Bonneville America Forums Forums Technical Forums Performance Mods NH DYNOS (finally)

Most of us were running rich by one jet size (pretty good for seat of your pants tunning one jet size off)...
I was puking gas out the pipes (but pulled some decent #s) check out Martins (bucky formerly LJ3000) PERFECT

and look at Tim's RWHP #S yikes

enjoy and gleen what you can from them...

Well, I think this proves it, the Black/ Sky blue Speedmasters are the fastest...
Unless you're willing to spend an obscene amount of money on mods

yeah but check out charlie and I...our #s are PDG and just pipe and jets...not even a freak...oh and we ride RED bikes

ok, ok, the red bikes are second fastest

Good job Rob!
We'll drag for beers in NY!
Last guy in buys the beer!
Uncle Charlie

Sweet! I'm safe

gonna havta do something about my dyno. come spring it will look a bit different

Frank

Wow nice numbers guys. Gotta love the great torque curves of these motors.

Those numbers are pretty impressive, you are not far behind Pat and correct me if I am wrong you are not running a big bore or any other major mods. Great Numbers! I need to get mine dyno'd to see what kind of numbers she can pull.

They are all posted here as well in full sized pdf files:
New Hampshire Dyno Runs

Hey Pat, is there anything you would do to correct your weird spikes and dips under 4K rpms? Also, can you FEEL them when you ride? Just curious...

Since Pat is not online at the moment...let me take this one...

Those spikes were more a function of the dyno guy tweeking with the throtle and less a function of the way pats bike was running...
I think he mis shifted...or possibly let it run down to low cause he almost stalled the bike when it was on the machine...thus the big dip...then smoother curve

plus pat if pig rich

Frank

Note the torque numbers with Pat's big bore runs
Schweet

Are any of the above bikes running an 865cc or are they all 790cc (except PAts bike of course)?

Rob,
Are you going to drop one main jet size and keep your pilots? Or, are you planning on lowering both one size?

Dyno talk
http://www.rc51.org/dynotuning.htm
Worth a read to help interpret the results and alternate tunings.

"The majority of tuning all comes down to the Air Fuel ratio. Optimum power is generally around 12.6:1 while the stoichiometric value for a gasoline burning engine is about 14.6:1 for a good compromise of performance & mileage while Dynojet themselves generally target 13.2:1 when they build their own maps."

"Exhaust dynamics is a tricky business, but if the flow is improved & the reversion waves are tuned properly then more fuel can be added & the more fuel you have the more power you get. If you have to remove fuel due to a poor flow design or the reversion waves are kicking back to the cylinder & meeting the next exhaust pulse at any point in the rev range then you simply are not going to get good power gains at that point."

If we could find pipes that would ideally scavenge the exhaust flow by introducing a low pressure zone along the way, or at the least, would not offer pressure backlash against the exhaust cycles, it's all downhill from there to maximize HP or find your desired balance of HP vs. torque via jets & needles et al. I'm not clear which pipes those are, or if they even exist for our bikes. At $300 to $700 a pop for aftermarket pipes, I'm not going to the trial and error method to find them. Got mouths to feed.

To the dismay of many seeking HP above all, I'm going to de-tune mine a little further and bring the MPGs back up to 50 MPG. At my current 13.2:1 offering 40 MPG, I apparently have plenty of head room to cut the fuel back a bit and still not exceed the magic threshold of 14.6:1 (or 14.7:1, depending upon which method you desire.) What can I tell ya - I'm an old fart with a tight wallet.


Footnote: RJS runs a Dynojet brand unit, with the Dynojet software mapping.

My other question is "was everybody running the same octane rating" since that also skews the A/F ratio result?

I was told that my pilot circuit and my needles were fine but the my main was WAY to rich (perhaps as much as 2 sizes) BUT as I intend to drill out the airbox I knew I would be rich...so I may only need drill and drop 1 size (to a 132.5 instead of 130'S)

I will re dyno after the mods and compare results

I think they were all 790s (the non big bore guys).

I'm a 790

the big bore is more for compression that cc's, and an added bonus is you get a WAY stornger forged piston

Frank

Besides being able to tell the third one down is an 865 because of the year SM you can also easily tell by the numbers. So far it seems to be easier with basic mods to get hp gains with the 790.

Finally some real results showing that even modest changes can equate to some impressive gains. What would be really good though is to know Exactly what mods had been done to each bike as some of these details have been left out? A table for instance comparing all these details would be really valuable to us HP deprived aspirants .

Then as different mods are made and a dyno done, these results can be added to the table for all to paw over. Just a suggestion but for me these details would be really interesting

That's an excellent idea. Hey Pat, would you consider hosting spreadsheet?

I think this thread needs to 'stick' around for a bit...

phil, when you gonna get yours dynoed?

Frank

Everyone around here wants $100 a pop so my next best is down in south Miami (I have two Dynojet coupons for free runs). Problem is time. I have none. I will get there, I promise.

I wouldn't mind helping out here with updating a spreadsheet or table, in fact I've done a simple one already and scanned it as a Jpeg but it doesn't come out clear enough to read.



Is there any way to upload a file onto this site cos I don't know how?

John,
Please put the bike type on the spreadsheet, too.

All I can offer is more specs on my bike:
03 TBA 790
Bubs slash cuts
UNI, no snorkle
45 pilots, stock needles, 1 shim, 135 mains
Wrong HD type thunbscrews (set too rich?)

I think I can fix my rich at idle condition by changing
the thumbscrews to Brent's new correctly tapered ones,
and re-adjusting/balancing the carbs.

Anyway, this dyno experience confirmed my seat of the pants
feeling that my bike pulls pretty good. It doesn't get good
mpg, but if I wanted fuel economy, I'd be riding a moped!

Uncle Charlie

Nice format John. I'd like to see motor size also.

No file uploads here but we just need someone with a site to host it....

Uh, Pat???

all that hark work & cash & Uncle Pat only has 70 ponies?

Send it to me and let me convert it to a table and I can set up a link...

Ed, I've just sent the table which I've modified again to you're personal email address. thanks for that Anyone who's detail appear may / will need to send their full details to Ed so he can fill in the gaps eg Type of bike and motor size etc

Bah! Horsepower Shmorsepower -- real men tune for torque



On a more serious note, here's a primer on how to determine optimum shift points for a given torque curve
http://www.allpar.com/eek/hp-vs-torque.html;
Horsepower needs to be where you can get at it (within a viable RPM range) for it to be most useful. For the bikes tuned to peak out their HP at the high revs, your general rule of thumb may be to redline it in each gear if a big ol' twin sidles up to you at the stop light and gives you a cheesy grin. I'd have to run the numbers to verify that though.

Ha ha! I'll be seein' ya in my mirrors while you try to twist it up to 7,000.