My NC30 Dyno Results.

The Hamster · Post by **The Hamster** » Mon Jul 27, 2009 12:07 pm

The way this thread has developed into etty bickering is quite funny!!

But dont get me wrong, I havent thought for a second anybody was having a go at me! It just seemd like you were all getting me down about my bike and slating my bike off as such, when there was clear facts in front of you to suggest otherwise!!!

As for the Dyno Day thread.... It was a bit like the ride-out I organised and led in April...

I had 40 bikes attending, but about 15 of them who initially showed an interest tried to put everyone else off because it was more of a tour around the Brecon Beacons than a fun ride, and they were annoyed because we didnt go over 100mph anywhere! They did turn up, but after about 25 miles they decided to go there own way at break neck speeds and the other members of the forum just carried on and made a great day of it.

Post by **Martin** » Mon Jul 27, 2009 12:25 pm

CRM wrote: Seriously i bet i have one of the slowest NC's out there, allsorts of attempts and permutations, and while on paper it looks and a clean curve, my arse dyno tells me its shite

I don't think it's so much a problem with the bike or your arse dyno mate, more just a problem with your arse and the size of it

Post by **CMSMJ1** » Mon Jul 27, 2009 3:43 pm

kevprojex wrote:
Hamster know's a good place for this
maybe not in this thread spike but i know a sarcastic comment when i see one so go:sex:

i get your point about BMC helping out on the forum, and yes they have a very good reputation for tuning bikes , but it was the way people hijacked hamsters dyno day thread .

and yes its a cracking thread,i bet most people are pissing blood by now .
ps , i wouldnt have made a sarcastic dig at students if i knew you were one ,we dont do things like that do we .

Howdo Kev,

What I wanted to know..and still we have not had it answered..

Is the 48bhp reading a rear wheel reading or a crank reading? If it was a crank reading, what conversion factor did you use?
As easy as that mate

I know that dyno readings vary a lot between manufacturers and types of dyno. Also that corrections for pressure etc can be used to tweak results either way...

The point being that Hamsters bike does have 48bhp and that a properly tweaked on, such as yours, should have 10% or so more...like your 55bhp - on your dyno.

BMC were mentioned, as they had already offered a forum dyno day and regardless of whether Hamster wanted to arrnage a session, I personally would rather support people who support 400 riders and racers.

I have no axe to grind and with the date being changed for the 5th I may get my bad ass down for a run.

Either way..rear wheel or crank? If crank, what correction! lol

The Hamster · Post by **The Hamster** » Mon Jul 27, 2009 4:18 pm

CMSMJ1... Are you blind??

Read the thread again and your question will be answered!!

I mean, what is the problem, wont you have the results from my mouth? Dont you trust what I say? Ive told you the answer to the question and your still bloody asking it? I just dont understand??

Post by **CMSMJ1** » Mon Jul 27, 2009 4:31 pm

The Hamster wrote:CMSMJ1... Are you blind??

Read the thread again and your question will be answered!!

I mean, what is the problem, wont you have the results from my mouth? Dont you trust what I say? Ive told you the answer to the question and your still bloody asking it? I just dont understand??

no..I am a bloody pedant

. I asked if this was rear wheel or crank. I, and everyone else, reckons this is a rear wheel reading. You decided that you would attach a random 1,25 correction to it et voila...a better result.

Kev noted that his tuned and fettled bike has 55bhp on his own dyno.

I want to know if this was rear wheel or is it arrived at with a correction figure.

No problem with you Dave - none at all.. I know you don't want to have a bike that is noted for 48 bhp..but it will be the case that when everyone else takes their bike down it will be low 50s for them too - Kev has a dyno that reads lower than others. It doesn't need the numbers massaging with a fabricated correction to equate to other dyno results.

Does that make sense?

The Hamster · Post by **The Hamster** » Mon Jul 27, 2009 5:54 pm

Post Re: My NC30 Dyno Results.

Let me just remind you of my earlier posting:

viper_biker wrote:
Likewise, crank figure have an calculation. 1RWHP = 1.25CHP

So let me work this out from what you are saying...

