| Author |
Message |
    
S2carl
| | Posted on Monday, April 09, 2001 - 11:03 am: | 
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Aaron,
Let me guess, you've been tinkering w/ your daughters Blast getting it ready for Bonniville????
LOL
Carl |
Travis
| | Posted on Monday, April 09, 2001 - 11:45 am: |
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RRRRRRRRRRRRRRRRRRRRRRRR
zoom fast.
Would you like fries with that Salt? |
Aaron
| | Posted on Monday, April 09, 2001 - 11:54 am: |
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I'm surprised someone hasn't picked this up yet, so I'll go ahead and give myself permission.
That's the LSR bike. Notice how the speed is consistent with our records. Still has the same sprockets on it.
Basically, I've been tuning it on nitrous. I got it all dialed in and ready to pull off the dyno and tear down, and I thought what the hell, let's toss in some bigger jets and see what happens. Got an impressive dyno sheet, for sure.
But I have no intention of running those jets at the salt, it's too much for it. Even if the motor lived, I seriously doubt we could keep it hooked up when we hit the button, that stuff is brutal when it comes on. So we'll have significantly less power at the event. Still should be able to nudge up those fuel class records though, they were done on just gasoline last year.
AW |
Tripper
| | Posted on Monday, April 09, 2001 - 11:58 am: |
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RRRRRRRRRRRRRRRRRRRRRRRR #50?
You wouldn't have posted the LSR bike, would you?
Oh what the hell, MotoGuzzi guys are too busy looking up each others pipes to look here. |
Tripper
| | Posted on Monday, April 09, 2001 - 12:03 pm: |
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you beat me. |
Aaron
| | Posted on Monday, April 09, 2001 - 12:05 pm: |
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Damn, shoulda given y'all just a little more time.
The Guzzi boys probably do lurk here. Doesn't matter, I won't be running that configuration, and far as I know, they're not interested in the fuel records anyway. Even if they are making a fuel effort, that's a pretty high bar. If they can do that, they deserve the records. I can't.
AW |
Rocketman
| | Posted on Monday, April 09, 2001 - 03:53 pm: |
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Ho Ho Ho and a bottle of rum. Someone f**ked up spinnin the drum.
Elsewhere on this board we have a 100" motor, that's 1638cc, projected to make 130 to 135 HP. I hope that's at the rear wheel !
Then we have another motor on this board, all of 91", that's 1491cc, and it makes a paltry 108 HP.
Ho ho ho, thank the powers of petroleum I've only got 100 horses from my pitiful 1204cc's.
I'm gonna get me a couple of big elastic bands and a garden roller. Hook it up to my grandads old Swiss watch, sit my Beast on top, and tune it with some Woolworths screwdrivers. Who knows, I might even get another ten horses  .
What's my chances ?
Rocket in England |
Jeffb
| | Posted on Monday, April 09, 2001 - 05:22 pm: |
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I had been waiting to post this because I am not finished tuning my bike, but since I brought it up myself in the photo section, here is some more info on my 91".
4" bore x 3-5/8" stroke
N9 cams
Stock throttle body and manifold modified to match S&S heads
CR 11.6:1
Powercommander W/heated O2
S&S Air cleaner, cut off
Super Trapp IDS with 16 disks and open cap
All runs made in fourth gear. (fifth is worth a couple of horse)
I need a less restrictive intake manifold and some more time tuning the fuel map. I have been using a wide band sensor, but it separate from the dyno so there are a lot of things to watch during a run. A race ECM was tried, but I think the lack of air flow didn't allow me to take advantage of the extra rpm. My goal is 115Hp.
Here is a graph of the 91" and the same bike bone stock. You will see that there are some obvious problems in the 91".
Rocketman,
I think what you are saying is that all dyno's are different. I have seen a well built and tuned 100" make 125hp on the same dyno I am using. 135 might be optimistic for a street engine, at least on the dyno I am using. |
Jeffb
| | Posted on Monday, April 09, 2001 - 05:34 pm: |
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Here is the dyno sheet
 |
Rocketman
| | Posted on Monday, April 09, 2001 - 07:19 pm: |
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Nah Jeff, all I'm saying is my old garden roller is probably as accurate as anything in America, providing of course, I use gran'pas trusty timer
Rocket in England |
Mikej
| | Posted on Monday, April 09, 2001 - 08:02 pm: |
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Nice watch Rocket. I've always wanted to visit England and get a hand made watch some day.
Anyway, with all this apparent variations in what are supposed to be calibrated test equipment, somehow deep down inside my head where I don't know what I know I've been thinking the variations are due to conversion factors and such. Bottom line as has been alluded to, dyno's are a tool to use at a specific time to adjust and test variations in components and state of tune. Two dyno's 4,000 miles apart, though they shouldn't be giving different readings, it shouldn't be too much of a surprise if they do vary. At least that's how I see the world thru the eyes of Mike.
