Dyno Hp/Torque - Triumph Marketing vs real-world Dyno

[Scuba Craig]

Can someone explain to me the differences between the HP/Torque figures quoted in Triumph's marketing literature vs the dyno figures for stock Rockets?

By way of example, Triumph market the Rocket Roadster as putting out 109kW (146 HP) @ 5750 and 221 Nm (163 ft-lbs) @ 2750. I've googled-up some stock dyno charts for Roadsters and I'm seeing 114.05 HP @ 5300 and 131.97 ft-lb @ 2500.

Am I right in assuming that Triumph's marketing figures are at the fly-wheel, whereas the dyno is rear wheel?

I understand that all manufactures will inflate their power figures whenever they can get away with it, but these differences are bigger than a marketing guru could hope to get away with.

 

[Steel]

That would be flywheel numbers. When @Boudreaux had his 13 R3R dynoed it was about 124hp/144tq IIRC.

 

[Claviger]

127/145 was my stock baseline pull on one dyno and 124/141 on a different dyno, so first remember not to compare from one to another, but if you do, remember there can be a difference.

Flywheel vs Rearwheel as steel mentioned are always different with the manufacturers universally quoting flywheel as a marketing tactic. The good part, is almost everyone quotes Flywheel HP trying to sell bikes, so that "160" hp SuzuHondKawaZuki is really more like 140 ish. When you consider a bolt on exhaust for the R3 makes rear wheel HPs in the 160s... kind of saying something about the guerillas asking to be released from the Rocket.

For the R3 the correction factor seems to be somewhere in the mid teens for drive train losses, 13-17 %, somewhere in that ballpark. That's actually not terrible considering the mass of some of the reciprocating parts along the way.

 

[ThingKing]

146hp Roadsters make at least 120 rwhp stock. The old 145hp Vmax made around 115 rwhp.
So the numbers are reasonable IMHO, the cardan just eats a little more hp than a chain drive.

 

[cr0ft]

Interesting - since Power-tripp's derestricting map for the R3T returned the Touring to about 115-117 with 140-142 lb ft on his dyno, basically you can get Roadster power out of an R3 Touring just by remapping. The minor discrepancies of a few hp are probably somewhat more restrictive exhaust. Nice.

 

[Claviger]

Yep. As long suspected they are the same internally and the Touring and Roadster exhaust are more similar than either the T or R was to the 3 muffler setup. It makes the tunes between T/R interchangeable.

I have run that R3T tune in my roadster Works very well.

 

[TriumPhil]

Of course there can be meaningful variations in dyno run results based upon changes in ambient temperature, relative humidity/barometric pressure and then there often are calibration descrepancies from the manufacturer and/or user from dynamometer to dynamometer. Generally the difference from HP at the crank to rear wheel HP is about 20%, or so I have been told.

 

[IMFASTTOO]

Of course there can be meaningful variations in dyno run results based upon changes in ambient temperature, relative humidity/barometric pressure and then there often are calibration descrepancies from the manufacturer and/or user from dynamometer to dynamometer. Generally the difference from HP at the crank to rear wheel HP is about 20%, or so I have been told.

IVE run at numerous DYNO_SHOOTOUTS on DYNOJET DYNOS and all the results came in within 2-3 hp as it did at the BRUTE HP SHOOTOUT in DAYTONA BEACH and the Hp and TRQ was almost identical to the CARPENTER DYNO and the DYNO JET is considered the standard but there are several other makes out there

 

[Neville Lush]

Bone stockers do 119 -122 on my dyno. DJ 250i. I have tested maybe onl;y 5 or 6 exactly stock. If the DJK dyno is set up properly they all read very close to the same. As ART said.

 

[IMFASTTOO]

Bone stockers do 119 -122 on my dyno. DJ 250i. I have tested maybe onl;y 5 or 6 exactly stock. If the DJK dyno is set up properly they all read very close to the same. As ART said.

YEP thats what weve found NEV is right on with those numbers