ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 03-03-2011, 11:06 AM   #91
midlman OP
Adventurer
 
midlman's Avatar
 
Joined: Nov 2007
Location: PacNW
Oddometer: 25
Quote:
Originally Posted by larryboy View Post
Yes, they get you back to a crank reading...a little misleading, but the whole tune on the same dyno still works and is a great tool. Do you really want to go looking for power with 85,000 on the clock?
Funny you ask...the bike runs great, but I always tinker...so why not fix it till it's broken LOL I've even tossed around the idea of dual plugging/40mm bings/exhaust etc..
__________________
Tom
91 BMW R100 GS/PD
04 Ducati 998 Matrix edition
93 Kawasaki ZX-11D
midlman is offline   Reply With Quote
Old 03-03-2011, 01:55 PM   #92
Lornce
Lost In Place
 
Lornce's Avatar
 
Joined: Aug 2003
Location: Way Out There.
Oddometer: 17,341
Quote:
Originally Posted by larryboy View Post
Do you really want to go looking for power with 85,000 on the clock?
Sure.

Why not?


Lornce is offline   Reply With Quote
Old 03-03-2011, 02:18 PM   #93
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,002
Quote:
Originally Posted by larryboy View Post
Yes, they get you back to a crank reading...a little misleading, but the whole tune on the same dyno still works and is a great tool. Do you really want to go looking for power with 85,000 on the clock?
What model Dynojet is suppose to get you back to a crank reading? Is it an option an the printout? I think their inertia dynos read high but not 20% high. Does their software have an at the crank button? No one has ever showed it to me. Is it a new feature? Where did you get the 20% figure. What about Dynojet brake dynos? They don't just make inertia dynos. Some don't even consider an inertia dyno as being a real dyno. Torque isn't really measured on an inertia dyno. It is estimated by a computer.
supershaft is online now   Reply With Quote
Old 03-03-2011, 02:51 PM   #94
anotherguy
Beastly Adventurer
 
anotherguy's Avatar
 
Joined: Jun 2009
Location: the hills
Oddometer: 5,879
Any of you guys experienced operators? 'Cause some of that stuff is just plain wrong.

You can do a negative run on a DynoJet and figure parasitic drag but it's not part of a roll on run. You must go into the software and select it. On some bikes it's a bad idea to do. Like a 2 stroke.


The DynoJet uses drum weight/diameter,gear ratio,RPM and time to calculate HP.
__________________
A lie has no feet......it can't stand alone.............
Jason Newsted
anotherguy is offline   Reply With Quote
Old 03-03-2011, 04:28 PM   #95
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,002
I'm not! I have helped with many a dyno run but I have never actually run the dyno.

Oops! Does Dynojet ONLY make inertia dynos? I thought their brake dynos were eddy current dynos? I don't understand how an inertia dyno brake works? I guess it is a combo electric/enertia that still depends on a computer model reading?

Back in the early seventies, our shop's dyno had a torque meter and a tach. No computer. No printer. Of course, it wasn't an inertia dyno. They hadn't been invented yet? If I understand it right, inertia dynos HAVE to have a computer?

supershaft screwed with this post 03-03-2011 at 04:38 PM
supershaft is online now   Reply With Quote
Old 03-03-2011, 05:01 PM   #96
Lornce
Lost In Place
 
Lornce's Avatar
 
Joined: Aug 2003
Location: Way Out There.
Oddometer: 17,341
Quote:
Originally Posted by supershaft View Post
I'm not! I have helped with many a dyno run but I have never actually run the dyno.

Oops! Does Dynojet ONLY make inertia dynos? I thought their brake dynos were eddy current dynos? I don't understand how an inertia dyno brake works? I guess it is a combo electric/enertia that still depends on a computer model reading?
As far as I understand it, the Dynojet dynos work with a speed sensor tracking speed/acceleration of the drum, which is a known weight.

All power and torque figures are derived by the dyno's computer from that collected acceleration data and monitored engine RPM.


Anyone know different?

Lornce is offline   Reply With Quote
Old 03-03-2011, 06:27 PM   #97
anotherguy
Beastly Adventurer
 
anotherguy's Avatar
 
Joined: Jun 2009
Location: the hills
Oddometer: 5,879
You have the gist of it. The load control DynoJets are hybrids. It's an eddy current brake used to load the engine for writing maps but isn't capable of steady state torque readings. It has a load cell that needs to be calibrated via an arm and weights. So it's physically capable of it. Not sure why they didn't go all the way.

It really doesn't matter (within reason) how accurate the numbers are as long as they're consistent. I don't consider it done until I get 3 consecutive runs with the same result. It's use is as a comparator so you can see the results of changes. An increase/decrease will give evidence of the path your on being right..................or not.

The DynoJet uses RPM,gearing and the acceleration rate from A to B to calculate the numbers. The RPM comes from an inductive sensor attached to a plug wire. Gearing is calculated by RPM vs. drum speed rate that is read via Hall Effect sensors. On set up it asks how often spark occurs,i.e. 180/360/720 degrees to help determine gearing. The software is calibrated for each machine via the drum serial number that allows them to determine the exact weight and diameter via records from manufacturing. The DynoJet dyno is better than it's detractor would have you believe. It's a solid tool that in the right hands allows the best to be extracted from and engine. The operator is the standard that makes it right. A good operator takes care of his machine and knows how to use it.

That being said notice the Factory Pro EC997 is my favorite. It's faster,lighter and easier to get consistent results from. It uses a far more reliable 5 gas analyzer vs. the DynoJet O2 sensor which has serious shortcomings. However those standards come with a price. A very steep price.
__________________
A lie has no feet......it can't stand alone.............
Jason Newsted
anotherguy is offline   Reply With Quote
Old 03-03-2011, 07:29 PM   #98
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,002
I am guessing the Pro Flow is an eddy current? Does anybody still use hydraulic? I would think hydraulic dynos would be the most consistent?

It baffles me why Dynojet didn't go all the way with their brake dyno's. I would think steady state would occasionally be handy.
supershaft is online now   Reply With Quote
Old 03-03-2011, 08:50 PM   #99
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,002
I have had people tell me that they thought their dyno itself changed more than a little when it warmed up and then got hot. It seems to me that hydraulic would do that the least.
supershaft is online now   Reply With Quote
Old 03-04-2011, 08:14 AM   #100
anotherguy
Beastly Adventurer
 
anotherguy's Avatar
 
Joined: Jun 2009
Location: the hills
Oddometer: 5,879
It's the engine that makes the difference. As the insides heat sink it reaches an equilibrium. That's accounted for in the engineering/design phase of development. Ever held a Harley TC88 cylinder head? Massive. Designed to hold the heat for emissions reasons. Takes 3-4 WFO runs after a 5 minute warm up to reach true operating temperature.
__________________
A lie has no feet......it can't stand alone.............
Jason Newsted
anotherguy is offline   Reply With Quote
Old 03-06-2011, 05:20 PM   #101
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,002
Everyone that told me that about their dyno was full well aware of the effects of the engine getting hotter. They were talking about the dyno itself.
supershaft is online now   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 12:51 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014