Top Speed - SH150i

Discuss the SH- the one in your garage or at the dealer showroom
YellowJacket
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Re: Top Speed - SH150i

Post by YellowJacket » Thu Aug 31, 2017 11:53 am

Re: Robber57's post of 2/19/16 @ 9:26pm
This is a pretty good description of the many factors that come into play when measuring top speed. Another factor is how are you measuring it? Are you going by the speedo? Of the Honda's I've owned the speedos were very accurate. Still, speedo's at best will give you a ball park figure of your speed. GPS probably will get you a little more honest speed figure. The most accurate way is a stop watch and mile markers on a highway if that is available to you. Find a level stretch of road, get up to speed and start the stopwatch as you pass a mile marker. Stop the watch at the next marker. Whatever you get for time in seconds, divide that into 3600 will give you MPH. Say your watch shows 58 seconds. 58 into 3600 = 62.07 mph. For most of my testing I have to use the GPS, not many flat roads where I live. Some day I intend to compare GPS and stopwatch methods just to test the GPS. I do not have total trust in the GPS, having seen some very inaccurate numbers pop up, like 28 mph when I knew I was over 45.

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robber57
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Re: Top Speed - SH150i

Post by robber57 » Fri Sep 01, 2017 3:34 am

If you are in to the mpg thing you may wanna take a look at the mallosi O2 controller, its a add-on box istalled in ten minutes which enriches the mixture when its running in controled loop mode, that means when it is using the lambda sensor from 1/8 throttle to about 7/8.
It does NOT WORK full throttle so it wont do anything for max power/speed, in fact you may notice that it will reach a ( tiny bit) higher topspeed on full load at 7/8 throttle because the gain of having a richer mixture at 7/8 will be more benefit then the gain of the last 1/8 more butterfly valve opening.

Due to the richer mixture it gives a more "punchy" feel to the engine (higher torque) which means that practically speaking you are more inclined to give less throttle to get the same amount of pulling power "feeling", in particulair coming out of corners accellerating.
Humans are very inaccurate at measuring quantities with one sense because the other senses interfere,thats why we invented scales and such, the most well know effect is giving someone 1 pound of lead and 1 pound of foam and asking which is the lightest/heaviest, your eyes screw you in getting it right, the same goes for "measuring" pulling power by sense.
I have neaver did a dyno on the o2 controller but i wouldnt be surprised if it turns out it actually delivers less power in the midrange while giving me the sense of getting more, the engine just is more enjoyable, crisper and more responsive.
Its sounds counter intuitive but the engine is so lean to meet enviromental specs that it is just on the edge of switching of due to the lean mixture, car mechanics from the carb era may recall this when first co2 measurement became required, the leaner you made it the higher fuel consumption went up and up, with carbs it was also neccesary to keep the choke much longer on which made it even worse.
With injection this translates to the ecu keeping the engine for a longer period in "cold" enriched mode as the engine needs longer to warm up and you also tend to give more throttle to get the same feeling of acceleration.

The attentive driver may have also noticed that the sh engines only perform at their best when its blazing hot outside, mine just keeps getting fastr and faster and more economical only after driver minimum 1 hour at full speed and load on the highway in mediteranian temperatures, its just to lean and the hotter it gets the richer the mixture becomes and the better it performes.

This may lead to the false conclusion that modding the cooling system to a higher temperature will do the same, it doesnt, you need a cool engine and a richer mixture, the "hot" running bike doing better is just a symptom, you dont want to take an aspirine, you want to fix the sicknes.

The ecu needs to be reprogrammed which cannot be done and a fully "programmable" box like the dynojet/twobros/malossi are a "dirty" solution which does more negative then good, these are bandaids for bigger cylinders and such and you NEED a dyno to get them right, without a dyno and the knowledge they are useless.

Last thing: experiments in the past let me to the conclusion that the ecu has some kind of memory/buffer for its controlled loop mode, it takes a little while before changes in the mixture become apparent as it slowly forgets the old sensor variables and the new read readings become valid, a few rides where it comes completly up to operating temperature will do it.

A personal note to the followers: i am slowly getting up with lots of backdrops but i am getting theree although the realisation is setting in that i will never be the old goliath i was, but hey!, i am lucky to be alive :P
Failure is not an option, it comes bundled with the package.

