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Dyno results from a Charmo 170cc

Posted: Sun Feb 26, 2017 8:07 pm
by BPT7594
Hey.
I dynoed a 170cc PCX (originally 125), this is a newer LED model.
Stock head and valves.
Stock cam.
Yuminashi 31mm TB and Manifold + A type 6 hole injector.
Kitaco Type X power variator.
Stock torque spring and rear pulley.
17gr rollers.
PCX150 gear (53/17 x 44/13)
APITech standalone to control and manage fuel.
11HP which is a gain of 3.5HP over stock (stock is 7.5HP). Also notice how the HP curve stays flat throughout most of the RPM range, which is good. This guy wants his scoot to be smooth, not too much powerful so I stopped at this.
Screen Shot 2017-02-27 at 8.03.59.png
Screen Shot 2017-02-27 at 8.03.59.png (411.46 KiB) Viewed 1439 times
Also I learned a very important lesson today. If you are using a bigger injector with a 125 ECU you will tend to be on the rich side of the AFR most of the time, especially in the low rev, low TPS range. On WOT you can do fine with AFR of 11, 11.5, 12, you will lose power but the chances of killing a plug is small on WOT. On low rev, low TPS, you will kill a plug if you run it too rich so be careful. Bigger injector is a temporary solution, I have to trim the fuel map a lot on this PCX for it to work ok. I used 12.5 to 13 AFR and it runs very well. No knock, no overheating etc.

Re: Dyno results from a Charmo 170cc

Posted: Sun Feb 26, 2017 8:17 pm
by chicaboo
Nice work. The blue line on the AFR graph look fine to me.

Re: Dyno results from a Charmo 170cc

Posted: Sun Feb 26, 2017 9:49 pm
by k2apache6.0
A 30% increase in power is pretty amazing! Nice flat curve, no drops or spikes, and decent safe AFR. Well done. Looking forward to Chicaboos tuning results, looks promising so far. All good stuff.

Re: Dyno results from a Charmo 170cc

Posted: Mon Feb 27, 2017 3:56 am
by BPT7594
chicaboo wrote:Nice work. The blue line on the AFR graph look fine to me.
That's AFR on WOT by the way.
AFR on partial throttle is kept below 13.5, which is pretty safe compared to bone stock 125 which tends to be 16 even 17 with partial throttle.
Stock valves, stock camshaft and 11HP, pretty good. I'm sure if I drop a mild camshaft in there say a Takegawa cam it will be even better.

Re: Dyno results from a Charmo 170cc

Posted: Mon Feb 27, 2017 4:57 am
by Dragon_uk
Hi.
Is it diferent hp we are talking about? Standard pcx 125 has 11.7hp but I'm guessing it's close to 7.5whp.
Am I right?

Re: Dyno results from a Charmo 170cc

Posted: Mon Feb 27, 2017 5:20 am
by chicaboo
Dragon_uk wrote:Hi.
Is it diferent hp we are talking about? Standard pcx 125 has 11.7hp but I'm guessing it's close to 7.5whp.
Am I right?
Manufacturer's rate HP at the crank, dyno's measure it at the wheel.
You lose a fair bit of power through the CVT to the wheel.

Re: Dyno results from a Charmo 170cc

Posted: Tue Feb 28, 2017 2:12 am
by Gil
Thanks for sharing.

gil