Oh, and I finished doing my taxes, actually getting a few pennies back. I might just have to dyno-tune my own bike just to see how it reads. Of course if it comes back and tells me my bike is putting out 135+hp I won't dare to post the curve, I'll just fold up a printout and carry it under the seat. |
Aaron
| | Posted on Monday, April 09, 2001 - 08:17 pm: |
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Just thinking about it, in what ways could a dyno be off?
The way I understand it, it's running a stopwatch, timing how long it takes for each revolution of the drum. From that and the mass of the drum it can calculate torque and hp, and then it can correct those to sea level using environmental measurements that it makes automatically. Doesn't seem like an overly complex device to me.
So what could go wrong?
The timing? I don't believe it, that's pretty mature technology, crystal time references have been around forever.
The correction factors? Well, on models like mine, I could see it. I mean, it's got transducers for making the measurements and they could need calibration, although my documentation doesn't say anything about it. The numbers it's showing seem reasonable, though. The temps certainly make sense.
The mass of the drum sure as hell ain't likely to change.
If the bearings supporting the whole assembly were to wear and gain friction, it could certainly cause a change. In fact, I was told, by a very reliable source, that Dynojet changed bearing vendors during production and literally had a software change that went with it. People have been known to change their bearings, get the new style but neglect to get the corresponding software, and inadvertently see a change in hp.
But worn bearings would make it show less hp.
Hmm, how are those bearings on JH's dyno?
AW |
Mikej
| | Posted on Monday, April 09, 2001 - 09:11 pm: |
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Hmmm, I wonder if that could have been what was off on Hal's dyno last summer, it was reading low across the board, wasn't it? |
Rippin
| | Posted on Monday, April 09, 2001 - 09:41 pm: |
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Aaron
Is the old addage still true about using a trusty ol' vacum gage to set your best performance/gas milage by the highest reading at 55-60mph? Just wondered. |
Blake
| | Posted on Monday, April 09, 2001 - 10:29 pm: |
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Ron, et al:
The mass is included within the inertia constant the dyno uses. Inertia is just the rotational equivalent to mass (M).
For a hollow cylinder (most of what a dyno drum cosists) the inertia (I) for rotation about it's axis is...
I = ½M(ro2 - ri2) (the r's are the outer and inner radii, respectively)
And torque can be found, if you know the angular acceleration (a) by Newton's 2nd law...
T=Ia
(same as F=Ma for linear motion)
And you already know that we can find a by measuring the dyno drum's rotation (like distance in the linear world) versus time.
Delta (change in) distance (or angular displacement) over time gives us velocity (radians/s for rotational cogitatin'); then delta velocity over time gives us acceleration.
Using Henrik's calc integration function, ò , we can reverse that too if we want.
The integral of acceleration versus time ( òa dt ) would give us velocity (area under the acceleration versus time curve); the integral of the velocity versus time curve ( òV dt ) would give us distance. Or substitute the rotational system components just the same.
Similarly:
Where Power is delta work over time (derivative of work versus time.. dW/dt), we can conversely find work (energy put into a system) by integrating power with respect to time (finds the area under the power versus time curve).
You want the rest (how to find force/torque versus time from the above) let me know. But I may have to find a textbook.
The prior algebraic cruching to calc Rocket's HP gives a average for the whole run. If we want to look at continuous data, like from a dyno, we need to use the above calculus methods. The dyno just does it numerically in timy little increments, like once per drum revolution or once per 1/1000th of a second.
Sorry, I had a flashback to 2nd semester calc class.
Blake (hopelessly boring everyone with crap) |
Peter
| | Posted on Tuesday, April 10, 2001 - 04:32 am: |
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I remember a discussion a fair while back about something technical and Ferris posting a very funny response about becoming a jibbering mess and needing to smell the flowers and aim for the light. I wish I'd saved it so I could use it here!
Where did Ferris go?
PPiA
Blake.
Don't stop. I don't find this crap at all boring. |
Aaron
| | Posted on Tuesday, April 10, 2001 - 04:35 pm: |
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JeffB, great running bike, congratulations!
Blake, you oughta go into business making dynos. They're not that complex and they get a small fortune for them.
Rippin, I've never heard that story, but I'd be real suspect about anything that general. I also don't understand the suggested process. Are they going for minimum throttle opening to support a given speed? I guess that would make sense if you're only planning to go that speed. I tend to think one-dimensionally, hold the throttle wide open and go for the biggest number 
MikeJ, it sure seemed that way to me, but I had a big elevation change and may have missed on my jetting.
