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Zed
7th July 2004, 09:37
Is it important to you to know exactly how powerful your motorcycle is? If you have it dynotuned and find out the performance does it change your attitude towards your bike & maybe even the way you ride it?

I've always been one to "feel" the power in my bike and know whether or not it is grunty, and I can't say that I've done much modifying over the years. Now that I am getting some mods done to my bike I am curious to know its stats, even though I won't be able to campare it to what it was like originally because I didn't ever have it dynoed. Stock standard these CBR's claim to put out:

CBR600F
Specifications



CBR600F - 200014 - E
Specifications CBR600F (ED-type)

Engine Liquid-cooled 4-stroke 16-valve DOHC inline-4

Bore ´ Stroke 67 ´ 42.5mm

Displacement 599cm3

Compression Ratio 12 : 1

Carburettors 36.5mm slanted flat-slide CV-type ´ 4

Max. Power Output





106PS/12,500rpm (95/1/EC) (78kW/12,500min-1)
110PS/12,500rpm (DIN) (81kW/12,500min-1)







Max. Torque



6.6kg-m/10,500rpm (95/1/EC) (65Nm/10,500min-1)

6.8kg-m/10,500rpm (DIN) (67Nm/10,500min-1)




Will be interesting to me to see my change in perspective about knowing exactly how powerful my bike is. :shit:


Zed

White trash
7th July 2004, 09:39
Nup. Not important to me. I couldn't give a rats arse.

I was still sticking in the slipstream of Gixxer 1Ks at Pukekohe a couple months ago and I'm pretty sure I've only got 2/3 their power.

vifferman
7th July 2004, 10:11
I think that knowing that is only important for "bench racing", or maybe ego masturbation. What's more important is how it rides - whether the power it does have is usable, is enough for what I want to do, etc. For that reason, I've regeared my last two bikes, and fiddled about with the tuning (shimmed the needles etc.) to eliminate flat spots, backfiring on deceleration, etc. I'm not racing, so I don't need every last poofteenth of power available, nor do I need to know if it's more powerful than other VTRs (what's the point of that, when it's less powerful than other V-twins on the market?) I do know that it has more power than the three other VTRs I've ridden, but that's measured solely by the seatofthepantsometer and the wheeliometer.:msn-wink:

Motoracer
7th July 2004, 10:30
Is it important to you to know exactly how powerful your motorcycle is?

Nup, not at the moment. I know that the only thing holding me back from being right up there in F2 is me and not my bike. I feel good about not having to worry about the bike cause I know that it is powerful enough, so all I need to do is improve my skill level.

I can confirm this cause after exiting Castrol at Pukie, I was chasing a ZX-6R racer who does 61s, I stayed with him for the whole of the back striaght right up to the braking point for the hairpin. Then I had to say :bye:, as he flew past a few more meters before anchoring it and attacking the hairpin like nothing I had ever seen before! :eek5:

Jackrat
7th July 2004, 10:32
I guess if your going to spend bucks, your going to want to know if the moneys been well spent.
I've never been interested in facts an figures myself,but if I wanted a more powerfull bike and was spending heaps it would simply be good to know.

merv
7th July 2004, 12:14
Zed, shame you didn't have a base set of numbers to compare with. I know its insurance paying so not quite as important as if you were spending your own money you'd want to get your monies worth.

Me, I'm a bit the other way, never bother modifying my bikes (too tight eh!). Just keep them in top shape and if I want to go faster just open the throttle. Reason I say this is we all know the power curve climbs all the way up to the peak power point. I don't race these days (and when I did it was in the dirt) and can ask how often do I ride at the peak of power? Rarely.

In my days doing enduros one of the fastest rides we did was in Waitarere forest - those long sand straights. I found I could ride past most people (I was lighter then eh!) and they'd say "what you done to your XR?", I'd say "nothing, just open the throttle and hang on". I must have been the only person in NZ running a stock muffler. Don't ask me about what happened in rough going though, I was slower there than I'd like due to lack of fitness, but then I'd be riding through the tight tree bits at nothing like peak power rpm. So what use would a hot pipe have been to me? Certainly no use on the wallet.

