Which mods to get?

[Valiant]

Okay, my current mods are as follows:
-SP Takegawa Silent Sport Oval(Silver)
-DNA air filter(removed snorkel as well)
-NCY Golden Teflon Variator w/ 13g rollers(no drive face)

My incoming pieces are:
-SP Takegawa Performance Camshaft(will likely be shelved and sold later)
-Advance Pro Large Diameter 120mm 14 degree drive face
-KN Planning Torque Cam
-2013 Honda PCX Counter Gear(53 teeth compared to 54 teeth in the 2015 model)

My sitting(on a shelf) piece is:
-NCY Secondary Slider Assembly

I wanted to get an idea of which parts help improve the performance of my PCX further, which parts overlap, and which parts are unnecessary altogether.

I was shown by a scooter shop that the KN Planning Torque Cam and the NCY Secondary Slider Assembly were identical, so I probably wasted money there already. I can't decide which of the two to use, though it was stated that the KN Planning had longer slots that drops the rpm too much. The mechanic I talked to wanted me to use the KN Planning because it would fit over the OEM part, which he recommended because "Honda parts are higher quality". I personally think I might encounter the rpm drop without a big bore kit, and I also think there might be a good reason why the NCY part includes the full assembly instead of just the torque cam.

Also not sure if the NCY vario is the same degree angle as the Advance Pro Drive Face, and if that matters as far as compatibility between the two parts, because it would mean more money to try to get the elusive NCY Drive Face.


Current top speed: 68 mph, not because it hits the rev limiter, but because I can't accelerate beyond that quickly enough before coming up on another car.
0-60 speed: Very good, though accel slows to a crawl past 60 mph, looking to boost the post 60 mph accel.
Uphill speed: Goes down on long stretches(47 mph prior to mods), but maintains a good 55 mph speed on short but steep inclines. Could use more oomph here.

I largely want to stay away from engine mods(hence, my decision to shelve the camshaft for now), at least until I've secured a career position in my intended field(IT software dev) and can afford to risk permanently FUBARing the engine.


The mods I'm looking at now(aside from the counter gear, drive face, and secondary slider) are:

-Yuminashi Inertia Power Booster Disk
This is basically a thick metal disk that sits between the flywheel and the fan of the radiator. I'm mostly curious if the added weight would also mean it'll take longer to slow down when rolling off the throttle and/or braking. I'd also need to get ahold of some washers in the proper diameter to fit around the disk. Seems like a pretty cheap upgrade for a small power bump.


-Short eSP Gear Set
This one is a little confusing, because the description doesn't mention if this is also identical to their Forged Final Gear Set, which boasts a 15/45T gear set. My concern is that it would mess with the speedo readings(which was warned with the final gear set, hence why it includes a sensor, and that particular item is out of stock). I'm also wondering if making the gearing too long without the torque to back it up would cripple uphill acceleration.

-Chameleon Factory Center Spring Slide System
This one is a little confusing to me, as is the clutch and clutch springs and clutch center spring in general. From my feeble understanding of it, mods to the clutch only improve launch/acceleration speed, but only at the low to mid range, and can have the effect of wearing out the belt faster and crapping on fuel economy as a result of that. Though I'm also wondering if this might help power my way uphill easier. I'm also wondering if the ball bearings alone could get me some top speed, as some of the aftermarket center springs seem to offer a caveat that it would essentially trade top speed for acceleration, and I'm wondering if the ball bearings help to get that speed back.


As I'm sure it's quite obvious by now, I have no engineering or mechanic experience whatsoever, but I'm quite enjoying my PCX, and even more so with the current mods. I'd also like to see how far this little scoot can be pushed without touching the engine, and I'm sure others might be interested in finding out what does what, and what the sum effect is if you layer everything on.

[sendler2112]

