Got the bike dyno tuned

TxRIIIRider

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Mar 8, 2006
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La Vernia, TX
Well, finally decided to cough up $150 and get the bike tuned on a dyno. It was money well spent! I am running Jardines, and a PC-III and my Rocket has 53,000 miles. I don't have the dyno sheet to post yet, as the guys printer was down, but I should have it next week. However, the first run netted 138 HP and 128 lbs/ft of torque. The bike was running rich and then lean on the top end. After tuning, the bike is now putting 142 HP and 140 lbs/ft of torque! I know all dynos read different.., but that was a significant gain.. and probably even get better MPG to boot!
 
I'm not a mechanic (I'm a CPA, Accountant), but I don't understand how you could get better mileage if you tune a bike that is lean (more air) to run richer (adding more fuel to the mix). The other thing I don't get with trying to tune modern bikes is the way I understand it, the bikes have sensors throughout and the computer monitors and adjusts things on the fly.

Examples:

The Tiger 1050 (other models too, I guess) mitigates heat via the computer. If the heat sensor reaches a certain point the fan will kick on and the computer will actually shoot more fuel into the engine to keep it from overheating.

The Thunderbird actually modifies the tune (for lack of a better term) on the fly to the riding style. It has 2 tunes that it uses for this purpose.

Thus, what I don't understand (I know it's done and works, but...) is how you can tune the bike a certain way and keep it there. Isn't the computer going to adjust and do it's thing anyway?
 
Daryl.. The bike was already running too rich, except for the top end of the rev range, where it was then running too lean, because my PC-III settings were not correct. I was running a canned tune from DynoJet, but I believe my dealer had put the TORs tune on my bike which would have made the canned PC-III Jardine tune run rich. A bike running too rich will make less power also. They actually took away fuel to achieve more power in the low to mid range.. but added some on the top end..

The PC-III comes with an O2 sensor eliminator, which plugs into the O2 sensor plug. With the O2 sensor in place, the computer would definitely try to adjust things to make sure the O2 readings were correct.
 
There is a lot to this, but here is an over-simplified version:

You can tune for lean cruise and still have best output everywhere else. Tune the region where you cruise to lean misfire, then add a couple of percent of fuel, then make sure there is plenty of fuel here for acceleration compensation so that you do not develop a lean hessitation whan you open the throttle rapidly at cruise. Altering when the MAP and TPS fuel tables switch can be a great benefit.

I have tuned my personal bike as lean at 19:1 at cruise with the stock ignition, and leaner than 26:1 when using a good CDI system. But you have to make sure mixture preparetion is decent, or the chamber can become stratified and have excessively lean reagions near the sparkplug(s) that will not fire consistantly. This is not hard in the R3's twin-plug chamber.

The adaptive trims only alter at low throttle position continous throttle and idle. If you adjust the AFR tables in TuneEdit or TuneECU, you can prevent this from occuring.

I hope this helps.
 
Okay, I think I get it. I have the TOR accessory pipe on my Tiger and the associated TOR tune. I have British Customs Hog Slayers on my T-Bird and they call for the TOR tune as well. I reckon I'm good since those are the recommended tunes from the respective companies?

Sounds like you guys are doing other mods that require figuring out new tunes?
 
Better Mileage

The reason your mileage will stay the same or get better is, your bike is running more efficient. The power gain goes along way in propelling it. I added over 50% increase in RWHP to my Bonnie and get the same mileage I got before I did the mods to the engine. Using Tuneboy and a dyno, you can get it spot on. Other than a perfect A/F ratio, by tweaking the timing in places, I increased the torque.
I just got my Roadster home today. I intend to put her on a dyno with the tuneboy as soon as I break her in.
All of th triumph tunes are generic. If you put it on a dyno you will see the lean, rich, lean, rich A/F. On an efi bike, the Tuneboy is the way to go. Or, any other means of remapping your ECU. Once you get it right, you can go back to the uppper % near wot and try richening it a bit. You might pick up some HP there. Won't effect your milage as you don't ride at wop that often or long.
Have a great day.
 
A perfect air/fuel ratio doesn't mean much by itself. You should tune to best output, and let the AFR fall where it will - GIVE THE ENGINE WHAT IT WANTS, not what you think it wants.

Frank - WHen you are ready for tuning, I would suggest contacting Andy at Metric Motorcycles. He has experience with TuneBoy/TuneEdit and will tune to best output, not just a set AFR. Tell him I sent you.
 
142hp, thats exactly what I am getting with a staintune exhaust, 3 pods intake and tuneboy. Maybe thats about it until you go internal with a cam. The guy who done mine said maybe another 10hp with one. A bit of cost for just 10hp. Maybe settle with 142hp for now.....
 
A perfect air/fuel ratio doesn't mean much by itself. You should tune to best output, and let the AFR fall where it will - GIVE THE ENGINE WHAT IT WANTS, not what you think it wants.

Frank - WHen you are ready for tuning, I would suggest contacting Andy at Metric Motorcycles. He has experience with TuneBoy/TuneEdit and will tune to best output, not just a set AFR. Tell him I sent you.
YES WAYNE true how true good info;)
 
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