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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Power to weight ratio and other speed info /cgi-bin/YaBB.pl?num=1250990663 Message started by shiphteey on 08/22/09 at 18:24:23 |
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Title: Power to weight ratio and other speed info Post by shiphteey on 08/22/09 at 18:24:23 Dynoed the Savage, about 7000 miles on the motor, double that on the odometer. Oil was old and overfilled 10W40. Tire pressure was normal albeit quite dry rotted. Stock sized 140/80 tire. NO air filter on pump 87 octane near a couple hundred feet elevation. 5 pulls, all about 26 RWHP. Correct oil level could have given a couple more HP. A/F ratio was in the 12s so a little rich. I'm presuming i have stock jets. Exhaust is stock. New plug and valves adjusted prior to runs. Put the bike on the scales with enough fuel to make it home 30 miles away with some still left in the tank: 341 lbs with 1 mirror, Honda turn signals, no battery box covers. I'll post up dyno sheets soon, just an FYI. Our dyno is quite stingy. I get 28 RWHP on the Ninja 250 when its REALLY warmed up. Speedo indicates 92 mph max on the streets, I will do some top speed GPS tests soon. Dyno shoed a hair past 100 mph actual before it sounded too dangerous....HP dropped to near 20 HP at those speeds so a taller tire will be needed to pull some more mph than 90ish....unless I get some nitrous hooked up. A. |
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Title: Re: Power to weight ratio and other speed info Post by jabman on 08/22/09 at 23:41:01 cool make sure you post up any more info you have |
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Title: Re: Power to weight ratio and other speed info Post by ralfyguy on 08/23/09 at 07:07:48 That shows that on the savage it's several factors, why it get's fairly quick to about 85mph and the struggles all the sudden to go faster. It's only about 30hp to begin with and at those speeds you need alot more to hit the ton. The gearing is too short so you reach the rpms where power drops significantly, and you actually need it to at least maintain maximum hp. I can tell when I accelerate hard in any gear that it doesn't help to rev it over 6,000 rpm, as it struggles above that. I can achieve better accel when I shift at 6,000. The engine if stock, doesn't like more than 6,000 rpm. Now with the appropriate mods, this might be a different thing. I still think, that with a tad of a longer top gear, it could do a little better. I changed my oil yesterday, and had a little Hwy run after and it went to 85 really quick and then it took another half a mile to reach about 93 indicated with the tach reading about 6,300 rpm, screaming like hell. But the bike didn't seem to be scary at those speeds. But it certainly seems to reach it's limits. The mirrors are buzzing so hard, that all I can see is, whether it is a semi or a car. I couldn't tell a cop behind me trying to get me for speeding. I'm not sure about going faster than 100mph on this bike, and I am not faint hearted. |
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Title: Re: Power to weight ratio and other speed info Post by PTRider on 08/23/09 at 10:35:55 I'd think that a fork stabilizer, if you don't already have one, would be a huge help at those speeds. Can you pick shift points where the new rpm for each higher gear starts off at the torque peak, 3400 rpm? I've read that this gives the fastest acceleration, but I haven't yet tired it. If it works, please let us know. The book says that the power peak is at 5400 rpm, and your observations are right in line with this. |
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Title: Re: Power to weight ratio and other speed info Post by Duane on 08/23/09 at 13:03:51 How many pounds of torque. My guess would be we have more torque than HP. |
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Title: Re: Power to weight ratio and other speed info Post by shiphteey on 08/23/09 at 13:31:46 Slight correction: After flooding my carbs and having fuel pour out of the bike, partly due to the petcock being on Prime after a fillup at the gas station I opened up the airbox to discover I had still left the old stock air filter in there, which would explain my relatively rich a/f ratio in the 12s. I have a new one I will replace it with and redyno it to see what the a/f ratio is. I suspect HP will go up from 26 to 28-29 because I have the oil level at the middle in the sight glass now plus a clean and new air filter usually perfoms better than one that is dirty with tons of crap wedged in the pleats! Here are the dyno runs, which were all done in 4th gear since it is closest to a 1:1 ratio, except for the 100 mph pull which was done in 5th, just to see how high it "could" go: http://i103.photobucket.com/albums/m135/shiphteey/Savage1.jpg http://i103.photobucket.com/albums/m135/shiphteey/Savage2.jpg http://i103.photobucket.com/albums/m135/shiphteey/Savage3.jpg http://i103.photobucket.com/albums/m135/shiphteey/Savage4.jpg http://i103.photobucket.com/albums/m135/shiphteey/Savage5.jpg http://i103.photobucket.com/albums/m135/shiphteey/Savage6.jpg You'll see that theoretically the Savage "can" go to 100 in terms of internal ratios, but the RPMS are higher than they should be and you are going past peak power! Correct, this bike is definately more Torque than HP which is why it feels so snappy compared to my Ninja 250. Weight is only a little heavier than the Ninja 250 too. I'm sure the stock head on the Savage has quite a bit of room for improvement...then again it was never designed for top end in the first place. Also, I agree at top speed the Savage is quite stable in a straight line. Lower center of gravity, longer wheelbase, and a little more weight, more rake....the bike really needs a 6th gear IMO! A. |
