True Rear Wheel Horsepower

True Horsepower - Effective HP scale - The Industry wide achievable HP standard

Today, about 75% of the entire world's hp values are a mess of dynojet "hp" and dynojet dyno clones' rough approximations of dynojet horsepower , some brake dyno mfgr's "dynojet channel" that's "+/- 10% of a dj number" , some dynos that out exaggerate the dj numbers and imply that they know what the transmission hp and crank hp is, and even other dynos with the most expensive brochure that read whatever the user wants them to read, True, Real, SF and DJ..... or make up your own inflation factor (sigh...)

All because some guy thought that a 1985 over bored 1400cc prerelease version V Max made 145 crank hp according to the marketing dept. and he couldn't have his "new" inertia dyno read 90 hp on a stock dealership V-Max. Well, he was correct at 90-95 effective hp, but he made it read 120 to sell more of his dynos. And that's where the chassis dyno hp mess started. Read more about inflated hp numbers

Simple Solution:

True / Effective HP. Every dyno company can all do it.

DEF:
Corrected True HP is the:
Actual power under Steady State (preferred)
or Sweep with CORRECT inertial mass value at 20 f/ps
delivered to the drive roller of a chassis dyno
to which is ONLY added the dyne coast down parasitics and then
corrected to existing atmospheric test conditions.

Factory Pro has confidentially refused to exaggerate measured and corrected horsepower figures to sell more dynos.

Since Factory Pro hasn't rescaled horsepower for the last 20 year and our software reads the same files the same from the very first EC997 dyne system.

Some Dynamometer companies add to measured rear wheel power readings a factor that is based on ESTIMATED rear wheel power losses (under what power conditions? 125cc? 1200cc? under coasting conditions? with a 3.00x17 bias ply tire? a 190x17 radial tire? New heavy radial tire vs. worn old, light, stock bias ply tire? Who knows?)

In short, there is NO meaningful "average" tire to get a correct rear tire power transmission loss measurement for all bikes - so obviously, unless they actually measure the power lost in the rear tire, under driven load conditions, NO dyno company should BE ADDING incorrect power figures into the measured power. It's simply wrong.

The fact that they add varying amounts of power to the actual, "true" amount of power delivered and measured to the surface of the drive roller creates a situation that makes it an onerous task to compare power figures from different brands of dynamometer systems.

On simple inertial dynamometers, some (most, actually, all that I know of in the MC market) companies use an average for the inertial mass value of the engine, transmission, rear wheel, sprocket and chain on every bike - as if a YZ125 has the same rear wheel or internal rotating mass as a 1340cc Harley Davidson. Needless to say, if the software thinks that the YZ125 had a HD rear wheel on it, it would look like the 125 makes more HP at the rear wheel than it does at the crankshaft. It's simply wrong.
And - that's why you hear of 125cc Karts that make 43 hp at the rear wheels!!!!!

It's expensive to measure frictional losses in the engine and drivetrain, requiring the dyno to be able to drive the vehicle with engine off. Add the cost of a 50+hp electric motor, controlled power supply, etc. It's just not likely that $20,000 dyno will be equipped with that equipment.

It is also common for dynamometer companies to add to the power readings by adding transmission and primary gear/chain losses back into the measured power readings. Some companies make a concerted effort try to measure frictional losses and, optionally, add the power to the measured readings. Other companies - some that would surprise you - say that it's not important and give a blanket, single factor for frictional losses in every engine. That includes some $25,000-$35,000 dynes.

Some simply say that there is a meaningful "average" for every motorcycle,(2 stroke, 4 stroke, 1 cylinder/1 transmission, 4 cylinder/1 transmission) and apply it to every bike and that it is not a significant difference.

Blanket estimates of "average" losses and corrections are, quite simply, incorrect. At the upper levels of the industry, (we are talking about $150,000 - $500,000 AC or DC 4 quadrant dynamometers) it is not tolerated - shouldn't be - and needn't be.

There is a dyno company that actually has different versions of software that displays their own identical data files as different amounts of power depending on whether you use the DOS version or the Windows version of their software!!

True Rear Wheel Horsepower (tm) is Factory Pro's standard of measuring the power that is actually delivered to the rear wheel. It is honest, true, fair and duplicable. It is the ONLY standard that can be duplicated by the entire industry - regardless of the dyno manufacturer.

Following is a reference table so that, if you are used to rather inflated HP figures, you can see what your vehicle would generally make on the True HP Scale.

True HP as compared to DJHP

It's not possible to give an absolute conversion factor, as it appears that dj dynos don't all read the same (my experience, other's, too - and Mag Articles and 2002 Roadracing World gsxr1000 and R1 comparison articles), but, you can take True HP from EC997's and produce an "average" djhp of of an "average" dj dyno - empirically derived, over 20 years of comparison of the two hp scales.

True / Effective HP Scale approximate DJHP +/- 2% multiplication factor

This is on a calibrated EC997 - all ec997's are supplied with quick, accurate calibration procedures. This number depends on whether the dj is a high or low or average reading dj. Dj dynos can be calibrated with a visit from dj tech support. (the dj dynos do not compensate for the differences in inertial mass of the bike - a HD/Cruiser has a heavier rear wheel, chain and crankshaft (resulting in a lower correction factor) and a higher dj correction factor for a YZ125 with a light crank and rear wheel)

Subtract up to 5% for high mass bikes. Add up to 5% for low mass bikes.
example: at 90 True hp, *1.15 average and *1.10 (high mass bike) to 1.20 (low mass bike)

50 True HP 55 djhp *1.10 = djhp

80 True HP 90 djhp *1.12 = djhp

90 True HP 103 djhp *1.15 = djhp

100 True HP 115 djhp *1.15 = djhp

120 True HP 138 djhp *1.15 = djhp

130 True HP 150 djhp *1.15 = djhp

140 True HP 168 djhp *1.20 = djhp

150 True HP 180 djhp *1.21 = djhp

160 True HP 192 djhp *1.15 to *1.22 = djhp - subject to revision
(Only a couple samples, all S1000rr's - Seems to be a wide range of S1000rr dynojet numbers, 179, 184, 185, 186, 191, 210?? )

170 True HP

I don't know what the scale is after 275 True or in between 170 True and 275, as I haven't tested any motorcycle that has also been run on a normal reading dynojet that makes that much power

275 True HP 375 djhp *1.35 = djhp

Need a reference scale?

True Rear Wheel Scale Samples

HD True HP page - click here

This is the oldest, largest public motorcycle hp database in existence that uses a consistent hp scale.
Includes many vintage bikes - If you are the owner of a bike that is not listed, email us and we may be able to give you a free diagnostic dyno run - I'm always curious about the RD350 - the H1, H2 and S3 as we used to race them many years ago.
Almost all tests were performed on one of 2 calibrated EC997 dynameters that were crosschecked for identical HP readings and calibrated on a monthly scale.
All hp is listed in TRUE HP scale.
To estimate DJHP, multiply True x 1.1 to 1.2. See TRUE / DJHP chart at bottom of page

50cc specific comment general comment All figures SAE Corrected

Honda, Ruckus 50 all stock 3.2 True HP

70cc specific comment general comment All figures SAE Corrected

Honda, ct70 all stock 3.0 True HP

100cc specific comment general comment All figures SAE Corrected

Hodaka 100 Super Rat, Ace 100, Dirt Squirt Free diagnostic dyno run - you get the diagnostic and we get the data

Honda cb or cl or sl 100 Free diagnostic dyno run - you get the diagnostic and we get the data

Kawasaki 100cc G31-M Centurion Green Streak about 1970 Free diagnostic dyno run - you get the diagnostic and we get the data

125cc specific comment general comment All figures SAE Corrected

Harley Davidson Rapido Free diagnostic dyno run - you get the diagnostic and we get the data

