MadMike
Moderator
FEAR THE BLACK FLAG!!!!!!!!
Posts: 6579
|
posted December 02, 2004 08:46 PM
quote:
quote:
I think the dyno you were on the operator sucked I would sue him for putting it on the dyno in the first place. he was a loser anyway his bike was sitting in the corner all broken down looking like crap
Like if this wasn't a total give away
LOL... I will be ready to come down and visit this spring.... I want to make some changes though...I will start with bearings... hehe.
____________
200-MPH CLUB MEMBER!
   
|
osti33
Needs a job
Posts: 2973
|
posted December 02, 2004 08:53 PM
quote:
quote:
quote:
I think the dyno you were on the operator sucked I would sue him for putting it on the dyno in the first place. he was a loser anyway his bike was sitting in the corner all broken down looking like crap
Like if this wasn't a total give away
LOL... I will be ready to come down and visit this spring.... I want to make some changes though...I will start with bearings... hehe.
Woo Hoo!! Count me in. Road trip!!! 
Had a blast last time. Can't wait to do it again.
I'm a little nervous about putting my bike back on the Cheeseman's dyno. I must have gotten lucky and dodged a bullet last time.
Just kidding J.C. I'd do it again in a minute!!
|
osti33
Needs a job
Posts: 2973
|
posted December 02, 2004 09:26 PM
quote:
LOL... I will be ready to come down and visit this spring.... I want to make some changes though...I will start with bearings... hehe.
LMAO! Bearings!!! I think that would be a good start... Your killing me here!
|
Johnnycheese
Pro
Posts: 1008
|
posted December 03, 2004 05:50 AM
quote:
quote:
quote:
I think the dyno you were on the operator sucked I would sue him for putting it on the dyno in the first place. he was a loser anyway his bike was sitting in the corner all broken down looking like crap
Like if this wasn't a total give away
LOL... I will be ready to come down and visit this spring.... I want to make some changes though...I will start with bearings... hehe.
bearings hell I keep them in stock .
I have to because the dyno keeps blowing up motors
____________
Builder and tuner of some of the fastest N.A. and P/A Hayabusas and ZX12 /14 in Texas
|
Ra12r
Zone Head
Posts: 919
|
posted December 03, 2004 09:13 AM
quote:
The really elegant function of the hydraulic plain bearing in a crankshaft is that when the crank rotates within the rod a "wedge" of oil is formed at the leading edge of the offset created by the rotation and the thrust. This wedge, which is constantly being replenished from behind, forms essentially a solid bearing surface made of oil. The only way this can fail is for the pressure and flow to drop below a point sufficient to keep the wedge in place. quote:
I agree, and have been trying to say this from several different ways. A mechanical oil pump supplied by sufficient oil is not going to fluctuate the pressure at a given RPM. But the wedge is still compromised and bearings are spun. Spun bearings are the failed mechanical item and that means the wedge was overcome by a stronger force so that direct contact on the bearing occurs. This opposing force is NOT the from the engine. I don't know why this is so complicated?!?! The engines flows the same A/F on rear wheel stand or a dyno at a given RPM. But you can run the engine almost forvever without a load, so please, the type and amount of load DOES AFFECT the conditions inside an engine. But you know this......
[Quote]Of course the clearances change, but no way in a manner that is any more stressful than when the wheel/countershaft/crankshaft is spinning against a continuous ribbon of road rather than one shaped like a drum[Quote]
Doug, according to your own answer, "clearances change" but then you say the external variables are equal. So what is producing the "change" since the oil pressure is a constant.
The amount of force required to turn a drum can be measured. The amount of force to roll a bike in neutral can also be measured. They are NOT equal. Yet, for some reason, educated minds here say they are?! Frankly i can turn my rear wheel with 1 finger, but as stated before NO ONE can turn the dyno wheel like that......
JC,,,,if the shoe doesn't fit then dont wear it. I understand that you or your anything in your shop CAN NOT be responsible because then you would be liable and that is not going to happen. (This is really a liability issue with a product that has a design flaw). quote:
nor is it supported by anyone that uses dynomometers of any kind with any regularity, or professionally.[quote} Liability is the primary reason why my premise is not supported!
They just took Vioxx off the market for the same "observation pattern" concerning an association with heart attacks. They ONLY noticed an association!!!! They did NOT prove it caused a heart attack. I notice the same type of association and I am crazy?!?! Yet the really funny part is that folks will blame the forces created by acceleration at the track for bearing failure but not acceleration on a dyno?!?! LOL..........prove it wasn't the dyno ......smile
What caused his "oil wedge" to fail at that predictable time?