Adding a heavier flywheel is the silliest mod I have ever heard of.
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I wouldn't want to mix and match the drive face. Who knows what would happen.
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Increasing the rate of the contra spring in the back does the same thing as going lighter with the weights. They balance each other. It raises the pulling rpm. It also increases the belt tension and it has been my experience that this results in increased heat loss in the belt causing a slight loss of top speed and fuel efficiency. The whole contra spring thing is an old school tuning tradition the came from the days when guys were nearly doubling the hp of 50cc two stroke scooters with big bore kits and radical pipes. In this case you might need more belt tension to avoid slipping. It is a net loss on our bikes. Tune the rpm with different weights to 8,000.
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Changing the clutch springs only affects the launch rpm from a stop. Once the scooter is moving, there is no acceleration benefit from this although I wouldn't mind having the clutch let go a little sooner when coasting up to a light since fuel economy is my goal.
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Changing to more slanted and straight torque slots in the back will make the down shifting more active at speeds below lock out. Say 40-50mph. So when you are cruising at 50, it will be more apt to rev up a little when you gun it or come to a hill. Probably can't hurt unless the slots are so sloped that the bike just revs up and doesn't accelerate well.
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I wouldn't waste money on changing 1 tooth in the rear drive. You don't have enough power to hit the rev limiter now that the gearing is already longer from the NCY vario. Nothing you can do to the drive train will change the acceleration from 55 mph to top speed as the weights are already locked all the way out. This just comes down to engine power. A loud pipe and air filter can give 8% and the O2 sensor can more or less adapt the mixture to this much change. Anything more than this will take $1,000's for a big bore kit, cam, injector, and a fuel computer.
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If you want to spend money, get a tach so we can tell how to tune the weights for the best accel up to 50 mph.
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A Forza is only $2,000 more than a PCX and has twice the power. A Burgman 400 is also pretty nice.

[Valiant]

Adding a heavier flywheel is the silliest mod I have ever heard of.

It sits between the flywheel and the cooling fan if that matters. This also begs the question of whether Yuminashi is running a con with that piece, and whether the 3 reviews are fake. Or rather, whether you're insinuating that they are.

I wouldn't want to mix and match the drive face. Who knows what would happen.

It might already be mix and matched. I'm not sure what the angle and diameter of the NCY vario is that I'm using with the stock drive face currently(so if they're different, I've already ran it mixed), and the Advance Pro Drive Face doesn't mention any restrictions on what vario it might be used with(other varios available on webike also don't mention angle and diameter).

If you want to spend money, get a tach so we can tell how to tune the weights for the best accel up to 50 mph.

Wholly unnecessary, the accel up to 50 is perfect, it's what's after that I'm focused on.

A Forza is only $2,000 more than a PCX and has twice the power. A Burgman 400 is also pretty nice.

$2,000 more, before or after dealer fees and BS? This one can't be found on craigslist.

As well, parking space is rather limited. There are some times when my mother's car and neighbor's car are parked close enough together that I literally have to squeeze my PCX between the two with half an inch of clearance on either side. A fatter bike would be a problem in that sense, and because the PCX is parked sideways in front of my mom's car, a longer bike wouldn't be able to straighten out to the sides of both cars.

Hence, PCX.

[Valiant]

Wouldn't a little more weight to the flywheel make sense in theory?

I'm still getting my ears wet behind the engineering concept, but it sounds like more mass would cut down on early acceleration, but could push the post 50 mph acceleration.

[sendler2112]

Wholly unnecessary, the accel up to 50 is perfect, it's what's after that I'm focused on.

Funny, I guess you don't want a tach. To me this is the most important $50 upgrade I can recommend to anyone modifying their PCX so you know what results you are achieving. Along with doing 10-50 mph two way timed runs on a known road. And top speed runs.
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Performance from 50 mph and up is totally based on engine power. You can increase theoretical top speed on the stand with a longer vario but this longer gearing may actually take away a few tenths of a second from 50 to 65 mph. The CVT is locked out. No drive train mods can improve performance in this range. The only way to go faster in this range is with more power from a bigger engine.

[Valiant]

Funny, I guess you don't want a tach. To me this is the most important $50 upgrade I can recommend to anyone modifying their PCX so you know what results you are achieving. Along with doing 10-50 mph two way timed runs on a known road. And top speed runs.

Didn't mean to sound like I'm dismissing the idea off-hand, but it seems like I need to read up some more before actually purchasing that and being able to make use of it.

As a novice to this, a tach reading doesn't mean anything to me. I don't know what the numbers are supposed to indicate, and how I'm supposed to use that information. For example, should I be reading 8000 rpms when pulling from 10-50? What if I get less than that? More than that? What numbers should I be getting when I get up to 60? Going uphill? Going downhill? Running on flats?

If I get 7500 pulling, do I lighten the weights? Add more?

If I can't get the magic 8000 number when switching between 12g(I go over) and 13g(I go under), do I then start messing with the clutch center spring to play with the number?

Might be worth buying the tools I need to crack the trans open if I could get my head around how the CVT works, then I could fine tune it however I want.

Performance from 50 mph and up is totally based on engine power. You can increase theoretical top speed on the stand with a longer vario but this longer gearing may actually take away a few tenths of a second from 50 to 65 mph.

