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Re: RE: RS v ST

Good info, Gerrit. I read pretty much every mag published each month, and when I'm interested in a bike, I compare all the stats from one to the next. I've noticed horsepower figures generally vary by as much as 8 hp per bike, probably due to the factors you cite, and also because of variations in individual bikes.

What I noticed comparing all the tests of the RS to the tests of the ST is that the RS figures, which had perhaps a 4 horsepower variation from mag to mag, were universally about 5 to 8 horsepower below the ST tests. My guess is that Triumph made some small tweak between the time they built the preproduction bikes sent to the mags and when the actual production bikes went on sale, perhaps to improve driveability, or perhaps to meet emissions standards. Whatever the reason, I bet if you dynoed production STs against production RSs, you'd find the horsepower figures varied by no more than the expected amount.

A similar situation occured when Suzuki introduced the TL1000S. The initial 1997-model-year magazine testbikes, which, as is often the case, were preproduction machines,  dynoed at higher numbers than later versions. As a result, there is a belief among TL afficianados that the 1997 bikes were the fastest TLs ever built. There may be some truth to that, but part of it is probably because there were some slight changes made between preproduction bikes and production bikes.

Darwin

>>> Gerrit Herbst <Gerrit@xxxxxxxxxxxxxxxx> - 2/13/01 1:07 AM >>>
Dear Dawgs,

There are so many variables that can influence performance output on a dyno
meter that the figures quoted by the various sources are of little relevance
(IMHO of course).
Factors such as air-temp, fuel grade, humidity, type of oil, odo reading,
software, barometric pressure all play a significant role in the peak
output.

IMHO the main purpose of a dyno is to measure the power curve to find dips
or peaks in the power band in order to rectify and retune. If a bike's peak
output is too low in relation to the rest of the power band, we say it runs
"flat" at top revs. This is usually due to a lean mixture at top revs at
must be rectified.

Peak output must be interpreted in relation to the rest of the power band,
not against the owners manual.

Two similar engines i.e. RS and ST should give similar outputs throughout
the power band in back to back dyno tests. If not, look at the test
conditions (odo reading, fuel grade) and eliminate any after-market add-ons.

  
I stay 5000 feet asl. I will wait for a dry hot day and have my bike dyno
tested, record all test conditions and report back. I guess the RS will make
about 85hp in these conditions.

Regards 
Gerrit '01 yellow RS

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