With Spud and his mates about he doesn't want me riding my VFR above 100km/hr which is 4,500rpm which its probably turning out about 35hp at if on the throttle and probably sweet f'all given the light throttle you've got to use to stay at that speed - maybe 10 - 15hp.

I've already given my WR a squirt on a sealed surface and found it easily does 160km/hr before I buttoned off and how many times am I going to hit that speed in the dirt? Does it need a hot pipe? Nah, its way fast enough now.

Would I dyno them? No need, too old to worry about it now.

Hoon
7th July 2004, 12:26
I reckon its important not only from a racer perspective but also a street rider.

If the specs say your bike should put out 100bhp but when you get it dynoed it only says 90 bhp, you know straight away that theres a problem that needs to be fixed (lets ignore dyno inconsistencies for now). A lot of people buy their bike, then read somewhere what the claimed output is and then automatically assume that is how much power THEIR bike is making.

The fact is on a good day, a good bike which has just rolled out off the factory floor might make close to that (once again ignoring factory inflated figures or deflated in the case of govt restrictions) but most the time the bike will be way off its optimum due to slack factory tolerances (and wear if its not new). Plus, Yagasumo who was on the milling machine that day might be fuming over the 200 yen he lost playing mah jong at lunch and not paying enough attention to what he was doing!

Anyway I reckon its important to know how much power your bike is putting out as it gives you a general idea of the state of tune and wear it is in. If you go throwing dynojet kits and race exhausts which promise 10 bhp increase before getting it sorted you will only reap a portion of those benefits.

Also theres a lot of piece of mind in knowing your bike is running sweet as and near optimum if you can get close to the claimed output!!!

Drunken Monkey
7th July 2004, 12:28
I think the dyno charts inthemselves aren't necessarily important, but, especially if you're racing, the data, combined with your seat-o-pants-ometer can tell you some useful information. You may make a change which, for whatever reason, makes you feel faster, then find your track times have dropped a second. A dyno chart may show you are building more mid-range power and torque, but you started suffering at the top. Seat-o-pants-ometers can at times pick up the most tiniest of differences, and other times miss some obvious changes - they're not exactly scientific.
Also, if you're going to spend the money on an after market EFI computer/tuner, you might as well get the best out of it, as 'generic' maps may not be best suited to the quirks of your particular machine.
The only other thing I can think of is from a diagnostic perspective (as per Hoon's comment) = you may find you're a lucky bugger who got a few more horsies than the other new bike buyers for whatever reason, or perhaps ended up with a lemon.

If you've got the cash to burn on a dyno test, go for it. Then you'll know for sure if it's you. It's also not like you'll get nothing out of it at all...

DEATH_INC.
7th July 2004, 12:41
I've done a few runs over the years,the gixx the 12 and of course the turbo.The gixx was just to see what it had,same with the 12,but the turbo was more diagnostic,playing with stuff to see what worked.That's where the dyno shines,try holding on with one hand at 200+kph trying to adjust a fuel map with the other.....

Mooch
7th July 2004, 14:05
Zed ,
If your moding your bike for more power then it's worthwhile getting dyno runs done , that way you'll know if your moneys well spent .
Use this site for your stock starting point.

http://www.sportrider.com/bikes/146_Weights_Measurements/

As for how important HP / torque is , Doesn't make me ride any better or worse and there's pently of bikes with a ton more power. More importantly there's pently of riders who can out ride me using half the HP (Eh paulinnz !)
A few of us had our bikes dyno'd at motormart , it was more about seeing where the bikes power was at compared to manufactures specs and a bit of fun .

Looked something like this.

