professional dyno tune - worth it?

zukdave wrote: I've had mine on one to look at the a/f ratio across the rpm range.
Looking at a print out of the a/f curve you'll see where it's rich or lean
and will know where to add/remove fue that's the first thing the dyno tuner is gonna do.

I's say take it and have about four pull's with a print out of each for an avarage reading
then go home and look at them and tune it your self.

The power sports department of the tech college I teach at has a rolling road bike dyno, but they are soooooo anal about letting anyone outside their program use it...which I would like to, just so I can cheaply test my theories on engine tuning. I would be there every couple of days if I could.

Still, I 've seen some pretty interesting stuff on theirs - how much would you expect a brand new, just broken in 2016 GSXR750 pull? Most readers of motorcycle magazines would guess somewhere in the 125 - 135 BHP range - right? Guess what our factory demo did.....96 RWHP, consistently, pull after pull.

Surprised? I'm not.....

Veley interestink. :lol:
Steve

I'm no engineer but I'm suspicious of the factory claims of HP. They measure at the crank typically, which is "interesting" but not terribly useful on the street/track/strip. Theres a bunch of stuff from the crank to the actual surface of the rear tire thats gonna lower that number. Plus I suppose the HP at the crank they publish is a hand built specimen tuned to within an inch of its life by factory engineers. Not something you get to ride home from the dealer.

Other dyno surprises...they (the college) tested a new FJR (1300) sport - tourer and it made something like 122 RWHP, if I remember what they said correctly. Not bad for the old FJ!

My buddy claims his previous '83 GPz1100 with RS34 flat slides and a free flowing 4-1, tested on a different dyno by the previous owner made 104 RWHP. I thought that might have been on the high side - as in I'm calling BS on that one. That was before he putt in an 1170 Wiseco piston kit and APE 410 cams... after that he ran a best of 11.4 sec. 1/4 mile...so I guess it must have been fairly close, but my guess is it was under 100 to start with. After the new pistons and cams, it probably was 115 - 120. My stock except BS34 carbs '83 GPz1100 is, and I guarantee this, not making any more than 85 at the rear wheel. Best ET was a traction limited 12.74 @ 109 mph. My '81 KZ1000CSR stock with a Mac 4-1 I pegged at 80 HP....best ET 12.67 second 1/4 @103 mph. My CBX never ran slower than a 12 @ 110, but was much easier to launch than either of my Kawasaki's.

My minty stock 2004 R1 was dynode by the original owner who bought it in Calgary, Alberta. It might be one of those rare engines that everything just worked out right when it went together at the factory. I saw the read-out (which he kept) at 149 RWHP! Again, I'm calling BS on that one (dyno is rigged!), but the damn thing sure is fast - scary fast at times, when the engine temp is in the sweet spot. It accelerates from 100 mph (160 kilometers per hour) like no other 1000 / 1100 cc street bike I've ever ridden, as long as the engine is running between 78 and 84 deg. Celsius, that is.....and holy hell does it get hot FAST in traffic and at low speeds - then the power really starts to drop off....but when it is "on", I've done power wheelies at over200 kilometers and hour (about 125 mph) in third gear!!!

Bowman wrote: I'm no engineer but I'm suspicious of the factory claims of HP. They measure at the crank typically, which is "interesting" but not terribly useful on the street/track/strip.

I am suspicious of both the factory claims and the times and numbers given by the usual motorcycle magazines. Sometimes I wonder how far they will go to promote a new model, or make readers buy a copy of the latest magazine issue.....

One of the most laughable and recent was test riding a new American made big displacement cruiser that was supposed to make 95 RWHP....felt more like 70 - ish to me. It did have enough torque to just chirp the tire in low gear, but ran out of steam at 4500 rpm. In no way would I call it "fast"....

Bowman wrote: I had my 76 750 twin dyno tuned. It definitely helped especially at idle and top end. The guy did 4 runs with different jets and dinking around with ignition. Not cheap and of course if you want to tweak out a last little bit of performance out of a vintage KZ you are probably a moron or have too much money and time. Like me.

And me.

I'm leaning toward getting my bike professionally tuned, or at least getting advice about what changes to make after running it on the dyno a few times. I have noticed the bike really takes off at about 6000-7000rpm. If it could have that kind of power more evenly spread across the rpm range I'd be a happy camper. I'm guessing jetting is spot on there but not elsewhere, or maybe it's more complicated than that. There's probably some sweet spot where the jetting, exhaust back pressure, intake velocity and all that good stuff meet.

I went ahead and tried 87 octane fuel. Seems my bike likes it - maybe a little more responsive? Quite possibly (probably) my imagination, but it's definitely not running worse.

JoHNY wrote: As Kray said, an EFI is a piece of piss. But I can't imagine a tuner taking off the carbs every Dyno run to change the jets, needles, what a malarkey.

I do the tuning myself on my Triumph. Downloaded TuneECU, plug it in and away you go. Having said that, you can fuck it up real easy and fry your ECU with not to much trouble. After 8 years of learning, got there in the end.

www.tuneecu.com/

I helped my buddy put a pair of pea shooters on, removed the EPA crap from the top of his 2014 Boneville and he took it in for $75 dyno-remap and gained 8 hp and I can actually feel the bike is more responsive from the stock set up.

The factory HP numbers were complete marketing BS, everyone was padding their stats to help sales especially with the "superbikes" of the 70's and 80's. The HP Kawasaki claimed was most likely at the crank. A real properly calibrated dyno does not lie, and true HP numbers are pretty disappointing, Many tuners shops run... lets say "a generous dyno" because their customers expect results.

www.superstreetbike.com/how-to/dyno-oper...-results-mythbusters

IMO. quarter mile times and 0-60 and 0-100 pulls are the best indicator of your state of tune.

I will say that if had a dyno run on any one of my bikes, I would be paying way more attention to the AF graph than anything else. That information is very useful, but you don't need a dyno to get that either...

I recommend getting an on-board wideband o2 system. It will be probably be cheaper than getting a Dyno run, and you will have it in case you decide to change the exhaust etc. The most valuable part of having it, is the knowledge you gain about jetting.

You can then also decide if you want to tune for maximum power on a given day, or would like to tune for overall drivability throughout the year, or try to tune for maximum fuel efficiency, etc.

Most people really like the Innovate brand of wideband o2 analyzers. They have many many options, and when they came out, they had a reputation for being as accurate as systems costing much more.

If you google Kzrider and innovate wideband, you will probably dig up quite a few threads on the subject.

I pretty much dyno tune every build I do carbed o DFI the key is to find a dyno operator that will tune correctly in my case I use the owners dyno pa him for dyno time and tune myself he has learned a thing or 2 from me on tuning and some times he will call with question some times I have had carbs off over 30 times changing jets, needle etc bottom line YES good dyno tune worth it take #s with a grain of salt if you put over 100 RWHP on the dyno I use and CAN RIDE that is very low 10s high 9 sec bike off street my own 84 GPZ 1100 made 110hp RWHP and is super streetable with DFI and as for GAS use lowest octane W/O detonating.