Go Back   Harley Davidson Forums > General Harley Davidson Forums > General Harley Davidson Chat
Sign in using an external account
Register Forgot Password?
Search


General Harley Davidson Chat Forum to discuss general Harley Davidson issues, topics, and experiences.
Sponsored by: J&P Cycles

Reply
 
 
 
P
 
Thread Tools Search this Thread
  #1  
Old 02-12-2008, 07:26 PM
rde rde is offline
Road Captain
Join Date: Nov 2005
Location:
Posts: 567
Default Stock 96 Twin Cam Hp and torque

I was looking through my owners manual the other day and noticed that the listed torque for a stock 96@ 3500 RPM is 92.60 ft-lbs. That seemed rather optimistic, so I thought I'd check around.
At my dealership they had pulled a few stockers on a dyno in 07 at were getting 77.87 ft-lbs @ 3500 with a maximum 0f 62.61 Hp.

That's a pretty big difference. So what is the values for a stock 96? I'd like to know what the ballpark is before I get my bike dyno'd in a couple weeks.
__________________

2008 Road King Classic
SE slip ons & SE Air Cleaner, SERT
ABS,Zumo 450,Corbin Classic Solo,
Reply With Quote
  #2  
Old 02-12-2008, 08:57 PM
bryan72 bryan72 is offline
Prospect
Join Date: Jan 2008
Location:
Posts: 111
Default RE: Stock 96 Twin Cam Hp and torque

the 92.60 figure is what the motor puts out by itself, no tranny, no drive, no wheel, etc..
a dyno measures at the rear wheel, the numbers there are always lower because you lose some power pushing the drive train around.
Reply With Quote
  #3  
Old 02-13-2008, 03:26 AM
davewear's Avatar
davewear davewear is offline
Road Master
Join Date: Feb 2007
Location: Vancouver BC
Posts: 1,157
Default RE: Stock 96 Twin Cam Hp and torque

yup the manual will show torque at the crank, dyno shows torque at rear wheel. you care about the dyno numbers.
__________________
...seize the dave...

have a nice dave
'09 RG, monster ovals, pcv, SE ventilator, Fuelmoto headpipe, TW 5-6 cams, J&M 7.25 Rokkers & 250W Amp.
Reply With Quote
  #4  
Old 02-13-2008, 03:36 AM
99octane 99octane is offline
Road Warrior
Join Date: Dec 2007
Location:
Posts: 1,430
Default RE: Stock 96 Twin Cam Hp and torque

A modern dyno has to take tranny into account.
You measure both power at the wheel and power at the crank.
You accelerate and get the torque and power curves (they are actually the same, power is derived from torque multiplied by rpm and a constant).
Then you pull the clutch and leave the bike decelerate by itself. Thedyno measures this deceleration and calculates the tranny internal friction and energy waste, then it sums it up to the measured wheel power to give the crank power.
There are some subtleties to the whole process, though.
Wheel must not skid on the drum.
The action of the wheel induces vibrations, which get measured and must be filtered. A good filtering program will smooth out the noise without smoothing out the measurements. A good dyno graphic will show fluctuations, because a real engine doesn't rev up and rise in power in a perfect way. We can't perceive it, but the dyno does.
If the curve is a perfectly smooth rising curve, chances are the dyno data has been over-filtered and is not as good as it should.
Cooling is also important. A good dyno should grant a good cooling action.

__________________
= TEMET NOSCE =

I listen to the music of the machine.
Reply With Quote
  #5  
Old 02-13-2008, 08:03 AM
rde rde is offline
Road Captain
Join Date: Nov 2005
Location:
Posts: 567
Default RE: Stock 96 Twin Cam Hp and torque

Quote:
A modern dyno has to take tranny into account.
You measure both power at the wheel and power at the crank.
You accelerate and get the torque and power curves (they are actually the same, power is derived from torque multiplied by rpm and a constant).
Then you pull the clutch and leave the bike decelerate by itself. Thedyno measures this deceleration and calculates the tranny internal friction and energy waste, then it sums it up to the measured wheel power to give the crank power.
There are some subtleties to the whole process, though.
Wheel must not skid on the drum.
The action of the wheel induces vibrations, which get measured and must be filtered. A good filtering program will smooth out the noise without smoothing out the measurements. A good dyno graphic will show fluctuations, because a real engine doesn't rev up and rise in power in a perfect way. We can't perceive it, but the dyno does.
If the curve is a perfectly smooth rising curve, chances are the dyno data has been over-filtered and is not as good as it should.
Cooling is also important. A good dyno should grant a good cooling action.
That was helpful information.