Lastly, it is a know "rumor" that certain shops have "HAPPY" dyno's. This premise is based on a change to the "WEIGHT/RESISTANCE" of the dyno wheel. Why would the weight of the drum affect the HP output of an engine if the "LOAD RESISTANCE" is the same as the street and 100% engine output is 100% engine output??? Shouldn't the output of an engine be basically a constant? Especially when we see at the track that MPH for an engine is basically a constant. MPH varies slightly day to day and track to track. However, engine output can vary greatly on a dyno. So the dyno and the road is NOT EQUAL.
Irregardless of the perspective, Dyno's have a direct affect on an engine due to the type or amount of resistant force that is used to measure HP and Torque. The decision to use this type of design for engine performance measurement is/was a choice. It is not the only way! Anytime the test equipment is "not designed to affect" the test subject and it "does in fact affect the test subject", the design is flawed. This is a fundamental design flaw issue and is not brand or operator dependant.
This thread from conception was never intended to cause division. But I feel the paradims of perspective are now at an impass, I am tired.............. People can look at themselves, nature and our universe and still say there is no God, and God remains still and quiet, so who am I to say anything else.
|
slug
Pro
Out in search of my mind...
Posts: 1433
|
posted December 03, 2004 03:39 PM
quote:
I agree, and have been trying to say this from several different ways. A mechanical oil pump supplied by sufficient oil is not going to fluctuate the pressure at a given RPM. But the wedge is still compromised and bearings are spun. Spun bearings are the failed mechanical item and that means the wedge was overcome by a stronger force so that direct contact on the bearing occurs. This opposing force is NOT the from the engine. I don't know why this is so complicated?!?! The engines flows the same A/F on rear wheel stand or a dyno at a given RPM. But you can run the engine almost forvever without a load, so please, the type and amount of load DOES AFFECT the conditions inside an engine. But you know this......
this whole thing makes no sense...
let's see, the wedge was overcome, which means that the oil pressure/flow was insufficient to maintain.
now what happens when oil get shot? oh, it flows more easily..
if it flows more easily, then it takes higher VOLUME to maintain the same oil level
so what happens when that oil pump's volume rating is exceeded because the oil got so hot it flowed like water?
we are getting in to the realm of operator here...oops didn't cool the thing down...
[Quote]
Doug, according to your own answer, "clearances change" but then you say the external variables are equal. So what is producing the "change" since the oil pressure is a constant.
The amount of force required to turn a drum can be measured. The amount of force to roll a bike in neutral can also be measured. They are NOT equal. Yet, for some reason, educated minds here say they are?! Frankly i can turn my rear wheel with 1 finger, but as stated before NO ONE can turn the dyno wheel like that......
to be a GOOD comparison you would need to not measure the force to turn the back wheel, but the force to move the entire bike (since that is the "load" on the engine on the street)
then you would need to factor in the force required to move the air out of the way of the bike, another "load" on the engine on the road.
your basic premise is flawed beyond belief, and WE are the ignorant ones?
but, as an engine runs, the crankshaft deforms slightly...this is what causes the clearances to 'change'. what provides the FORCE to deform the crankshaft? the power stroke of the engine....
nothing else would act JUST on the bearing clearances. if the dyno WAS adding energy*** to that system, it would seem to me that the FIRST place to get that added energy would be the output shaft bearings, then transmitted internally by the clutch and drive gear....if you trash a rod bearing, the energy came from the combustion chamber, not the dyno....
***And since the dyno is a load, it is ROBBING energy from the engine, not adding to it.....
quote:
What caused his "oil wedge" to fail at that predictable time?
predictable? if it was "predictable" why did they not just rebuild the engine instead of trashing the cases too?
see your premise is that it is "predictable" based on your rpeconception that a dyno WILL destroy an engine. this leads to a self-fulfilling prophecy... which is definately NOT scientific in the least.
quote:
Lastly, it is a know "rumor" that certain shops have "HAPPY" dyno's. This premise is based on a change to the "WEIGHT/RESISTANCE" of the dyno wheel. Why would the weight of the drum affect the HP output of an engine if the "LOAD RESISTANCE" is the same as the street and 100% engine output is 100% engine output??? Shouldn't the output of an engine be basically a constant? Especially when we see at the track that MPH for an engine is basically a constant. MPH varies slightly day to day and track to track. However, engine output can vary greatly on a dyno. So the dyno and the road is NOT EQUAL.
actually, a lighter wheel WILL enhance the numbers due to the shorter time it takes to spin up.
this reduces the accuracy, and due to rounding the numbers WILL come out higher.
please, for the final time, explain to me HOW a dyno exerts MORE load on the bike engine, than it gets on the road.
PLEASE tell me how it is possible for the dyno to add MORE load to the bike than it gets riding on street.
now, after you are done with all of the BS that surely will follow, PLEASE answer this question:
Why is it that a dyno run, from 2000RPM in 4th gear, takes 2.5 seconds on my 600cc bike
why is it that on the road, if i WOT in 4th gear starting at 2000 rpm it will take me at LEAST 15 seconds to get to redline?
