tttario
Expert
Hey Guys,
Thought I would take some pics when I got my stock helix cut for more shift out. The first few pics are before I had it cut. You can see the amount of ramp travel that the stock helix prevents due to the inside ridge by the bushing. You can also see the wear marks(ring) where the helix and sheeve touch, so I know it was stopping the shift out.
I just had my machinist at work put it in a lathe and maching the ridge down ALMOST flush with the bushing. You can see the difference in ramp travel in the after pics.
Thanks to Allen Ulmer for this little tip. I made sure it was OK with him before I posted these pics and he had no problem with me doing it. I should mention he did not mention any gains in MPH or performance by doing this.
No testing on the top end as the ice track isn't plowed yet. Same performance as stock low and mid. Will update with top end results when available.
Cheers.
Trevor
http://s483.photobucket.com/albums/rr20 ... mview=grid
Thought I would take some pics when I got my stock helix cut for more shift out. The first few pics are before I had it cut. You can see the amount of ramp travel that the stock helix prevents due to the inside ridge by the bushing. You can also see the wear marks(ring) where the helix and sheeve touch, so I know it was stopping the shift out.
I just had my machinist at work put it in a lathe and maching the ridge down ALMOST flush with the bushing. You can see the difference in ramp travel in the after pics.
Thanks to Allen Ulmer for this little tip. I made sure it was OK with him before I posted these pics and he had no problem with me doing it. I should mention he did not mention any gains in MPH or performance by doing this.
No testing on the top end as the ice track isn't plowed yet. Same performance as stock low and mid. Will update with top end results when available.
Cheers.
Trevor
http://s483.photobucket.com/albums/rr20 ... mview=grid
LazyBastard
TY 4 Stroke God
I wouldn't expect ANY change in top end.
Few things to think about;
1) In order for the secondary to shift further, the primary also must.
2) If you don't have enough power to keep at peak rpm when shifted further, then you won't go any faster.
The REAL benefits from overdrive come from two possibilities;
1) Increasing the power available -- i.e. turbo, s/c, nos, cams, etc.
2) Lowering the overall gearing -- allows you to get to the same top speed, but gives you much easier engagement and better bottom end.
Few things to think about;
1) In order for the secondary to shift further, the primary also must.
2) If you don't have enough power to keep at peak rpm when shifted further, then you won't go any faster.
The REAL benefits from overdrive come from two possibilities;
1) Increasing the power available -- i.e. turbo, s/c, nos, cams, etc.
2) Lowering the overall gearing -- allows you to get to the same top speed, but gives you much easier engagement and better bottom end.
Ya Mahn
Veteran
On my sled the belt does not ride up to the top of the primary sheaves. It runs down approx 3/8". By cutting the secondary helix, you effectively lengthen your belt by opening wider giving you 1:1 ratio?? Is this correct thinking?
First thing you need to know before speculation is where is the belt ride when primary closed. Remove your spring & observe with your actual belt. 3/8 from top seems to be dead close to me. Do it again with secondary in the picture (no spring) then you know the first limit.. primary weight, belt length or gearing.
I looked at doing this to my clutch, then machining the primary to do the same.
A buddy brought to my attention that if I did this, there might not be enuff travel left at the end of the ramp.
If the roller runs past the end of the ramp, the ramp will drop below the roller and stick the clutch wide open, therfore creating a dangerous situation where the clutches will not let the belt go.
Anyone thought of this???
A buddy brought to my attention that if I did this, there might not be enuff travel left at the end of the ramp.
If the roller runs past the end of the ramp, the ramp will drop below the roller and stick the clutch wide open, therfore creating a dangerous situation where the clutches will not let the belt go.
Anyone thought of this???
LazyBastard
TY 4 Stroke God
Not quite.
First, having the secondary stick wide open will DEFINITELY let go of the belt -- it is the PRIMARY that is responsible for letting go of the belt, and having the secondary stuck wide open means that the primary will have to be shifted FULLY OUT in order for the belt to grip. If the helix got stuck, then as soon as you let off on the throttle, it would disengage from the belt.
Second, the modification you are thinking about is spacing the helix out from the clutch body. In this case, the buttons (these are not roller clutches, so there are no rollers), IF the helix is spaced WAY out from the clutch, could conceivably jump over the TIPS of the helix. What this does is it allows the helix to ride DEEPER into the fixed sheave (assuming that the spring doesn't hold it out, which it may depending on the particular spring), which means that there is no risk of jumping over the helix.
Third, even if the helix is spaced very far out, the helix towers on the moving sheave will stop the helix from rotating beyond the buttons on the fixed sheave. That means that what you propose is just not going to happen under any circumstances.
First, having the secondary stick wide open will DEFINITELY let go of the belt -- it is the PRIMARY that is responsible for letting go of the belt, and having the secondary stuck wide open means that the primary will have to be shifted FULLY OUT in order for the belt to grip. If the helix got stuck, then as soon as you let off on the throttle, it would disengage from the belt.
Second, the modification you are thinking about is spacing the helix out from the clutch body. In this case, the buttons (these are not roller clutches, so there are no rollers), IF the helix is spaced WAY out from the clutch, could conceivably jump over the TIPS of the helix. What this does is it allows the helix to ride DEEPER into the fixed sheave (assuming that the spring doesn't hold it out, which it may depending on the particular spring), which means that there is no risk of jumping over the helix.
Third, even if the helix is spaced very far out, the helix towers on the moving sheave will stop the helix from rotating beyond the buttons on the fixed sheave. That means that what you propose is just not going to happen under any circumstances.
Dear Mr. Lazy...LazyBastard said:
The title of this thread is about cutting the stock helix.
My post was: if enuff is cut of the center bushing, and then the primary center is also cut, there is a danger of running the ramp past the roller on the primary and sticking the clutch CLOSED.
The owner of Supertorquer told me he has seen this happen. The ending result was a ride into the haybales.
Please read my post completely
D
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