Dyno results hot off the presses!

[pggg]

Like you say T.C. numbers on paper are pretty much just academic. I've swapped various 80' 78' cams around and they always slotted in perfect. Actually 78' cams have less lift on the exhaust and the slight duration increase knocks the low/mid, even with the bigger 80' valves. A good kick from 5000 on though.

[Dan Hodges]

cam journals

Originally posted by TopCatGr58
Hey Pggg,

Thanks for the input. No, the shop was very nice, I had stated that I was looking for the "HP" results, not really looking for Tuning process.....my faux paux, and so I got it done for $50.00. The guy sitting on the bike was the newbie being taught by the guy on the ground. So...I wondered if he really cracked the throttle wide open or not? But aside from like you said, a slight lean condition going into the mains, it pulls fairly steadily up to the 7.7k range and only then slightly drops off. I'm happy with the driveability and performance of this machine, and I don't usually run below 3.5k anyways, so that little blip doesn't really ever come into play with how I drive.

Next time I'm into the carbs I may drop another size larger jet in, 120's vs. the 117.5's, but that's about it. I don't have the adjustable needles on my slides, and I don't want to go tearing them apart to try to put shim washers in them!

Maximan came up with the idea of getting some of the 78-79 series cams and putting it in my head, for more lift and duration, would be a nice combo with my larger valves, but I'm concerned with how well a different set of cams would match up with the cam journals/bearings in my head, since I thought they were machined matched to each other at the factory?

But this bike has more than enough power to get me into trouble if I'm not careful and respectful of it, so I think I'll leave well enough alone for now!
T.C.

Maximan is correct and the cam's are interchangeable.I have several set's of cam's both early and late and the cam journal's are all within one thousand's of one another.You can check the shop manual to verify this. I also have three set's of pristine head's and the journal's are within spec from journal to journal.The 78-79 cam's will make 3-5 hp more in the 5000 rpm and up range vs the 80 and up cam's.I used 78 cam's in my 81 for sometime before I bought a set of hardweld cam's.I sent a set of used cam's from a 79 motor to have the cam's hardwelded and reground.I installed them and they have over 5000 mile's on them at this time and are perfect.I bought a ton of part's just so I could compare all this stuff because the dealer was too stupid and could not answere all these question's.Yamaha went to the big valve head's because when they removed the big cam's for emission's purposes they gutted it.The head's got some of it back,but not all.The early cam's have 12 degrees more duration and tighter lobe centers than the late one's and will definately help the top end,but no they are not as strong from 4000 rpm rolls in high if you do that sort of thing.An eleven has lot's of midrange to begin with but need's top end,so a cam change is in order for you, especially with the 1180 motor.More cubic inches without better breathing will only make more low and midrange,but little if any more on top.

[dragxs11]

Good info Mr. procamper, You've finally inspired me to get down to the dyno. That rich dip you've got on the low end can be helped by turning in the pilot screws slightly. If thats not enough, you've got to find a way to drop the needles just a bit. That will immediately take away your accross the board richness. The main jets may come into play if you still go rich up top. My bike ran great at lower altitude, but up here in Reno I'd get the same low end bog. So yesterday, I dropped the needles and it transformed the bike. Now I'm testing to make sure I didn't go too far. I'll get back to you in a bit if I can get into the dyno.
80sg
1179 kit
mac 4-1
stage 1 jet kit
drilled air box
accel coils

[MAXIMAN]

TC

I just gotta know who did your overbore? Who actually bored the cylinders? I know you have an '81 and they didn't turn up as much power but with that kit and a 4 to 1 header it seems you'd be turning out something in the mid 80's on RWHP. Are you sure the Dyno operator knew what he was doing?

Cg

[TopCatGr58]

Hey Maximan,

Well, he's a little funny bike racer, at least it was his shop, perhaps you've heard of him??

http://www.larrymcbride.com/news.htm



So... I think they knew what they were doing, as to the matching of the size of the pistons, rings, and bores, cause they said that that was what they did!

The Dyno people may not have done my run as good as they could have, the guy actually sitting on the bike was "LEARNING" how to run the Dyno, but the instructor tech was there. So..whether he really cranked it WOT from the beginning, I don't know? And, I don't know if there is any calibration process that they put the Dyno thru to verify that it's measuring properly?

No biggie, Godzilla roars plenty for me!
T.C.

[MAXIMAN]

TC

What did that dyno run set you back in $$$ ?

[TopCatGr58]

Hey Maximan,

It was only $50.00, I think other places had quoted $75.00 or so, until they found out it was a 20+y/o Metric machine, then they wouldn't touch it, they only wanted American V-twins!
T.C.

[pggg]

An accurate calibration process is a crucial requirement for an accurate dyno result. If the operators are 'slap happy' then the resulting figures aint gonna be trustworthy.

[octane]

Hey T.C. - those guys at Sport Cycle Center are pretty cool, but if you decide to do a comparative run on another dyno, D&D Import Cycle is a great place. It's on Little Creek Rd. in Norfolk just a few miles from SCC. Not sure if they're one of the shops that didn't want to take a chance on an older machine, but it would surprise me if it was! They helped me do some dyno tuning on my little GS500 last year. Good guys. They're online at www.danddimportcycles.com

[GNEPIG]

.. i dig the springer on that triumph
did you see the crash page?

[xs650mike]

I knew there was a reason I don't do stoppies when on a group ride!

[octane]

Originally posted by xs650mike
I knew there was a reason I don't do stoppies when on a group ride!

Maybe he'd have pulled it off if he were wearing his yellow pants!

[turbopete]

Can't see why any dyno operator shopuld refuse to dyno any bike that has enough oil in it and passes a visual inspection. A full-power dyno run puts only about 40% of the strain on a bike as a full-power road blast from what I understand.
Take my turbo bike as an example: I would never use more than 300HP on the road as it is pushing the boundaries of the rods. Heard of some snapping recently at 360HP. Now, I know a guy called Roger who had stock rods in his bike and it dynoed at 460HP

[GNEPIG]

Here it is men....the good about the 'Ugly'

First picture is of Donny's backside on the 'Ugly', second picture is the results -- check how straight and fat the lines are! Not great big numbers, just a good long, flat powerband.

It looks like I need to go up 1 on my pilot jets to smooth that part out on the emissions line

These guys at Precision Cycle in Sarasota Florida are good!
Cost of run $60 bucks.
Dinner afterwards with the woman: $20.00
Having a big powerful bike....priceless

[IMG][/IMG]

[IMG][/IMG]

[GNEPIG]

Oops...forgot the important part....

Numbers: Max torque - 63.1 at 3500 rpm
Max horsepower - 79.6 at 7500 rpm

and this is me putting the carbs back on after making adjustments