Triumphrat

johnyC · 01-23-2007

Modifications from stock:
 
 Exhaust: standard headers, Norman Hyde silencers (with mute tubes fitted)
 
 Inlet: K&N pod filters / airbox cut away, 42 pilots, Thruxton needles with two shims, slide holes drilled 3mm, 140 mains.
 
 dyno' results:

The dyno' operator said I was a bit rich at the top and bottom, bang on in the middle. The bottom end was tweaked in on the pilot screws, the top requires 135 mains instead of the 140. But that's only when it's revved over 6000rpm where I rarely go, so I'll leave that for just now. I'm pleased that my 'butt dyno' readings were near enough right to begin with.
 
 I didn't do any dyno' runs as I went along the well trodden path of snorkel removal, restrictor removal, de-baffling the silencers, re-jetting, etc. But I'd say there are two distinct jumps: from standard to modified standard inlet and exhaust, and from there to replacing inlet / exhaust with the pods and Hydes.
 

[ This message was edited by: johnyC on 2007-01-23 18:48 ]

johnyC · 01-23-2007

Sorry guys,

I would go and 'gild the lilly'. I forgot about the curse of the hacker and now the post is full of BR bits.

pabonne · 01-23-2007

Nice looking curves. :-D

How's the seat-of-the-pants dyno feel?

Bonnie1000th · 01-24-2007

Regardless of your power and torque figures, your A/F ratio was lean, not rich like the Dyno operator said.
12:1 is the ideal ratio, your bike had that ratio at 2100 rpm's only and
at the top of the dyno run(6400-6500 rpm's)then was lean all the way.I wonder why the dyno chart shows the ideal A/F ratio at 13:1.
Also notice like the other member said the run was cut out short, there was more power in reserve.
I suggest you to work in the needles, specially if you use the mid range of the powerband.
I hope this help! :-D

johnyC · 01-24-2007

Bonnie1000th,

I already have Thruxton needles with two shims, but If you think I'm still a bit lean in the middle (I must say, the bike goes better than ever currently) it's easy enough to put another shim or two under the needles and see how it goes then.

I had a hunch that I was lean with the 140 mains, but the dyno' man says no :???:

The dyno' operator does a lot of race tuning, races himself, but I'll be speaking with him later today. I'll get back to you.

kliff · 01-24-2007

Quote:

On 2007-01-24 01:44, Bonnie1000th wrote:
 Regardless of your power and torque figures, your A/F ratio was lean, not rich like the Dyno operator said.
 12:1 is the ideal ratio, your bike had that ratio at 2100 rpm's only and
 at the top of the dyno run(6400-6500 rpm's)then was lean all the way.I wonder why the dyno chart shows the ideal A/F ratio at 13:1.
 Also notice like the other member said the run was cut out short, there was more power in reserve.
 I suggest you to work in the needles, specially if you use the mid range of the powerband.
 I hope this help! :-D

Most tuners, myself included, usually looked for a narrow band of 13.4-13.8 : 1 as an ideal performance Air Fuel ratio.
 12:1 is a RICH reading, not lean, as you only have 12 parts O2 to 1 part fuel, whereas a 14 : 1 ratio is lean as you have 14 parts O2 to 1 part fuel.
 
 Johnuc's chart is a GOOD looking AF chart, especially considerring they were able to lean out the near 12:1 numbers on the bottom with the pilot screws.
 
 Your Dyno operator KNOWS what he's talking about Johny, listen to him.
 
 Good deal Johny......looks real good!

[ This message was edited by: kliff on 2007-01-24 06:59 ]

ftl40 · 01-24-2007

looks good to me

Olderyoungster · 01-24-2007

I must first preface that I don't know sh!t.......
I only know how various and assorted Dyno runs and Dyno operators have responded/reacted to the runs of my past: Sportster, Roadster, Sprint, two Bonnies, and one FZ1.

And for a bike with two carburetors (problematic from the onset), that's a run that would suggest that you NOT TOUCH A THING! If your Dyno operator attached his A/F sniffers to those bung fittings at the front of the headers (instead of stuffed up the pipes AFTER the cross-over tube), made sure the filters on his machine were virgin clean, and had all day to mess around with your bike...... his efforts might result in an improved run. On the other hand, he could muck up an already good thing.

Once dialed in on the Dyno, then a guy might wanna be so anal as to attach a portable sniffer to the bike and take it for a spin under a variety of conditions. Only to discover that another day or two could be wasted trying to eek out a better ratio..... but it would then be ideal for only THAT day, over those roads, under THOSE conditions, with temp's & humidity at that time of year.

Your run has resulted in a tad rich upon start-up, and that could be a good thing..... one never rides there anyway. You have a relatively smooth ratio/run with an absolute MINIMAL characteristic 5500 dip! And you're right there in the safe & somewhat environmental friendly zone. With regard to cutting it short, it's obvious there would be nothing more to gain by continuing to spin her up another 900 rpm. HP & torque figures themselves mean little, it's HOW the power is delivered...... and your bike be DELIVERING!

panthercity · 01-24-2007

The ideal, stoichiometric fuel-air ratio is 14.7:1.

Dangerously close to lean and awfully hard to maintain in a carburatted, non ECU engine.

sweatmachine · 01-24-2007

Quote:

On 2007-01-24 08:58, panthercity wrote:
The ideal, stoichiometric fuel-air ratio is 14.7:1.

Dangerously close to lean and awfully hard to maintain in a carburatted, non ECU engine.

Not in my engine! I thought ideal was 13-1. you're saying almost 15-1, that would run hot as hell! No thanks!