Now, tell me which is more load on the engine?
please explain this mystery, oh great and all-knowing one..
(that last line was a little sarcasm pointedly aimed at your last comments in the above post, the implications of which are slightly snide, bordering on outright arrogance....)
  
|
slug
Pro
Out in search of my mind...
Posts: 1433
|
posted December 03, 2004 03:53 PM
oh i forgot to go after the second half of your flawed point up there
quote:
Especially when we see at the track that MPH for an engine is basically a constant. MPH varies slightly day to day and track to track. However, engine output can vary greatly on a dyno. So the dyno and the road is NOT EQUAL.
that's rubbish....
what is the limit for top speed?
and what OTHER factors go in to the bike's top speed at different tracks?
what about gearing?
what about wind?
what about air temperature?
what about altitude?
all of these affect engine performance, ALL of these affect the final speed, and final performance
"engine output can vary greatly on the dyno"
on the same dyno? or different ones?
please clarify, because the comment is too vague to be useful
however i will attempt to adress the issue anyway
i have run my bike at 4 distinct times on the dyno.
2 different dynos
my output numbers have all been within 11HP of each other.
the difference between stock setup runs was nil.
the difference with new exhaust and jetting, +5hp of stock
the difference with stock setup and poor jetting, -6 HP of stock
if i toss the 2 oddball numbers out (poorly jetted, and full exhaust) the remaining 3 runs, done in a 4 year period, over the course of 30000 miles, all read within ONE HP of each other...
these are real results, REAL numbers, REAL charts....on 2 different dyno machines (and 2 different brands even) and over the course of a "normal" bike's lifetime.
i am willing to say that the NEXT run i get done, will be within 1HP of the others....
IF your machine shows that kind of power output swings, with NO OTHER CHANGES then there is a problem with the math....or you have a SEVERE engine management problem....
if your power output changes as result of a mod, or new fuel curve, then your argument is frivolous.
And when you are talking about drag strip runs, you should be aware that small changes in final speed require large changes in engine performance...
as such i cannot believe that you made such a blatant attempt to correlate constant drag top speed and changing engine HP readings
|
Spyral
Pro
Unpredictable individual.
Posts: 1071
|
posted December 03, 2004 07:14 PM
I have run my 12R on one dyno so far, two different times. First time the bike did 173.9, next run it did 174.5 RWHP. Then I put it on the dyno a week later, same dyno, but different conditions. Nothing was changed on the bike. It was a little more humid. It did 169.5 then 171.5RWHP. I was wondering if the ideal condition for a dyno run is a warmed up bike and cold ambient air? Me and some friends were discussing this and figured since the second run seems to always be higher if this was the case? I am going to take it to a different dyno to see how the numbers match up. I have to check the dyno sheets for the exact atmospheric conditions of the two different runs, but I believe the humidity was the only real difference.
____________
Now, I am become Death, the destroyer of worlds.
|
canadamaxxer
Pro
Posts: 1090
|
posted December 04, 2004 01:58 AM
Spyral:
Basically, the engine being an air pump, is effected quite a bit by temperature and humidity. The higher the air temperature, the less air that can be packed into the engine during a given stroke. This is what volumetric efficiency is all about.. Imagine your 12 engine (1200cc give or take, or 300cc per cylinder per stroke) running at a peak of about 110% volumetric efficiency. This means that for every full stroke the piston moves, the engine is taking in 330cc. That is really good. basically this is the premise behind any type of forced air induction (tunnel rams, ram air scoops, turbos, superchargers): inlreasing volumetric efficiency to increase horsepower.
The problem is that in a normally aspirated engine (primarily anyways), altitude (or effective altitude) varies as a result of effective air pressure based on temperature, humidity, and barometric pressure. You can call your local airport and often get that info on an hourly basis. I believe this term is "density altitude".
This means that despite the fact that you may be at 200 ft above sea level, on certain days the weather may be such that you are actually at a density altitude of 1500 ft or more above sea level. This means the engine is getting the barometric pressure of 1500 ft altitude pushing down on the air, which lowers volumetric efficiency and therefore horsepower. In some cases jetting (or in our case Powercommander settings) will help, but it can be really tough to try to adjust for the perfect mixture day after day.
You are pretty much right on the money though.....a cool day and a warm bike are a good pair to make good power...but always keep in mind that the numbers on an individual dyno are best interpretted against themselves: I have a dyno sheet to prove that I made over 210 HP on one of my 12R's. I do not trust those numbers relative to another dyno, but any gains I saw during tuning would still be shown relative to the baseline run I first saw.
