Vrod on the Dyno..

[MisterB]

Noticed this Vrod being dyno-d at my local bike shop, here in sunny Warrington. I've been thinking of getting a Vrod, now that secondhand prices have dropped a bit. So I was interested to see how much power in put out on the rolling road dyno.

First it was run as it came in, that is std apart from a set of loud silencers and a K&N air filter. Thats the red line on the print out. Then it was fitted a dynojet 'Power vison' which is like a power commander, but with a screen on the bars to let you play around with the settings, etc. After a custom map was loaded, it ended up with the blue line on the print out. What is interesting is the line at the bottom of the print out, thats the air/fuel ratio, you can see how far out it is initially from the ideal (the dotted red line), above that line its runing too weak, the final a/r ratio is the blue line, which is much better. Anybody else had their Vrod dyno'd, what did it make?

 

[Fast Lane]

Re: Vrod on the Dyno..

That's an odd looking graph, almost pointless.

There's no reference to RPM or torque output?

 

[Urrell]

Re: Vrod on the Dyno..

That's an odd looking graph, almost pointless.

There's no reference to RPM or torque output?

I agree, it could be the same set-up just in a different gear.

The only difference in the "details" of the two runs is the "PV Mapping"!

 

[MisterB]

Re: Vrod on the Dyno..

Your right, there is no torque curve on that printout, and the scale is speed not RPM. It wasnt my bike so I could hardly demand they print off everything for me. However, I'm back there tomorrow, so if they have time and if I remember, I'll ask if they can give me another print, this time including torque and an RPM scale.

However, the point is still valid, that it runs much better just with a decent fuel map (97.7 bhp to 112.32 bhp). Just interested in how those figures compare to anyone elses Vrod.

I had the impression that Vrods were for the rider who wanted a lot more performance than the air cooled Vtwins could give, therefore I'm surprised if no one on here has even bothered to have their own bike de-restricted and dynoed.

 

[Dazzlin]

Re: Vrod on the Dyno..

The graph is the top gear roll on, so it shows speed against hosepower.

They would have printed off a torque curve which would show revs against torque and also a through the gears curve so you can see the peak power in each gear.

If it came in running a filter and pipes without any form of mapping adjustment I am not surprised the Red Curve looks rough.

This simply shows the improvement made from a corrected set up.

 

[Foxster]

Re: Vrod on the Dyno..

Would be interesting to know if they actually tuned it or whether they got the results by putting a canned PowerVision map on. That AFR line certainly looks much better than before.

I've only heard good things about the PowerVision since it came out. There's a much better selection of canned maps than you get with the SEPST and you the nice option of leaving the PowerVision plugged in if you want and seeing in realtime what's going on.

 

[MisterB]

Re: Vrod on the Dyno..

The graph is the top gear roll on, so it shows speed against hosepower.

They would have printed off a torque curve which would show revs against torque and also a through the gears curve so you can see the peak power in each gear.

If it came in running a filter and pipes without any form of mapping adjustment I am not surprised the Red Curve looks rough.

This simply shows the improvement made from a corrected set up.

The graph I posted isnt a top gear roll on, it was done in 4th gear as are most full power roll ons. The dyno records both RPM and road speed, so it just happened that I was given the printout with road speed, it didnt seem that relevant at the time.

Anyway, I got a bit more info today, the map that was finally loaded wasnt from a std range, it was custom 'made' for the bike.

Here's another printout showing power and torque and RPM, but dont shoot me as its a bit confusing...

The red line is now the final (highest) run while the blue is an intermediate run, when an initial map was loaded, which as you can see made matters worse. For those who dont know how a custom map is developed, its an interative process, done by the dyno operator. After each power run, the map is adjusted in an attempt to give a perfect Air fuel ratio across the rev range. Sometimes an existing map from Dynojet works perfectly, or just needs a couple of runs to tweek it. But in this case, a custom map had to be built over many runs. This process not only includes full 100% open throttle runs, but also part throttle openings, and through the gear runs too. Altogether, I think this one took around two hours of dyno time.

