dyno questions

[HobbyMan]

I am just kinda wondering about how to find a motorcycle dyno in my area. i know that there are services who rent them out but that seems a little pricey. I just want to find out how exactly my bikes are performing and tune them accordingly. If/when I do find one, What is involved in setting your bike on one of these? Anyone who has used one chime in here please. Any tips would be appreciated. I have thought about using the local car dyno but that seams really dangerous. I did not see motorcycle dyno in the phone book soo I don't know where to start.

[mro]

dino's

MC shops are where to look.
Most don't seem to want the business of older bikes like the XS11 so you may be looking for awhile.

Also "you" won't be using the dyno, the shop will.
Having one do more than just make a run on it could get XSpensive.

Use the search Luke..........

Check out the posts where the dyno runs are posted on this site.



mro

[webbcraft2150]

The ones I have scored have been at large bike rallies. Most bike shops can't afford one of these. I am thinkin one of the HD shops in Austin has one now, might wanna call around. I don't know if they will run your XS, might embarass them too bad. What you do it pay your money and then they strap your bike down. Usually will put a exhaust probe in one pipe and sometimes a pyrometer on the head. Then the young buck commences to run 'er thru the gears up to redline in 5th. Not for the faint of heart. They give you a printout and your done. The printout will give you peak torque and horsepower and sometimes exhaust gas readings to check your mixture.

After the run you walk around goin, I"mm bad, uh-huh, I be bad.

[HobbyMan]

well that what I wanted to know. I don't like the fact that some guy is going to touch my bike much less operate the throttle. At a place like that, what would I look at paying for them just to run it through? What are the risks of damaging my bike if I decide to do this? I kinda want to see the difference between the "advertised" HP and what my bike will actually do. Actually, when my friend doesn't beleive what a 27 year old bike can do, I want shove the dino results in his face. Thanks for the Info. I will start calling all of the local shops to find out what they know.

[webbcraft2150]

Can run from $45 to $90 depending on the shop/location. Most I ever paid was $55. More than likely an insurance thing with them operating the bike. They usually roll em up slowley on the rpm. Not trying to do a 1/4 mile time.And they do not redline every gear, usually only the top cog. As for possible damage, I guess you could blow something up, it is after all a full rpm and full load, more than you could put on it on the street. Ain't nuthin gonna happen 'cept raise an eyebrow when you 27 year old bike surpasses a big inch HD HP reading.

[AlanB]

Hi Guys,

My SG has GSXR carbs, Dyna ignition, and a Four into one pipe, and I had it set up on the Dyno at a shop which specialised in that type of work.

The dyno was made and supplied by Dynojet- the American company who supply carburettor kits, So I would start by looking at their website for other locations.

The operator had gone to the States for training,(I am in Scotland!) which included a week in the Dynojet booth in the pits at Daytona, setting race bikes; The guy was good at setting carbs!

The work took most of a morning and cost £120... Don't know where the Exchange rate is now?....

We worked through full-throttle mixture, part-throttle acceleration, and cruising , then played around with the ignition timing. It is pretty scary standing beside your bike as it goes from idle to red-line in top, with the throttle on the stop all the way!

Was it worth it? The bike made 70 BHP before the work, and 95 afterwards; AND uses less fuel. I think it was worthwhile!

AlanB

[TopCatGr58]

Hobby/Andrew,

I found a shop that was willing to do it on my old beast. The Harley/V-twin shops would NOT do it. They only worked on AMERICAN machines!

They do make you sign a release saying that IF your engine explodes, it's NOT their fault! I told the operator to take it easy and to NOT take it over 9Krpm. They have their OWN Sparkplug tach they monitored. But while I was standing there, I could have sworn I saw the bike's tach peg 10K! !

Tech: " Oh, it doesn't have an rpm limiter?? DUH"! ! ! ! !

They didn't run mine to redline in every gear, only took it to 4th, and then started just above idle, and took it WOT to redline!

I was foolish and told them I only wanted a HP run, so I didn't get the AIR/FUEL mixture values, just torque and HP, so was a little cheaper, paid ~$50.00 .

This shop did lots of work on sport bikes and such, so they weren't terribly impressed with the values, just with the WEIGHT!
T.C.

[MAXIMAN]

TC

Zilla's tach pegged ten grand several times when we were tuning it. But that is not accurate. The dynojet we used has a rpm pickup on the #1 plug lead. Zilla was actually "only" spinning about 9400-9500 rpm...

Andrew

Unless you're wanting to "re-tune" the bike a dyno run will simply inform you what it's making. I can tell you a '78-79 stock bike will be making about 78-80 rwhp at the most. The 80-81 will be ginning up a couple or three less and an 1982 Maxim will make about 71 to 73 at the rear wheel ...stock because it is de-tuned for emissions. Mine was making 72 rwhp on the base run. Of course after all the smoke cleared Zilla ripped off a 96 rwhp burst on dyno run #69.

If you're wanting to tune the bike for maximal performance then you need do a few things before you ever put it up on the dyno. Putting a bike on a dyno is analogous to a musician going into a $300 per hour recording studio. He doesn't go in un-rehearsed...it's not cost effective.

Same goes for a dyno run. You can go in "rehearsed" so to speak...or in other words pre-tuned. The closer you have the bike to being tuned the less time it will take to get it spot on.

Then when you put it up on the dyno....if it's lean or rich just pull the carbs and adjust them accordingly...re-install them and make another run until you get it right on.

The Kawasaki shop here charges an hourly rate for the dyno. They would prefer their mechanics to tune the bike. But if you bring your own tools you can do it and fore go the shop rate.


ALSO - Make sure the sniffer filters are clean and the pump is actually "sniffing". This happened to me once on a few of the runs and luckily we caught it. It was giving bogus F/A ratio readings. It is the operators responsibility to make sure that sniffer is actually calibrated and analyzing the F/A accurately. Have him turn the pump on and hold your finger over the end of the probe to make sure you can feel a suction.

The bad thing about an Eleven stock exhaust is it's a 4-2 setup. You'll only get an F/A reading on a stock exhasut for cylinders 1-2 or 3-4 depending on which side you sniff.

If you need any more dyno tips...PM me. In the past year I've ALMOST spent more time on a dyno than I did on the bike with well over 100 runs on my Maxim.

[HobbyMan]

Thanks for the info, I will send you a pm shortly.

[MikeFromMT]

I know this may not help you Hobbyman but I have to tell the story. My buddy called me one day begging me to meet him at a crappy car lot he’d just made a delivery to, “bring your truck, ramps and a winch” he excitedly said. Well it turns out the car lot was once a snowmobile repair shop and sitting in the back covered in snow was a dyno! The owner said “if you can pick it up, it’s yours, it doesn’t work” 3 hours later it was in my garage getting cleaned up and checked out, turns out the problem was a $50 dollar part. Because we were building custom Harleys at the time owning this machine did not make us any more popular with the neighbors. He sold it 1 year later at a bike show we were at for $2,000.
Someone told us used dynos were kind of worthless, maybe you could score one like we did.
(then all of us can show up at your place with our bikes)

[HobbyMan]

yeah, I wish