110 vs 103 Dyno Comparison

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Sep 23, 2010 | 02:23 PM

#21

mtclassic

Outstanding HDF Member

Joined: Oct 2007

Posts: 3,437

Likes: 15

Quote:

Originally Posted by harleytuner

For the record, I wasn't putting your OP down, just informing ou about the differn't correction factors. As far as the "wavy" lines go, I can't see what the smoothing is, it's in the top right corner right by the correction factor. The C/F is a unit of measure, think of it like standard and metric tools. in the U.S. S.A.E. is the unit of measure we use on the dyno. STD gives higher results, around 4% or so. The smoothing factor is usually set at 5, if the smotthing factor is 5 and you still have the choppy lines, your timing could be off. Your 103 was run in horrible conditions, so that didn't help you any either. Just remember, the dyno is just a tool, used to tune your bike. Other than that it isn't worth anything except to give a guy bar stool bragging rights. Somebody mentioned here that the 103 wouldn't do anything but look at the 110's taillights. Depends, if the 110 was in an Ultra and the 103 was in a dyna i'd beg to differ.

Anyways, welcome to the forums. I remember when my status was "hang around", heck, everybody here was hang around once to, right?

I have seen correction factors higher and in my part of the country it is rare to see a C/F lower then about 1.08 or so due to elevation and bad air. I called Dyno Jet and they said that is 100% normal for the conditions. I dynoed a bike at 3300 feet with a correction factor of 1.13 and took it to sea level (portland) and correction factor was .99 (no changes to the bike) and both 250i's and the .99 graph showed better numbers.

Sep 23, 2010 | 08:30 PM

#22

producer

Road Master

Joined: Jan 2008

Posts: 853

Likes: 5

From: Mnpls MN

That's the way that I chose to address the OP. He hasn't objected yet.

By the way Tatoo 1964-hang around, thanks for posting this comparison for everyone to chew on. It's a good one. I've learned some things today and it even brought back some recent memories.

Quote:

Originally Posted by jeff.georgalas

'Ya, what's up with that "hang around" term?

Sep 23, 2010 | 10:58 PM

#23

thereal142

Road Captain

Joined: Sep 2007

Posts: 602

Likes: 51

From: central MN

To say that STD will always read 4% higher than SAE is wrong, at least as I understand it. I have seen back to back runs where one is SAE and one is STD where the STD shows HIGHER numbers, especially if it is really humid. Also, what is so horrible about the 103's run conditions? I always figured hot and humid was bad, hot and dry much better........

Sep 24, 2010 | 02:33 AM

#24

davewear

Road Warrior

Joined: Feb 2007

Posts: 1,730

Likes: 199

From: Vancouver BC

SAE and STD are just ways to correct for weather conditions. STD allows for higher pressure and cooler air than SAE which means STD results will always be higher than SAE.

Sep 24, 2010 | 06:11 AM

#25

Faast Ed

Banned

Joined: Sep 2009

Posts: 7,580

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From: The Internet (& Dyer, Indiana)

Quote:

Originally Posted by thereal142

You can change a map in Winpep 7 from SAE to STD and the numbers will jump accordingly (you can do this after the run even).

Not sure if there is a set rule or set percentage,.... but it's always been around 3 + 3 on the ones that I played around with.

Sep 24, 2010 | 07:59 AM

#26

Mike

Ultimate HDF Member

Joined: Jun 2009

Posts: 6,786

Likes: 40

From: Centralia, Wa

Over a fairly wide range of atmospheric conditions (air pressure and temperature) STD will read roughly 2.6 percent higher than SAE on average. To convert STD to SAE, a reasonable estimate is to multiply the STD numbers by .974. Part of the problem is that the reference conditions for STD correction has changed over time. The reference temperature has changed, and the assumed mechanical efficiency has also varied between 85 and 100 percent. A few years ago, the difference between STD and SAE was even greater, more like 4.7 percent. A somewhat loose definition for the STD correction is one reason SAE has become the generally preferred correction.