Horsepower figures

[Rob S.]

Anyone care to share their dynamometer numbers? I'll go first (1982 1100e w/ V&H "Street Megaphone" and APE pods):

99.30 rear wheel horsepower @ 8400 rpm
67.73 lb. ft. torque @ 6500 rpm

As reported in the July '82 Cycle World, Suzuki claimed:

108 bhp @ 8500 rpm
67.6 lb. ft. torque @ 6500 rpm

I understand that the 108 "bhp" was measured somewhere else (crank? tranny? brakes?) and that the 99.3 is a real world, rear wheel number. So I'm a little surprised that the new torque figure seems to agree with Suzuki's 1982 claim. Can anyone explain that?

My bike is stock except for the intake and exhaust, and was jetted on a Dynojet dyno by Frank of Powerhouse using the Dynojet stage 3 kit. In addition, Frank had to drill out some other jets that were not part of the stage 3 kit.

PS I can't say for sure that she's noticeably faster, she was no slouch to begin with. But she is definitely running cooler, with a lot less of that lean 'popping' out the exhaust.

I'm going to warm her up and go for a ride right now.

[posplayr]

A stock 82 1100E should dyno typically at 91.8 (using consensus 15% hp loss). Of course this is very much a function on dyno calibration as well.

http://www.thegsresources.com/_forum/showthread.php?t=169468&highlight=dyno

If you are measuring close to 100 hp (99.3), the that is clearly a boost in performance much more than the typical calibration errors of the dyno.

It basically confirms, that if you do pods,pipes and proper jetting that you will give a noticeable increase in hp. This is in direct contradiction to the conclusions drawn by others that pipes don't matter because a pipe by it self doesn't affect output hp.

Your dyno results also don't show the benefit fromt the reduction in weight of 4:2 vs. 4:1 so there is still more than that indicated by the dyno hp numbers.

At face value you are showing an 8% boost in hp. Of course there are plenty of factors that could either make this an under statement or over statement of the conclusions drawn.

[Nessism]

Data from a Motorcyclist magazine article written by Joe Milton. My bad on the title (it should read 1100).

.

[qcktvr]

Horsepower info

Hi Everyone,
Hope you all had a good Easter.
I am still soaking up knowledge about my 1150EF, it has a leaky base gasket that I am gathering up parts to tackle and will have questions for the group...
Meanwhile I have some old info re HP and dynos that I can share, that is not engine specific; my engineering training was in a plant that made engines.. some may find this new?
The value that we use for HP was determined, I believe, by James Watt, his original beam steam engine was used to replace horses that were being used to pump water out of tin mines, so it was the amount/weight of water that was lifted / foot in a time period
Horsepower is not a measured number, torque is measured, horsepower is then calculated from the measured torque value.
I have trouble remembering names these days, but not...
HP = 2 x pye x rpm x torque / 33,000 (pye = approx 3.142)
So, when you transpose the constants you get 5251, and you will find that at 5251 rpm the torque and HP values for ALL engine are equal..
If Suzuki quoted HP and torque numbers back in the day then they would almost certainly have been measured at the crankshaft, to give the best numbers.
SO, if you are now measuring that same torque value at the rear wheel then you have actually GAINED the 10 - 15% that would have been "lost" in getting there..
It is somewhat surprising that your mods did not move that peak torque value up a few rpm, but that's good.
My 1150 has a yosh 4 :1, so seeing the low value at 7500rpm does not make me happy, although by my seat of the pants dyno the power increases smoothly, and rapidly above 6000rpm (has the original airbox with a K&N in it, must have been rejetted well by a PO)
All the best

[rapidray]

The last 1166 I did had 10 to 1 Wisecos, with .348 Web cams, street ported head with stock valves, 36 Mikuni RSs & a V&H pipe. It made 140 at the rear wheel. If has run 9.29 @ 147 with a slick & wheelie bars.
Ray.

[posplayr]

The last 1166 I did had 10 to 1 Wisecos, with .348 Web cams, street ported head with stock valves, 36 Mikuni RSs & a V&H pipe. It made 140 at the rear wheel. If has run 9.29 @ 147 with a slick & wheelie bars.
Ray.

Grocery getter

[matt1100]

I think crank horsepower is the game the manufacturers play to boost their numbers. This takes all the drivetrain loses out of the equation. The Vmax was rated at 143 but the dynos on a near stock one are around 120. Suzuki probably did the same and this was the convention

[sharpy]

GS1000, weisco 1085 pistons, stage 1 yoshi cams, ported, cams dailed, 29mm smoothbores and tingate pipe. 105hp rear wheel. Can clutch the front wheel up in 2nd gear at 60 mph with 15/40 630 gearing, but dont do that too often.

[rapidray]

Normally, rear wheel HP will be about 18-20% lower than crankshaft HP due to parasitic losses.
Ray.

[posplayr]

Normally, rear wheel HP will be about 18-20% lower than crankshaft HP due to parasitic losses.
Ray.

I thought it was determined by consensus to be 15%

[850 Combat]

I believe that the 108 was rated at the brochure (BHP)

[Rob S.]

Normally, rear wheel HP will be about 18-20% lower than crankshaft HP due to parasitic losses.
Ray.

That's why I'm surprised that my torque numbers don't show the same parasitic losses as the HP. It just seems strange to me that the exhaust, pods and jetting would have brought the torque back up to (almost) exactly the claimed 1982 number.

I wish the tuner would have remembered to give me a "before" printout.

Oh, and I do notice a difference from the "before" (probably stock) jetting with the APEs taped 90% closed. I might have lost a teensy amount around 3 or 4k rpm, but it's much stronger from 6 to 9k rpm.

[Rob S.]

Normally, rear wheel HP will be about 18-20% lower than crankshaft HP due to parasitic losses.
Ray.

So is that also true of rear wheel torque?

[posplayr]

So is that also true of rear wheel torque?

As per the definition of transmission efficiency, that would be correct.

[jimb12]

A stock 82 1100E should dyno typically at 91.8 (using consensus 15% hp loss). Of course this is very much a function on dyno calibration as well.

I think you're forgetting that his bike is 32 years old. Don't assume that it had the same hp stock in 2014 as it did when it came out of the crate.