I think this information is accurate, but it's very early, so I may have missing something........anyone feel free to fill in the blanks?
|
junior s
Pro
?
Posts: 1644
|
posted December 04, 2004 08:56 AM
volumetric efficiency is affected greatly as well by cam profiles and cam timing /overlap - resonance in the intake port and you're right 110% is awesome .
cool dry air , warm engine make the best power , cool humid air loses some . The water molecules in the humid air take the place of fuel , while this may cool the combustion temperature it won't really make as much power unless you are so close on your air fuel mixture to get detonation occurring on occasion , too lean at that point
The only way to compare one set of numbers against another is side by side back to back tests , without as much as the sky clouding over in between ....
Just my .02
____________
Get up off your ass and ride !!
|
Spyral
Pro
Unpredictable individual.
Posts: 1071
|
posted December 04, 2004 06:44 PM
Makes sense. I am going to a different dyno to have a custom map done. I imagine he will do a pull to ge a base line before he programs anything. I will keep you posted.
Thanks
____________
Now, I am become Death, the destroyer of worlds.
|
slug
Pro
Out in search of my mind...
Posts: 1433
|
posted December 05, 2004 05:01 AM
actually i would INSIST on a pull before starting, and a printout. that way you can SEE the difference instead of just taking his word on it ;P
|
MadMike
Moderator
FEAR THE BLACK FLAG!!!!!!!!
Posts: 6579
|
posted December 05, 2004 07:14 AM
Do 3 pulls before you change anything! as the bike warms up the power will increase.
MM
____________
200-MPH CLUB MEMBER!
|
Spyral
Pro
Unpredictable individual.
Posts: 1071
|
posted December 05, 2004 08:34 AM
I am taking it to either JEff at HPC in Lake City or Kevin at SMTW. I know Jeff does pretty thorough work and have gotten mixed reviews on Kevin. Either way, I will keep you posted as to how they do.
____________
Now, I am become Death, the destroyer of worlds.
|
jonwright
Needs a job
Posts: 2416
|
posted December 05, 2004 09:52 AM
What we have here is an extended exercise in mental masturbation.
|
TurboBlew
Moderator
BUSY DOING THE SCHIAVO
Posts: 4590
|
posted December 05, 2004 09:56 AM
Isnt it funny how you are always around for the money shot ol Jonny "appleseed" Wright???
____________
Official Charter Member of the RIDERS OF KAWASAKI MEMBERSHIP REVOCATION CLUB
Also a BadAss Internet Forum Moderator 4 Hire!! Come at me brah!
|
jonwright
Needs a job
Posts: 2416
|
posted December 05, 2004 10:00 AM
Don't think we've seen the money shot yet, there, TurboHandJobber!
And, you usually aren't that far behind, now are you?
You heard "masturbation" and your little ears perked up, didn't they?
|
Tearinitup
Expert Class
VP Code Monkey
Posts: 298
|
posted December 27, 2004 01:52 PM
 Edited By: Tearinitup on 27 Dec 2004 13:53
quote:
Dynojet rollers are (from what I've been able to find) approx 900 lbs.
True.... But we aren't trying to throw it... just spin it. You are really trying to compare bike weight to rotational inertia. If you run through the math (assuming you were to measure the inertia of a drum) you would actually see that the drum puts a load similar to about 450-600lbs on the street. Just Info.
|
dougmeyer
Needs a job
moderated
Posts: 2713
|
posted December 27, 2004 03:30 PM
Don't provoke 'em Tear. They're liable to start discussing this again.....
|
slug
Pro
Out in search of my mind...
Posts: 1433
|
posted December 27, 2004 06:44 PM
hehe
too late.
i still want to know why a dyno pull in 4th gear from 2000 rpm to redline takes >3 seconds, and why on the street it takes me 12-15 seconds to go from 2k to redline in 4th gear...
i wonder how thent he dyno is working the engine harder...
but the answer doesn't support the hypothesis so he won't answer this question ;P
|
dougmeyer
Needs a job
moderated
Posts: 2713
|
posted December 28, 2004 08:39 AM
Because the load imposed by the unmoving dyno is constant and the load imposed by the rising aero drag is exponentially greater as the vehicle speed increases. The output of the engine is the same in both cases but the work it is being asked to do is greater on the moving vehicle. That's why we need transmissions with multiple gears.
|
slug
Pro
Out in search of my mind...
Posts: 1433
|
posted December 28, 2004 03:23 PM
i wasn't asking YOU for the answer ;P
|
dougmeyer
Needs a job
moderated
Posts: 2713
|
posted December 28, 2004 03:52 PM
Oh, sorry. Sometimes I can't help myself. I'll shut up now....
|
slug
Pro
Out in search of my mind...
Posts: 1433
|
posted December 29, 2004 04:17 AM
|
|
|
HOME
NEW TOPIC