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Title: Re: Power to weight ratio and other speed info Post by shiphteey on 08/23/09 at 13:34:09 PTRider, I have gone 112.7 mph on my Ninja 250 and 229.6 mph on my ZX-12R...no worries about 100 mph on the Savage for me. My "sense of speed" is probably a little different than most riders. I have stood on the pegs of the ZX-12R at 170-171 mph on GPS to see at what speed the ZX-12 seems to stop pulling with me barely able to hang on and my helmet choking me....just to see how much aeros play a part in terminal velocity....not to mention it was fun looking down at the fast Busa guy trying hard and still passing him. ....not that I advocate this sort of behavior, just saying... A. |
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Title: Re: Power to weight ratio and other speed info Post by LANCER on 08/23/09 at 14:21:47 223938213925343428510 wrote:
You are fortunate that you did not go into a "Rocky the flying squirrel" imitation while doing that ... not smart dude. |
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Title: Re: Power to weight ratio and other speed info Post by shiphteey on 08/23/09 at 16:44:53 With all due respect, you probably don't know much about what I do, how I ride, etc. It isn't like I just decided to stand up at 170 out of the blue. There was a progression with stability tests, braking tests, etc. I do quite a bit of land speed racing and real world aero testing as well. In the end you and I don't know each other well so you aren't qualified to determine whether or not what I do is 'smart'. I routinely go over 200 mph, one could argue that isn't smart. Suffice to say I may have more experience at 200 than many riders do at 100. As the old saying goes, "Judge not..." A. |
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Title: Re: Power to weight ratio and other speed info Post by LANCER on 08/23/09 at 18:35:14 7B606178607C6D6D71080 wrote:
You make a valid point; I do not know you or your experience level and it would have been better for me to ask you about those things first, so my apology for that ommision. That said, when I read something like "with me barely able to hang on and my helmet choking me", my first impression is that someone is doing something foolish. To me, regardless of your experience level, if you are barely able to hang on then your safety is compromised at that point, which is not a good thing. When reading your post I thought I detected a bit of "brag" from you when you were describing what you did at speed, especially about looking down at the Busa guy, and rightly or wrongly that was a type of "judgment" on my part. Sorry if that offended you, but that was the impression I got when reading it. I tend to live on the safe side of the line. Part of that is my age but mostly it comes from training and experience; having spent most of my adult working life in military aviation. I have had my share of living on the ragged edge of life and death, and choose to avoid those situations when at all possible. With that as some background on me, that may help you understand why I wrote what I did. Nothing personal, that's just the way I see it. So, bottom line, please be safe. I enjoyed seeing the dyno info you posted on your Savage, and look forward to your future posts. |
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Title: Re: Power to weight ratio and other speed info Post by bill67 on 08/23/09 at 18:55:32 Amen |
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Title: Re: Power to weight ratio and other speed info Post by FreeSpirit on 08/23/09 at 19:19:23 606B6E6E3435020 wrote:
bill,I think you missed your calling. A man of many talents and your timing is perfect. |
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Title: Re: Power to weight ratio and other speed info Post by justin_o_guy2 on 08/23/09 at 19:24:20 I could stand a bit of a "clinic" in understanding those dyno posts.Not today, Im burnt.. |
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Title: Re: Power to weight ratio and other speed info Post by Charon on 08/23/09 at 19:43:13 The problem I had with the dyno posts is that they did not reference engine rpm, but mph. I find it difficult to believe there would be an air/fuel ratio, but not rpm. I can understand that the dyno measures mph, since that is its "native" measurement. I thought it interesting that once off idle speed the mixture went to about 12:1. That sort of number is considered good for maximum power. Slightly rich is usually good, and it helps engine cooling. Airplanes usually go "full rich" for takeoff for that reason. EPA measurements do not usually include wide-open throttle, so the makers can go rich enough to get good power in a region not EPA tested. I am a little suspicious of dynojet runs, because they do not test the engine under any sort of steady-state loading. They measure only transient loading. I think more realistic testing would plot the engine's torque and power at some steady speed under different throttle settings. But that sort of testing takes a LOT longer, is more expensive, and is much harder on the engine. |
