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4-5 Gas Dyno Tuning 101

Started by 1931jamesw, November 12, 2013, 01:27:51 AM

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1FSTRK

Quote from: INDEPENDENT 1 on November 22, 2013, 08:04:22 PM
It looks like your post was edited. At any rate never mind my post; sorry it wasn't helpful. If you do decide to try a 4 gas tune out, please let us know your experience.

The edit was clearly maked ADDED. I have high lighted the edited part in red for you below. Not sure what I added has to do with anything you posted.

So far we have that the 4-5 gas makes it quicker for the tuner that does not have enough O2 tuning experience to know how to interpret the graphs and data logs, that is once he learns to interpret the 4 gas data. The 4 gas also reads O2 when tuning the fuel curve so it seems that it has been implied that most of the emphasis is on time saved when tuning.  The biggest implied advantage is when tuning the timing tables, but that is just my understanding so far. It seems that when specific questions are posted we get general answers or no answer at all.

Quote from: 1FSTRK on November 22, 2013, 04:18:57 AM
I too have learned from this thread. I never questioned the usefulness of the additional information and insight you get with 4 or 5 gas data. I have wondered about some claims made that it is a better, and faster way to tune a Harley running the Delphi fuel injection system. Because I am both a performance and efficiency nut I have contemplated traveling to find a tuner that uses the 4gas system and have my bike tuned just to see what I might be leaving on the table. It is presently tuned with TTS and runs closed loop in the cruise section of the AFR table. This combination delivers just over 130hp from a 110ci that gets 45-48 mpg on a trip and no heat issues in normal town traffic (I do not do parades and such).

My questions to marc99 are

What specifically will I gain from a good 4 gas tune?

Should I expect improvement in some of these areas, or somewhere else (high rpm, midrange, touring, blasting around town, smoothness, or engine life)?

What will I give up? I see that not much effort is put into utilizing the O2 feedback and closed loop that the Delphi is capable of. I can often ride in southern NY and NJ at sea level one day and be in the mountains of NY and VT the next burning god knows what different gas.  I am not married to closed loop but I do like the trouble free performance that it has provided and do not want to rob Peter to pay Paul. So what if any is the downside?

Unlike many here I have no problem traveling to get a quality tune, I bought the bike to ride it and it does not care where we are going or why. As far as the cost of the tune I see that as an investment to get the most out of other money already spent as long as there is clear improvement to be made.

I look forward to your answers and thank you in advance for your time.

ADDED
Is there part throttle and mid rpm areas that can be tuned with your system that can not be reached with the Dynojet and O2 sensors?

Or, will I just get more power in these areas because you get more,or better data there?

"Never hang on to a mistake just because you spent time or money making it."