DYNO Numbers for Baggers???
Stellar HDF Member
Joined: Sep 2007
Posts: 2,459
Likes: 674
From: Vancouver Island B.C.
The dyno sheet shows WOT, or when you have the throttle open 100%. When you are cruising at 2500-3000 rpm your tp will normally be anywhere from 10-20% (the bigger the engine, the lower the tp). On a wot pull on the dyno the manifold pressure (map) will be around 100 kpa (depending on elevation). Cruising down the highway you will be around 40-45 kpa, again each bike will be a little different. A lot of the tables in your calibration are kpa/rpm based. When you are running down the highway at 3000 rpm you are in a completly different "area" of your calibration than when viewing a dyno sheet.
Road Warrior
Joined: Feb 2007
Posts: 1,730
Likes: 199
From: Vancouver BC
of course it does, the chart you get from your dyno run shows full throttle thru all rpms fom the start.
what it doesn't show is how much power you are making at part throttle at any given rpm.
what it doesn't show is how much power you are making at part throttle at any given rpm.
Road Warrior
Joined: Aug 2010
Posts: 1,788
Likes: 5
From: Tennessee
Cams are definitely your problem. 257s are race cams. My motor was built to run 1/4 miles at a time in a quick manner. Not cruising friendly to most riders. I'm one of those 0-80 jack rabbit types so it suits me. I love dumping the clutch in 2nd and doing a smokey burnout. If you keep the 257 cams you will shift a lot more than your buddies, but you will also out run most of them.
Road Warrior
Joined: May 2010
Posts: 1,294
Likes: 1
From: South FL
The dyno sheet shows WOT, or when you have the throttle open 100%. When you are cruising at 2500-3000 rpm your tp will normally be anywhere from 10-20% (the bigger the engine, the lower the tp). On a wot pull on the dyno the manifold pressure (map) will be around 100 kpa (depending on elevation). Cruising down the highway you will be around 40-45 kpa, again each bike will be a little different. A lot of the tables in your calibration are kpa/rpm based. When you are running down the highway at 3000 rpm you are in a completly different "area" of your calibration than when viewing a dyno sheet.
What I have meant before is, let's say, at 3000 RPM, the Dyno says 50 HP/100 ft/lbs, for instance, then while riding at 3000 RPM, then engine will produce maximum 50 HP, or less.
SO, the 3000 RPM on the Dyno should be the same as 3000 RPM on the speedometer, regardless the TP.
Please correct me, if that is the case.
Last edited by jackhis; Feb 16, 2012 at 01:12 PM.
Road Warrior
Joined: Feb 2007
Posts: 1,730
Likes: 199
From: Vancouver BC
Thanks for the info, but it does not apply to my question.
What I have meant before is, let's say, at 3000 RPM, the Dyno says 50 HP/100 ft/lbs, for instance, then while riding at 3000 RPM, then engine will produce maximum 50 HP, or less.
SO, the 3000 RPM on the Dyno should be the same as 3000 RPM on the speedometer, regardless the TP.
Please correct me, if that is the case.
What I have meant before is, let's say, at 3000 RPM, the Dyno says 50 HP/100 ft/lbs, for instance, then while riding at 3000 RPM, then engine will produce maximum 50 HP, or less.
SO, the 3000 RPM on the Dyno should be the same as 3000 RPM on the speedometer, regardless the TP.
Please correct me, if that is the case.
Road Warrior
Joined: Aug 2010
Posts: 1,788
Likes: 5
From: Tennessee
Thanks for the info, but it does not apply to my question.
What I have meant before is, let's say, at 3000 RPM, the Dyno says 50 HP/100 ft/lbs, for instance, then while riding at 3000 RPM, then engine will produce maximum 50 HP, or less.
SO, the 3000 RPM on the Dyno should be the same as 3000 RPM on the speedometer, regardless the TP.
Please correct me, if that is the case.
What I have meant before is, let's say, at 3000 RPM, the Dyno says 50 HP/100 ft/lbs, for instance, then while riding at 3000 RPM, then engine will produce maximum 50 HP, or less.
SO, the 3000 RPM on the Dyno should be the same as 3000 RPM on the speedometer, regardless the TP.
Please correct me, if that is the case.
Road Warrior
Joined: Feb 2007
Posts: 1,730
Likes: 199
From: Vancouver BC
don't think that's what he's asking? i think he was asking if the rpms on a dyno would be the same as what was shown in the tach, regardless of tp. obviously tq and hp is going to be affected by tp.
4th Gear
Joined: Mar 2010
Posts: 8
Likes: 0
i would be happy with 40 mpg. have over 10k on this setup. maybe have other issues, I am on my 4th (you read that correct fourth) throttle body in less than 3 years. the last HD shop found some bad sensors, we will see if it helps when the weather gets better.
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Road Warrior
Joined: May 2010
Posts: 1,294
Likes: 1
From: South FL
Again, the "riding range RPM" is what counts, as that is the real HP, and torque is produced at that RPM and the TP relatively. Obviously, the power (HP & Torque) will be lesser than the reading from Dyno.
I am wondering whether anyone has done the Dyno at 20%, 30%, and 50% TP, rather than 100% WOT.
Stellar HDF Member
Joined: Sep 2007
Posts: 2,459
Likes: 674
From: Vancouver Island B.C.
Sure, that's part of tuning. 0,2,5,7,10,15,20,25,30,40,60,80 and 100% tp's, each cylinder. While you can look at torque and hp you are looking at the afr line to calibrate the ve tables. Here is before and after afr lines at 20,40 and 60. Target afr for tuning is 13.5 to reference a straight line and then changed to different values once calibrated.