Forums
New posts
Search forums
What's new
New posts
New media
New media comments
Latest activity
Media
New media
New comments
Search media
Members
Registered members
Current visitors
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
FJR Motorcycle Forums
FJR Parts & Accessories Discussions
Having my fuel injection cake and eating it too!
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Help Support Yamaha FJR Motorcycle Forum:
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Message
<blockquote data-quote="UselessPickles" data-source="post: 672683" data-attributes="member: 3256"><p>Manually tweaking a PCIII map is dangerous because you don't know how much you are affecting the air/fuel ratio. You could get the same gas mileage at 75mph as a stock FJR (what does a stock FJR get at that speed?) by using a map that is tuned to run at 14.7:1 AFR around 4000 RPMs between about 10 and 20% throttle. Unfortunately, you end up using that same area of the map when accelerating normally in lower gears (most noticeably 1st and 2nd gear), which causes some hesitation/surging as you pass through the lean area of the map. The stock system addresses this problem by having its base map tuned a bit richer than 14.7:1 so acceleration is smoother, but then enters a closed-loop mode under steady throttle/speed, using the narrow-band O2 sensor to maintain 14.7:1 AFR. I believe PCIII maps are generally tuned to 13.8:1 at 20% throttle and lower for a compromise between fuel economy and smoothness (if you use a DynoJet-supplied map or get a standard custom map made for your bike).</p></blockquote><p></p>
[QUOTE="UselessPickles, post: 672683, member: 3256"] Manually tweaking a PCIII map is dangerous because you don't know how much you are affecting the air/fuel ratio. You could get the same gas mileage at 75mph as a stock FJR (what does a stock FJR get at that speed?) by using a map that is tuned to run at 14.7:1 AFR around 4000 RPMs between about 10 and 20% throttle. Unfortunately, you end up using that same area of the map when accelerating normally in lower gears (most noticeably 1st and 2nd gear), which causes some hesitation/surging as you pass through the lean area of the map. The stock system addresses this problem by having its base map tuned a bit richer than 14.7:1 so acceleration is smoother, but then enters a closed-loop mode under steady throttle/speed, using the narrow-band O2 sensor to maintain 14.7:1 AFR. I believe PCIII maps are generally tuned to 13.8:1 at 20% throttle and lower for a compromise between fuel economy and smoothness (if you use a DynoJet-supplied map or get a standard custom map made for your bike). [/QUOTE]
Insert quotes…
Verification
Post reply
FJR Motorcycle Forums
FJR Parts & Accessories Discussions
Having my fuel injection cake and eating it too!
Top