The Honda PCX / Forza / ADV150 / SH Forums

the yuminashi 31mm performace injector, manifold, and throttle body for the 150 at about 405 usd
has anyone tried it out. i am looking for at least 5 mph more.
i have the yuminashi speed booster vario and gates belt which was a great improvement on the stand its 81 mph but with me on it i have yet to hit 70.

waspmike wrote:

you you wrote:

dustin91 wrote:Question from someone who knows nothing about engine size, other than bigger is more powerful... how fast could a 175cc or 190cc engine go?

Watch moto3?

I'm in GN2 mode.

I was mulling the above statement in the shower this morning and it's relevance to PCX performance.

A 1400cc F1 engine produced, in race trim, about 1000 hp. In contrast a Skoda Fabia 1.4 TSI produces about 180hp.

So using your analogy if a Fabia driver wants to know the potential of his vehicle he should watch F1 or maybe GP3?

Watching Moto3 is fun and sure a Moto 3 is 250 and may produce about 50HP but of little relevance to a bored out PCX.

The question was how fast. The moto 3s are certainly fast for a tiny single cylinder

You are thinking about me in the shower?

Well the shower is always the best place to think, at least for me. Of course no good if one is in a hurry to go to work etc. I guess a good walk in the country would be close but...

Yes Moto 3 is fast for a small single cylinder bike but has no relevance to how fast a PCX can go.

waspmike wrote:Well the shower is always the best place to think, at least for me. Of course no good if one is in a hurry to go to work etc. I guess a good walk in the country would be close but...

Yes Moto 3 is fast for a small single cylinder bike but has no relevance to how fast a PCX can go.

Even with a change in rollers?

you you wrote:

waspmike wrote:Well the shower is always the best place to think, at least for me. Of course no good if one is in a hurry to go to work etc. I guess a good walk in the country would be close but...

Yes Moto 3 is fast for a small single cylinder bike but has no relevance to how fast a PCX can go.

Even with a change in rollers?

Please explain how they roll?

dustin91 wrote:Question from someone who knows nothing about engine size, other than bigger is more powerful... how fast could a 175cc or 190cc engine go?

I feel like no one answered this yet. The actual answer is, just as fast as a 125 or 150. You won't gain any top speed just by adding a big bore kit. You'll just get to the top speed faster, since the RPMs are electronically limited on the PCX regardless of bore size.

That's why I had to change the gearing on my 170cc, and am still increasing it further.

My gearing mods:
- Takegawa speed up variator (increased by 18% over stock)
- Kitaco final drive gear (increased by 8%)
- Yuminashi drive gears (increased by 20%)

Doing the math (gearing is multiplicative, not additive) 1.182*1.08*1.2=1.53 times the stock gearing. Given my stock redline at 55mph, the new gearing should be at the same redline at 84.26mph. The additional displacement and therefore power allows the PCX to push harder, driving that gearing further. Without that additional power, the engine would bog down and run out of power, not being able to rev up enough to get to the top speed.

Does that make any sense?

Yes. Perfect.
I essence, you can gear the bike to go faster but if you don't have the power to push it though the air at higher speeds you wasting you time and money. You have to upgrade both to see any benefit.

Alibally wrote:Yes. Perfect.
I essence, you can gear the bike to go faster but if you don't have the power to push it though the air at higher speeds you wasting you time and money. You have to upgrade both to see any benefit.

Precisely!

If you're an expert with fiberglassing, you could also make some wicked aero fairings and increase gearing without touching the engine, like this brilliant man: http://www.velomobiel.nl/allert/Recumbe ... orbike.htm

^ If I had more free time, a bigger garage, and more money, I would totally do that with the PCX. Nothing he did is outside my scope of abilities, but that much fiberglass is costly. I'm not going to lie, I actually priced out doing all that crap to a Sym Symba (closest thing to an Innova that we can get here). It ended up being about the cost of a new PCX... but would have taken literally half a year's worth of weekends to do right. Maybe one day.

Edit: pic in case you're too lazy to click the link above:

The above table is from an old test to establish the effect of a fairing on a bike, but I thought it interesting as it does show how much effect aerodynamics has on a bikes top speed and even roll on acceleration. As shown by the upwind/downwind speed differences and the 40-65mph times.

FYI it was an old 350 cc bike so probably a bit more Hp than a PCX but maybe not a lot more

Make of it what you will.

Do you have a picture of this somewhere? Thought there was but can't find it.

"After that I put on a K&N R1100 filter in the airbox by enlarging the airbox outlet hole with a file until a 1.5" I.D. piece of exhaust pipe fit and then ran a piece of 1.6" ID radiator hose from the outlet of the airbox to the throttle body"

Do you have a picture of this somewhere? Thought there was but can't find it.

"After that I put on a K&N R1100 filter in the airbox by enlarging the airbox outlet hole with a file until a 1.5" I.D. piece of exhaust pipe fit and then ran a piece of 1.6" ID radiator hose from the outlet of the airbox to the throttle body"

maddiedog wrote:

Alibally wrote:Yes. Perfect.
I essence, you can gear the bike to go faster but if you don't have the power to push it though the air at higher speeds you wasting you time and money. You have to upgrade both to see any benefit.

Precisely!

If you're an expert with fiberglassing, you could also make some wicked aero fairings and increase gearing without touching the engine, like this brilliant man: http://www.velomobiel.nl/allert/Recumbe ... orbike.htm

^ If I had more free time, a bigger garage, and more money, I would totally do that with the PCX. Nothing he did is outside my scope of abilities, but that much fiberglass is costly. I'm not going to lie, I actually priced out doing all that crap to a Sym Symba (closest thing to an Innova that we can get here). It ended up being about the cost of a new PCX... but would have taken literally half a year's worth of weekends to do right. Maybe one day.

Edit: pic in case you're too lazy to click the link above:

Sidewinds?