On the 13th Dyno Run on the fully calibrated speedometer, my bike managed to pull peak power at roughly 48.22 RWHP. So lets convert that to CHP as you suggest, 48.22 x 1.25 = 60.025 CHP. So that would go to suggest that previously my bike had been running around 57bhp, almost exactly what it should be according to Honda in 1994, and now with a bit of fettling and fine tuning the bike has gained nearly 3bhp.

More importantly, throughout the mid-range the bike has found an extra 6bhp in general making the bike much much better throughout the rev range. It pulls harder/faster and responds quicker now and compared to what I took to the Projex it is almost a completely different machine.

Does this answer your question?? Note the Abbreviations... RWHP and CHP, as Viper_Biker would put it Rear Wheel Horse Power and obviously Crank Horse Power.

And if you will also read Viper_Bikers posts earlier on in the thread, you will notice that he gives the equation to work out the comparative CHP from the RWHP.

None of this made up by myself. I have purely gone on from what has been said on here by the fellow members amongst us, and also with the information from Honda UK Themselves!!!!

So what exactly is it that you need to clarify with Kevin?? I just dont get it????

arsey30 · Post by **arsey30** » Mon Jul 27, 2009 6:53 pm

If dyno readings vary so much, why can't they be calibrated, they must be set up and tested initially.

Is it because they are only used to measure gains or losses after changes and adjustments to the bike?

Just for interest, I found an old dyno chart and spec sheet from a company developing EFI for a bike.
Stated converted crank hp 133, measured wheel hp 119 [around 11%]

That makes my NC30, 64crank, around 57wheel, seems reasonable.

The main gain from carb setting, according to the previous owner, was a large gain aroung 5000, judged by road test.
It certainly pulls far better than my previous NC30, mainly in the 8k to 10k range.

Dave.

Post by **CRM** » Mon Jul 27, 2009 7:31 pm

Martin wrote:
I don't think it's so much a problem with the bike or your arse dyno mate, more just a problem with your arse and the size of it

Yep your prob right, 15 stone aint going to do it any favours is it ?

Post by **CMSMJ1** » Tue Jul 28, 2009 12:02 am

The Hamster wrote:Post Re: My NC30 Dyno Results.

Let me just remind you of my earlier posting:

viper_biker wrote:
Likewise, crank figure have an calculation. 1RWHP = 1.25CHP

None of this made up by myself. I have purely gone on from what has been said on here by the fellow members amongst us, and also with the information from Honda UK Themselves!!!!

So what exactly is it that you need to clarify with Kevin?? I just dont get it????

Right - I typed an answer and crashed my PC..lol

The bottom line is that you got a 48RWBHP figure out of the dyno at Projex. Stop sticking a correction figure on it to massage the numbers. The dyno reads low as Kev told us, so be glad it now works better than it did.

Simple as that. Honda might have said yes, all bikes are crank power. but there are enough of us on here that have had dyno results that show a healthy NC, on a "normal" reading dyno, get between 57 and 60 bhp. More if you tune them. Your religious adding of a 1.25 correction figure is not right. Go read the magazines of the day - they report rwbhp as per everyone else on here. Not in crank adjusted voodoo numbers.

When everyone else goes and gets a dyno run at Projex you will see that they all make from 48-52 bhp on that machine...especially if Kev's moto gets 55bhp and has been fettled by a dyno operator himself...! The people won't have to go and make up a correction figure, or adopt one that Viper offered (no dig G

A quick google will show you multiple options for a conversion for rear wheel to crank..but why bother? The losses your bike has from crank, gearbox, chain, bearings, tyre pressures, brake drag etc etc are different to everyone elses.. the final result, rear wheel power, is what matters. What you got was 48.

Hope that makes it clearer for you - didn't want to poke you in the eye and shout loudest but to purloin a phrase used by kiddies everywhere "You made me do it"

Post by **Spike16** » Tue Jul 28, 2009 12:30 am

surely the conversion figure changes from bike to bike depending on efficiency of the engine and final drive which would be different from bike to bike and model to model