Tuning the Forza 300 CVT

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Re: Tuning the Forza 300 CVT

Post by BRed »

sendler2112 wrote:
BRed wrote:I have to doubt it when it comes to the Honda 249cc or 279cc engines, in view of the fact that some 23x18 rollers are 1.5mm larger than sliders....
you can visually see they're taller at any point along the ramp.
Of course there are oversized rollers that will also increase gearing. But at the expense of the low gear at launch.
OK, I see where you're coming from now.....you're also tuning for more bottom end on the PCX.

Lowering the starting gear on a CVT is useful if your scoot is under powered (or if you're over weight?), but if you have enough torque when you pull out and have the HP to back it up, you can start off in a much higher gear and still get up to speed even faster.

The more power you make, the taller the gearing you can effectively run.

The Forza makes over 25HP and it doesn't need a lower starting gear.

In mixed weight tuning, you attempt to tune the total weight to shift the CVT as the acceleration curve reaches max torque and then tune the ratio of the 3sx3r weights to flatten the curve out and reach max HP just as the variator closes.

The 3 heavy sliders are used to alter the acceleration rpm curve due to the unique way sliders move up the ramp.
The 3 lighter rollers are used to maintain the original starting and final gearing of the variator.
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Re: Tuning the Forza 300 CVT

Post by sendler2112 »

The critical issue with the PCX is to optimize top speed which was originally intentionally limited to 100kph in both revs and power to comply with A1 licensing. Increasing displacement to 150 and redline to 9,600 allowed more power and more revs to go faster but there is more to be had if one can get the gearing longer. A stock 2013 PCX150 will just kiss the rev limiter at 66 mph/ 106 kph when everything is new, drifting down to 63 at redline with a half worn belt. A new belt, vario, and drive face with my used sliders got me up to 74 on the stand and 71 mph at redline with a tail wind and an honest 68 mph top speed which is just enough to keep up with the slow lane traffic with the added benefit of cruising at or near full throttle without constantly running on and off the rev limit. Changing to an aftermarket vario and face such as the NCY can get the PCX150 to 80 mph on the stand and an honest 70 on the road since you are now topping out closer to the 8,300 rpm power peak.But the coating on the ramps of the NCY doesn't work well with the increased bearing area of the sliders. Too bad since the biggest advantage with the sliders is that they literally last forever with no worn spots stealing your top speed back after a few thousand miles as with rollers.
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Re: Tuning the Forza 300 CVT

Post by you you »

sendler2112 wrote:The critical issue with the PCX is to optimize top speed which was originally intentionally limited to 100kph in both revs and power to comply with A1 licensing. Increasing displacement to 150 and redline to 9,600 allowed more power and more revs to go faster but there is more to be had if one can get the gearing longer. A stock 2013 PCX150 will just kiss the rev limiter at 66 mph/ 106 kph when everything is new, drifting down to 63 at redline with a half worn belt. A new belt, vario, and drive face with my used sliders got me up to 74 on the stand and 71 mph at redline with a tail wind and an honest 68 mph top speed which is just enough to keep up with the slow lane traffic with the added benefit of cruising at or near full throttle without constantly running on and off the rev limit. Changing to an aftermarket vario and face such as the NCY can get the PCX150 to 80 mph on the stand and an honest 70 on the road since you are now topping out closer to the 8,300 rpm power peak.But the coating on the ramps of the NCY doesn't work well with the increased bearing area of the sliders. Too bad since the biggest advantage with the sliders is that they literally last forever with no worn spots stealing your top speed back after a few thousand miles as with rollers.
Anyhoo. It's puting out about 8 or 9 bhp.

More important things to think about, like paragraphs?
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Re: Tuning the Forza 300 CVT

Post by BRed »

I think we're tuning for two different purposes....
you're tuning the PCX to push the upper limits of the stock setup and I just want to change the time when certain things in the shift cycle occur.

Here are a couple of pics from the DR PULLEY website:

Image VS Image

These supposedly show the relative extended position of sliders vs rollers. These look like small diameter rollers to me, based on the core.

I think that what happens in larger engines and variators is the taller sliders actually start to tip inward at the end of the ramp which prevents it from reaching maximum closure.
If you increase the weight of the sliders to the point it will fully close the variator, you're running too much weight to get good acceleration.
That doesn't seem to be an issue in the smaller scoots.

