Go Back   EcoModder Forum > EcoModding > Motorcycles / Scooters
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 06-26-2011, 02:38 PM   #81 (permalink)
Master EcoModder
 
Join Date: Jan 2010
Location: Alberta Canada
Posts: 744

redyaris - '07 Toyota Yaris
Team Toyota
90 day: 45.54 mpg (US)

Gray - '07 Suzuki GS500 F
Motorcycle
90 day: 70.4 mpg (US)

streamliner1 - '83 Honda VT500 streamliner
Motorcycle
90 day: 75.63 mpg (US)

White Whale - '12 Sprinter 2500 Cargo Van
90 day: 22.01 mpg (US)
Thanks: 81
Thanked 75 Times in 67 Posts
Gray is getting upgrades, the new windshield is curved at the top and 50mm taller at the center, and the foam peaces are being replaced with ones that protect the hands better and are shaped better for aero. I may reshape the upper cargo box also... I suffered no damage, my riding pants have a small tair at the knee.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 06-27-2011, 12:04 PM   #82 (permalink)
Master EcoModder
 
Join Date: Feb 2008
Location: West Coast, USA
Posts: 513

B2300 - '96 Mazda B2300 SE

Focus - '05 Ford Focus ST
Thanks: 6
Thanked 75 Times in 54 Posts
Redyaris, glad you were not hurt and Gray wasn't damaged too badly. Sometimes the crash repairs provide an opportunity to infilct modifications, sounds like you are going to take full advantage of that.

On the carb size. The size of the carb is more relevant to engine power output rather than engine displacement.

The ninja 250 puts out 37.4 hp and has 2X30mm carbs for a total carb area of 1,413 sq mm, divide this by 37.4hp gives 37.7 sq mm /hp.

The gs500 puts out 47 hp and has 2x34mm carbs for a total carb area of 1,815 sq mm, divide this by 47hp gives 38.6 sq mm /hp. Pretty close to the same.

By going to smaller 30mm carbs on the gs500 gives 1,413 sq mm, divide this by 47hp giving 30.06 sq mm/hp.

As a cross reference, a Yamaha tw200 1X28mm total carb area of 615 sq mm, divided by 15 hp gives 41.05 sq mm/hp

So it looks like a carb cross section area somewhere between 37 sq mm and 41 sq mm per horsepower seems about right. Motorcycles are usually carbed to flow the maximum amount of mixture the engine can flow which directly translates into the ability to horsepower.

Motorcycle carbs are what was once known as variable venturi. The size of the venturi changes as the engine can accept more and more mixture. It's like having a small carb at low engine horsepower outputs and a large carb at higher engine outputs, so a smaller carb probably won't increase efficiency much at lower speeds but would definitely hinder top-end output. If the engine was optimized for lower speed operation by substituting lower lift and/duration cams (hindering top-end output), the original carb size would be too large to utilize it's potential, therefore a smaller carb would be better matched. It would also increase throttle response at lower loads somewhat.

It would be interesting though to fit a ninja 250 programmable fuel injection system and see what the result of a dialed-in injection system would provide. I saw a link a few weeks ago and it looked promising, just can't find it now though. It may be just the ticket as the top-end output of the GS500 is more than you need anyway. The injection system can be more finely tuned to the engine than a carb can, though we're really splitting hairs here.

I'd look at cam alterations to improve low speed operation first. Compare cams to other bikes optimized for lower speed operation. Look to decrease valve overlap, increase dynamic compression and decrease reversion into the intake so the carb doesn't try to meter fuel to air twice. Test. Then re-jet as needed. Could be that just advancing cams a few degrees would have a beneficial effect for not much invested.
__________________
Good design is simple. Getting there isn't.