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Mikey
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Re: Top Speed - SH150i

Post by Mikey » Mon Sep 04, 2017 4:38 am

I have noticed a great variation in the top speed to my SH150. The first is incline. Heading up to Mt. Charleston from 2000 ft to 8000 ft, I cant break 50 mph. I usually take a GPS with me also. Going down is no problem and I could probably get to speeds the bike was not designed for. Wind drag is another. If I duck down with my head above the head light I can increase my speed 4-5 mph. Also temperature and humidity seem to play a part. The other day I was on a stretch of highway I do 62-64 easy and it would not go over 56 full throttle. This is where the posted speed limit is 65 and some people are doing 75.
That said I look at my SH150 as a short trip and urban commuter. When I lived in Chicago, I told everyone it was my urban assault vehicle. I have passed through miles of stopped traffic with lane splitting, and had always found a parking spot at my destination. It made an unbearable rush hour a driving pleasure. I had driven to Indianapolis which was 210 miles one way, but the SH is limited by it's displacement.
I love it. I don't think I would ever sell it. Doesn't take up much room in the garage. I really have my eye on a Piaggio BV 350 as a long distance 2nd scooter. Maybe if I can find a good price on a used one.

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Mikey
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Re: Top Speed - SH150i

Post by Mikey » Mon Sep 04, 2017 10:29 am

I also want to mention that it seems as cylinder displacement increases with scooters the weight goes up dramatically. I think a 150-300 cc scooter is a good balance of power and weight. A 500 cc scooter weighs more then a 500 cc motorcycle. I think you lose some of the benefits of the scooter riding at that point.

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TommyXP
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Re: Top Speed - SH150i

Post by TommyXP » Tue Sep 05, 2017 7:09 am

I agree with your ratio.
Once an individual (majority) makes the intellectual decision to incorporate a SH (scooter) into ones day-to-day 'dealings' with the outside world of vehicles, we should also learn to content ourselves with the notion that we must leave our boyhood dreams of the Daytona 500 and the Bonneville Salt Flats behind; EXCEPT for those few rare individuals ('gear-heads' of exceptional mechanical abilities) who are by Nature enthused and inspired to see how very close to Perfection (God) they can manipulate this lower order of physical-being within 'these' always severely limited bounds; though this finite aspect of our existence (should) always aspire to the Infinite (Spirit) till inevitable death do we anxiously and joyously part and finally fully succeed to the extent of His (Cause) universal judgement.....
Its a Wonderful World on either side of the coin with a SH150 and please forgive the meanderings.......
https://www.youtube.com/watch?v=m5TwT69i1lU
Freedom is not something you are given. Its something you take.

YellowJacket
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Re: Top Speed - SH150i

Post by YellowJacket » Fri Sep 29, 2017 6:18 pm

My new to me SHi came with Yoshimura exhaust, power commander, K&N air filter and snorkel removed did a top speed two way GPS average on level ground of 65.5 mph @ 8442 rpm. Later with all the "performance" mods removed so the bike was as stock as it left the showroom it did 63.5 mph at 8200 rpm. As riding the bike, boots, jacket, helmet, cell phone etc. I probably weigh about 245.

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luxroller
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Re: Top Speed - SH150i

Post by luxroller » Sat Sep 30, 2017 3:09 am

:shock: that sounds to me like no big difference at all :roll: , thanks for the testing ;)
Toni

P.s. Your mobile phone is probably too heavy :mrgreen:

YellowJacket
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Re: Top Speed - SH150i

Post by YellowJacket » Sat Sep 30, 2017 6:12 pm

That's right Lux, phone was too heavy. If I had left the phone at home I would have gotten almost as much of a performance gain as all those "performance" parts did. I've been putting performance in parentheses because not too sure of their worth. Very glad it wasn't my money that paid for all that stuff.

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TommyXP
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Re: Top Speed - SH150i

Post by TommyXP » Sun Oct 01, 2017 4:48 am

Gratefully, I am content to leave well-enough alone and/or am too lazy to fiddle with near perfection.
Though I am guilty of using an Iridium spark-plug and believe in the virtue of the K & N air filter.
Freedom is not something you are given. Its something you take.

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