Honda cb or cl 125 Free diagnostic dyno run - you get the diagnostic and we get the data

Kawasaki 125 Free diagnostic dyno run - you get the diagnostic and we get the data

125cc roadrace specific comment general comment All figures SAE Corrected

K. Murray cylinder, tz125 cases This was the very first Murray cylinder pretty good! :-) 33.8 True HP

Honda, rs125 Ulrich, Sears Point, 1999 best rs125 tested, multiple tests 35.8-36.4 True HP

Honda, rs125 Webb, Adrian, 5/1999 2nd best rs125 tested 35.3 True HP

Honda, rs125 stock engine, properly tuned
(we all know that you can't properly tune 2 strakes on a dynojet) 30 to 32 True HP

Yamaha tz125 31-34 True HP

175cc specific comment general comment All figures SAE Corrected

Hodaka 175 Free diagnostic dyno run - you get the diagnostic and we get the data

Honda cb, cl 175 Free diagnostic dyno run - you get the diagnostic and we get the data

Kaw 175 Free diagnostic dyno run - you get the diagnostic and we get the data

Puch / Allstate 175 "twingle" Free diagnostic dyno run - you get the diagnostic and we get the data

250cc Street specific comment general comment All figures SAE Corrected

Aprilia 250, street legal
(with aftermarket exhaust and supposedly "stock" engine) Aprilia Series
(supposedly stock engines) all stock engine class - many samples, many done at Cup races, Laguna Seca ~ 48 - 52 True HP

Aprilia 250, almost street legal
(common hp results with modified engine and aftermarket exhaust) Modified engine / comp. exhaust AFM 250cc Superstreet class ~51-57 True HP
(common results)

Aprilia 250, production racer, 2 stroke
(BEST EVER) Modified engine / comp. exhaust
(Desmoto / San Francisco, CA) AFM 250cc Superstreet class
Unfortunately, the powerband was so narrow and so high that the stock ECU (which had reasonable midrange) hit the rev limit while power was still rising - and the kit ECU had terrible midrange and had too much advance at high rpm (causing terminal detonation) - and with either ECU, the stock transmissionwas had too wide ratios. ~61-62 True HP
(best EVER seen! Equal to a stock tz250)

Kaw, ex250 notes:
There is much debate as to which is the strongest year ex250.
As it turns out, maybe the "average" rejetted 89-07 might be a horse stronger than an "average" 08-09, there is a rather wide % of power difference, bike to bike - meaning, that YOUR 08-09 might be a "strong one" and your buddy's 89-07, might be, not such a strong one - and YOUR 08-09 may be stronger than his 89-07.
Also, the stock carb is usually (but not always) a bit on the rich side and properly jetted, the mains that you end up with are likely to be smaller than stock, even at sea level. When people are talking about the "lean" stock jetting, they are talking about the needle and pilot circuits - not the high rpm area.
Remember, all of these HP numbers are the True HP scale - to get an approximate dynojet (djhp) number multiply True x 1.1 to 1.15 - depending on whose dj horsepower numbers you are trying to make it read like.
What is good about True HP is that the EC997 dynos have always been easily calibratible for .05% accuracy and that this HP list is almost completely done on the same Master EC997 dyno.

Kaw, ex250, 08-09
all stock with stock exhaust all stock - stock exhaust 1 sample, Cullen 23.8 -27 True HP

Kaw, ex250, 08-09
stock exhaust, rejetted all stock stock exhaust, no snorkel,
rejetted 1 sample, Cullen 25 True HP
(started at 23.8)

Kaw, ex250, 08-09
stock with stock exhaust all stock, stock exhaust, snorkel, UNjetted ~ 24-28 True HP

Kaw, ex250, 89-07
stock with stock exhaust all stock, ~3k miles many samples ~ 23-27 True HP

Kaw, ex250,87-07, prod racer modified engine, stk exh 32 is pretty darned good ~ 32-35 True HP

Suzuki X6 Hustler Free diagnostic dyno run - you get the diagnostic and we get the data

Yam, fzr250 (unknown year) stock engine with Yoshimura slipon 1 sample, done in 1999 33.8 True HP
(and it was 1-2 "mains" too rich in jetting)

250cc Grand Prix specific comment general comment All figures SAE Corrected

RR, Aprilia, 250 GP ex factory.... you wish.... :-) ~82+ True HP
at best, corrected for high altitude - usually, the same bike was 75 - 76 at sea level - Something about rotary valves vs. reed valves at altitude?

RR, Honda, rs250,98, kitted pretty good one. rs's have great midrange (9k-11k) power. Similar powerband as 00-01 TZ ~66-70 True HP
70 was "kitted"

RR, Honda, rs250,98, stockish rs's have great midrange power ~64-68 True HP

RR, Yam, tz250,00-02, not even close to stockish BEST, BEST USA ones this is with USA leaded fuel ~74-76 True HP
Remember - this is True HP -and not inflated dynojet hp.

RR, Yam, tz250,00-01, stockish 00-01 tz's have great 9k-10k power, and a bit less topend than a kitted 96 model ~65-70 True HP

RR, Yam, tz250,91-98, stockish pre 2000 tz's have great high rpm power ~64-70 True HP

RR, Yam, tz250,96, kitted really good one. pre 2000 tz's have great high rpm power, peaky compared to RS and 00-01 TZ ~69-73 True HP
72-73 was "kitted"

Factory Pro's 4 Gas EC997 was the single, most popular dyno used by AMA Pro 250 race teams and racers - Including Chuck Sorensen's AMA #1 Aprilia 250, Simon Turner's Priority Racing TZ250 and Roland Sands Performance Machine's Daytona 250 lap record breaker TZ250 and Rich Oliver's Championship TZ250.
In addition, 250 Privateers overwhelmingly choose the EC997 as a primary source of meaningful tuning information.
Yep - that was us dynoing in the dark at Road America at 10:30pm and again at Virginia International.........

350c Street specific comment general comment All figures SAE Corrected

Yamaha, rz350 / rd350lc ported, big reeds, milled, unifilter, stock Canadian exhaust tuned carbs on EC997 dyne system ~50 True HP (GOOD!)

Yamaha, rd350, 1973-1975 Production Racer ported, big reeds, milled, stock USA chrome exhaust, one of 3 Top AFM 410 Production bikes tuned carbs on track and at the Nicasio - Cheese Factory GP ~32-35 True HP

400cc Street specific comment general comment All figures SAE Corrected

Honda cb1 Sudco exhaust tuned carbs on EC997 dyne system ~44-47 True HP

Honda cb1, ported and milled Ported and airbox modified by Factory Pro with TBR exhaust system - tuned carbs on EC997 dyne system. Note! Float bowl vents must be vented into the airbox with a modified airbox -
Probably should be vented into the airbox, even if it's stock, too. It WILL change the required jets. ~53-54 True HP
woohoo! :-)

Honda cb400f,76-77 all stock bike dyno run 1/2 price for stockish bike in San Rafael

Suzuki, DRZ400, SM, 2005 all stock bike - stock exhaust ~30-32 True HP

Suzuki, DRZ400, SM, 2005 no snorkel, 4" airbox hole, comp exhaust ~36-38 True HP

Suzuki, DRZ400's with cv carb all stock bike - stock exhaust ~25-30 True HP

Suzuki, DRZ400's with cv carb comp exhaust w/o spark arrester, no snorkel ~27-32 True HP

Suzuki, DRZ400, early
with Keihin FCR original carb stock engine - comp exhaust w/o spark arrester, no snorkel ~28-29 True HP
with one fluke of 30

Suzuki gsf400 Bandit, 96 competition exhaust and Config 30 / no airbox / individual air filters ~40 True HP

Yamaha fzr400, 88-89 competition exhaust and Config 30 / no airbox / individual air filters ~40-41 True HP

