Squeezing out more mpg from the suzuki

[RedDevil]

Originally Posted by saturndude

The image doesn't show I'm interested in seeing what you came up with.

Also, how do I get my fuely to show up in my sig like that?

See http://ecomodder.com/forum/showthrea...ture-2117.html

And here's Grant-53 's picture for ya:

If you click on Reply at that post you get the BBCode in that post too, whether functional or not.
Whenever you see something in a post that you'd like to do too just hit Reply and study the code

Saw his photobucket link does show up in a browser but it is a page; you need to copy the actual picture address (right-click on it) and paste that between these [IMG][/IMG] tags to make it work.

[saturndude]

Thanks!!

[saturndude]

A little update, for a few weeks I was tucking anytime over 45mph. There was about a 10% increase in effeciency. But it was hurting my neck/shoulders. I have decided that it isn't worth the 50 cents or so I'd save daily. especially where I depend on my strength in my current line if work. So now I'll occasionally tuck in to reduce turbulence especially at speeds over 70, but I'll have to look into and aero tail box for long term use. Thanks!

[naturalextraction]

Hi Saturndude... I've posted my

modifications to my 02 SV650

and my mpg gains. Before the extreme modification I got about the same. I have tried other modifications related to some of my other

research you can see here

that put it 52 to 55 mpg. (That proto-bike is an extreme example of mpg and available power on tap of course) With the current mods and practical driving (key here) I have my best now at 64.3mpg with the SV. With many hills I should add between here and Santa Fe NM. In city driving is best with the turbo mods due to less throttle and and I was able to lean out the bike anyway. Gearing helps in your case btw I'm sure you all ready know. Less effort from the engine and running 15.5 to 16.6 AFR will never hurt anything and at sea level you wont hardly feel the power loss. I can go on but just thought I'd make mention you can get better mileage with some tuning details. Also Graig Spears (Spears Racing) makes the advance timing keyway that will help as well with MPG. Talk to some of the guys at SVRider.com, some of them with carb SV's are getting mid 50's as well with some good tuning techniques.

[saturndude]

Cool I think I'll look into slightly leaning out the carbs next.

This weekend I installed a new chain and two new sprockets. I decided to stick with the o-ring because I want to reduce required maintenance. And I swapped the sprockets from 45/15 to 44/17. It feels fine and I'll post back results once I run through a couple tanks. Unfortunately I don't usually have a chance to get up to speed so well see.
Also, I ordered a second rear pillion passenger seat and plan on constructing an aero tailbox around it.

[ProDigit]

For best mpg, I would recommend a 150 CC, 5 speed transmission,double overdrive motorcycle.
I tried the Roketa 127, best i got is 96mpg at 60mph tailgating trucks, and 120mpg at a constant 35-40mph.
127cc is too small for highways, and made to go 35-45mph, however it's for speed step through gearbox with clutch started slipping, and acceleration was sluggish (a WOT departure was very similar to cars departing from a red light)
Therefor a standard 5 spd gearbox is just the right thing for small bikes of <200cc.
A thumper or single cylinder is most efficient, more so than a twin cylinder, and excellent for <200cc engines.

a single cylinder 150 cc engine, with a 5-speed transmission, & a double overdrive doing roundabout 3000 rpms at 45 miles per hour, will be the closest results you can get to a hundred MPGs, while at the same time, downshifting doing 7-8k rpm allows you to go to about 60 miles per hour at ~70mpg.

Trying to keep the rev range between 2500 and 3500, at your regular cruising speed maxes out mpgs. I usually change +1t front, and -5t rear, or the equivalent of 7 to 8t down on the rear. Most bikes come with a ~16/41t, and mpg is directly affected by sprocket tooth change. Going from a 16/41 to a 17/36t should increase mpg from 50 stock to 60mpg (a change of just under 20%).
Upshifting 1 or 2 gears should give you very similar gear ratio as a stock gearing final gear, so you could do almost the same top speed in 5th or 4th gear.



For prolong highway rides of 65mph tops, you will need A 250 cc engine, single cylinder at 85mpg peak, 75mpg @75mph.

if you ride a lot of highway and interstate, at speeds over 75 miles an hour, you will need a 500 cc engine minimum. a 650-750 cc engine is recommended if you are doing more than one hour at interstate speeds a day.