Yamaha FZ1 143 hp , 123 bhp (Standard)
MV Augusta 135 hp , 114 bhp (Standard)
Ducati 748R 106 hp , 104 bhp (Lots of mods but not sorted)
Last week
Ducati 748R 106hp 110bhp ( Sorted part throttle fueling I hope)
The power isn't important , I'm trying to get the bike sorted in the 4.5 k to 7 k region where it's riden most of the time.

Out of general interest , any of you hyper bike riders had your bikes dyno'd ? R1's GSXR's ZX12's ?.

vifferman
7th July 2004, 15:06
There's one problem with the latest crop of 'hyperbikes' that use ram-air to gain a few extra ponies: the dyno doesn't allow for this. There was a recent test in Sport Rider http://www.sportrider.com/tech/146_9912_ram/ where they tried to simulate this, and the best they could do was using a compressed air hose, as even the most powerful fans didn't work properly to simulate riding at speed. I guess the factories either use computer modelling, or buy some wind-tunnel time, or both.

Motu
7th July 2004, 15:14
I had my Honda dynoed before and after I made a set of mufflers for it,just to see if I lost or gained HP,I'm not really interested in what it puts out,but it was interesting to see the power curve.It;s not so much what it puts out,but how it does it,a stunning motor.

I've always been interested in the laptop dynos like Homedyno - these mimic the inertia dyno - with a pick up off an ign point you just do standing start run,then feed in the variables,like weight,tyre circumferance,gearing.Some of them you can take out on the track(trackdyno) and map your HP for all points of the track.Do a google on those key words,I haven't looked at them for a while,but are very cheap for what they can do.

DEATH_INC.
7th July 2004, 21:31
Out of general interest , any of you hyper bike riders had your bikes dyno'd ? R1's GSXR's ZX12's ?.
My ZX12(2000)dyno'd at 157hp,stock apart from a kerker can and modded tailpipe.
The gixx at 118 with just a kerker can,119 with a full rs3 yoshi system......

geoffm
7th July 2004, 23:01
"What'll it do, Mister" is the reason I made my dyno originally (and then the project gained a life of it's own...)
http://pages.quicksilver.net.nz/geoffm/

It is very interesting, and lots of little gains add up, and you would never feel the difference. Moreover, the way the power is developed is also important - a flat spot or peaky delivery "feels" more powerful.

The dyno black box can also be used for an onboard datalogger of racing - I have the loom and software for it but never used it for that purpose, as I ran out of money for racing around then. One day I will take it out for a track day.
Guess I am a geek...
Geoff

bluninja
8th July 2004, 08:23
Dynos are a good way to stop you lying about your riding....Returning to Manfeild to race for the first time after a triple thumb fracture I expected to be slow, but at the next meet I was even slower and I had 400s leaving me out of slower corners. I had it popped on the dyno at the track and it was making 64 bhp absolutely stock. So i was me riding like a nana.....no more blaming the bike.....there was a 130kg guy on a 400 pissing all over me too so I knew it wasn't just that I was a bloater either :rolleyes:

Would agree about power delivery...my old zx9 was reasonable till I hit the spot when it took off at warp speed...fantastic FEELING of acceleration. The RSVR by comparison felt tame...the power just poured on from start to finish...I was going just as fast but it felt easy.

TTFN

AMPS
8th July 2004, 08:37
If you do any mods beyond, say, a can. Then it'll be almost mandatory to get a baseline dyno run so that the tuner knows where fiddling is needed.
Attaining the last nth of horsepower is not as important as getting a nice usable power curve. Taking out the noise/emission control dips in the curve, for example.
Lou

wkid_one
8th July 2004, 20:29
If you do any mods beyond, say, a can. Then it'll be almost mandatory to get a baseline dyno run so that the tuner knows where fiddling is needed.
Attaining the last nth of horsepower is not as important as getting a nice usable power curve. Taking out the noise/emission control dips in the curve, for example.
Lou
Yeah I agree - much nicer to have a flat hp and torque curve than one that goes higher yet has peaks and troughs all over it.