Yamaha fzr400, 88-89 with competition exhaust and stock airbox and filter tuned carbs on EC997 dyne system ~48-50 True HP

Yamaha fzr400, 88-89 with competition exhaust, stock airbox and filter well built race engine, EC997 tuned ~48 - 50 True HP

Yamaha fzr400, 88-89 with competition exhaust and Config 30 carb kit / no airbox stock engine, EC997 Tuned ~52 - 55 True HP

450cc Street specific comment general comment All figures SAE Corrected

Aprilia SXV 450 Super Motard modified mod engine with aftermarket exhaust Tuned with PC3, but would have preferred using Tuneboy for better tuning options ~57 True HP

Aprilia SXV 450 Super Motard stock all stock bikes with stock exhaust Improved mapping to Best Power would be even better - but great power as is! 48-49 True HP (tested at AF1 Racing, TX)
49-50 True HP (tested at Wheelsmith Racing)
(60 claimed crank horsepower)

Honda, cb450 DOHC, 1971 all stock engine, exhaust, air filter all stock
rejetted with 110 main jet ~26-27 True HP

Honda, cb450 DOHC, 1971 all stock engine, exhaust, air filter all stock
(note: original 130 main jet was much too large) ~23.5 True HP

Husaberg FS450S, 2006 w Akrapovic comp exhaust w/o quiet baffle, carb tuned
Compliments SF Moto, San Francisco, CA tuned FCR carb with Factory Pro HDJ FCR carb kit ~42-44 True HP

500cc specific comment general comment All figures SAE Corrected

Yamaha rz500 all stock engine with Toomy pipes
tuned on EC997 dyne system Ghadiri ~65 True HP

Yamaha TX500 Free diagnostic dyno run - you get the diagnostic and we get the data

550cc specific comment general comment All figures SAE Corrected

Aprilia RXV 550 Dual purpose all stock engine, mod airbox, Sil Motor exhaust remapped with Tuneboy 48 to 50 True HP (tested at Wheelsmith Racing)

Aprilia SXV 550 Super Motard all stock bike with stock exhaust Improved mapping to Best Power would be even better - but great power as is! 55-56 True HP (tested at AF1 Racing, TX)
54-55 True HP (tested at Wheelsmith Racing)
(70 claimed crank horsepower)

Yamaha XZ550 Vision Free diagnostic dyno run - you get the diagnostic and we get the data

600cc Street specific comment general comment All figures SAE Corrected

600, Hon, cbr600 fi, 01
mod unrestricted version FI
w/ comp exhaust Excellent midrange, pretty good topend. ~88-92 True HP

600, Honda, cbr600 f4, 99-00,
mod unrestricted version,
w/ pipe, 1.7-RK jet, advance stock, unmodified engine-> ~87-92 True HP

600, Hon, cbr600 f4, 99-00, stock CA version / restricted Excellent midrange, not so good topend, install 49 state / unrestricted cams AND Igniter unit to convert to unrestricted ~72-75 True HP

600, Hon, cbr600 f4, 99-00, stock unrestricted version Excellent midrange, OK topend. ~78-83 True HP

600cc Street specific comment general comment All figures SAE Corrected

600, Kaw, zx6r, 09
April 2009, track, Official CCS EC997 dyno 1 bike tested stock engine, pump premium fuel 102 True HP
(only one bike tested)

600, Kaw, zx6r, 01-02
AMA race mod - best AMA Supersport
(best ever AMA at the time - by 4&6 Cycle, 02) Blueprinted engine, AMA spec, w/ race fuel (2-3 hp) ~ 96-98 True HP
(almost unobtainable)

636, Kaw, zx6r,
Akra slipon, kit ECU Akrapovic slipon, KRT Race ECU tuned with EC997 dyno pump premium
John Farkas ~ 105.5 True HP

600, Kaw, zx6r, 01-02
AMA race mod - usual AMA Supersport
(common AMA) Blueprinted engine, AMA spec, w/ race fuel (2-3 hp) ~ 91-94 True HP
(obtainable with care)

600, Kaw, zx6r, 98-99, stock unrestricted version
(no hp restricted version in USA) Good midrange, good topend.
(Best CA hp 600) ~ 81-84 True HP

600, Kaw, zx6r, 98-99, unrestricted version
lots tested
w/ pipe, ,jet, advance Good topend, excellent midrange ~ 84-90 True HP
(exceptional 90hp was CA model w/ Remus street slipon! - 08/12/99)

600, Kaw, zx6r, 95-97, unrestricted lots tested
w/ pipe, ,jet, +6 advance Good topend, excellent midrange ~ 84-89.9 True HP
89.5hp was Team Kinkos backup 600 w/ Muzzy 5/95. 85-87hp is not uncommon.

600, Kaw, zx6e, 95-98, unrestricted lots tested
w/ pipe, ,jet, +6 advance is usually best Good topend, excellent midrange ~ 83-85 True RWHP
rare 87hp was w/ street slipon

600cc Street specific comment general comment All figures SAE Corrected

600, Suz, gsxr600,06
stk bike w stacks w stk exhaust added Factory Pro Velocity Stacks
VEL-S64-1545 pump premium fuel 104.5 True HP

600, Suz, gsxr600,06
all stock bike with stock exhaust completely stock, 600 miles pump premium fuel 99-101 True HP

600, Suz, gsxr600,05
AMA spec / Yosh engine removed power commander and tuned with Teka 106 True HP
(Highest HP ever tested on AMA Suzuki 600cc till 06!)

600, Suz, gsxr600,05
AMA spec / Yosh engine with power commander 105.0 True HP
(2nd Highest HP ever tested on AMA Suzuki 600cc!)

600, Suz, gsxr600,02
AMA spec According to Anthony, the engine was stock (it looked original) and was borrowed from a friend AMA bikes tested w/ race fuel 99.97 - 100.05 True HP

600, Suz, gsxr600, 01-02
AMA spec (?) "AMA" spec - but...
I'm suspicious that it would pass tech AMA bikes tested w/ race fuel (2-3 hp) ~95-96 True HP
(rare)

600, Suz, gsxr600, 01-02
usual AMA spec "AMA" spec AMA bikes tested w/ race fuel (2-3 hp) ~91- 94 True HP
(not uncommon)

600, Suz, gsxr600, 96-99, mod lots tested
w/ pipe, ,1.7-RK jet, +4 advance stock, unmodified engine-> ~84-90 True HP

600, Suz, gsxr600, 97-00, stock unrestricted version stock, unmodified engine-> ~81-84 True HP

600, Suz, gsxr600, 97-00, stock CA version / restricted stock, unmodified engine
Replace cam / cams. ~73-77 True HP

600, Suz, Katana 600, 99 CA version / restricted stock, unmodified engine ~65-68 True HP

600cc Street specific comment general comment All figures SAE Corrected

FZ-6, 06-07 stock engine, stock exhaust all stock w pump premium 82-85 True HP

FZ-6, 06-07 stock engine, Leo Vince slipon exhaust all stock w pump premium 86-88 True HP