So what can you expect to see in a stock 96 engine at the rear wheel? Is it close to the numbers I quoted:
78 ft-lbs torque and 63 Hp @ 3500 RPM?
__________________

2008 Road King Classic
SE slip ons & SE Air Cleaner, SERT
ABS,Zumo 450,Corbin Classic Solo,
Reply With Quote
  #6  
Old 02-13-2008, 09:47 AM
99octane 99octane is offline
Road Warrior
Join Date: Dec 2007
Location:
Posts: 1,430
Default RE: Stock 96 Twin Cam Hp and torque

63 wheel HP vs. 95 theoretical cranck HP seem to me a LOT of dispersion.
It's over 33%, and that's more than a 4wd car typically has, with three differentials, two driveshafts and four wheels.
I'm not familiar with usual internal dispersion of a motorcycle drivetrain, but for a two-wheel-drive car it usually is between 18 and 22%, and there's the differential in the middle...
So, 63 seems a little low to me, but I could be wrong.
__________________
= TEMET NOSCE =

I listen to the music of the machine.
Reply With Quote
  #7  
Old 02-13-2008, 09:50 AM
sportncruise sportncruise is offline
Road Captain
Join Date: Oct 2007
Location:
Posts: 508
Default RE: Stock 96 Twin Cam Hp and torque

Quote:
ORIGINAL: 99octane

63 wheel HP vs. 95 theoretical cranck HP seem to me a LOT of dispersion.
It's over 33%, and that's more than a 4wd car typically has, with three differentials, two driveshafts and four wheels.
I'm not familiar with usual internal dispersion of a motorcycle drivetrain, but for a two-wheel-drive car it usually is between 18 and 22%, and there's the differential in the middle...
So, 63 seems a little low to me, but I could be wrong.
I only see the listed TQ not HP so the relation is 96 crank 77 wheel.
__________________

08 Night Train
ThunderMax w/AutoTune
Arlen Ness Big Sucker
Skull Air Cleaner Cover
D&D 2-1 Fat Cat exhaust
HD Mini Tach
HQ 500 Cam's
Reply With Quote
  #8  
Old 02-13-2008, 09:59 AM
jeeplite jeeplite is offline
Hang Around
Join Date: Aug 2007
Posts: 39
Default RE: Stock 96 Twin Cam Hp and torque

I have a 07 Springer softail classic(B engine 96) with Sert, SE Touring slipons, and SE a/c. It was Dyno tuned and was 64 Hp and 79 Tq, I thought I should get a little more than that but the "B engine won't make as much Hp as a rubber-mount with same equipment. Sure runs smooth though....
It was making 62 Hp and 78 tq with just the Sert maps before the Dyno tune, hate to think what the stock output is!!!!!
Reply With Quote
  #9  
Old 02-13-2008, 10:08 AM
sportncruise sportncruise is offline
Road Captain
Join Date: Oct 2007
Location:
Posts: 508
Default RE: Stock 96 Twin Cam Hp and torque

Quote:
ORIGINAL: jeeplite

I have a 07 Springer softail classic(B engine 96) with Sert, SE Touring slipons, and SE a/c. It was Dyno tuned and was 64 Hp and 79 Tq, I thought I should get a little more than that but the "B engine won't make as much Hp as a rubber-mount with same equipment. Sure runs smooth though....
It was making 62 Hp and 78 tq with just the Sert maps before the Dyno tune, hate to think what the stock output is!!!!!
Also realize that every dyno is different in what they read, you take it to another dyno and it could read more or less.
The important thing is A/F and the before and after results of your bike on the same dyno, same conditions and perhaps compared to similar bikes on the same dyno.

I have seen huge differences on different dyno's same bike.
__________________

08 Night Train
ThunderMax w/AutoTune
Arlen Ness Big Sucker
Skull Air Cleaner Cover
D&D 2-1 Fat Cat exhaust
HD Mini Tach
HQ 500 Cam's
Reply With Quote
  #10  
Old 02-13-2008, 10:21 AM
99octane 99octane is offline
Road Warrior
Join Date: Dec 2007
Location:
Posts: 1,430
Default RE: Stock 96 Twin Cam Hp and torque

Quote:
ORIGINAL: sportncruise

I only see the listed TQ not HP so the relation is 96 crank 77 wheel.
Sorry... You're obviously right. This is what happens writing from the office between an antivirus setup and a linux format...
That's obviously a far more reasonable value. 19-something % is entirely reasonable.

__________________
= TEMET NOSCE =

I listen to the music of the machine.
Reply With Quote
Old 02-13-2008, 10:21 AM
 
 
 
P
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
2014 Engine Torque Specs. one-up Touring Models 26 10-14-2013 06:52 PM
Mileage stinks! Guitardude Touring Models 81 10-09-2013 12:24 PM
Which torque value to use: Service manual's or replacement part's instructions? Tedjay Touring Models 3 04-07-2013 05:58 PM
Half the sound of V&H Big Shots, similar dyno numbers. PICS bvkamp Softail Models 16 11-13-2012 04:00 PM
Andrews 54H...happy boy Gruamach Touring Models 30 08-09-2012 10:27 PM


Tags
2007, 500, 96, bad, cam, cooling, crank, davidson, harley, horsepower, hp, hq, map, stock, touring, twin


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Join HDForums

Advertising
Featured Sponsors
Vendor Directory
Sponsors

All times are GMT -5. The time now is 04:49 AM.


Internet Brands, Inc.