Last edited by beatr911; 06-27-2011 at 12:20 PM..
  Reply With Quote
Old 06-27-2011, 07:54 PM   #83 (permalink)
Master EcoModder
 
Join Date: Jan 2010
Location: Alberta Canada
Posts: 744

redyaris - '07 Toyota Yaris
Team Toyota
90 day: 45.54 mpg (US)

Gray - '07 Suzuki GS500 F
Motorcycle
90 day: 70.4 mpg (US)

streamliner1 - '83 Honda VT500 streamliner
Motorcycle
90 day: 75.63 mpg (US)

White Whale - '12 Sprinter 2500 Cargo Van
90 day: 22.01 mpg (US)
Thanks: 81
Thanked 75 Times in 67 Posts
beatr911 the problem I was trying to address was the engine response at 3000rpm and lower. The engine surges and bucks when I try to run it below 3000rpm with low throatle opening. if I open the throatle to 3/4 or more the bucking and surging goes away. With smaller carbs the velocity through the carb would be higher at all rpm this may solve the low engine rpm performance under light throatle problem. This would also reduce the total power output, although the better aero would compensate for the loss of power.
The fuel injection solution would be better but the cost may be prohibative. I have looked at the fuel/air monitoring system I bought and find that the O2 senser is so big that I am having dificulty findng a spot on the bike exhaust to put it. The most promising spot is in the cross over tube, because it is the only spot that is protected from being knocked off, or damaged!
That 82 mpg on the 200 looks good you should join the Motorcycle team.
  Reply With Quote
Old 07-10-2011, 09:33 AM   #84 (permalink)
Master EcoModder
 
Join Date: Jan 2010
Location: Alberta Canada
Posts: 744

redyaris - '07 Toyota Yaris
Team Toyota
90 day: 45.54 mpg (US)

Gray - '07 Suzuki GS500 F
Motorcycle
90 day: 70.4 mpg (US)

streamliner1 - '83 Honda VT500 streamliner
Motorcycle
90 day: 75.63 mpg (US)

White Whale - '12 Sprinter 2500 Cargo Van
90 day: 22.01 mpg (US)
Thanks: 81
Thanked 75 Times in 67 Posts
I have been doing more Engine Off Coasting [EOC] with the GS500 and yesterday did a comparison with the redyaris. The test strip starts at the 1Km sign and ends when I have to turn right at the intersection. I start at 80km/hr and with the yaris EOC I have to brake from 50km/hr to 40km/hr to make the turn. The GS500 comes to a stop aprox 50 meters before the turn. The Yaris goes aprox 400 meters further. This is not a flat section of road, it goes downhill to the intersection then uphill after the intersection.

Last edited by redyaris; 07-10-2011 at 10:28 AM..
  Reply With Quote
The Following User Says Thank You to redyaris For This Useful Post:
alvaro84 (07-20-2011)
Old 07-11-2011, 02:07 AM   #85 (permalink)
Master EcoModder
 
alvaro84's Avatar
 
Join Date: Jul 2010
Location: Fehérvárcsurgó, Hungary
Posts: 384

Teresa - '04 BMW F650CS
Motorcycle
90 day: 80.53 mpg (US)

The YARDIS - '99 Toyota Yaris 1.0
90 day: 59.52 mpg (US)
Thanks: 4
Thanked 11 Times in 10 Posts
That's a very useful info! I've never driven a cage and always wondered how well they coast. They are heavier (=more momentum) and usually better at aerodynamics. So the difference is quite significant, but not as large as the difference in weight.
  Reply With Quote
Old 07-11-2011, 10:37 AM   #86 (permalink)
Master EcoModder
 
Join Date: Jan 2010
Location: Alberta Canada
Posts: 744

redyaris - '07 Toyota Yaris
Team Toyota
90 day: 45.54 mpg (US)

Gray - '07 Suzuki GS500 F
Motorcycle
90 day: 70.4 mpg (US)

streamliner1 - '83 Honda VT500 streamliner
Motorcycle
90 day: 75.63 mpg (US)

White Whale - '12 Sprinter 2500 Cargo Van
90 day: 22.01 mpg (US)
Thanks: 81
Thanked 75 Times in 67 Posts
The Yaris is aprox 1200kg and the GS500 is aprox 300kg both with the driver/rider. The estimated Cd of the Yaris with aeromods is Cd=0.27 and the estimated Cd of the aeromoded GS500 is Cd=0.5 - 0.6. with respect to frontal area the Yaris is 2.5 - 3.0 time larger. Subjectively on a down hill section of road the yaris will start at the top of the hill at 100km/hr and be going 120km/hr at the bottom of the hill EOC. The GS500 on the other hand will start at 100km/hr at the top of the hill and will be going 90km/hr - 100km/hr at the bottom EOC. I can only recall 2 or 3 times when the GS500 gained speed going down hill!