I think the reason for this is with smaller sliders like those used for the PCX, the jacket makes up a higher percentage of the total weight and can apply more outward force above the lip of the ramp.
The larger sliders like those used in the Forza have too much plastic sticking up in the tall side and don't apply enough outward force to lift the thrust plate.


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Re: Tuning the Forza 300 CVT

Post by sendler2112 »

BRed wrote:Image VS Image
I like the DrPulley Sliders. They work perfectly in the PCX. Very brilliant industrial design. They abandon the simple round profile so that every dimension can be optimized to do it's job. The working diameter pushing on the plate can be the same as the roller while the areas at 3:00 and 9:00 o'clock can be thinner to move the plate through a greater range. And the flat top portion doesn't have the issue of the corner digging in which quickly ruins a roller.
.
At $30 and they last forever the Sliders are a no-brainer fo the PCX since the stock weights are way too heavy anyway.
.
Looking at your charts it seems that Honda has made a big mistake with the profile of the torque slot of the Forza which you are trying to flatten by mix and matching different diameters and weights of rollers. The rpm versus speed of the PCX is nearly flat at full throttle throughout the entire active region of the trans.
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Re: Tuning the Forza 300 CVT

Post by BRed »

Actually all the graphs I've posted so far are of various Big Ruckus or Reflex 250s I've tuned over the last 8 years....
I still haven't wired the Veypor harness into the Forza yet.

I suspect the stock Forza will look similar to the above graphs of a Big Ruckus running 126 gram weights, based of the speedo and tach readings....
just less fade near redline.


The early Forza 250cc derivatives all came with 156 grams of weight in stock configuration....they accelerated like a slug.
We eventually determined they were a lot more fun to ride with 110-126 grams of weight.

The Forza came a little closer to what I would consider optimum with 126 grams total weight, but there's always a little room for improvement.
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Re: Tuning the Forza 300 CVT

Post by sesdave »

Bred - i am still running with the 17gms - great fun running locally but down to about 25-26 kpl. I notice I run above 7K on acceleration. Rather than going for a mix of sliders/rollers do you think just changing to 18gm sliders would keep my acceleration improvement , give me back my top end and improve my Kpl by reducing overall revs. Your advice appreciated. On another note I changed Dunlop Scootmart tyres to Michelin Power Pure SC's. What a difference in handling - went from relatively heavy to light handling and great grip/lean in corners. Recommend to all.
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Re: Tuning the Forza 300 CVT

Post by BRed »

Yes, it would help.

I think 17gram x 6 (102 gram total) is just too light for the size (diameter) and type of the weights you're using.
If you were using all 6 rollers, you could probably run 17 grams per roller and still not top 7000rpm at the shift point.

Sliders give a shift point and top end rpm roughly equal to rollers that are two grams lighter.....
6 each 17 gram sliders will show rpm readings close to 6 each 15 gram rollers (the shape of the rpm curve will be very different).

What I have found (and it took me a while to accept it)...only in rare circumstances should large scooters (250+cc) run all 6 sliders.
An oval track race bike is a good example....accelerate as hard as you can for a few seconds then let off and set up for the corner, then roll it wide open again.

If you're going very light on weight, rollers will always rev lower than sliders of equal weight.

So going to heavier sliders will improve your rpm and fuel consumption at top end, but.....
an identical Forza running the right mix of weights (3 x 3) will smoke your ass in a drag race, will be able to hold 85mph at a lower rpm than you and will use less fuel doing it! ;)
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Re: Tuning the Forza 300 CVT

Post by sesdave »

Haha - I hear you :D So then what mix ? 19/16 or 20/15 - which will best give me what I want. Locally I have a mix of windy flats and hills but bike rides to other places in Thailand are mainly motorways . So a mix that best suits both is what I would like but as I mainly drive locally I don't really want to lose the acceleration I am getting with the 6 x 17gms. Another question - what stops the sliders falling over in a mixed slider/roller setup - I just want to make sure I fully understand the workings of the variator with a mix of sliders/rollers. When I asked Dr pulley about mixing different weightent slider only mix they advised never to mix with all slliders as one set would likely fall over.
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Re: Tuning the Forza 300 CVT