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Title: Re: Power to weight ratio and other speed info Post by PTRider on 08/23/09 at 20:19:38 5766727D76130 wrote:
Whether the torque number or the horsepower number is bigger is not a significant thing. It tells more about the rpms the numbers are produced at than anything else. Torque x distance ÷ time = power In our English system of measurement, pounds-feet of torque x rpm ÷ 5252 = horsepower 5252 is a constant derived from converting the original horsepower formula, 33,000 ft-lbs per minute, into our convenient meaure with rpm. The fact that the number for the torque value equals the number for the horsepower value at 5252 rpm is meaningless and an artifact of our English system of measure. It is totally different if the torque is measured in metric units. |
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Title: Re: Power to weight ratio and other speed info Post by shiphteey on 08/23/09 at 20:26:52 Charon, only the last couple of pulls had torque logged (off the coil) and I didn't convert it on the chart, I can do that next time. Again, I realized afterwards that my DIRTY STOCK air filter was still in there so running a little rich makes some sense. I gutted it tonight and can put it on the dyno in a couple days and do pulls with the gutted air filter followed immediately by pulls with a new clean replacement stock-type filter for some unifrom data across the board with comparision. Would you like fries with that? ;-) A. |
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Title: Re: Power to weight ratio and other speed info Post by Duane on 08/25/09 at 07:30:16 6B6065653F3E090 wrote:
ditto |
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Title: Re: Power to weight ratio and other speed info Post by Charon on 08/25/09 at 11:45:01 The thing about dyno runs, is that they are usually done at wide-open throttle. That's because most folks are interested in the maximum power and torque. Carburetors meter fuel mostly according to throttle position, not engine speed. So about the only air/fuel information you get is for wide open, as the engine accelerates. You will know whether the main jet is about right, but you will know little about anything else. To get more information you would have to make more runs at different throttle settings. Lower throttle settings will show less torque and power, but the A/F ratios might be interesting. The images seem to have vanished, but from memory it seems the A/F ratio stayed pretty constant. That would tell me the air filter isn't too restricted, or else the mixture would have gone richer as the engine speed increased. It would be nice to have access to a load dynamometer instead of an inertial one (Dynojet). Then you could pick an engine speed of interest, vary the throttle setting (and the dyno load to hold the speed steady) and see what the A/F ratio did at various throttle settings. |
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Title: Re: Power to weight ratio and other speed info Post by cursal on 08/25/09 at 12:14:12 65627D2E0 wrote:
My stock 1998 Savage shifts up at around 3400-3800 rpm. You can feel the torque peak through the first 3 gears. I get a little more rpm before 4th and hit that at 3400-4000 rpm. 5th gear I can feel it after I hit 50 mph and around 3400-3800 rpm, depending on what sort of road I'm on and if I'm going up or down a hill. My speeds and shifting are around 1st gear 0-15mph (3000 rpm) 2nd gear 15-25 mph (3400 rpm) 3rd gear 25-40 mph (3400 rpm) 4th gear 40-50/55 mph (3400-4000 rpm) 5th 50+mph (3400-4000 rmp) After 65mph (4200 rpm) She doesn't seem to have much more to give.... and the bike is shaken like nervous hula dancer. Fork stabilizers and re-jetting and new muffler (or just baffle?) is what I'm looking to do next. Got to get my cash right first. Next month or so. |
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Title: Re: Power to weight ratio and other speed info Post by verslagen1 on 08/25/09 at 13:25:14 Tkat $90 jet set $20 DJ straight pipe and home made baffle, priced less Tell your girl to cook tonight, you're staying in and watching a movie on the TV. |
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Title: Re: Power to weight ratio and other speed info Post by cursal on 08/25/09 at 14:55:11 Quote:
tkat http://www.tkat.com/forkbrace.html This? Jet set http://shop.ebay.com/i.html?_kw=savage&_kw=ls650&_kw=jet&_ckw=set&_ipg=&_trksid=p3286.m104.l1198 what's the difference with stage I, II, or III? As for Muffler What has the performance boost of DJ long shot, but has chrome and not a chop shop look? I like the look of the stock muffler, big beefy...just lack of power and sound...deep and louder would be better 8-) |
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Title: Re: Power to weight ratio and other speed info Post by verslagen1 on 08/25/09 at 15:00:22 get a lancer jet set, full range of jets for less more sound cheap use 1/4" drill on end plate, inbetween rivets more power get supertrapp |
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