Peter, yep, I miss him too. |
Blake
| | Posted on Tuesday, April 10, 2001 - 08:00 pm: |
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Aaron, great idea. Who wants to help finance my startup? |
Court
| | Posted on Wednesday, April 11, 2001 - 05:07 am: |
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Blake:
Keep it coming.....you are causing flashbacks to some of my favorite classes AND you have just provided me fodder to send to the young'en to prove that what they are laboring over has practical application. I just hesitate for tehm to see all of us and figure out what it does to you. Keep it coming....keep it coming.....(only meaningful if you have ever heard Ray Charles do his only Rap hit...
You get serious, financing is available.
Court |
Xlwp
| | Posted on Wednesday, April 11, 2001 - 12:08 pm: |
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Aaron,
Have you considered using a progressive controller for the Nitrous, to keep it from coming on too hard when you hit the button?
Just a thought.
PB |
Aaron
| | Posted on Wednesday, April 11, 2001 - 12:30 pm: |
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Paul,
Yeah, it crossed my mind!
Just fits where the speedo was originally.
Unfortunately, it's maximum ramp time is only 9 seconds, I think these things are more made for drag racing. Not sure that's enough to keep the wheel from spinning.
Also, after 20 seconds total it resets, killing the nitrous and requiring a release & press of the button again and getting you a fresh 9 second delay. But I worked out a way to deal with that.
AW |
Peace
| | Posted on Wednesday, April 11, 2001 - 05:08 pm: |
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Rocket, been reading some past posts of yours, and having a bit of a snigger to myself. Your heads were skimmed by 30 thou, tightening up your squish, not only just to get a tighter squish but because your combustion chambers were reworked, and we wanted to keep your engine at 10:1 compression and streetable. With all the reliability problems you have experienced in the past we chose to use some caution on how far we took your engines state of tune.
Reading about a discussion you had recently concerning the difference between one persons 100hp and another here is something for you to think about, take two Buell engines, tune both to produce 100hp rear wheel, one uses redshift cams stock heads, the other stock cams but reworked heads, which do you think is the best?
P.S see you on Monday at the strip, Gazza's bikes run in and flying now. |
Rocketman
| | Posted on Wednesday, April 11, 2001 - 05:22 pm: |
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The one that breathes the best, but which one is it ?
Anyway, I've resigned now. My Nighthawk is ordered and I've asked 'em (Honda) to de-tune it. 35 RWHP is to much for anyone in my opinion.
FOR SALE
One slightly tuned S1W. Bags of carbon but no real power. Has potential to break sound barrier, if you tow it behind an F14 !
Quick sale, 40 bucks. No warranty implied or given. Buyer to collect.
Rocket in England |
Blake
| | Posted on Wednesday, April 11, 2001 - 07:54 pm: |
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Peace:
I'd guess that the engine with stock cams, but reworked heads would have better overall performance. |
Blake
| | Posted on Wednesday, April 11, 2001 - 07:55 pm: |
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Rocket:
You got a deal sprocket boy! |
Aaron
| | Posted on Wednesday, April 11, 2001 - 09:01 pm: |
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Blake: I agree ... it seems to me that good head work improves the cylinder fill over a broad rpm range, just look at Christensen's torque curve to see that.
Getting more fill with just cams will require more duration, with associated powerband shift upward. Lift ain't gonna do it, look at a stock head's flow sheet, it dies at about .500". More area under the curve could help, but fast ramp rates generally means more spring and more wear and tear.
Nope, give me head work any day.
AW |
Rocketman
| | Posted on Wednesday, April 11, 2001 - 09:31 pm: |
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Aaron : So how do you account for a stock motor with good head work versus a tuned motor with good head work, and both produce more or less equal HP and torque ?
You know where I'm going don't ya
Say, what's the chances of you bringing your Dynojet to Europe ? You could make a killing at Croix Should I bring my Woolworths screwdrivers ?
Rocket in England |
Aaron
| | Posted on Wednesday, April 11, 2001 - 11:16 pm: |
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How do I account for it? I have no idea. Without knowing all the details, anything I throw out there is a wild-assed guess. Hell, even if I knew all the details it could be a wild-assed guess. It may very well be measurement error for all I know.
Put your boat anchor in a box and send it over here!
AW |
S2no1
| | Posted on Wednesday, April 11, 2001 - 11:36 pm: |
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Rocket,
I've got a good home for those Dymag wheels!!!.
Arvel |
Jmartz
| | Posted on Thursday, April 12, 2001 - 01:49 pm: |
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RP
Have you tested the rims at speed? Any noticiable difference in acceleration when you have 20 fewer lbs. in your wheels. You must feel fortunate to posses those things. Watch out for pot holes. They are the reason I get a new wheel from time to time.
J |
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