Triumphrat

BlueJ · 09-13-2007, 04:45 PM

Whee! Popped over to the local motorcycle place with a dyno for an A/F run, they threw in HP as well (slow day at the shop). Fun to watch the Black on the Rack, I didn't have my glasses on but the curves coming out looked GOOD! Nice and smooth, no lumps no bumps.....

So then the tech hits the print button. Nothing.

And again. Nothing.

They're out of **** ink!!!!

So, *sigh*, I wait for them to get ink to print and send me the results. Bonnielass will stop by on her way home from work with a data cable and a flash drive (she's like that) to try to get the files. I *promise* I'll post the results asap.

One thing I did notice, and discussed with the tech, was that A/F was higher (leaner) than I'd have liked. He said that the fourteens are pretty much as good as it gets, I said I thought 13.1 was ideal, he said, well, yeah, that's the stoichiometric ideal but that only happens on days when the gods are smiling on you and angels singing.

He *did* say that the curves looked way better than a lot of the sportbikes he gets in, smoothness-wise. So now I'm afraid to touch the bike for fear of knocking it out of tune!

Does anyone know if the files I'll get from the Dynojet machine will have RPM's in them? The tech's graphs all had MPH on the X axis, it looked like our choices were MPH or time for the X axis. Without RPM I can't get torque.

sweatmachine · 09-13-2007, 05:28 PM

that sounds wrong, you can change the jetting to whatever a/f ratio you want, angels singing or not.

BlueJ · 09-13-2007, 05:57 PM

Sweat, I agree with you about the jetting. From the looks of it, I probably need to step up to 130 maybe even 140 mains (865cc '07). I think the tech's point might have been 'don't mess with it if it looks good'. But then... these babies looked good on the showroom floor, that hasn't stopped us from messing with them.

What's your feeling on the impact of shims vs. jets on the A/F at different places in the RPM curve??

And, unrelated question - do you have your M's down so far that they hit the tank when they're turned all the way? In the position I like the best, mine do, I'm trying to decide how to stop getting my thumb smashed in there when I'm wheeling it around.

BlueJ · 09-13-2007, 08:29 PM

Well.. the tech didn't hook it up for RPM (miscomm between us). So I've got MPH. I'll calibrate that tomorrow and try to extract torque - but if the RPMs are linear with speed in 4th gear, then I've at least got a relative torque curve already - 94% of max torque at ca. 2800 rpm, goes up fairly smoothly to 100% at 5100 rpm, then down smoothly to 82% of max at 7000 rpm. No big dips that I can see.

Here for your viewing pleasure is the HP vs. MPH plot. 4 traces, 4 runs (2 on each side with the A/F sensor). Pretty consistent, and, to my eye, pretty darn smooth:

And then we have A/F. Same 4 runs, the 2 blue ones the right (runs #1 and #4), the others on the left. Here's the big question: Is this too lean? What can I do (shim, mixture screws, pilot jet, main jet) to richen it a tad at the low end without mucking up the high end? Will this impact my power plot in any significant way??

Thanks for your input - I'd have never done any of this without the inspiration of you ratters, thanks a million!!

bonnieblackinfl · 09-13-2007, 09:17 PM

Yes, you are too lean. If you put a 42 pilot in it, it will help richen it up throughout the power band. The pilot circuit suppies fuel throughout the band.

Greg

edit: I take it that the light blue line was pull #4?

BlueJ · 09-14-2007, 09:26 AM

Not sure whether the light blue was pull #1 or #4 - need to get the files.

42 pilot, huh? I thought that was only for the very lowest end of the throttle. Remember this is an 856cc... does 125 still make sense for the main or should I consider bumping it (and how far?)? What about adding a shim (I've got one 0.5mm shim already)??

I don't mind doing the work swapping these bits in and out, but at $65 a pop for the dyno runs, I'd like to not do TOO many more of them!!

Thanks again, folks!!

bonnieblackinfl · 09-14-2007, 09:55 AM

Sure you could...go to a 127 main and a 42 pilot. Yes the pilot circuit plays thoughout the powerband. However slight, after 1/4 throttle, but it does.

Greg

bronsonj · 09-14-2007, 12:56 PM

BlueJ, where did you get it done? Criswell? can I ask how much it cost?

sweatmachine · 09-14-2007, 03:58 PM

Quote:

Originally Posted by BlueJ

And, unrelated question - do you have your M's down so far that they hit the tank when they're turned all the way? In the position I like the best, mine do, I'm trying to decide how to stop getting my thumb smashed in there when I'm wheeling it around.

They are close, but I raised them up just a hair so they don't smash my thumbs on the tank badges. I was actually thinking about removing the badges all together, but now I have clip ons so I don't need to anymore!

Pics to come in a couple weeks when it's all back together.