I'm not exactly racing. Taking away a few whole seconds from 50-65 might interest me, but I won't lose sleep over a few tenths of a second. And wouldn't longer gearing be desirable if the sum of the transmissions mods are enough to get me to say, 65 mph on flats reliably, and maybe I cruise most often at 60 mph? As I understand it, you go at higher speeds at the same revs/rpms, and I do recall reading about running at lower revs and staying under redline helps with fuel economy.

At the very least, it seems like it might be necessary for big bore setups where you burn more fuel for more power. It's something I'd might like to look into if an added aftermarket drive face helps me pick up better acceleration, and I do believe that transmission mods can effect how efficiently power is delivered to the rear wheel, hence the overall improvements I've experienced thus far with my current mods.

The CVT is locked out. No drive train mods can improve performance in this range. The only way to go faster in this range is with more power from a bigger engine.

Or burn a richer fuel mixture via the camshaft & FI Con right? Kind of hoping to put that off and see if I can get away with getting my performance(personally, I don't think I'd need much to tour my little island, and hopefully without Princess Obama blocking up traffic ) without sacrificing too much fuel economy.


Really enjoying the technical talk. I'd probably shoot the scooter shop some questions about these when I have my parts installed, hopefully this Saturday.

[Valiant]

Okay, this needs to be stickied on this forum section:
http://modernvespa.com/forum/wiki-cvt-p ... mprove-it-

From what I can understand of the literature, the NCY Vario likely provides "longer" gearing by allowing the belt to rise higher, which might mean higher angle/larger diameter, so it's possible it's compatible to the Advance Pro Drive Face, and the NCY Drive Face might be completely identical if they both increase speed or lengthen the gearing in the same manner.

It also sounds like I might want to seriously try Dr Pulley sliders in mine to improve accel over the rollers. I'm not above purchasing another vario, but is there anything that might rival the NCY vario in performance? Is it confirmed that the Dr Pulley sliders don't work with that particular vario?

Also, would the ball bearings help with anything? From what I understand, the contra spring itself shouldn't spin, though it also doesn't sound like it would rub against the rear pulley plate either, or both faces would wear off in no time. So I'm kind of wondering what the point would be to stick ball bearings between the contra spring and the rear pulley, and the translated description doesn't clear up anything.

Merry Christmas all!

[sendler2112]

The rpm doesn't have to be exactly 8,000 but this is about the leading edge of the power peak. If it is too low you need lighter weights. After the weights have pulled all the way out at 50-55 mph, then speed judt rises linearly with rpm up to redline (on the stand) or top speed against the wind (65 mph or so). Changing the cam can take away power and fuel economy from the 4-6,000rpm range, and increase power and fuel use from 8-9,000. If you get the fueling right. The FICon is a crude attempt. The Bazzaz would be much better but costs a fortune and then you still need a good dyno session to tune it or buy the wide band O2 logger for another fortune.
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here is a dyno chart of a PCX125 which was done the correct way with super heavy weights that were locked all the way out before 4,000 rpm so we can see power versus rpm. And there was a good article on tuning a variator here but they did not lock the vario so theor charts show power versus wheel speed.
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http://www.pedparts.co.uk/blog/moped-tuning-with-a-dyno
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[sendler2112]

The modern vespa article is a good primmer on CVT function. Their animation of low and high gear could be better. It kind of shows the drive face moving to squeeze the belt out to the higher ratio which it does not. It is bolted solid to the end of the crankshaft. Only the variator face is moving in and out to squeeze the belt up from the pressure of the weights.

[sendler2112]

And, they are completely wrong about different variators (or DrPully sliders) not increasing top speed on the stand. The factory variator and rollers are set to not let the belt go all the way out to the edge. Some varios like the Mallosi are actually larger in diameter and do go all the way out. Your larger drive face that you are waiting for is larger. But it can't use any more of it's face than the vario diameter.

[ScooterMan]

A heavier flywheel will never benefit accel. Well, in very odd instances, like in a car dropping the clutch on a launch, but no help on the PCX. You're still down 6mph or so on the top speed due to the lack of a NCY or advance pro drive face. Mix and match on those not a prob to me assuming the advance pro is capable of working solo (minus a vario upgrade). In that case it should work just fine paired with the NCY vario and have a similar effect to the NCY drive face.

The rear final drive gear upgrade to the 53 or 54t (forgetting at the moment) is a steal for $25 for the parts. A bit more labor involved to get to it though and not worth it to pay a mechanic, but should get you that last 2-3mph to get the bike up to 79mph assuming you have a new belt, vario and drive face and the final drive gear. =)

If it's top speed you want, stay with the stock windscreen and go full tuck for the best profile for cutting through the wind when needed. Also, pay attn to the type of jacket you wear too. Wear a snug fitting perforated nylon jacket for best top speed capability. Or better yet, a t-shirt! Yep, not going to advocate no protection, but a motorcycle jacket is a big "sail" and I do see several mph lost when I wear mine.

And, I've said it before, weight reduction is part of accel. I have a Li Ion battery on my 2015 that shaves 5lbs and has 50% more cranking power than the OEM battery for $79.

[sendler2112]

We really don't know why the NCY drive face increases top speed above what the NCY vario adds as was stated by one user. The only explanation I can think of is that it is shaved down at the boss so that it fits closer to the moving pully of the vario. Which would create a slight misalignment. Not good. Other brands of drive faces may not have this. Or it has a more straight up and down angle than the stock vario. I can't see how this wouldn't cause premature belt wear. But cursory side by side examination was stated to show no real difference from the stock drive face. Maybe the report that doing the NCY vario first got some additional top speed, and then adding the NCY drive face second, more top speed (on the stand)
was seen, is because the stock drive face was already grooved and was holding back the full travel of the belt.
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I hope all of our readers will keep in mind that this "79 mph" that keeps getting stated is only a theoretical top speed on the center stand or down a really steep hill. If the OP is still topping out at 65 with the NCY vario due to power balancing the wind, he will still be stuck at 65 with any other drive face, torque slot, contra spring (may loose a couple mph), ect.

[ScooterMan]

We really don't know why the NCY drive face increases top speed above what the NCY vario adds as was stated by one user. The only explanation I can think of is that it is shaved down at the boss so that it fits closer to the moving pully of the vario. Which would create a slight misalignment. Not good. Other brands of drive faces may not have this. Or it has a more straight up and down angle than the stock vario. I can't see how this wouldn't cause premature belt wear. But cursory side by side examination was stated to show no real difference from the stock drive face. Maybe the report that doing the NCY vario first got some additional top speed, and then adding the NCY drive face second, more top speed (on the stand)
was seen, is because the stock drive face was already grooved and was holding back the full travel of the belt.
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I hope all of our readers will keep in mind that this "79 mph" that keeps getting stated is only a theoretical top speed on the center stand or down a really steep hill. If the OP is still topping out at 65 with the NCY vario due to power balancing the wind, he will still be stuck at 65 with any other drive face, torque slot, contra spring (may loose a couple mph), ect.

I can hit a true (on the road) 79mph on my 2013 and the 76mph on my 2015 (due to final gear difference with same parts) but I am also 150lbs and those speeds are attained in a tuck on a flat or draft, or downhill. But also, remember that even if Valiant can't hit the theoretical top speed due to hills and cargo carrying, it's as you always say Sendler...it's about keeping the scoot in the happiest spot of the powerband. Gearing it to go higher top speed even if you never hit it means that our scooters will be making more HP and TQ at 68mph modified than when stock as the RPM will be lower at that speed and closer to the peak power making zone of approx 8k RPM.

[Valiant]

And, they are completely wrong about different variators (or DrPully sliders) not increasing top speed on the stand. The factory variator and rollers are set to not let the belt go all the way out to the edge. Some varios like the Mallosi are actually larger in diameter and do go all the way out. Your larger drive face that you are waiting for is larger. But it can't use any more of it's face than the vario diameter.

While the Dr Pulley sliders should make for better acceleration, it doesn't sound like it's compatible with a lot of varios with any kind of coating inside, which includes the Malossi Multivar 2000.

A heavier flywheel will never benefit accel. Well, in very odd instances, like in a car dropping the clutch on a launch, but no help on the PCX. You're still down 6mph or so on the top speed due to the lack of a NCY or advance pro drive face. Mix and match on those not a prob to me assuming the advance pro is capable of working solo (minus a vario upgrade). In that case it should work just fine paired with the NCY vario and have a similar effect to the NCY drive face.

That's good to know, but would the drive face help with accel at all? Not sure if it's lighter than stock, or if that matters. The Yuminashi gear also boasts lighter weight than stock, and claims it will improve accel because of that. I'm not sure if lighter parts on the moving components help with acceleration, and if that might suggest that a lighter clutch bell might also help in that regard.

The rear final drive gear upgrade to the 53 or 54t (forgetting at the moment) is a steal for $25 for the parts. A bit more labor involved to get to it though and not worth it to pay a mechanic, but should get you that last 2-3mph to get the bike up to 79mph assuming you have a new belt, vario and drive face and the final drive gear. =)

Parts are all new, even swapped out the old belt(700 miles on it) for a reinforced belt.