Look at the latest thous - they all seem to have a stutter in the mid range which is wickedly pronounced........the price of total hp pursuit?

bluninja
8th July 2004, 21:00
Yeah I agree - much nicer to have a flat hp and torque curve than one that goes higher yet has peaks and troughs all over it.

Look at the latest thous - they all seem to have a stutter in the mid range which is wickedly pronounced........the price of total hp pursuit?

Hey WKID isn't the stutter at about 5K? All Euro bikes have a hole round about 5k to get them through the european noise tests, which you can then sort after you've bought the bike. If not I'm typing bollox as usual <_<

wkid_one
8th July 2004, 21:08
Hey WKID isn't the stutter at about 5K? All Euro bikes have a hole round about 5k to get them through the european noise tests, which you can then sort after you've bought the bike. If not I'm typing bollox as usual <_<
Yep - check out the dynos of the new thous tho

Penta
13th July 2004, 19:04
Is it important to you to know exactly how powerful your motorcycle is? If you have it dynotuned and find out the performance does it change your attitude towards your bike & maybe even the way you ride it?

I've always been one to "feel" the power in my bike and know whether or not it is grunty, and I can't say that I've done much modifying over the years. Now that I am getting some mods done to my bike I am curious to know its stats, even though I won't be able to campare it to what it was like originally because I didn't ever have it dynoed. Stock standard these CBR's claim to put out:

CBR600F
Specifications



CBR600F - 200014 - E
Specifications CBR600F (ED-type)

Engine Liquid-cooled 4-stroke 16-valve DOHC inline-4

Bore ´ Stroke 67 ´ 42.5mm

Displacement 599cm3

Compression Ratio 12 : 1

Carburettors 36.5mm slanted flat-slide CV-type ´ 4

Max. Power Output





106PS/12,500rpm (95/1/EC) (78kW/12,500min-1)
110PS/12,500rpm (DIN) (81kW/12,500min-1)







Max. Torque



6.6kg-m/10,500rpm (95/1/EC) (65Nm/10,500min-1)

6.8kg-m/10,500rpm (DIN) (67Nm/10,500min-1)




Will be interesting to me to see my change in perspective about knowing exactly how powerful my bike is. :shit:


Zed


Yes, Zed they are all good things to know. The stats you are talking of you will learn lots from, and then you modify things, learn some more and make better changes which makes you bike do all kinds of cool things.

Penta
13th July 2004, 19:06
Is it important to you to know exactly how powerful your motorcycle is? If you have it dynotuned and find out the performance does it change your attitude towards your bike & maybe even the way you ride it?

I've always been one to "feel" the power in my bike and know whether or not it is grunty, and I can't say that I've done much modifying over the years. Now that I am getting some mods done to my bike I am curious to know its stats, even though I won't be able to campare it to what it was like originally because I didn't ever have it dynoed. Stock standard these CBR's claim to put out:

CBR600F
Specifications



CBR600F - 200014 - E
Specifications CBR600F (ED-type)

Engine Liquid-cooled 4-stroke 16-valve DOHC inline-4

Bore ´ Stroke 67 ´ 42.5mm

Displacement 599cm3

Compression Ratio 12 : 1

Carburettors 36.5mm slanted flat-slide CV-type ´ 4

Max. Power Output





106PS/12,500rpm (95/1/EC) (78kW/12,500min-1)
110PS/12,500rpm (DIN) (81kW/12,500min-1)







Max. Torque



6.6kg-m/10,500rpm (95/1/EC) (65Nm/10,500min-1)

6.8kg-m/10,500rpm (DIN) (67Nm/10,500min-1)




Will be interesting to me to see my change in perspective about knowing exactly how powerful my bike is. :shit:


Zed


Yes!! Zed they are all good things to know. The stats you are talking of you will learn lots from, and then you modify things, learn some more and make better changes which makes your bike do all kinds of cool things.

