Dr pulley clutch + Yuminashi variator can be used together ?

[gasolina77]

so far i have purchased the whole yuminashi 164cc set with the fi controller, i want to increase the top speed + acceleration for a bit. My bike can only hit 120km/h-125km/h GPS speed not more than that because of the current sliding roller, valve springs, clutch ....the local Dynojet guys told me that after the test. During dynojet test my bike could reach to 140km/h but in real case may be the wind, the street surface i can only reach 120-125, i use double disc brake for my front wheel that may be the case for lower speed.
I've currently having some trouble with the valve spring :
- the original valve spring is 2,6mm this can help me accelerate very fast but the dynojet guys warned me no to go over 120 because it will break,
- yuminashi double valve springs : the big one outside is 2,9mm ( and one small valve spring ) when i install these two i can only go to 110 and nothing more acceleration is also much slower but this can with stand higher rpm can reach higher than 12000 rpm
- I use some custom Honda Dylan valve springs ( i currently use ) 2,8mm can go up to 120-125km/h but acceleration is slower than the original 2,6mm but faster than 2,9mm yuminashi .

The dynojet guys give me solutions :
- try to use lighter sliding rollers ( i currently using yuminashi 10gr ) i might purchase some 7gr, 8gr, 9gr mix together
- try to use custom clutch like Dr pulley, malossi
- try another valve springs like 2,65 , 2,7 , 2,75 .
- try custom sliding pieces

i'm curious is the double front disc brake is a big issue ? i had this modification before i installed the yuminashi kit, as i tested the top speed without double disc is 110km/h and with the disc it's 102-105km/h ( base on PCX speed meter )

[gasolina77]

to mod/admin i'm sorry to post this in the wrong section of the forums......i have created this in the performance section where it should be in the first place......

[Mel46]

it would be nice to know your location so that we can be more helpful. also, is this a pcx 125 or a 150?

[Oyabun]

While Mel is right it would be nice to know your location - it does not change the situation at all.
I hqve read back and I found that you're in Saigon and as you write that you already have installed a yuminashi 164 kit including variator so it also does not matter whether it was a 125 or a 150 originally.
Based on your post I assume that the tuners told you you have to restrain from using higher speeds over 120 kmph as those high speeds are only enabled by an rpm increase. In case you have got your bike on a dyno - proper tuning can be done if you have a power graph.
My specific comments
As an upfront answer to the topic header - there should be no compatibility issues between the dr pulley clutch and the yuminashi variator.
You need longer gearing to reach higher speeds safely - so either the yuminashi or kitaco, or my mixed oem honda gearbox should give you an increase in gearing. Now this will not mean higher top speeds, but lower revs at the same speeds.
Again deciding on roller weights can be properly made if you know the power delivery of the modified engine. To be more exact - the stock 125 engine has peak power around at 8000rpm - so rollers has to be selected that the variator keeps the engine revs in this range throughout the acceleration. So a dyno graph would be the point of start here.
Clutch has nothing to do with top speed. As long as it is not slipping under load - there's no increase possibility in either power or top speed from a clutch change.
Same stands for the sliding pieces. The best possible outcome with better sliding pieces could be smoother variator operation, but changing those will not change neither acceleration or top speed.
I hqve not seen a dual front disk installation on a PCX, so unfortunately I cannot comment on if they would rob you top speed or not. As per physics they might hinder acceleration due to increased rotating weight, should not alter top speed. Can you please post a link, or pictures and a writeup how did you manage that? Also you have mentioned changing the front forks - can you please start a different thread and explain how and what did you do there?

So short summary:
Work on your final gearing and post up a dyno chart so we can give you more advanced help.

[Alibally]

Hello. I've moved this to performance and locked and moved the duplicate post.






Sent from my iPad

[gasolina77]

This is the original valve springs 10 without yuminashi camshaft 10hp with the cam it can reach up to 13.98hp which give me best acceleration but i got warned not to go pass 120/125.... ( i lost that paper or pic i will try to find it )
https://scontent-hkg3-1.xx.fbcdn.net/t3 ... 1415_o.jpg
With Yuminashi double valve springs 12,251 hp but the speed drop at 110
https://scontent-hkg3-1.xx.fbcdn.net/t3 ... 5441_o.jpg
WIth custom Honda Dylan valve springs 13,13 hp with this i can reach 120/125km/h but on the dyno test it can up to 140 ( i feel it's not going up or kinda stuck at 125 the meter, the meter goes very slow or stop i haven't tried to keep running for 5 min to see if it can goes higher normally at 125 i keep running for 1 or 2 mins can't see it get higher so i stop but there are still room for throttling i feel like i just get 3/4 of the speed ).
https://scontent-hkg3-1.xx.fbcdn.net/t3 ... 1273_o.jpg
Finally the dual disc .....
https://scontent-hkg3-1.xx.fbcdn.net/t3 ... 4620_o.jpg
https://scontent-hkg3-1.xx.fbcdn.net/t3 ... 6185_o.jpg
https://scontent-hkg3-1.xx.fbcdn.net/t3 ... 3935_o.jpg

