Dyno results and elevation interpretation. - Star Motorcycle Forums: Star Raider, V-Max, V-Star, Road-Star Forum
 
LinkBack Thread Tools Display Modes
post #1 of 4 (permalink) Old 12-27-2011, 07:22 PM Thread Starter
Senior Member
 
TheBrain's Avatar
 
Join Date: Dec 2009
Location: Redneck Minnesota
Posts: 396
Dyno results and elevation interpretation.

Hi All, i was wondering if anybody has Dyno knowledge/experience. the reason i ask is i ran on a dyno when i was at Sturgis. the elevation at Sturgis is 3650 ft. my question is this. on the bottom of the dyno sheet it shows the air fuel mixture. as you can see, the upper RPM range the bike starts to run very rich. this is the stock ecm. no changes. would the air fuel mixture be leaner at Minnesota elevation 935 ft? everybody says the stock settings are lean but i am showing rich at WOT which i believe is a fixed loop (or something like that). if you have any input please let me know what you think.
Attached Thumbnails
Click image for larger version

Name:	2007 Stratoliner Dyno Chart at 2011 Sturgis2.jpg
Views:	146
Size:	85.8 KB
ID:	1350  

R.I.P
2007 Stratoliner "S"
Totaled out on 8/14/17 at 69,985 miles.
She was Bad Ass, It has cool Brain stuff in it.
K&N, BAM, BRA Mod (only one on the planet),
Stock 2:1 header pipe and Roadhouse Slip-on muffler
I loved my Strat
TheBrain is offline  
Sponsored Links
Advertisement
 
post #2 of 4 (permalink) Old 12-27-2011, 11:36 PM
Senior Member
 
hdeater113's Avatar
 
Join Date: Mar 2011
Location: rainy side of washington state now reside in Blackfoot,Idaho
Posts: 1,452
My thought would be there is not that big a change in elevation that the computer couldn't make up for.In theory the lower elevation should run leaner and the high elevation run rich less air.Now the stock computer may be set up to run rich on wot so we won't burn a piston from running too lean.Just my thoughts of an old mc rider.

2007 Stratoliner S
Reckless batwing
Sony am/fm cd mp3 4 speakers w/500 watt amp,8in sub
12 inch ape hanger bars
Roadhouse slip on exhaust
K&N air filter with lid mod
Cobra Fi2000 powrpro auto tuner
Kuryakyn mustache bar
Corbin low profile solo seat
LED running lights front and rear
21 inch chrome raider front wheel
200 tire on the rear
113 Hd eating tire smoking cubic inches
hdeater113 is offline  
post #3 of 4 (permalink) Old 01-03-2012, 04:14 PM
Senior Member
 
dcody40's Avatar
 
Join Date: Aug 2011
Location: Westminster Maryland
Posts: 294
In theory, Air/fuel mixture should be the same at any altitude.

My take on the air/fuel mixture, knowing we're ECU controlled, electronic fuel injection, and in a perfect world, changing from near sea level to less than 4000 above sea level should not be an issue with power on any modern engine. Pilot's use a mixture control for peak EGT on a gauge, for keeping the engine happy while flying at all altitudes.
So my idea would be the power output curve should stay close to the same on a properly setup engine. Also keeping things in order here, our light General avaition aircraft are using 30's technology with the engines, Magneto's, dual plugs per cylinder, manual throttle bodies (fuel injected) or carbs, manual mixture controls and commonly fly from sea level to 12k.
I hope this don't confuse the issue here.
EGT is Exhaust gas temp.

OH and the idea of making our monster engines go rich for cooling and protection at near the max designed output is a valid point. The engineers knowing how we tweak and modify our engines, I'm sure there are some limits in there somewhere.
I did find my RPM limit in 4th last week, didn't realize how different the bike sounds when I'm wearing my full face helmet and balaclava. OOPs. can't go there. I am planning on using my helmet cam to watch my GPS for real speed measures as I don't want to be looking down so far with a full face helmet blocking my view of the speed indicator. I'll post it oneday. I already know my speedo is off a few miles. Mine reads about 4MPH faster than the GPS so it's protecting me in the long run.