Post by sesdave »

Looks like I can only get Malossi HT 23x18x15 or 23x18x17 delivered here when I searched online so what slider/roller mix would you recommend with either of these roller wieghts.
Re sliders falling over question - having though about it I think I understand that in a slider/roller mix the heavier sliders wont fall over as they push out first so they are always in contact whereas if an all slider mix the lighter ones could potentially fall over - correct?
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Re: Tuning the Forza 300 CVT

Post by BRed »

Big Ruckus and Reflex riders have been mixing sliders with rollers for years.....
always use sliders that are at least 3 grams heavier than the rollers so the sliders are always loaded and control the shift points.
I've never seen any tip over but if you dropped light sliders in with very HEAVY rollers, I guess it could happen?


Even if they tipped over the result would not be life threatening....it would change the shift points.
We know of one rider who rode over 800 miles with his sliders installed backwards....
the only thing he noticed is it backfired just as it shifted (when it hit the rev limiter) and it stumbled at about 75mph (again, bumping the limiter)


I'm running 3 20g DR Pulley sliders with 3 15g Adige rollers in the Forza and it's close.....
in one Big Ruckus, I'm running 3 19g sliders with 3 15g rollers and it is STILL faster than the Forza in a 1/4 mile.

I think the final mix for the Forza will be 19 or 20 gram sliders with 14 -16 gram rollers...
a little bias towards lighter for more bottom end and a little bias towards heavier for more top end.

I should tell you that the effects of mixing weights can be had with rollers only as well....
3- 20 gram rollers and 3- 15 gram rollers will give you most of the advantages of higher fuel mileage when accelerating gradually combined with much faster acceleration on demand due to lighter total weight, but you will still have the rpm loss during upshift due to the characteristic shape of the roller rpm curve.
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Re: Tuning the Forza 300 CVT

Post by BRed »

Yes...you have it correct!

go with the 15 gram rollers.
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Re: Tuning the Forza 300 CVT

Post by BRed »

Here's a graph that helps show this.....
the graph show 3 sets of runs, all using 102 grams of weight.

two of the sets of runs are using slider/roller mix and one is using 6 rollers.
the runs also show some effects of rear clutch tuning, but the important thing to notice is how the setup using 6 rollers loses several hundred rpm shifting and what effect that has on their 1/4 mile times

Image


Image


so even though the rollers had the advantage of delayed clutch engagement and started off even with the HiT clutch, when they lost rpm during the shift they fell behind and even a stock clutch with a slider/roller mix was doing better towards the end.
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Re: Tuning the Forza 300 CVT

Post by sesdave »

Thanks for all the info - its really helped the learning curve for me. I couldn't find a site to order and ship Adige carbon rollers to Thailand or UK so I ordered Malossi HT 15gm rollers as they get good reports re wear . I will go with a mix of 19gm sliders/15gm rollers and see how it performs. I need the extra speed to avoid and overtake the drivers over here as all they use the mirrors for is makeup and checking how they look lol
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Re: Tuning the Forza 300 CVT

Post by BRed »

these are posted elsewhere on this site but I thought I'd add them to this thread for clarity.

here are several runs on a Big Ruckus 250cc using 6 - 19 grams sliders.....
as you can see they are fairly consistent and usually show this same type of rpm curve....
they accelerate extremely fast, maybe faster than any other combination, but rev high!

Image


Image


changing slider weights only changes the shiftpoint rpm....the shape of the curve is always the same.
DR Pulley has a variator that will flatten this out when using sliders but in the stock variator you hit peak power band and pass through it a second later.

to contrast the two (rollers vs sliders) here is a graph showing 6 -26 gram rollers...

Image
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Re: Tuning the Forza 300 CVT

Post by BRed »

Here's another graph showing some runs with weights that are TOO light!

Image

these give a very good visual explanation as to how the rev limiter on the ECU works...

a Big Ruckus is rev limited to 8500rpm, 500 revs lower than the Reflex and Foresight
(it has a monoshock and a rear drum brake whereas the others have disc brakes)

on a Honda ECU, when the rev limit is reached, the unit shuts off every other spark cycle...fire one, skip one, repeat until in spec.
(some think it shuts off the spark completely, but that would get you killed!)