The final point being that if you modify your exhaust/air filter etc, it really is worth getting the fueling right on a dyno.

 

[MisterB]

Re: Vrod on the Dyno..

Would be interesting to know if they actually tuned it or whether they got the results by putting a canned PowerVision map on. That AFR line certainly looks much better than before.

I've only heard good things about the PowerVision since it came out. There's a much better selection of canned maps than you get with the SEPST and you the nice option of leaving the PowerVision plugged in if you want and seeing in realtime what's going on.

I havent used one myself, as my Harleys have carbs, but I found this ad on youtube, which explains what a Powervision can do..
Dynojet Power Vision - YouTube

 

[stevel]

Re: Vrod on the Dyno..

Had my '07 1130 done a few years ago - only engine mod is a V&H Indy exhaust , stock air filter , tuner is a PCIII:

 

[CROOKY]

Re: Vrod on the Dyno..

I do a lot of two stroke tuning on my mopeds,big barrels,big carbs,fancy pipes and filters etc.What takes weeks to set up by the old tweak,test,tweak, test method out on the road can be done in a morning on a dyno with a skilled operator with no seized cylinders from being too weak and normally a 20% increase in power.Also really good to get an understanding of just how critical set up is.A couple of hundred pounds dyno day is cheaper than burnt out valves and ruined bores and a great day out.

 

[heliharley]

Re: Vrod on the Dyno..

I ve just put a k&n filter on, SE race fueler and I think the pipes are tab slash cuts without baffles as they were already on the bike when i bought it. I want to get it dynoed, anybody know who does it near Doncaster

 

[100rs]

Re: Vrod on the Dyno..

"Rocket Centre" at Blackburn are doing a "Dyno & Dine" day on Good Friday. just ?15 for a dyno run and dinner ( probably something from the bacon butty van) usually ?25 for a dyno run
anyone can attend, contact Rocket Centre on 01254297810 if interested
Booked my Sportster in this morning and there is still places left
Not sure what i will learn, but it should be interesting !!!!

 

[stevel]

Re: Vrod on the Dyno..

"Rocket Centre" at Blackburn are doing a "Dyno & Dine" day on Good Friday. just ?15 for a dyno run and dinner ( probably something from the bacon butty van) usually ?25 for a dyno run
anyone can attend, contact Rocket Centre on 01254297810 if interested
Booked my Sportster in this morning and there is still places left
Not sure what i will learn, but it should be interesting !!!!

There's a very big difference between a Dyno run and getting it tuned on a Dyno. IMHO these dyno run days usually have the dyno set 'optimistically' so that those who have paid leave happy with some big numbers

 

[MisterB]

Re: Vrod on the Dyno..

I ve just put a k&n filter on, SE race fueler and I think the pipes are tab slash cuts without baffles as they were already on the bike when i bought it. I want to get it dynoed, anybody know who does it near Doncaster

You could try here, its a list of all Dynojet UK dyno centres...

http://www.dynojet.co.uk/index.php/atcs?type=3

Though since you have a SE fueler not sure how easy it will be for them to set it up for you. Still, the main point is that you'll be able to see how well your bike is fueling (air/fuel ratio) at the moment, it could be ok, or it could be really weak or rich or both during the rev range, the Dyno will tell all..

I dont know much about SE fuelers and SERTS etc, as my bikes have carbs, though I have used PC IIIs and Vs on my other bikes.. but I would make the comment that using 'Harley specific' black boxes for want of a better description, does limit you in terms of dyno shops who are familiar / can set them up in the UK. For that reason alone, I'd go for a PC V as there are plenty of places who can set them up, and it gets you out of the HD dealers grasp, where everything tends to cost a lot lot more ..

 

[MisterB]

Re: Vrod on the Dyno..