All of these are best with a ptwin engine, fuel injected, but some modern vtwins also get good gas mileage.

Honda engines are better than suzuki engines. They have lower peak rpm, but higher low end torque, which is excellent for eco riders, and those that want to make their engines last.
For high performance, lower mpg, Kawasaki engines are quite good.

your gas mileage, when fuel injected, can be between 66 and 75 miles per gallon on a 500-750cc engine.
On most carbureted engines it's a good 15% lower

[Grant-53]

Some of the smaller bikes are offering a 6-speed trans. Bikes with 125 to 150cc are not as common as 250cc machines. See the latest Vetter Challenge results where 'low&slow' topped 175 mpg on his streamlined 250cc Ninja. A 150 cc at 3000 rpm and a 50cc at 9000 rpm are moving the same amount of A/F mixture. Key factors in fuel efficiency are compression ratio and air drag.

Rider comfort is a persistent problem. The individual's settings of handlebar height and reach are a function of arm and torso dimensions. Build the bike to fit you. Once you have your body position optimized your shoulder height will determine the vertical dimension of your fairing. Max width is at the shoulders so the cross section would be an inverted egg shape. Vetter just updated his fairing tail section see Chapter 83 at craigvetter.com

[ProDigit]

If I had an opportunity again, I'd love to try modding the Sym Wolf150.
A very nice, simple, and mod friendly bike.

Most 150cc or below bikes are chinese bikes, with their inherited problems of screws falling off while riding, chrome rusting, 3-5k miles before a valve adjustment (2k miles on the 50-100ccs), low engine life expectancy, bad electrical cable wire harness, etc...

The Sym Wolf 150 is Korean, not inheriting all those chinese flaws, and probably the perfect city commuter.
It can go on highways, but not too far. Forget interstates on this. It would be dangerous, unless going on the right lane tailgating trucks to reach 65-70mph.
It's a great tradeoff between power and mpg, hitting just right in the sweet spot for city rides.
eco modders would love doing sprocket changes to rev that 150 in the sweet 3k rpm range, while doing a nice 30-35mph, clutch allowing you might be able to get it to do 3k rpm @40mph, surpassing 110mpg when cruising comfy.

The Honda Rebel 250 slightly has too much power in the city, while just not enough for the interstates (7.5k rpm @ 85mph when ducked forward, or 6k rpm @75 mph is about the best you can get out of it, though it generally only can get 65-75mph reliably top speed, accounting for head wind and hills).
It's a great Highway bike, and with the correct gearing great for going 40-55mph all day long, and mpgs surpassing 85mpg. A great number, but not great enough, when 100+MPG is achievable!
It's engine is a lot better than the Suzuki GS500 in terms of low end torque, and low RPM performance.

The chinese bikes stock have 80+mpg, and can be modded for 100+mpg, but they have no oil filter, and their oil consumption is quite high.
from both an environmental and economical point of view, they aren't very good investments at all in the long run.
The increase in oil changes, offset all gains done in fuel MPGs.
The increase in valve adjustments, and repairs on broken parts will catch up on you in the long run. Their lower resale value makes them worth nickels at the end of their lifetime, which often is only 1/4th that of a Japanese bike.

For that reason, without trying it before, I'd probably nominate the Sym Wolf 150 as the perfect econo-bike for the city.

It'll be perfectly possible to mod any 125 to 150cc to do over 150mpg, but when gearing becomes too tall, it no longer becomes a practical bike to ride in city traffic.
Too tall gears cause bad acceleration, and difficulty departing from a dead stop.
Wind drag on small bikes increases exponentially from 35mph onward, so your sweet spot for max mpg would be 35mph on a 100cc, 40mph on a 150cc, 45mph on a 250cc (trying to keep revs between 2.5 and 3k rpm.

[Grant-53]

I checked the Sym website for information on the 2015 models. The bikes are now from Taiwan and the 250cc fuel injection bike is a 6 speed rated at 25 hp and 96 mpg.

[sendler]

Originally Posted by Grant-53

I checked the Sym website for information on the 2015 models. The bikes are now from Taiwan and the 250cc fuel injection bike is a 6 speed rated at 25 hp and 96 mpg.

How much?