PCX150 Power Curve

[wingz]

Does anyone have a proper power curve for the PCX150?
kW vs engine rpm.
I have seen some kW vs kph curves; Their usefulness is limited to illustrating that the gearing could be better below 75kph and above 100kph.

[sendler2112]

I doubt you will find a proper dyno chart of the PCX to really see the power curve. Testing a scooter requires taking the drive train apart first to lock the variator. Let's discuss it here.
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http://www.hondapcx.org/viewtopic.php?f=9&t=1061
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[Honda4me]

Here's one from Yoshimura:

http://shop.yoshimura-jp.com/files/expa ... 0-53-0.pdf

http://shop.yoshimura-jp.com/files/expa ... 0-53-0.pdf

[Honda4me]

and.... http://shop.yoshimura-jp.com/files/expa ... 24a80a.pdf

[wingz]

Disclaimer: I pulled this graph out of my imagination and do not guarantee its accuracy.
It is however based on calculations and not guesswork so I don't think it is far from reality.

est power curve.jpg (64.06 KiB) Viewed 3566 times

Torque curve is irrelevant - I used it to verify the power curve.
What is quite important is the steep drop in power above 8500rpm.
You can even see this on the stock curves (power vs speed) where the variator is maxed out (above 100km/h)
Cruising at 107km/h (GPS), I estimate I only have about 8kW available.
This is why I believe the PCX150 can go quite a bit faster if one can bring down the rpm above 100km/h.

[sendler2112]

How did you calculate that? I think your power peak may be a little high in rpm and the torque peak is showing too broad and too soon.
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There are dyno programs for Android phones that might actually work ok with a slow vehicle like the PCX.
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Needless to say, you are right about longer gearing giving a better top speed because the power is definitely falling away well before redline. A top speed at 8,400 rpm would be about right which needs 10% longer gearing.

[wingz]

Oops, I forgot to divide by 1000 on the kW axis.

I started with Honda's quoted figures (10kW @ 8500rpm and 14Nm @ 5250 rpm).
From there I analysed a power vs speed curve of a stock PCX150 from one of the aftermarket suppliers.
Then coupled the above with knowledge of rpm at various speeds.
I am quite confident regarding the steepness of the drop in power above 8500rpm.

[Mgalutia88]

But is 10% taking into account the increased air resistance at higher speed?

[wingz]

I think it is more than 10% hence my interest in the Yuminashi gear set which gives 12.8% increase in gear ratio.
IIRC the PCX150 could handle an even higher increase in gear ratio but that was going to be my starting point.
Now I have decided to take a more frugal approach and measure exactly what increase can be achieved just by optimising the variator.
I hope to do this in the first week of January 2014. I'll be sure to share my findings.

[markz]

Disclaimer: I pulled this graph out of my imagination and do not guarantee its accuracy.

I wish management at my job presented their shit with this disclaimer!

[wingz]

Disclaimer: I pulled this graph out of my imagination and do not guarantee its accuracy.

I wish management at my job presented their shit with this disclaimer!

I should use it at work next time I present a graph.

[waspmike]

How many guys would put their PCX on a dyno if they could?

[Pcxdemon]

How many guys would put their PCX on a dyno if they could?

Id love to see what my output is now.....It has unbelievable speed for 170cc,very easily a good 300cc contender!
Hey ya all chipped in to maddie running this site ,so how about ya all chip in to me a little bit so i can dyno it for everyone?!
It will be a usefull bit of info for everyone interested modding their scooter on here...

[wingz]

What is the most cost-effective mod to boost peak power by say 10%?

[you you]

What is the most cost-effective mod to boost peak power by say 10%?

Hmm 1.5 bhp?

Gosh.

Difficult to be interested really

Nitrous?

[Mgalutia88]

Changing to a aftermarket variator and lighter weights. Essentially it puts more power to the ground. It does nothing to increase crank hp but it increases effective wheel hp.

[Mgalutia88]

Pcxdemon would tell you that the Daytona variator is the strongest variator currently available for acceleration and a top speed of 125kph or 77 mph. This is pending the fact that nobody has shared results with the new malossi variator for the 150.

[wingz]

I was enquiring about ways to boost peak power - not change the gearing.
As far as I know, there is no inexpensive power mod available but I would like to be proved wrong.

[Mgalutia88]

Changing the vario and weights changes peak rwhp. That's my point. Changing ratios does change the engines ability to put power to the ground. Every vehicle has a percentage of power loss through the drivetrain. What we are talking about here is reducing that loss. Most vehicles lose 20-30% of their power between the crankshaft and the drive wheels. Changing the variator and weights will reduce power loss and increase power to the wheels. As long as you increase both acceleration and speed or increase one and maintain the other, you've increased power.

[wingz]

I'm asking about inexpensive ways to increase the peak power of the engine.
I already know how I want to optimise the transmission.