FZ-6, 06-07 stock engine, Leo Vince slipon exhaust and TEKA 4 all stock w pump premium 87-88 True HP
(TEKA 4 added much improved driveability)

yzf600 R6, 2008
AFM Formula Pacific Engine modified engine, BMC, comp exhaust, +2
Tuned by Factory Pro / Marc Salvisberg modified engine, R Tech Outlaw fuel 120.1 True HP
(highest HP "600" ever tested as of April 2009)
est 135-140 djhp, depending on which dj dyno you go to)

yzf600 R6, 2008
AMA Supersport spec engine AMA Supersport engine w BMC air filter, comp exh mod engine and R Tech Outlaw fuel 108 - 110 True HP

yzf600 R6, 2008 stock engine, stock exhaust all stock w pump premium 97-102 True HP (99-100, 2 samples)

yzf600 R6, 2008 stock engine, comp exhaust all stock w pump premium 97-102 True HP (99-100, 2 samples)

yzf600 R6, 06-07
stk eng, AMA 600SS stock engine, Leo Vince exh, TEKA 4usb, VP U4 Spencer Stuart, AFM ~ 107.1 True HP

yzf600 R6, 06-07
all stock!! all stock all stock engine and exhaust ~ 98-100 True HP

yzf600 R6, 2003
mod all stock engine Factory Pro V Stacks
Hindle exhaust
Super Race fuel
stock fueling ~ 112 True HP

yzf600 R6, 2003
mod all stock engine Factory Pro V Stacks
Hindle exhaust
pump premium
stock fueling ~ 108 True HP

yzf600 R6, 2003
ALL STOCK, Jim @ Duc, Tri, Yam of Marin
415 456-3345 all stock engine all stock ~ 93-95 True HP

yzf600 R6, to 02 Best HP on R6 -
Jamie Barkley's bike - Entered in HP limited class (!) in Canada, 01
w/ race fuel (2-3 hp) ~ 105 True HP
(best one tested and the quickest R6 in Canada, 2001)

yzf600 R6,to 02 Best "AMA" spec ever tested
AMA blueprint engine, stock v stacks AMA bikes tested w/ race fuel (2-3 hp) ~ 97.5 -98.5 True HP
(best one tested)

yzf600 R6, all to 01
tuned to max, best one. Highest hp stock engined 600 ever tested. +4 Advance, Y78-1.7-RK carb, V Stacks, stock air filter, aftermarket exhaust,
"maybe" AMA legal AMA bikes tested w/ race fuel (2-3 hp) ~ 96.5 -97.5 True HP
(best one tested)

zf600 R6, all to 01
mod Usual True HP with +4 Advance, Y78-1.7-RK carb, V Stacks, stock air filter, aftermarket exhaust best hi rpm power, pump gas ~ 92-94 True HP

yzf600 R6, all to 01
mod unrestricted version,
race slipon race slipon usually adds 3 hp
pump gas ~ 89 - 92 True HP

zf600 R6, all to 01
stock unrestricted, 15.5k redline
49 state / Euro best hi rpm power ~ 85 - 86 True HP

yzf600 R6, all to 01
stock CA / restricted version,
14k redline Unrestricted this bike - Cams and optionally, igniter box and +4 Advancer ~ 76 - 78 True HP

Yamaha, srx600 with stock carbs, Supertrapp 13 discs ~ 33 True HP

Yamaha, srx600 with dual 31,, CRS Keihin carbs, Supertrapp 13 discs ~ 35 True HP

Yamaha, srx600 modified engine, with dual 31,, CRS Keihin carbs, comp exhaust Kevin Crowther's AFM bike ~ 47 True HP

650cc Street specific comment general comment All figures SAE Corrected

Husaberg, FS650S, 2005 w Akrapovic comp exhaust w/o quiet baffle, carb tuned
Compliments SF Moto, San Francisco, CA tutuned FCR carb with Factory Pro HDJ FCR carb kit ~51-54 True HP

Triumph 750 twin (early) Free diagnostic dyno run - you get the diagnostic and we get the data

Yamaha XS650 twin Free diagnostic dyno run - you get the diagnostic and we get the data

675cc specific comment general comment All figures SAE Corrected

Triumph 675, 2008 ~96-98 True HP

748cc specific comment general comment All figures SAE Corrected

748, Ducati 748 R, 00-01
w/ shower injectors modified engine mod, 120 minute engine w/ exhaust and race fuel (2-3 hp) ~102-105 True HP
(best ever was 107 Desmoto!)

748, Ducati 748 R, 00-01
w/ shower injectors unmodified engine stock engine w/ exhaust and race fuel (2-3 hp) ~90-92 True HP

750cc specific comment general comment All figures SAE Corrected

Honda CB750k, sohc, aprox. 1970 all stock all stock ~ 45-48 True HP

Kawasaki 750 H2 all stock all stock ~ 58-62 True HP
90209-21080

Norton 750 Commando Free diagnostic dyno run - you get the diagnostic and we get the data

gsxr750, 06-07 Leo Vince exhaust, pump premium, Factory Pro velocity stacks, BMC Race air filter 8-10 hp big upper midrange increase ~ 123 - 124+ True HP

gsxr750, 06-07 all stock ~ 116-118+ True HP

gsxr750, 06 Ti Force exhaust, VP U4 fuel, tuned on EC997 dyne system Kim Nakashima
AFM race winner ~ 124.5+ True HP

gsxr750, 06,
AMA spec highest HP
AMA spec engine (?) Kim Nakashima
AFM race winner best ever tested, probably pass tech.... inc. race fuel (2-3 hp) ~ 132True HP
(cams and porting help streetbikes get here!)

gsxr750, 02,
AMA spec very good HP
AMA spec engine
Could win at any US track Very good
should pass tech....
w/ race fuel (2-3 hp) ~ 120 True HP

gsxr750, 02,
AMA spec common HP
AMA spec engine
can win at short track usual HP expected with no tuning mistakes.
Should pass tech....
w/ race fuel (2-3 hp) ~ 115 True HP

gsxr750, 02,
w/ stock engine w/ exhaust usual HP usual HP expected with no tuning mistakes. ~ 110-114 True HP

gsxr750, 00-02,
w/ comp exhaust all stock all stock ~ 106-108 True HP
(110true = 134 djhp 23% ???)
(115.9 true=138.9 djhp 20% ???)

gsxr750, 96-99,
mod street w/ comp exhaust, jet, +2 advance ~ 102-104 True HP

gsxr750, 96-99,AMA Supersport usual AMA bikes make much better power at 8k - 11k ~ 102-110 True HP
(102-103 easy - 107-110 hard to get)

gsxr750, 98-99,AMA Supersport best ever tested ~ 111.2 True HP

gsxr750, 00-01,
w/ comp exhaust ~ 106-108 True HP
(110true = 134 djhp 23%)
(115.9 true=138.9 djhp 20%)

gsxr750, 86-87
w/ comp exhaust w/ comp exhaust + config 30 ~ 78-80 True HP

Triumph 750 twin (early) Free diagnostic dyno run - you get the diagnostic and we get the data

Yamaha TX750 Free diagnostic dyno run - you get the diagnostic and we get the data

Yamaha XS750 Free diagnostic dyno run - you get the diagnostic and we get the data

850cc specific comment general comment All figures SAE Corrected

tdm 850, Juan Vera Special w/ 41mm FCR mild port, Devil exhaust (??slipon or full system) 41mm Keihin FCR with K&N RU-82 filters ~ 73.5 at 8k True HP

tdm 850, Juan Vera Special w/ stock carbs mild port, Devil exhaust (??slipon or full system) stock rejetted 38mm CV carbs, K&N stk replacement air filter ~ 70 at 8k True HP

tdm 850 all stock air filter and exhaust 2 different bikes ~ 60 True HP

Yamaha XS850 Free diagnostic dyno run - you get the diagnostic and we get the data

900cc Street specific comment general comment All figures SAE Corrected

cbr900rr, stock ~ 97-98 True HP

cbr900rr, APK, pipe and +2 Advance, cam degree ~ 102-104 True HP

rf900

996cc Street specific comment general comment All figures SAE Corrected

996, Ducati 996
Les Oglesby extremely modified 996
(J. Hackett, Nash engine - final cam timing and FI tune Factory Pro, San Rafael) pump gas, exhaust ~125 True HP
(w/ 60mm throttle bodies)

996, Ducati 996
Les Oglesby extremely modified 996
(J. Hackett, Nash engine - final cam timing and FI tune Factory Pro, San Rafael) pump gas, exhaust ~119-120 True HP
(w/ std throttle bodies)

996, Ducati 996 stock engine pump gas, exhaust ~90-92 True HP

929cc Street specific comment general comment All figures SAE Corrected

cbr929 all stock all stock ~ 108-110 True HP

cbr929 w/ slipon Erion ~ 110 - 112 True HP

954cc Street specific comment general comment All figures SAE Corrected

cbr954 w/ slipon Erion ~ 117-120 True HP

990cc specific comment general comment All figures SAE Corrected

ktm 990 Super Duke Akrapovic slipon EC997 Best Power / 4 gas ega tuning 99.4 True HP

ktm 990 Super Duke Akrapovic slipon with zero map in PC3 98.5 True HP

ktm 990 Super Duke Akrapovic slipon "official dynojet Akra map" - too rich 96.6 True HP

999cc specific comment general comment All figures SAE Corrected

Ducati 999r, 2005
(several bikes tested) Termi system tuned with a pc3 141-143 True HP
(same as stock gsxr1000 k5!)