I scaled the graphs so you can see the rpm it kicks in, the spark rate while it is "limited" and what happens once revs fall under 8500 again.
some of those are incorrectly installed sliders and some are of a J.Costa with 4 of the 14 pins removed.

Hit the limiter under hard acceleration and you know it.....it wil miss and backfire.
Hit the limiter while cruising at top speed and you may never even know it....it just feels like that's all there is!

The Reflex rev limiter was @ 9000 and I've heard (but not confirmed ) the 300's limit is 9500revs....
we'll find out for sure eventually!
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Re: Tuning the Forza 300 CVT

Post by sesdave »

Your graph using 6x 19gms sliders has now got me thinking -apart from higher revs you indicate it accelerates quicker than any other combo - does that apply all the way up to top speed of 85? If so what revs is it hitting at that speed. I am just wondering if it would be better just using the 6x19 with a total weight of 114gm to give me fast acceleration and bonus of retaining top end rather than the 15g roller/19gm slider mix I was intending to do. I don't mind higher revs as long as I can keep top end and gas is cheap now lol!. I can of course just try both but your experienced advice appreciated.
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Re: Tuning the Forza 300 CVT

Post by BRed »

What I meant is that for any given total weight combination, 6 sliders will always give you the fastest 0-60 time with that weight.
If raw acceleration is what you want then 6 sliders are the way to go.

Keep in mind those 6 sliders will also have the highest cruise rpm of any combo with the same total weight and they will always run closer to redline.

But..... 6 - 19 gram sliders is definitely preferable to 6 -17 gram sliders for a road bike that needs to cruise at 75-80mph.
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Re: Tuning the Forza 300 CVT

Post by sesdave »

BRed - thanks for all the info. Which setup would you recommend over my current 6x17 sliders to try first - the 6x 19gm sliders or the 3x19 sliders/3x15rollers? Thats for mainly driving locally windy roads, hills and straights with the occassional long ride where I would like my topend that I lost with 6x17 sliders back . I ask as I to pay a garage each time I change - I don't have the tools to do it myself. Doesn't cost much in Thailand and I will probably try both anyway but your experienced advice appreciated. I might even try mixing the 19/17 sliders just for fun to see what happens lol
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Re: Tuning the Forza 300 CVT

Post by BRed »

Try 6 x 19 gram sliders first (you're probably going to be bummed out by the slower 0-60 time!)
That's the biggest issue with swapping rollers....going from 10 to 12 seconds in 0-60 time is very noticeable.

with the graph comparing a slider curve to a roller curve it was pretty easy for me to see that splitting the difference seemed most logical.

The problem is, you cannot match that imaginary rpm curve using either 6 rollers or 6 sliders...the curves for each are too well defined.

with 6 rollers, as you go lighter, the rpm drop during variator shift starts to flatten, but just as you think you're reaching a flat curve, the shiftpoint jumps up about 800 rpm and the whole process starts again.

with 6 sliders, as you go lighter, the rpm of the shiftpoint increases, but you still have that sharply rising curve during shift.

rollers move out the ramps smooth and fast, holding revs low and slow
sliders move out the ramps erratically and slower, allowing engine revs to go much higher thus excellent 0-60 times.

For a road bike, I want a compromise of the two.
Mixing the two styles of weights allow each type to counter the worst attributes of the other.

There are other ways to accomplish this acceleration curve while using only ONE type of weight...

you can re-machine the faces of the variator pulleys
you can change the angle or arc of the helical cuts on the torque driver pulley
you can modify the ramps of the variator for either slider or roller



Image

Image

before there were sliders, this is a variator mod I did to flatten the rpm curve of heavy rollers...
no, not very expensive...a caveman could have done it! :)

All of these mods are expensive and/or labor intensive and in the end may yield less gain than can be seen by using the unique attributes of each of the types of weights in combination.

The only way you can realistically use total weights in the 90-105gram range is to combine 3 heavy weights with 3 lighter weights.
If using 6 identical weights, you want at least 6 -17g rollers or 6 -19g sliders in order to not lose too much of your topend on the highway.
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