Bonneville America Forums Forums Technical Forums Performance Mods Had my bike dynoed

Bad news is I don't have a scanner so I can't put up the dyno printout. My setup is Epcos, Freak, 155 mains, 45 pilots, TBS needles with no shims.

Almost feel like I wasted $30, but I'm glad it was only $30. They measured a peak 76.97 hp at 7200 rpm, and peak torque was 56.16. Now I told the guy this can't be right. I've seen enough dynos posted here to know that there's no way a Freak is going to put out that kind of hp. He said that their dyno was spot on having run many Victorys(my run was at a Victory dealer) through it getting 85hp out of the box from their 100 inch motors. I still don't believe him though that this dyno is accurate.

They couldn't measure air/fuel ratio, because their dyno doesn't have that capability. Torque and HP have a slight dip from ~4700 rpm to ~6500 rpm, but the dip is only about 3 ft/lb. Horsepower shows a similar dip as expected, but nothing dramatic.

I wish there was another dyno here locally for the same price as they charged for a run so I could compare.

Not a chance in hell, unless you have like the powerplant of the century. You're not sporting a turbocharger that you didn't tell us about are you?

Beg your pardon, SalMaglie, let me rephrase: those numbers aren't impossible, just rather unlikely. I'd love to see what another dyno would say.

Well, I did ask for his pardon, after I thought it over, and realized that my first post had been unnecessarily critical and abrupt. I do have my moments where I'm "that guy" like anyone else

Nope, that's why I don't believe them when they say it's an accurate dyno. I even told him about your bike Pat, and how much work you had in it and what your dyno numbers were.

Oh well, at least I got to see that my bike doesn't have any nasty dips in the midrange, so I won't need to shim the needles. But I still don't know if I'm running rich or lean or if my 155 mains are spot on or not. I did put a fresh set of spark plugs in before getting it dynoed, and the old ones were a nice tan color.

I think I'll leave everything as is, and just ride the pi$$ out of it.

No offense taken Michael. Like I said, I don't believe those numbers for a minute. That's why I said I almost feel like I wasted $30. But then going in I didn't really care what the peak numbers were, I just wanted to see if my needle and main jet setup were the right combination.

Sal,
As long as the hp curve is a constant upward line and the torque is near flat, you are good to go.
Maybe I should get my bike dyno'd there and get really high numbers?

Yep, the graph looks good enough for me.

I don't think those Victory owners could handle your bike dynoed there. You'd embarass those stock 100 inch engines by putting out the same or more hp as them with that little 900cc motor of yours.

But you're welcome to come out Pat and stay at my place. It's only just down the road from you, right?

Ah, maybe when they realized it was a Brit bike, they instinctively did the Euro HP conversion

On the bottom of your printout, look for a sae rating. This rating would tend to make the #'s read a bit higher than normal if this feature was used.

It would not however add 10 hp to a 60hp machine.

Something definately up with their dyno.

SC

Nothing of note on the bottom of the printout, just says "*Correction Method: Standard". This was done on a DYNO-mite dynamometer.

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Something definately up with their dyno.

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Well they didn't believe me, and I tried to press the point. Told them I'd seen 30-40 dynos posted on this forum over the last 3 years and those with similar setups as mine weren't getting anything close to the kind of hp that Victory delaer was saying. I said typically it's around 60-65hp with the same setup I have. After reinforcing this 3 or 4 times to the guy running the dyno when he tried to refute what I was saying, I just let it go. Let 'em live in a dream world. But I will tell everybody who asks and wants to take their bike in to get it dynoed that they won't get a realistic readout of peak hp.

And while it is nice to get accurate readings of peak torque and hp, more importantly is to get a nice linear curve across the rpm range. And for that I suppose their dyno was useful to me. At least the guy running the dyno was impressed by my bike, but obviously he's livin' in a different world.

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DYNO-mite dynamometer.

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Was this guy the one running it then, maybe?

Sounds to me like they need to take one of those "85hp Victorys" to a different dyno...

It was disappointing to say the least since there's few dynos in Tucson, and none this cheap. Might have to go to Phoenix to find one that's accurate and inexpensive.

I've worked at a race car shop here in Phoenix (Performance Chevy Products) which has a dyno and does circle track engines, mostly. Also, my life-long best friend works in an engine shop in Tiffin, Ohio, which has a dyno (Riverside Engine, Inc). These are regular engine dynos, not chassis dynos, by the way.

Computer controlled dynos can be programed to print out whatever the dyno man wants. Typically, a shop will load in a 10% fudge factor - higher, of course. This is because they dyno their own motors and don't want to have lower powered products than their competitors.

Another thought I had, Derek, is that the Victory shop there in Tucson (usually pronounced TUCK-sun here in Phx ) might have programmed their dyno to show estimated crankshaft figures, which are higher than what a chassis dyno would show, i.e., rear wheel HP.

I don't know of a reliable bike dyno here in Phx. or I'd suggest it. You could PM DanB from this site, to see if he knows of a good place.

I know some people who should be able to point me in the right direction up in the Phoenix area. A couple of guys I know own Biker's Bay up in your area, and while they don't have a dyno, I'm sure they can recommend one.

You might be on to something about how Victory gets their numbers. I was reading a comparison test that had a Victory Hammer in it and they said it had 74 hp at the rear wheel. That's nothing close to the 85hp I was told.

Your numbers sound about right at the crank. Some dynos can be programmed to estimate crank power, but I have no idea how accurate that would be.

That sounds more likely. Considering the Victorys run belts and different trannies, I would imagine the driveline losses would be different than ours, so their fudge factor would be off too.