Last edited by redyaris; 07-11-2011 at 10:43 AM..
  Reply With Quote
Old 07-11-2011, 11:45 AM   #87 (permalink)
Master EcoModder
 
alvaro84's Avatar
 
Join Date: Jul 2010
Location: Fehérvárcsurgó, Hungary
Posts: 384

Teresa - '04 BMW F650CS
Motorcycle
90 day: 80.53 mpg (US)

The YARDIS - '99 Toyota Yaris 1.0
90 day: 59.52 mpg (US)
Thanks: 4
Thanked 11 Times in 10 Posts
Quote:
Originally Posted by redyaris View Post
...The GS500 on the other hand will start at 100km/hr at the top of the hill and will be going 90km/hr - 100km/hr at the bottom EOC. I can only recall 2 or 3 times when the GS500 gained speed going down hill!
I experience the same with Teresa: she needs a pretty steep decline to accelerate without the engine, especially at these high speeds. To keep a lower pace like 50km/h (with the engine turned off) is much easier. Of course it's coded in the bad Cd.

But in the Alps she likes to coast too fast on downhills - yet the engine brake is just too strong to constantly use it So I have to choose then what to waste: brake pads or gas... (because I have to start the engine at the transitions between engine braking and coasting)
  Reply With Quote
Old 07-11-2011, 12:22 PM   #88 (permalink)
Master EcoModder
 
Join Date: Jan 2010
Location: Alberta Canada
Posts: 744

redyaris - '07 Toyota Yaris
Team Toyota
90 day: 45.54 mpg (US)

Gray - '07 Suzuki GS500 F
Motorcycle
90 day: 70.4 mpg (US)

streamliner1 - '83 Honda VT500 streamliner
Motorcycle
90 day: 75.63 mpg (US)

White Whale - '12 Sprinter 2500 Cargo Van
90 day: 22.01 mpg (US)
Thanks: 81
Thanked 75 Times in 67 Posts
Alvaro84
I see that we are the only active members of the motorcycle Team. I have mentioned it to beatr911 but he has not joined yet. It looks like I will be joining you in the 70mppg - 80mpg, 90-day zone before the end of the rideing season in Canada. I may have to resort to an 80km/hr "slow" 400km tank, if I want to get there sooner rather than when going 100km/hr.
  Reply With Quote
Old 07-11-2011, 12:43 PM   #89 (permalink)
Master EcoModder
 
alvaro84's Avatar
 
Join Date: Jul 2010
Location: Fehérvárcsurgó, Hungary
Posts: 384

Teresa - '04 BMW F650CS
Motorcycle
90 day: 80.53 mpg (US)

The YARDIS - '99 Toyota Yaris 1.0
90 day: 59.52 mpg (US)
Thanks: 4
Thanked 11 Times in 10 Posts
Haha, you can get there faster by going slower, I like it
I hope to surpass 80mpg as a 3-month average soon (and go below it when it gets cold again) - I could do it 2-up with the last tank, after all. Even though it took P&G'ing (my most typical pattern on the open road is to pulse to 100km/h, then glide down to 70, preferably downhills) ~330km on Saturday, melting in the sun (it was 38C in the afternoon) - good that we came back at night
  Reply With Quote
Old 07-31-2011, 10:41 AM   #90 (permalink)
Master EcoModder
 
Join Date: Jan 2010
Location: Alberta Canada
Posts: 744

redyaris - '07 Toyota Yaris
Team Toyota
90 day: 45.54 mpg (US)

Gray - '07 Suzuki GS500 F
Motorcycle
90 day: 70.4 mpg (US)

streamliner1 - '83 Honda VT500 streamliner
Motorcycle
90 day: 75.63 mpg (US)

White Whale - '12 Sprinter 2500 Cargo Van
90 day: 22.01 mpg (US)
Thanks: 81
Thanked 75 Times in 67 Posts
The last three refuels I have been getting 70 -78 mpg and have been developing/adapting the hypermiling techneques to the motorcycle. what I learned today is that if I coast in neutral with the engine off the transmission grinds when I put it back in second gear while still coasting at 30km/hr, no matter how long I pull the clutch in. If I hold the clutch in there is no grinding when changing gears.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com