[Oyabun]

Just a quick reply to avoid this ropic to die off.
Nice setup, and a lot of time and resources invested.
As scooters have continously variable transmissions, the best way to get them dynoed is to lock the variator and exacly measure the engine power available at certain RPMs, like here.
http://s742.photobucket.com/user/Spy69_ ... c.jpg.html This way it is measured like they would be in a certain gear so transmission weights can be adjusted to the proper rpm. The above example have peak power around 8000 rpm, so variator weights and torque spring should be selected accordingly. At least ask the tuner to put RPM on the y axis of the middle graph, to see how enginesoped changes during acceleration.
My theory with the double valve springs is that they are significantly stronger than stock, causing mechanical drag in the engine, but they are not needed until higher RPMs are reached. If you provide measurements ( free length, wire diameter and spring outer diameter, number of coils) I can calculate a rough compression power and preload for all of the springs you have.
Based on your dyno runs, to me it seems that your engine runs out of breath at higher revs - as your peak Hp is always measured at quite low speeds. What exhaust, intake, cylinder head are you running?
I understand you have the yuminashi intake rubber and 31mm throttle body installed from the kit. Do you use the stock filter in the original filter box with the snorkel still installed? What exhaust you have? Do You use the original 125 head?

[gasolina77]

Just a quick reply to avoid this ropic to die off.
Nice setup, and a lot of time and resources invested.
As scooters have continously variable transmissions, the best way to get them dynoed is to lock the variator and exacly measure the engine power available at certain RPMs, like here.
http://s742.photobucket.com/user/Spy69_ ... c.jpg.html This way it is measured like they would be in a certain gear so transmission weights can be adjusted to the proper rpm. The above example have peak power around 8000 rpm, so variator weights and torque spring should be selected accordingly. At least ask the tuner to put RPM on the y axis of the middle graph, to see how enginesoped changes during acceleration.
My theory with the double valve springs is that they are significantly stronger than stock, causing mechanical drag in the engine, but they are not needed until higher RPMs are reached. If you provide measurements ( free length, wire diameter and spring outer diameter, number of coils) I can calculate a rough compression power and preload for all of the springs you have.
Based on your dyno runs, to me it seems that your engine runs out of breath at higher revs - as your peak Hp is always measured at quite low speeds. What exhaust, intake, cylinder head are you running?
I understand you have the yuminashi intake rubber and 31mm throttle body installed from the kit. Do you use the stock filter in the original filter box with the snorkel still installed? What exhaust you have? Do You use the original 125 head?

My exhaust is Akrapovic titan, cylinder head is 125 though.......
i have custom filter though......

[Oyabun]

I have worked my magic in PhotoShop (it is a great achievement, as the last time I used Photoshop was in the last century) and overlayed the dyno graphs of the Takegawa 170cc kits.
One set is with the 125 head, TB etc, and the other one is with the 150 head. otherwise seemingly the same.
Blue line = stock engine, Green = big bore kit, Red lines big bore kit+fi-con, cam, and exhaust.
The 150 based config seems to have about 2hp advantage over the 125 based kit. Given the fact that the Takegawa kit does not change the TB and intake manifold, and it is also 6cc larger disparagement than the Yuminashi kit - the difference might be smaller, but it is still significant.

Nevertheless. I believe that you still want to reach higher top speed. I would stay with the stock rev limit (or potentially have a hair increase) to stay safe with valve floating, and install a significantly longer gearing. If you send me your email in a PM, I'll send you my excel sheet with the calculations of potential gearing setups.

[chicaboo]

But you didn't post the dyno graph image.

[k2apache6.0]

Interesting topic, and Kudos to Oyabun who's obviously put in his time and expertise here. I'd like to see the dyno graphs too. I havent gone into power mods yet outside Dr Pulley sliders least not yet, and on getting interested in doing certain engine/cvt mods it's often as not pro's vs cons with seemingly a price to be paid in power delivery, tractibility or some other issue somewhere down the line. Been looking at the NCY super transmission kit and some are using the factory 1500 rpm spring instead of the one supplied because of blah blah blah, it's most frustrating to not have a decent resource from folks like Oyabun (and Chicaboo too who's done much 'Guinea pigging' with various combinations of variators et al) who know what they're talking about and go the extra mile to illustrate or prove a point. Whether you're a modder or not it's interesting reading nonetheless. Seriously hope this topic dont die a quick death hence this bump.

[Oyabun]

Thanks for the reminder. seemingly I did not pay enough attention that the size was out of the allowed range.
Here are the dyno charts. Mind that these are all rear wheel hp figures, and look for the relative differences rather than the exact numbers.
So while your's with the nice flat power curve around 13-14hp correlates with the full takegawa kit with the 125 head, there seems to be another two hp everywhere in the power curve to be gained with the 150 head.
What I'm saying that with the extra power and longer gearing one can achieve higher top speed even without raising the rev limit.