Penta
13th July 2004, 19:13
Nup. Not important to me. I couldn't give a rats arse.

I was still sticking in the slipstream of Gixxer 1Ks at Pukekohe a couple months ago and I'm pretty sure I've only got 2/3 their power.


WT ?? Are you for real!! Sounds like you are full of *&*@. Nothing worse than someone who thinks the're all that and arn't.

FROSTY
13th July 2004, 19:13
for certain Zed -you need to know the stock HP of YOURbike
Before you modify it --otherwise you have no idea if you have gained or lost.
Ill be dynoing my zxr once ive (hrumph) got the motor together.
But only to see if we can iron out the flat/dead area from 6-9.5 thou
If it dyno's up ok Im wondering if i have a low rpm overfuel problem.

FROSTY
13th July 2004, 19:17
WT ?? Are you for real!! Sounds like you are full of *&*@. Nothing worse than someone who thinks the're all that and arn't.
Penta--If you were there--and clearly you weren't You would have seen the Trashman in action. I can vouch that he was having a huge battle with gsxr1000's and I think a GSXR750.
I had the best seat in the house-The seat of a bandit 600 as they warped past me.

White trash
14th July 2004, 07:58
WT ?? Are you for real!! Sounds like you are full of *&*@. Nothing worse than someone who thinks the're all that and arn't.

Penta I don't think I've had the pleasure of making your aquaintance? *extends hand*

Yes, I am full of shit as most of the posters here will attest to. However, in this instance, I remain mostly truthfull.

If you want a demo, get off your arse and come to Puke' on an open test day. I'm sure there's a 600 owner on here somewhere who'll let me rape their bike for a few laps in the interest of scientific testing.

Word of advice: Never question someones integrety/skill level having never met them or seen them ride. :whistle:

riffer
14th July 2004, 08:12
I'm sure there's a 600 owner on here somewhere who'll let me rape their bike for a few laps in the interest of scientific testing.
Shit mate you would definitely keep up with them in the corners on the 250...

Abot time some of these blowhards who hassle WT come out and actually put their bike where their mouth is, I reckon.:whistle:

White trash
14th July 2004, 08:44
Shit mate you would definitely keep up with them in the corners on the 250...

Abot time some of these blowhards who hassle WT come out and actually put their bike where their mouth is, I reckon.:whistle:

Nah, bring it on. Bit of friendly ribbing's all good.

I just prefer people who know me or have ridden with me to take the piss.

Paul in NZ
14th July 2004, 09:40
Wadda bunch a wimps...

The crushing (and optomistic) 56 / 57 RWHP of the Mighty 850cc Guzzi propelling all that iron and blubber along will make mince meat of the lot of yas....

Yes.. Even the mighty Mk2 has been to the dyno. Its a very useful tool in the hands of a skilled operator who can diagnose all sorts of problems from looking at a graph. I've seen people find everything from a buggered chain to the usual ignition / fuel things. Dead clever some people.

Cheers

ps. 56/57 bhp at the rear wheel is actually pretty good for a largely un modded roundfin Guzzi. It picks up 3 to 4 bhp as mine has the rare ZD close ratio, straight cut gear box. (Whines like a banshee) The gutted run about pipes (it's a notto a noise, it'sa budeifull a music) and re jetting chime in one or 2 more as well...

pps All the HP in the world won't change a flywheel (light by Guzzi standards) that is so massive it has it's own gravity field. So the bike won't spool up like a modern 4 and engine braking is pretty well non existant but while I trail in the HP stakes, on the character dyno, my Mk2 is TOPS!

White trash
14th July 2004, 10:48
Wadda bunch a wimps...

The crushing (and optomistic) 56 / 57 RWHP of the Mighty 850cc Guzzi propelling all that iron and blubber along will make mince meat of the lot of yas....

