Dyno tested today

[MikeWa]

In an earlier thread http://www.venturerider.org/forum/showthread.php?t=60093 I expressed concern over power loss and low fuel economy at altitude. (See the trip report on page 2) So today I had my RSV run on a dyno to see if some electrical or mechanical problem might be the culprit. The first chart is 'one run' in fourth gear and 'one run' in fifth. The Second chart is 'two runs' in fourth and 'two runs' in fifth. We ran in fifth because that is where I experienced the most problems on my trip. The bike was flawless on the dyno.

The rev limiter on my bike clearly cuts off at different RPM depending on which gear it is in. Fifth at about 5600 and fourth at about 6600 rpm. My guess is this is probably because of the speed rating on the stock tires.

Both techs at the dealer reported I could expect about a three percent loss of power for each thousand feet in altitude. Since a lot of my riding on the trip was at 5,6, or 7,000 feet that seems consistent with my experience.

Horsepower is on the ground and after gear reductions and drive train loss. So it is less than the engine horsepower in the specs.

[dingy]

Did they give you any indication as to why the torque curves are dipping around 2700 rpm?

 

That dip is consistent on all 6 runs.

 

Gary

[MikeWa]

Nope. No information. But it is just a couple of ft lbs so overall I am pretty happy with the broad torque band. Might be where the carbs transition or something. My concern was that I was dropping a cylinder or something under a high speed load. But it seems ok.

Mike

[MikeWa]

The dip got me curious. Here is a scan from a magazine comparison of a Royal Star and an old Harley RG. Hmmm same torque dip. I still think it could be carbs from starting out in high gear. Anyone else have thoughts on this?

Mike

[wildwolf]

Hello all.

 

Sorry to bring up an old thread, being a newb to your forum and all, but I have questions and I'm sure you got answers.

 

I'm looking for a new bike. Or even a new used bike.

 

I really like my get up & go (currently riding a Suzuki VS800 Intruder), but find it's aired out when in the mountains or when I want to pass when I'm already going about 50-60 mph.

 

I stumbled across a review of the Yamaha Royal Star Venture S (which I think you guys refer to here as the RSV?) here.

 

This review says this bike has 97 HP and 89 ft.-lb torque. These look way higher than your dyno charts above, so can I assume correctly that the review is using "at the crank" measurements and not the rear wheel?

 

I'd be ALL over this bike if it had FI. I have two carbs on my bike now - and because everything is crammed in there like sardines, a carb sync is a bear. I can't imagine doing 4 carbs! (though I do already have a Morgan Carbtune that can).

 

Are there any performance mods (pipes, air, rejetting?) that can be done to improve things and still keep the engine as smooth as everybody says?

 

Thanks for talking to a newb.

[wrenchrob]

Hello all.

 

 

Are there any performance mods (pipes, air, rejetting?) that can be done to improve things and still keep the engine as smooth as everybody says?

 

Thanks for talking to a newb.

The best performance mod you can do is buy a VMAX.

[jfoster]

Hello all.

 

Sorry to bring up an old thread, being a newb to your forum and all, but I have questions and I'm sure you got answers.

 

I'm looking for a new bike. Or even a new used bike.

 

I really like my get up & go (currently riding a Suzuki VS800 Intruder), but find it's aired out when in the mountains or when I want to pass when I'm already going about 50-60 mph.

 

I stumbled across a review of the Yamaha Royal Star Venture S (which I think you guys refer to here as the RSV?) here.

 

This review says this bike has 97 HP and 89 ft.-lb torque. These look way higher than your

dyne charts above, so can I assume correctly that the review is using "at the crank" measurements and not the rear wheel?

 

I'd be ALL over this bike if it had FI. I have two carbs on my bike now - and because everything is crammed in there like sardines, a carb sync is a bear. I can't imagine doing 4 carbs! (though I do already have a Morgan Carbtune that can).

 

Are there any performance mods (pipes, air, rejetting?) that can be done to improve things and still keep the engine as smooth as everybody says?

 

Thanks for talking to a newb.

 

 

The carb sync is fairly easy, you don't have to remove anything (body panels, etc) and it's very straight forward. There's a tech post with photos that makes it really easy.

 

Some people like the carbs, some don't. The main issue I had with them is the tolerances when they're assembled. One rider will claim to get 40+ mpg and others in the mid 30's. Granted, there's ALOT of variables. I had an 06 rstd and in La with fuel with ethanol it avg 32 to 37 mpg in its three year life I had it. To me it had plenty of power, especially two up riding. If you do decide on one, go with the RSV over the RSTD, from what I can tell, they have better resale. You can't hardly give a rstd away.

[twigg]

Usually manufacturers quote max hp at the crank.

 

A dyno run measures hp at the rear wheel.

 

97 at the crank and 75 at the rear wheel sounds about right.

[M61A1MECH]

I'd be ALL over this bike if it had FI. I have two carbs on my bike now - and because everything is crammed in there like sardines, a carb sync is a bear. I can't imagine doing 4 carbs! (though I do already have a Morgan Carbtune that can).

 

Are there any performance mods (pipes, air, rejetting?) that can be done to improve things and still keep the engine as smooth as everybody says?

 

Thanks for talking to a newb.

 

As stated previously, carb sych on the Venture is pretty simple and only takes about 15 minutes, provided you have a 4 column Morgan Carbtune, otherwise you will be moving the Carbtune around as you do it.