Ducati 999s, 2004 ZART exh. system tuned with a pc3 128.8 True HP

1000cc Street specific comment general comment All figures SAE Corrected

Aprilia, RSV4
999.6cc, 2010
Tested by Micah Shoemaker's AF1
2009 #1 USA Aprilia dealer w/ race slipon all stock engine 140.2 True HP

note: claimed crank HP = 180
Take crank hp, subtract 15% from reported reading, take that and subtract 10% for tire losses and 3% to 5% for drive train losses and add 4-5 for the slipon and you come up with about 140 True. Perfect.

Aprilia, Mille, 04 NERA, owner Jay Larson w stock quiet Akrapovic exhaust all stock ~ 113+ True HP

Aprilia, Mille, 04 w/ typical full system all stock ~ 104-109 True HP

Aprilia, Mille all till 03 all stock all stock ~ 94 - 96 True HP

Aprilia, Mille w/ typical full system w/ pc ~ 100 - 102 True HP

Aprilia, Mille w/ typical full system w/ rsvz1413 chip ~ 102 - 104 True HP

Bimota SB8r TL1000 engine, large Magneti Marelli TB's, w/ MagMar ECU Big boost in midrange!! ~ 112.8 True HP

BMW, S1000rr all stock engine with Arrow exh system FI retuned EC997 dyno 163.3 True HP w/ GT260
(measured at 205 djhp on official dynojet dyno = 25% inflation)

Ducati, Desmosedici, 2008 Ducati supplied slipon exhaust Desmoto Sport / Matt Green, San Francisco ~ 162 True HP @ 13,500 rpm !!!!!! Wow!!

Ducati, ST3, 1000, 2004 Leo Vince exhaust Big boost in midrange!! ~ 92 True HP @ 8000(!) rpm

Ducati, ST3, 1000, 2004 all stock ~ 91 True HP @ 9000 rpm

Excelsior, 1919 OHC 1000cc board tracker
REPLICA For Sale by Flashback Fabrictaions Replica OHC 1000cc V Twin -
Engine internals updated with current technology cams, porting, pistons ~ 60 True HP

Honda, RC-51, all years all stock all stock ~ 100-106 True HP

Honda, RC-51, all years exhaust, BMC filter ~ 106-109 True HP

Honda, vtr1000, all years all stock all stock ~ 84-88 True HP

Kawasaki, zx10,08 Smith all stock, stock exhaust all stock engine, pump premium fuel 142.5-148.3 True HP (145.5 ave)

Kawasaki, zx10,08 Smith stock exhaust
w/ PROTOTYPE Superflare Velocity stacks all stock engine + 4.9 HP
153.2 True HP (orig. 148.3 Tue HP)

zx10,08 Smith Racefit slipon exhaust
w/ PROTOTYPE Superflare Velocity stacks
Retune FI all stock engine + 9.7 HP
158.0 True HP (orig. 148.3 Tue HP)

zx10,07-08 all stock, stock exhaust all stock engine 142-146 True HP (144 ave)

zx10,07-08 with Factory Pro V stack, no FI tuning, stock exhaust all stock engine 147-151 True HP (149 ave)

zx10,07-08 with Factory Pro V stack, BMC air filter no FI tuning, stock exhaust all stock engine 149-153 True HP (151 ave)

gsxr1000, 09-10
April 2009, track, Official CCS EC997 dyno all stock bike all stock, pump premium fuel 140 True HP

gsxr1000, 07-08 all stock all stock, pump premium fuel usually 144-146 True HP

gsxr1000, 07-08
BEST stock one ever all stock owner DC 153 True HP @ 13k, bike tach rpm

gsxr1000, 07-08
BEST stock one ever with changes Yoshimura exhaust VEL-S51-5050 stacks, BMC Race air filter owner: DC 155.2 True HP at 12k bike tach rpm
( +4 to +6 in low, mid and upper mid)

gsxr1000, 06 mod race gasket, ported, milled, U4,, Laser, stk cams degreed, FPT V Stacks, etc. Barry Teasdale and Andi Notman, built by Joe Proctor 170-172 True HP

gsxr1000, 06 all stock 136 to 141 True HP

gsxr1000, 05 mod race gasket, race fuel, exhaust, cams degreed, etc. Michael W. ~ 159 True HP

gsxr1000, 05 all stock all stock 136-141 True HP

gsxr1000, 01-03 all stock all stock ~ 121(lowest) - 129(highest)

gsxr1000, 01-03 w/ comp exhaust ~ 138 - 140 True HP

TL1000r, all years stock ~ 97-98 True HP

TL1000r, all years comp exhaust, BMC ~ 105 - 108 True HP

FZ1, 2006 stock engine with STOCK exhaust
GRAVES STACKS 1 sample tested, Pantoja 128 True HP

FZ1, 2006 stock engine with STOCK exhaust and
FP R1 SUPERFLARE STACKS 1 sample tested, Pantoja 129.6 True HP and a lot better upper midrange than graves

FZ1, 2006 stock engine with STOCK exhaust and
SUPERFLARE STACKS and AIRBOX MODS and FI tuning 1 sample tested, Pantoja 133.8 True HP with lot's better low, mid and peak power

FZ1, 2005 stock engine with STOCK exhaust 1 sample tested, Pantoja 108 - 111 True HP

Yamaha gts1000 all stock, stock exhaust ~ 70 True HP

yzf1000 R1,09 (USA MODEL only)
(note! These are USA models - the non-USA models are supposed to peak about 8 hp more) All stock 4+ samples tested ~136 to 138 True HP (USA model)
(but 10 hp stronger than 08 is the upper mid)

yzf1000 R1,09 (USA MODEL only)
(note! These are USA models - the non-USA models are supposed to peak about 8 hp more) stock engine with "RACE" exhaust 4+ samples tested
(the R1 has cylinder stagger issues with most pipes. Because of that, the patented Teka 4 is suggested for tuning instead of a PC5 - before you say, "yah, sure", note that the 09-10 R1 is the only bike on this list that I've said that on),
~140-143 True HP (USA model)
(but 10 hp stronger than 08 is the upper mid)

yzf1000 R1,07-08 Viets
prototype V Stack testing - stacks installed "RACE" SLIPON exhaust With Y83 prototype stacks 154-156 True HP

yzf1000 R1,07-08 Viets
prototype V Stack testing - stock stacks "RACE" SLIPON exhaust with stock stacks 149 -150 True HP

yzf1000 R1,07-08 stock with "RACE" SLIPON exhaust Viets 148-151 True HP

yzf1000 R1,07-08 stock with STOCK Exhaust 1 samples tested, 1596 ~141-145 True HP

yzf1000 R1,04-06 w/ stock exup, slipons, Factory Pro V stacks. 3 samples tested ~145-147 True HP