There's a very big difference between a Dyno run and getting it tuned on a Dyno. IMHO these dyno run days usually have the dyno set 'optimistically' so that those who have paid leave happy with some big numbers

Indeed lol... one trend I've seen recently is bikes claiming big numbers on the dyno, but they are 'at the crank' figures .. strange given they were measured on a rolling road dyno? Seems the shop get one number from the dyno, then multiply it by say 25% to give a much bigger 'at the crank' number that impresses the owner and he goes away happy and can brag about it to his mates. Problem is no one can really know what the loses are from crank to rear wheel for any one bike, there are so many variables, but for a Evo HD its about 13 to 15% or so I've read.

 

[Tomo.T]

Re: Vrod on the Dyno..

I was given both figures at DWR Aylesbury on my '97 (modified) Evo. Crank was 81 hp and 96 ft lbs, this dropped to 76 hp and 91 ft lbs at the back wheel. I found this a useful comparison and yes, I left with a large grin, which faded somewhat when I later hit reserve at 96 miles. This equates to approx 32 mpg, where before I was getting 42. Oh well ! Its a good job petrol is so cheap !!!:A:

 

[stevel]

Re: Vrod on the Dyno..

I was given both figures at DWR Aylesbury on my '97 (modified) Evo. Crank was 81 hp and 96 ft lbs, this dropped to 76 hp and 91 ft lbs at the back wheel. I found this a useful comparison and yes, I left with a large grin, which faded somewhat when I later hit reserve at 96 miles. This equates to approx 32 mpg, where before I was getting 42. Oh well ! Its a good job petrol is so cheap !!!:A:

I don't want to decry your figures but a mere 6% loss from crank to back wheel is remarkable , double that is a more usual figure.....

 

[Fast Lane]

Re: Vrod on the Dyno..

I don't want to decry your figures but a mere 6% loss from crank to back wheel is remarkable , double that is a more usual figure.....

My thoughts too. Also would like to know how these crank output figures are measured - unless of course your engine is hooked up to an engine only dyno. If that's the case then the rear wheel output can only be guessed and not measured. Why would anybody be interested in figures at the crank anyway?

 

[Foxster]

Re: Vrod on the Dyno..

My thoughts too. Also would like to know how these crank output figures are measured - unless of course your engine is hooked up to an engine only dyno. If that's the case then the rear wheel output can only be guessed and not measured. Why would anybody be interested in figures at the crank anyway?

Only know this from reading up and not experience, but I gather that the crank numbers are handy for factories to use to check that engine power is good when comparing one engine to another as it ignores drive losses. Also used for fine-tuning race engines for the same reason, you can compare true differences in the engine and not have the figures buggered by tyre wear etc.

Pretty unlikely that anyone is going to test crank power for a street machine, its just too complicated to set up. Dynojet drive-on machines are much more convenient and, even though they are less accurate, they do have the advantage of giving something closer to real world numbers i.e. the drive/wheel losses are included. These losses are 10% to 18%. Some dyno places make up a conversion factor for this and tell customers a crank number, but its generally inflated simply to be able to give the customer a big number.

Oh and peak HP numbers are fairly pointless, with a big area under the torque graph in the gear shift area being what to aim for on a Harley.

 

[Bike26]

Re: Vrod on the Dyno..

TOMO8717 had his bike on my FUCHS Dyno DWR Motorcycles, which is running MI systems software, these Dyno's work like no other Dyno, when running the bike the we have a laser looking at the rear wheel rotating so we can measure the exact percentage of tyre slippage between roller and tyre, we then after a full power run hold in the clutch and maintain engine rpm so as to measure the deceleration figure without the crankshaft engaged, this gives us an accurate mechanical drag/loss figure for the gearbox and drive train, with all of these measurements we can give a true rear wheel and crank figure.
The figures we had for his 1340 Fatboy were:-
83.2 hp 99.4ft lbs torque @ 5626 rpm @crank DIN
76.0 hp 91.0ft lbs torque @ 5626 rpm @rear wheel DIN
I think I may have given TOMO8717 a dyno print out with a different correction factor however DIN is the one most people seem to use.

And that's how you get crankshaft figures without removing engines or guessing!