Yes.. Even the mighty Mk2 has been to the dyno. Its a very useful tool in the hands of a skilled operator who can diagnose all sorts of problems from looking at a graph. I've seen people find everything from a buggered chain to the usual ignition / fuel things. Dead clever some people.

Cheers

ps. 56/57 bhp at the rear wheel is actually pretty good for a largely un modded roundfin Guzzi. It picks up 3 to 4 bhp as mine has the rare ZD close ratio, straight cut gear box. (Whines like a banshee) The gutted run about pipes (it's a notto a noise, it'sa budeifull a music) and re jetting chime in one or 2 more as well...

pps All the HP in the world won't change a flywheel (light by Guzzi standards) that is so massive it has it's own gravity field. So the bike won't spool up like a modern 4 and engine braking is pretty well non existant but while I trail in the HP stakes, on the character dyno, my Mk2 is TOPS!

One of my favourite bikes ever is a mate of my dads MKI, full Stuchi (?) fairing, lump of 6X4 as an excuse for a seat. Open megaphones....

Lovely! :love:

Zed
14th July 2004, 12:25
...makes you bike do all kinds of cool things.
My bike already does all kinds of cools things! I'm hoping that the mods will enhance those cool things...if you get my drift. :whistle:

Have you done any mods to your gixxer Penta?


Zed

Paul in NZ
14th July 2004, 12:36
One of my favourite bikes ever is a mate of my dads MKI, full Stuchi (?) fairing, lump of 6X4 as an excuse for a seat. Open megaphones....

Lovely! :love:

Wasn't that for sale recently?

Not sure but I'm sure I saw that on bikepoint????

Paul N

White trash
14th July 2004, 12:48
Wasn't that for sale recently?

Not sure but I'm sure I saw that on bikepoint????

Paul N

Can't imagine Pete ever selling it but maybe.

I hope not, I loved that thing. Used to blag a ride on the not so comfortable pillion seat every chance I got. The old man thought I was mental getting of a cushy GS thou' S seat onto that.

Mongoose
14th July 2004, 13:39
One of my favourite bikes ever is a mate of my dads MKI, full Stuchi (?) fairing, lump of 6X4 as an excuse for a seat. Open megaphones....

Lovely! :love:
That must have been the delux export only model that came equipt with the 6x4 seat :not:

Paul in NZ
14th July 2004, 14:51
Yes, I was suspicious too..

Mine has the std factory 2 x 4 petrified rubber building block with the square edges... What were they thinking??

Mind you.... bang it into a corner and whack it down through the gears and listen to the whine of the straight cut gears under the basso profundo note for the (ha ha) mufflers and all thoughts of sore bottoms disappear...

Cheers

F5 Dave
14th July 2004, 15:59
Zed, back to the thread. Before & after runs are good idea. I’ve done a million runs on my racebikes to determine whether the mods I’ve done are a good thing. Many non intuitive things have shown up. Carbs that are too big have produced more midrange than smaller carbs. Mid size ones have been worse than both. Didn’t ness feel like this on the track.

On my 750 putting on a K&N replacement (in airbox) filter made it lean on top. Maybe it felt a little less rampant after 10,000rpm. Turns out I’d lost over 10hp! Hard to tell on the road. Put some bigger jets until it got worse & then back to best position & the curve overlayed with the original pre K&N, so it had improved breathing but wasn’t the restriction. Removing airbox restrictions can liberate or lose significant power.

Obviously use the same dyno. Dynojets for any failings are the std you can compare with what you may read in mags. A couple of shops in wgtn have special Harley or Ducati friendly dynos that give the ‘right’ numbers :Pokey: , & that’s cool but you have to apply a conversion factor to the readings.