yzf1000 R1,04-06 w/ stock exup, slipons, Stock V stacks. 4 samples tested ~140-144 True HP

yzf1000 R1,04-06 w/ all stock bike 3 samples tested ~132 to 134 True HP

yzf1000 R1,02-03 int102, ex105, mod airbox, 59mm stax, BMC, exhaust system the cam timing was "what somebody said worked", not what actually was best....... ~ 134 - 135 True HP

yzf1000 R1,02-03 w/ Akrapovic exhaust. this bike was 122.8 True, with the stock exhaust ~ 128 True HP (+~5 hp)

yzf1000 R1,02-03 w/ stock exhaust. ~ 120 - 126 True HP

yzf1000 R1,98-01 w/ stock exhaust ~ 115.5 - 118.5 True HP

yzf1000 R1, 98-01 w/ full system most full systems add 6-8 True HP ~ 122 - 124 True HP

yzf1000 Thunder Ace stock exhaust and air filter, FP carb kit retuned ~ 108-113 True HP

yzf1000 Thunder Ace with race slipon, K&N air filter, carb retuned ~ 118 - 120 True HP

fzr1000, 89-86 with race slipon and carb retuned ~ 106-111 True HP

fzr1000, 89-86 estimated with stock exhaust ~ 102-107 True HP

fzr1000, 87-88 Murray exhaust, FP Config 30, cams degreed Pat Burns ~ 118 True HP

fzr1000, 87-88 don't have a stock run

1030cc Street specific comment general comment All figures SAE Corrected

Benelli, 1130cc, TNT Cafe Racer, 07 w/ custom exhaust slipon
LIGHT OFF!
Light ON = MUCH richer map Tuned with Tuneboy.
Oddness: missed at full throttle / 1500 rpm and couldn't tune out
Tune with dash light OFF. ~ 90 True HP

1098cc Street specific comment general comment All figures SAE Corrected

Ducati 1098s, 07 gutted exhaust, RACE ECU, aftermarket air filter ~ 131 - 135 True HP

1100cc Street specific comment general comment All figures SAE Corrected

cbr1100xx, stock exhaust ~ 126 - 128 True HP

cbr1100xx, competition exhaust ~ 132 - 136 True HP

zx11d, Mr. Turbo, 7.5psi boost low compression pistons ~ 150 True HP

1100cc Street specific comment general comment All figures SAE Corrected

Kaw, zx11c/d w stock exhaust retuned 110 to 115 True HP

Kaw, zx11c/d w aftermarket exhaust retuned 115 to 120 True HP

Suzuki gsxr1100, 87-88 w stock exhaust untuned 82-87 True HP

Suzuki gsxr1100, 87-88 w Yoshimura exhaust Config 30 individual filters and retuned 98-100 True HP

Suzuki gsxr1100, 89-02 w competition exhaust Config 30 individual filters and retuned 103-105 True HP

Suzuki gsxr1100, 95 Calif model
(the year with the little cams) w competition exhaust all stock 85 True HP

Suzuki gsxr1100, 95-98
(the years with the bigger cams) w competition exhaust w stock airbox and and retuned 95-96 True HP

Suzuki gsxr1100, 95-98
(the years with the bigger cams) w competition exhaust Config 30 individual filters and retuned 102 to 105 True HP

Yamaha xv11000 Virago w aftermarket exhaust retuned about 52 to 55 True HP

1125cc Street specific comment general comment All figures SAE Corrected

Buell 1125r all stock exhaust all stock, untuned 116 True HP

Buell 1125r Free Spirit exhaust with baffles rough tuned 118 True HP

Buell 1125r
custom power commander mapping by Wheelsmith Free Spirit exhaust WITHOUT baffles - VERY VERY LOUD....... tuned on EC997 Dyne System 126 True HP

1130cc Street specific comment general comment All figures SAE Corrected

Benelli Amazona, 08 - stock All stock exhaust, TB restrictors installed stock exhaust 94 -98 Power Light on
91 Light off

Benelli Amazona, 08 - stock -
custom Tuneboy mapping by Wheelsmith All stock exhaust, TB restrictors still installed Custom Tuneboy mapping to Best Power on EC997 dyne system w/ stock exhaust 101 - 103 Power Light on

Benelli TNT
custom Tuneboy mapping by Wheelsmith REMUS slipon and EVOLUZIONE Air Box kit - tuned with TEKA 4 on EC997 Dyne System Free diagnostic dyno run - you get the diagnostic and we get the data

1198cc Street specific comment general comment All figures SAE Corrected

Ducati Diavel
custom Tuneboy mapping by Wheelsmith slipon muffler and K&N air filter un tuned base test with Tuneboy on EC997 Dyne System 123 True HP
(165 crank hp)

1200cc Street specific comment general comment All figures SAE Corrected

BMW, K1200r
custom Teka 4 usb mapping by Wheelsmith REMUS slipon and EVOLUZIONE Air Box kit tuned with TEKA 4 on EC997 Dyne System 153 True HP

BMW, K1200r stock bike with REMUS slipon untuned 142 True HP

Kaw, ZX12 Notes: There seems to be about a 10 True HP range in ZX12 horsepower - ranging from 150 to 160, even with the same exhaust. All these tested were done on the same dyno - so that variable is eliminated. We have found that valve clearance makes a difference in power in zx11's and zx9's.

Kaw, ZX12 stock bike stock bike Jay Larson 132 to 135 True HP

Kaw, ZX12 Muzzy exhaust +more - our test bike Factory Pro Prototype V stacks Jay Larson 160 True HP

Kaw, ZX12 Muzzy exhaust - typical bike just a Nuzzy exhaust retuned with EC997 dyno typically 150 True HP

Yamaha, FJ1200 stock bike with quiet slipon Factory Pro carb kit 97 True HP

Yamaha, FJ1200 stock bike w/ stock exhaust Factory Pro carb kit 93-94 True HP

1250cc Street specific comment general comment All figures SAE Corrected

V Rod, VRSC-SE2, 2006, Golden Gate HD / Hastings, with high flow air filter and SE exhaust with EC997 dyne system tuned with Race Tuner software. (6-8 hours to do to Best Power) tuned with EC997 dyno and Race Tuner 111.4 True HP
(True hp x 1.15 for djhp)

1300cc Street specific comment general comment All figures SAE Corrected

Hayabusa, 99-07
comp exh, Megacycle cams, Factory Pro V Stacks Factory Pro drop-in TopKick cams and Superflare velocity stacks, stock pistons stock engine except:
TopKick cams, FP stacks, BMC
tuned with Teka SFI ~ 175.3 True HP
(So..... $4000+ and 1397cc gets you .4 less hp than an unported, std bore Busa with a pipe?

