughout the longer pull

I then went to a plowed road to test if I lost any real top end. I managed to get 118 mph GPS with rpms around 8800-8900.

When I got home I checked the clutches for Black marks and Heat. The secondary was a bit warmer than the primary, but could leave my hands on both for as long as I wanted without a burning sensation. All rollers are still nice and snug to the helix!

The clutches are actually cleaner now than they were before I went for a ride. Only sign of slippage is at the very top of the primary. Could be binding in the secondary or the shallow finish angle on the new helix. Overall looks really good. I think a 35/33 helix would be better with the stock primary weights!!

Next I am going to test the same setup with the QAY66 Dalton weights. I'm hoping this will give me more bottom end and maintain good rpm up top with no slipping.

Will Keep everyone posted.

This should be in its own thread as this may get lost in a blown belt thread. Just my 2 cents

 

[journeyman]

Are people blowing the 8DN belts too or just the stockers

According to what I read on the SW facebook page, Yes.