Manufacturers claim crankshaft horsepower, which is probably 25% higher than what you’d get at the rear wheel. Just use the same dyno (preferably in similar weather/pressure conditions) & at least your horses will be the same breed.

speedpro
14th July 2004, 21:53
I just had to have a look to see what F5 could possibly be contributing to a discussion about horsepower and "torque". Just thinking back to his RG50 powerbands as recorded on the dyno - :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh:

Motu
14th July 2004, 23:12
Just a note about K&N air filters that we all fit for performance (me included) the filter part of the name is just that,a word.Do an oil analysis before and after,they pull heaps of crap into your motor - who cares for racing,who cares if you're going to sell it,but if it's a keeper,dump the K&N.

F5 Dave
15th July 2004, 09:13
I just had to have a look to see what F5 could possibly be contributing to a discussion about horsepower and "torque". Just thinking back to his RG50 powerbands as recorded on the dyno - :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh:

Hey! it has lots of torque. :apumpin: Just in a very limited rpm range. . . :o

Mongoose
15th July 2004, 10:03
Lowest rerading on a print-out I have ever seen was 1.5hp and yes it was a motorbike. :thud:

F5 Dave
15th July 2004, 10:11
They put a bicycle on the dyno & we all had a go. Man it was sad. What was scary was Anstey’s attempt.

Low reading from a 250 was when we put on a Beta Trials bike at about 10hp. & yes my 50 would whup that quite easily. :bleh:

speedpro
15th July 2004, 22:03
Lowest rerading on a print-out I have ever seen was 1.5hp and yes it was a motorbike. :thud:
Sounds like F5's RG50 below 18,786 rpm. From there to 19,000rpm though it was a real mean machine. I recall that Anstey actually managed more horsepower than F5's 50 below the aforementioned 18,786 rpm. Wasn't it over a horsepower??

geoffm
15th July 2004, 22:31
Zed, back to the thread. Before & after runs are good idea. I’ve done a million runs on my racebikes to determine whether the mods I’ve done are a good thing. Many non intuitive things have shown up. Carbs that are too big have produced more midrange than smaller carbs. Mid size ones have been worse than both. Didn’t ness feel like this on the track.

On my 750 putting on a K&N replacement (in airbox) filter made it lean on top. Maybe it felt a little less rampant after 10,000rpm. Turns out I’d lost over 10hp! Hard to tell on the road. Put some bigger jets until it got worse & then back to best position & the curve overlayed with the original pre K&N, so it had improved breathing but wasn’t the restriction. Removing airbox restrictions can liberate or lose significant power.

Obviously use the same dyno. Dynojets for any failings are the std you can compare with what you may read in mags. A couple of shops in wgtn have special Harley or Ducati friendly dynos that give the ‘right’ numbers :Pokey: , & that’s cool but you have to apply a conversion factor to the readings.

Manufacturers claim crankshaft horsepower, which is probably 25% higher than what you’d get at the rear wheel. Just use the same dyno (preferably in similar weather/pressure conditions) & at least your horses will be the same breed.

There are conversion factors. the great thing about standards is that there are so many to choose from...
Dynojet generally use SAE, being US based. Others are DIN and JIS. they are all slightly different. It also depends on where they are taking the readings from.

I have found Dynojet (and some other inertia dynos) tend to read a bit high when compared to brake dynos, like the old Heenan and Froude DPX2 I had for a while. There are a number of reasons.

It is interesting playing with dynos. On the FZR, an old beaten up Formula 1 can gave a consistant 1-1.5hp more than a shiny new Pipemasters can. Intake stack lengths made a difference, but the best one on the dyno didn't work on the track
The dyno is at http://pages.quicksilver.net.nz/geoffm/

If I can get some time to work on it, and get it running reliably and consistantly, we will have a KB dyno day at the end of the year or Jan next year (depending on the thesis research timetable). Everyone will have to sign a really bulltproof disclaimer tho.
Geoff

Wonko
16th July 2004, 17:59
. Everyone will have to sign a really bulltproof disclaimer tho.
Geoff

"I will not hold Geoff liable for any damages, and will slide a box of beer his way, as long as my bike dyno's at least 25 HP higher than anyone elses"