Belt trouble at high road speeds means overtravel of the primary. Well that's one possibility. Hunterworks sells a thicker washer to limit travel.

 

You need to focus on your secondary !!
it is torque sensitive while primary is rpm sensitive
Allot of people overlook the secondary’s
A better than stock helix is going to provide better belt life and acceleration, performance running larger than stock, and you can still get a EBS notch cut from nothing to aggressive.

Problem is a lot of aftermarket won’t give you the helix angles- they don’t like to give you their so called secrets.
I though, have mine all custom cut for the clients needs
a lot to gain,for minimal cost and the time pulling a tranny for gear reduction which a guy should running 35’ for sure ….

 

For 32s, I'd just run stock clutching plus a stiffer secondary spring. Gilomen or EPI sells them, either is good to talk to.

 

A stiffer secondary spring is going to generate additional heat,trying to compensate for belt squeezing,and will only provide undue heating of the secondary and the belt

 

That's not true.
I agree with Ryan K because what you think a clutch kit does it comes with stronger springs and weights.
I run stronger spring in the secondary clutch and it worked great, harder take off so less belt slipping and better back shifting.
I did a 30% gear reduction in all gears so I thought that would be better with the stock spring back in the secondary clutch.
But I was wrong it was horrible slipping of the belt less hit the gas hard.
I'm putting the Stronger EPI spring back in when I get time .

 

23 XP1K. For topic question, ignore the aftermarket clutch, as I still have a stock primary and secondary on the bench. For running 32s, what do I need to maximize belt life, still have engine braking, and not lose power?

Direct answer ignoring everything else; If you are not familiar with custom clutch tuning, get a kit, which it sounds like you already have. If you are familiar with custom tuning you probably wouldn't be asking this question.

So what we are actually asking is how can we tune your existing kit to solve some problems you are experiencing, not ignore what you already have.

• problem 1: you are "eating belts" at high rpm/speed. This can be a few issues; one is the belt is overdriving the primary (common issue) and Ryan K answered this above by using the washer. Two is the belt is slipping, more weight needed on the primary, too much however you might run into other issues, ie custom tuning/testing needed!!! Three could be an alignment issue, again very common, get the secondary spacers, 100s of post on the forums about this.
• problem 2: Engine Braking. Just to be clear, are we talking about EBS or backshift? To be honest I didnt look up your machine to see if it has EBS, so I'm just mentioning it for reference, and unless your clutch kit came with the EBS 'delete' there really is no adjustment for this feature, its either on or off. Backshift however can be increase with a stronger spring in the secondary as Ryan K said, but this comes with its own issues Highrider points out. It will increase the pull on the primary potentially increasing belt slip and adding heat into the system making your issue worse, so back to the primary to get this right.

Clutch tuning is a fun game of give/take/test... If you dont know, a kit from a reputable company is all you really need and follow their instructions. Maybe give Mother Clutcher a call and see what they say?

 

Again
This is a secondary issue that needs attention . Clutch tuning is easy once you comprehend, what each clutch does and how it effects the other.
The basic function as posted prior is ..
And should be followed if you really want a basic understanding
Primary is only rpm Sensitive…
While the Secondary is Torque sensitive.

Modifying one will effect the other but easily compensated to allow a true up ANback shift / which has NOTHING to do with the EBS notch in a persons secondary,(if equipped).

 

Basics to clutch tuning first understanding what all the parts are and how they affect the system. Going try and make this simple, it can be complicated because a change anywhere in the system can affect other parts of the system. As I said earlier, its a game of give/take/test...

• Primary Spring - This primarily affects the engagement RPM, heavier spring = higher engagement RPM.
• Primary weights - RPM control. This is probably the easiest adjustment to make, or how I do it once I have everything else is where it should be, do a WOT run and aim for your preferred max RPM. If its too high, add more weight, or reverse.
• Primary Ramps - RPM curve. Simply put how much the does the primary open/close at a given RPM aka shiftout. Let the smart people figure this out, this is not something a weekend warrior should be tinkering with.
• Secondary Spring - This primarily affects upshift/back-shift, aka torque transfer. Heavier spring will increase backshift but will also increase RPM because the secondary will stay closed longer on on acceleration ex. (making stuff up for ref only) Lighter spring you will have 5000RPM going 45mph, heavier spring you will have 6000RPM going 45mph so more torque at a lower speed which = faster acceleration. The flip side to this on deceleration, heavier spring the secondary will clamp close much faster (backshift) so when you get back on the gas like exiting a curve the re-acceleration will feel much snappier, but your RPMs may be too high, add weight to the primary to get this back where you need it.
• Helix - This affects the torque curve, kind of like the ramps in the primary affect the RPM curve. Straight angle pulls the same regardless of how open/close the secondary is, a variable angle can give give you different amounts of upshift/backshift depending on how open/closed the secondary is. Again like the ramps, let the smart people figure this out! The helix is also half of your EBS, if your helix has a notch for the roller at the bottom, you have EBS, no notch = no EBS. I say this is half the EBS, because EBS is also determined by the primary roller bearing, is it 1-way or 2-way; 1-way bearing you have full EBS and all the way down to 0mph the machine will slow itself, 2-way bearing and once you get to around 5mph the machine will free-spin and will no longer slow down.

Belt slip is a fun one as there are 2 places this can happen; primary and secondary and determining where the slip is is step 1 to resolving this issue, just loook for the black marks. If both clutches are marked up from the belt, you have an alignment issue or bad belt. The primary cause of belt slip is you have the two clutches unbalanced, ie the belt is riding up/down too fast in 1 vs the other. More weight on the primary increases primary pinch, less belt slip in primary but this has the opposite affect on the secondary and too much weight can cause the belt to slip there. Increasing the secondary spring will reduce belt slip in the secondary, but again will have the opposite effect on the primary.

Depending on your gearing and/or tire size, you'll want to adjust torque in the clutch to compensate, see above, but a reminder that you cant just put in a heavier secondary spring because you have big tires, this will affect everything else in the system and as OP puts it you'll have a "fustercluck". Start with a kit, follow their instructions based on wheel size and gearing, and make macro adjustments from there!

 

I agree with most of what you said.
Just to be clear that I love the performance of the stronger spring in the secondary clutch and never had any problems with it and it did what I was looking for.
Better engine braking, harder take off and just a little higher RPM.

 

Could of not said it much better- just way to much on a I pad to type.

Clutching is a Science, but an easy one to master once a person understands how each part effects the other