Hayabusa, 99-07, 1397cc engine 1397cc Wiseco, Web cams, comp exhaust, stock stacks big bore, ported, milled head, tuned pc3 ~ 174.9 True HP
(True hp x 1.15 for djhp = ~200 djhp)

Hayabusa, 99-07, comp exh, BMC filter Fatback cams and stock velocity stacks, Teka SFI tuned stock engine except cams was 140.2 True HP before cams
149.3 True HP after cams

Hayabusa, 99-07, full system at least 20 samples tested ~ 142 - 148 True HP
(True hp x 1.15 for djhp)

Hayabusa, 99-07, slipon, race at least 20 samples tested ~ 140 - 145 True HP

Hayabusa, 99-07, stock exhaust all stock bike at least 10 samples tested ~ 138 - 142 True HP
(True hp x 1.15 for djhp)

Yamaha fjr1300, 02-03 all stock, stock exhaust ~ 110-112 True HP

Yamaha fjr1300, 02-03 all stock, SLIPON exhaust ~ 113-116 True HP

Yamaha V Max, till 08 all stock ~90 True HP

Yamaha V Max, till 08 with Holeshot exhaust ~97-99 True HP

Yamaha V Max, till 08 with Cobra exhaust ~93-95 True HP

Yamaha xvz1300 Royal Star all stock John Baron's bike ~60 True HP

Yamaha xvz1300 Royal Star w aftermarket exhaust and our big air kit John Baron's bike ~63 True HP

1340cc Street specific comment general comment All figures SAE Corrected

Hayabusa, full system, 08-09 comp exh sys and tuned FI with Teka SFI minimum number of bikes tested ~ 166-170 True HP
(True hp x 1.15 for djhp)

1400cc Street specific comment general comment All figures SAE Corrected

ZX14, 2006, comp exhaust system, EC997 tuned
custom Teka 4 usb mapping by Wheelsmith bike #1: tuned Teka 4usb ~168 True HP

ZX14, 06, comp exhaust system, AFR tuned
custom Power Commander Tuning Link bike #1: tuned to AFR ~ 164 True HP (down 4 hp from EC997 tune)

ZX14, 06, comp exhaust system, untuned bike #1: untuned ~ 160True HP

ZX14, 2006, competition slipon exhaust
custom Teka 4 usb mapping by Wheelsmith bike #1: tuned Teka 4usb ~164 True HP

1500cc Street specific comment general comment All figures SAE Corrected

Kaw, vn1400, comp exhaust system
custom Teka 4 usb mapping by Wheelsmith bike #1: tuned Teka 4usb ~168 True HP

Kaw, ZX14, 2006, comp exhaust system
custom Teka 4 usb mapping by Wheelsmith bike #1: tuned Teka 4usb ~168 True HP

1500cc Street specific comment general comment All figures SAE Corrected

Kaw vn1500, Mean Street w Cobra exhaust about 55 True HP

Kaw vn1500, Mean Street w Cobra exhaust plus Hypercharger about 62 True HP

Suzuki, VL1500, Mean Street w Cobra exhaust about 55 True HP

1600cc Street specific comment general comment All figures SAE Corrected

Yamaha, xv1600 w custom exhaust retuned Factory Pro Carb Kit about 52 True HP

1700cc Street specific comment general comment All figures SAE Corrected

2000cc Street specific comment general comment All figures SAE Corrected

Kaw, VN2000, 04 w Vance Hines Long Shots tuned w EC997 dyno 90 True HP, 120 ft lbs torque

2300cc Street specific comment general comment All figures SAE Corrected

Triumph, Rocket 3, 2300 w race exhaust, 3 individual air filters tuned w EC997 dyno 144 True HP and 145 ft lbs torque

True HP as compared to DJHP

It's not possible to give an absolute conversion factor, as it appears that dj dynos don't all read the same (my experience, other's, too - and Mag Articles and 2002 Roadracing World gsxr1000 and R1 comparison articles), but, you can take True HP from EC997's and produce an "average" djhp of of an "average" dj dyno - empirically derived, over 20 years of comparison of the two hp scales.

Example: You made 116 True HP and you want to know what that is in an average djhp number:
See above chart -
Locate at 110 and 120 True - they are both "*.1.15 = djhp" -

So take:
116 x 1.15 and multiply it - get and average 133.2 djhp +/- 2% reading.
Proper tuning, especially on high HP bikes, like gsxr1000's, ZX12's and Hayabusa's GREATLY affects the power difference.

Due to the fact that the dj dyno's sweep so quickly on sweep hp tests, they get the acc. map and the main maps to occur during the test, ending up over-rich, affecting the HP difference - For example, a ZX12, tuned to run fully loaded, with the Acc. map NOT triggered, will be too rich on a dj at full throttle and will be too rich, requiring leaning them out a fairly large amount to make best power (remember - fast acc triggers both Main Fuel and Acc. Maps - both working at same time).
The average HP conversion factors assume that the bike was leaned out and tuned for best power on an average dj dyno.

The other factor that needs to be taken into account is that dj dynos assume that every vehicle has the same rotating mass - they don't - and that disregard is another reason why the hp conversion figures are different. The EC997's can measure power in Steady State Mode (inertia is not a factor in power equation), the inertial mass changes on each bike affects the dj power, but not the True HP.
There's another message in the above example, besides the average THP to DJHP conversion factor -It's up to the more experienced reader to figure it out.

Chassis dyne HP
What is it? What to call it?

EC997 = "True HP"
Dynojet = "DJHP"
It's not really proper to call "djhp" "rwhp", as neither the EC997, dynojet, Fuchs, Superflow or Land and Sea will necessarily produce the same numbers as a dj dyno, except by luck - and the whole idea of True HP is that EVERY dyno manufacturer HAS the capability to provide those numbers.

The Superflow chassis dynes, the EC997's, Land and Sea and Mustangs are all capable of measuring power in steady state mode and producing the same numbers - they can all measure: torque x rpm / 5252 = true horsepower

The only factor that is added to the measured reading, in True HP Mode, is the additional energy (dyne parasitics) required to spin the dyno roller to whatever speed the roller is turning at - logical, proper and required for any measuring instrument,

torque x rpm / 5252 = horsepower + parasitic power = True HP
We've not diddled with physics and joined a power "puff" derby.

Whether they provide a number that is comparable to other dynes (like Factory Pro did), or not, is completely up to the manufacturer - some like to squirrel away their "puff factors" and some actually "lost" their source code and made up new ones that were 2% higher than the old DOS ones.

Chassis dyne HP - Intertia
What can inflate HP readings on an inertia dyno, but not really make more engine power in the real world?

A few things can affect HP when using inertia dynos (not a dyne in Steady State Mode) to measure power (what else would you do??:-):

Changing to a light, worn stock rear tire will improve power output on an inertia dyno, but, not improve real world top speed.

A heavier (brand new race) tire that replaced the above, light, worn tire, will decrease measured power on an inertia dyno, but not decrease real world top speed.

Lighter wheels are a good thing!
Better acc. in lower gears, esp. 1st and 2nd (accelerating less inertial mass!).
Better suspension is possible, too!
Flicks from side to side easier and hence, quicker in the "esses".
Riding hard on worn, light tires is foolish.

Problems with Inertia dyno test procedure and fuel injected vehicles:

A Sweep Test (hold throttle wide open and sweep from low rpm to high rpm) will often trigger the ACC. FUEL Map, along with the Main FUEL Map, causing the dyno operator to to lean out the main fuel map to compensate for the additional fuel the ACC. FUEL Map delivers. Of course, in the real world, upper gears, the acceleration rate of the engine is much slower than what they tested, doesn't trigger the ACC FUEL Map, and the bike ends up a lot leaner in reality in top gear.
It's not that common of a problem, since most people never ride that fast for that long to cause engine damage - but, the manufacturers will find out soon enough about that.

Work around:
Tune full throttle fueling in real world usage at dragstrip (to best trap speed) or in Steady State Mode on different dyno.

Chassis dyne HP
How can a bike with 132 djhp race and lead with bikes with 141 djhp at Daytona?

You can optimize tuning for a dj dyno and make big numbers - and you can tune the bike to make best power under load on an EC997 and blow off the big dj dyno numbers - That's what that happened at Daytona a couple of years ago...
132 djhp Jimmy Moore gsxr750 (115-116 True HP) lead Daytona CCS over 141djhp Team Suzuki's gsxr??? and Zlock Racing's ZX9 -
How? It's impossible to spot competitors 8 real hp and lead the last few laps until the drafting battle at the line on the last lap!
The answer is obvious (no - Jimmy's bike was legal - we didn't need to limit the power on it.... It was an end of the year experiment that went awry....)
The answer is obvious (read above rantings :-) and is just another example of non-real world power figures.

Can a tuner cheat and make an EC997 read higher?