 

As far as performance mods , yes there are pipes available, Bubs makes a full header to muffler system, but they are not always available right away, Bub will not make a production run until they have a certain minimum number of orders booked so the wait for a complete system could be quite long. Many of us have changed out just the muffler portion with slip ons, the performance increase is minimal at best, but it does improve the sound if you like a bit louder exhaust tone. Changing to K&N air filters offers some additional performance as does the install of an after market ignition system like the DYNA 3K. Overall the best mod for changing the overall performance is probably the one where you swap out the read end with a V-max read end. It does not increase the engine horsepower output, but it does change how the bike pulls and performs overall. The factory stock rear end is geared very high for long range cruising comfort at low rpms, the V-max rear end is made for quickness and speed and takes advantage of the engines high rpm power band better. I have not done that particular mod (yet) but the feedback form all the various threads here and other forums is always positive.

Try one you will like it.

[Chaharly]

The dip got me curious. Here is a scan from a magazine comparison of a Royal Star and an old Harley RG. Hmmm same torque dip. I still think it could be carbs from starting out in high gear. Anyone else have thoughts on this?

Mike

 

So do the 1st gens have this problem?

[skydoc_17]

Hey Mike,

NOT to "steal" your thread back on topic, but I wanted to make a few comments about the information you have posted. I have seen this "dip" in torque in other "long rod" bikes before. I call this torque area the "Anti-Sweet Spot" I believe this area is where the engine overcomes the mass of the rotating parts of the motor. This is why everyone says you need to "rev these motors up"! To get past the Anti-Sweet Spot. In other words, if you are "lugging" your RSV around in 5th gear at 2700 RPMS, you have settled into the zone where the engine is actually loosing torque, as apposed to generating it. Your information graphically shows why you shouldn't hover in the 2700 RPM range. We got it right in suggesting that you rev the engine, but until now, we didn't know why it was true. Thanks for sharing these Dyno Charts. I would also like to mention that your bike and the high altitude riding you do would be an excellent candidate for the VMAX final drive! Without any other mods to the engine, you would effectively move your cruising zone out of the 2700 range by about 600 RPMS back into the area where your engine is generating torque. "Bang for the buck wise", this would be money well spent.

Earl

[wildwolf]

As stated previously, carb sych on the Venture is pretty simple and only takes about 15 minutes, provided you have a 4 column Morgan Carbtune, otherwise you will be moving the Carbtune around as you do it.

 

As far as performance mods , yes there are pipes available, Bubs makes a full header to muffler system, but they are not always available right away, Bub will not make a production run until they have a certain minimum number of orders booked so the wait for a complete system could be quite long. Many of us have changed out just the muffler portion with slip ons, the performance increase is minimal at best, but it does improve the sound if you like a bit louder exhaust tone. Changing to K&N air filters offers some additional performance as does the install of an after market ignition system like the DYNA 3K. Overall the best mod for changing the overall performance is probably the one where you swap out the read end with a V-max read end. It does not increase the engine horsepower output, but it does change how the bike pulls and performs overall. The factory stock rear end is geared very high for long range cruising comfort at low rpms, the V-max rear end is made for quickness and speed and takes advantage of the engines high rpm power band better. I have not done that particular mod (yet) but the feedback form all the various threads here and other forums is always positive.

Try one you will like it.

 

Thanks for the excellent response and helpful information. I'm 99% convinced I'll get this as my next bike. I need to evaluate some finances first to see if I can buy new (hate the idea of depreciation, but LOVE the idea of 5 year unlimited mileage warranty!) or used.

 

Maybe I can find a really good priced used Blue 2011 one in the near future.

 

Ride safe.

[playboy]

You do know that the warranty is transferable if you can find a late model one whats left of the warranty is yours. I bought my 07 and had close to 18 months left. Good hunting

[MikeWa]

Skydoc_17

I agree the dip in torque is probably from lugging. The readings are for me of very limited value. A good comparison or baseline to see if things are alright or not. That is about it. Bike dynos such as this one are not showing the actual torque delivered to the wheels. They use a computer program that converts the real torque and hp readings to a guesstimate of what the engine is doing. Hence the similarity of readings for all of the transmission gears. They also factor in some power losses that I don't always agree with. And different dyno manufacturers may use different programs.

 

For those who may not believe this, you don't actually think 74 foot pounds of torque is going to get a thousand pounds of bike and rider moving in any kind of a hurry do you? That is what gear ratios are for, multiplying torque. So I would rather have seen what was actually hitting the ground. Beyond that I can do the math.

 

Also I think converting my differential to the v-max after this test probably alleviated most of the lugging. One of these days I will have it run on the dyno again just to find out.

 

Mike

[florycr3170]

The carb sync is fairly easy, you don't have to remove anything (body panels, etc) and it's very straight forward. There's a tech post with photos that makes it really easy.

 

Some people like the carbs, some don't. The main issue I had with them is the tolerances when they're assembled. One rider will claim to get 40+ mpg and others in the mid 30's. Granted, there's ALOT of variables. I had an 06 rstd and in La with fuel with ethanol it avg 32 to 37 mpg in its three year life I had it. To me it had plenty of power, especially two up riding. If you do decide on one, go with the RSV over the RSTD, from what I can tell, they have better resale. You can't hardly give a rstd away.

 

 

I rode my RSV from Va. to Texas last Sept. At 65-70 mph I got 43-45 mpg. At 75-80 I got 36-40. The bike was a dream to ride that far. No issues with being sore. We rode abour 400-550 miles a day. Plan to make the trip again. I had the carbs synched, valves adjusted, and new plugs before the trip. I run the Blue Sta-bil in every tank.