If it's top speed you want, stay with the stock windscreen and go full tuck for the best profile for cutting through the wind when needed. Also, pay attn to the type of jacket you wear too. Wear a snug fitting perforated nylon jacket for best top speed capability. Or better yet, a t-shirt! Yep, not going to advocate no protection, but a motorcycle jacket is a big "sail" and I do see several mph lost when I wear mine.

I'm not after anything beyond 75 mph, as anything beyond that is something I probably couldn't use except for odd roads.

My left leg also still hurts from when I broke it in August, so it'll be a damned cold day in hell before I go without ATGATT

And, I've said it before, weight reduction is part of accel. I have a Li Ion battery on my 2015 that shaves 5lbs and has 50% more cranking power than the OEM battery for $79.

Isn't saving 5 lbs kind of laughable when the rider weighs upwards of 200 lbs? Maybe I shouldn't have had that mac n cheese last night .


As for my speed, I don't "top out" at 65 mph, it's more like it takes so long to accelerate that I typically have to drop my speed before colliding with the car in front of me, and I generally don't make a habit out of constantly weaving around cars to keep my speed up. I suppose improving 0-50 speed could help in that regard by giving me a second or more to accelerate in the post-50 zone. It might actually be fruitless to go faster until I actually travel far enough and in a fast enough zone(preferably without turns) to make use of that speed, as the furthest I've gone is only about a 30 mile stretch from home.

Would like to do a lap around the island someday though .

[sendler2112]

Isn't saving 5 lbs kind of laughable when the rider weighs upwards of 200 lbs? Maybe I shouldn't have had that mac n cheese last night ..

Very true. Saving 5 pounds would be 1% of the combined vehicle and rider weight. which would shave .5% off of the 10-40 mph time. Instead of taking 10 seconds or whatever, it would take 9.95 seconds. Saving 100 grams at a time for a lighter vario, drive face, or clutch bell is even less of a payback on acceleration. And increased weight means almost nothing to top speed where the vast majority is drag from the wind and very little of the total power is being used to overcome road rolling resistance.

[Valiant]

I was rather curious whether weight of internal components mattered, whether the inertia drag is at the gears/trans or the wheel.

I'll probably get the Givi wind screen when it's available in February, seeing as how I pretty much never ride without my gear.

[ScooterMan]

Weight uphill matters, on a flat or downhill not a big deal. Don't laugh off 5lbs though. But if you're not a believer, that's ok. JUst remember to upgrade to a Li Ion battery when your OEM battery goes out.

Regarding top speed, again, it's not what you need it to rev limit at, it's whether or not your engine is capable of making power to sustain 75mph if it hits the limiter at 75mph. May be easier to have it reach 80mph but cruise at 75, then modify it in such a way that it hits the limiter at 75mph. Because for the former, you may be at 8800rpm at 75mph vs 9600rpm for the latter at 75mph, and the motor is making more hp and tq for the former, yet also also allows you to hit 80 during a draft or downhill, tuck, etc.

BTW, really enjoy chatting about all these details with you guys. Sendler, I appreciate all your knowledge too. =)

[sendler2112]

May be easier to have it reach 80mph but cruise at 75, then modify it in such a way that it hits the limiter at 75mph. Because for the former, you may be at 8800rpm at 75mph vs 9600rpm for the latter at 75mph, and the motor is making more hp and tq for the former

A key point. This is true. but even with super long gearing it seems there are only two guys here quoting numbers like 79 mph on the road and other guys with the same parts still struggle to make 65 at 8,000 rpm. I hate to see people get the wrong idea about spending money thinking they will be the next ones to 79 mph on the flat , two way, no wind. Not happening without engine mods.

[ScooterMan]

Maybe part of the reason I get higher speeds is due to at least 3 maybe even up to 7 different factors.

1) My relative light weight at 150lbs
2) The fact that I don't wear my motorcycle gear anymore (heavy and acts like a sail, I used to be a gear Nazi!)
3) When I am attaining the higher speeds on a flat, even when not drafting, I'm on SoCal freeways with plenty of other cars that are at least providing some sort of aerodynamic benefit to me by the fact that I'm not hitting the wind head on, but am in sort of a quasi-draft
4) I have done about 10lbs of weight reduction
5) I'm at sea level giving my engine the most power possible
6) I'm in a moderate climate with warmer air giving me less aero resistance in general
7) Maybe my scooter is just extra special? If nothing else, both have at least 2k miles on them and are fully broken in, which makes a difference

[Valiant]

Not with my fat ass behind the handlebars .

But I guess I was right in assuming that rpm on the tachy should read close to 8,000 rpm consistently from say, 10 mph and up? I'll buy it sure, but I just need to know what to look for.