The only way that could happen is in a Sweep Test - Sweep Tests are the least reliable of all tests. Period. Ours or others. There is NO question about that.
Since the Rotating Mass is a variable in a Sweep Test (but NOT a Steady State Test! - where it's not a factor), the actual inertia factor entered affects the final HP figure - - Tell the software that the vehicle has a lot of rotating mass to accelerate, and the HP number increases. (torque, rpm, acc. rate and mass are the factors) - just like dj dyno ignoring the difference in mass of all bikes -

So - True HP, again -
Steady State Test - No acceleration, mass makes no difference, anymore. Torque, RPM and dyne parasitics. Period. True.

Can you make a Steady State Test (normal EC997 mode) read higher?
I can squeak, maybe, 1/2 to 1 HP extra out of an rpm point, at the most. I was curious (big surprise??) and I tried and tried - 1/2 to 1 True HP. That's about it. And that's pretty hard and you have to consciously try hard to do it - and you have to know how to do it -
The software will NOT take data unless speed and load are completely stable - eliminating cheating (the accuracy is hard coded into the program, so it can't be diddled with!)
As far as other dynos - and being able to make "flash readings" - that's now, ancient history on most newer dynes. Our dynes have always factored a base inertial mass factor to prevent "overloading" and resulting high hp "flash" readings - even in the Steady State Test.
I think that that's more possible in older manual controlled systems that happen to be water brake type engine dynos, but, I can't really talk much about them because I do not have recent firsthand experience.

As far as atmospheric conditions making a +/- 10% difference? Unless you really(!!!) mess with the barometric pressure (and you can look at every atmospheric factor on every test report sheet - it's hard coded to display - not an "option" to display, it is simply, absolutely impossible to do without obvious evidence.

Some dynamometers will actually display "actual HP" and not specify that it is "uncorrected" to standard air ("SAE Corrected", for example) - A STD HP shouldn't ever be given to a customer - The customer probably doesn't know that "actual" means "uncorrected" and that the results can't be compared to anybody else's dyno chart - I was just reading some UK dyno operator explaining on a cbr600rr forum that "STD" hp was some sort of recognized "standard"... (April, 2006). It's not a standard hp number - it's the actual amount of power the bike made THAT day with that temp, baro pressure and humidity. You can't compare it with any other day and different atmospheric conditions. Period. It's a pretty useless chart for comparison purposes. The only time anybody gives an "STD" hp chart is if he's trying to make the power look bigger than another test with different atmospheric conditions.

I saw a recent South Bay (San Francisco south bay) chart reading "Actual HP" instead of "SAE Corrected" HP - The dynojet "tuning center" had just installed an undercut transmission on a gsxr1000 and had somehow lost 10-15 djhp - They gave the customer a chart displaying "Actual HP" because it was 3-4 djhp higher than "SAE Corrected" - to try to hide some assembly error - They denied all responsibility......... They should have just figured it out and I never would have had their customer at my door telling me the story -
The moral? Sometimes the cheapest isn't the best deal - or an honest deal either -

Are final tuning optimal dyno settings different on an Inertia dyno vs. an EC997
For many reasons, final tune settings are different - and, since the EC997 does Sweep and Steady State horsepower testing, we have a choice of tests - from a dj style Sweep Test to Steady State.
Having a choice of those types of tests to do - and having been, firsthand, involved in all sorts of racing - AFM, AMA (250 GP #1,#2,#3,#4), WERA, CCS, Formula USA (750 National Champ and 6 USA Track records!) road racing, drag racing, MX, Speedway, dirttrack, scooter - we have had the opportunity to verify the results of different types of tests and their relevance to the real world operation -
Without a doubt - the Steady State test Mode is the most consistently superior method of tuning - anybody who has the capability to do it will echo that sentiment - it's only an arguable point with those who can't do it properly.
One of the reasons why the EC997 provide settings that work better in the real world is that combustion chamber temperatures are more in line with the actual operating temperatures that the engine - Tests done by Champion Spark Plugs at 4&6 Cycle, Chicago area, provided information that combustion chamber / spark plug temps, on a a common inertia dyne were 300f to 400f LOWER than the real world and the EC997 Steady State Test Mode - Nobody should ignore that - that means ignition timing AND fuel are incorrect when set at sub normal temps - too rich and too advanced is not un common error. (unless you are tuning FI - then it can be either too lean or rich)
On a TZ250? A dj dyno indicated that 3.1mm btdc was optimal ignition timing for best power - and the EC997 indicated 2.6mm btdc - if you knew gp bikes (or even rd350's like me!) that's a HUGE difference!
How much different? About 6 to 7 hp improvement on the EC997 at 2.6mm - and the bike, now, "ripped" on the track instead of droning in sorry misery - it lost a bunch of power on the dj dyno, but, who cared anymore, the EC997 said that the bike was better and the track performance verified it. The only dissenting opinion was the inertia dyne test results.
Given an open mind, desire and equipment, one could make up their own mind -
As for me? I've been here and I've been there - And I like "here" a LOT better!
If I had to resort to sweep tests, only, I'd quit this line of work (boy - would some people be happy!)

Final statement - "It's not important which dyno you use - it's only the amount of power improvement that's important." has never been said by a qualified tuner who has the ability to use modern designed dyno systems and verify results on the track.
Never.

"True HP" vs. "False HP"
"True HP" is a term that signified that the rear wheel horsepower figure was derived from the actual power delivered to the drive roller - nothing added (except normal dyne system parasitic drag).
If some other dynamometer company provides HP figures that will conform to that, they can use the term "True HP". If they don't, then they can't.
Truth in advertising.
If they did, then their dyne systems would at least read the same as another "True HP" dyne system - eliminating a bit more confusion in the industry. (but what would make the internet boring).
Superflow has agreed in principle, so has Mustang and Land and Sea.

Does altitude make any difference at all in HP?
The engine couldn't give 2 hoots at what altitude it is tested at - it only cares what the air pressure, temp and humidity is.
Sea level at 28.02 inches baro is exactly the same as 4000ft/1000 meters at 28.02 inches, as far as the engine is concerned -
When we test at 5000 ft, we get virtually exactly the same power (corrected to atmos. conditions, of course) as we do at sea level - It's just about 24%-25% less on the track and on the EC997 dyno!
I am confused (sometimes, easy to do - but not this time :-) why some dyno manufacturer's insist on putting altitude on their charts and having the dyno operator swear that it's a factor....... Might as well swear that there's some Merlin the Magician reason as to why one should test in 4th gear!!!

Crank HP vs. True Rear Wheel HP
That's a tough one - and LONG....
The short?
Take crank HP, subtract 14.6% (please don't email me and ask - I won't answer - search SAE and old Yamaha), take that, and subtract around 10% to 15% and you'll get about True HP at rear wheel.
The actual formula contains a curve for power loss through gears and there SHOULD be another curve for power lost in a tire (it's the majority of loss on a motorcycle....
Remember, too - that you are only likely to get a crank number from the manufacturer and that's probably a "good" one that the marketing department is providing... (sound of blowing up a marketing and sales balloon? :-) That's not everybody - but it has happened - leaving names out! :-)
When someone gets engineering data from engineering...... give me a call - :-)

What TEST would you suggest that I ask for when I Go to a Factory Pro Dyno Center?
Ask for the Steady State data, base and final tests - that has the 4 Gas EGA information and you can see the gas differences and how it relates to True HP - and you get the True HP numbers -
Some EC997 operators who are afraid that the information is too confusing and just give the owner the Quick Sweep (rough dj simulation) to keep - Get the True information - we can always work with that here, at 800 869-0497. Marc

And finally,
This stuff is confusing!!!
If you've got questions, give me a call at 415 883-5620
between 2pm and 5pm pst, tues. - thur.
I left out a ton of information -
Have a great, curious, open minded day -

Marc Salvisberg

under construction

How does the EC997 compare?

Interesting? Yes or No?