Just for info and fun, our aircraft engines are air cooled, most are 4/6/8 opposed cylinders, and designed for 1/2 HP per Cubic inch.
All typical Lycomings and Continental use two plugs per cylinder for redundant ignition, they all have dual magneto's. And can run on one as designed in the years 20-30's. No DC power required other than for the starter.

Enjoy.

07 Stratoliner S with MS Batwing, MS lowers, Buck lowers, custom large trunk rack, King tourpack trunk, air horn, See me Now tail light and headlight pulser mods. Led lighting all over. Night rider tail light setup on the trunk.

Last edited by dcody40; 01-03-2012 at 04:24 PM. Reason: typo
dcody40 is offline  
Sponsored Links
Advertisement
 
post #4 of 4 (permalink) Old 01-03-2012, 08:40 PM Thread Starter
Senior Member
 
TheBrain's Avatar
 
Join Date: Dec 2009
Location: Redneck Minnesota
Posts: 396
I wasn't sure.

Quote:
Originally Posted by dcody40 View Post
My take on the air/fuel mixture, knowing we're ECU controlled, electronic fuel injection, and in a perfect world, changing from near sea level to less than 4000 above sea level should not be an issue with power on any modern engine. Pilot's use a mixture control for peak EGT on a gauge, for keeping the engine happy while flying at all altitudes.
So my idea would be the power output curve should stay close to the same on a properly setup engine. Also keeping things in order here, our light General avaition aircraft are using 30's technology with the engines, Magneto's, dual plugs per cylinder, manual throttle bodies (fuel injected) or carbs, manual mixture controls and commonly fly from sea level to 12k.
I hope this don't confuse the issue here.
EGT is Exhaust gas temp.

OH and the idea of making our monster engines go rich for cooling and protection at near the max designed output is a valid point. The engineers knowing how we tweak and modify our engines, I'm sure there are some limits in there somewhere.
I did find my RPM limit in 4th last week, didn't realize how different the bike sounds when I'm wearing my full face helmet and balaclava. OOPs. can't go there. I am planning on using my helmet cam to watch my GPS for real speed measures as I don't want to be looking down so far with a full face helmet blocking my view of the speed indicator. I'll post it oneday. I already know my speedo is off a few miles. Mine reads about 4MPH faster than the GPS so it's protecting me in the long run.

Just for info and fun, our aircraft engines are air cooled, most are 4/6/8 opposed cylinders, and designed for 1/2 HP per Cubic inch.
All typical Lycomings and Continental use two plugs per cylinder for redundant ignition, they all have dual magneto's. And can run on one as designed in the years 20-30's. No DC power required other than for the starter.

Enjoy.
I agree with you as far as running at less than WOT but i think i read somewhere that when at WOT the bike doesnt run off the O2 sensor but is in a closed loop ( i think this means hard programmed) fuel mixture. the reason i bring this up is because my bike is running way rich at 4500 rpm and higher. there would be more power made with the correct AF ratio. If i was at sea level i would get denser air and it might lean it out some which might make more power in the closed loop condition. also it could be a sign of inadequate inlet air. in essence i'm choking the bike. if it is a restriction i can raise the top cover and tank a bit more. if it is altitude them maybe i shouldn't mess with it. they make a real time O2 sniffer that you can install. read about it in my Car Craft magazine. with this unit a guy with a power commander could fine tune your own bike at any time as all you would have to do it look at the gauge and mentally log the RPM where it runs out of spec. i think the thing cost a 100 bucks. less than a dyno run and you have it all the time. getting off track a bit. mainly i'm trying to figure out if i need to raise the top cover of the airbox more due to restriction or not because of altitude.

R.I.P
2007 Stratoliner "S"
Totaled out on 8/14/17 at 69,985 miles.
She was Bad Ass, It has cool Brain stuff in it.
K&N, BAM, BRA Mod (only one on the planet),
Stock 2:1 header pipe and Roadhouse Slip-on muffler
I loved my Strat
TheBrain is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Star Motorcycle Forums: Star Raider, V-Max, V-Star, Road-Star Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome