to tuner or not to tuner

[Hoople]

There is also something else which needs to be factored into the equation that is often overlooked. Most all documentation you read these days refer to the fuel we are using as being non ethanol. A stoichiometric ratio for non-ethanol gasoline is 14.6. For just 10% ethanol, it is 14.3. That is a big difference and must be factored in.
Example; If your bike was originally set up to have perfect A/F ratios for idle, cruise, and WOT using non ethanol fuel and now all you can get is 10% ethanol fuel, guess what... You must make another GLOBAL enrichment of .3 of 1 A/F ratio to ALL cells just to keep the mixtures what they were.

I am certainly Happy to see you have not had any problems associated with lean mixtures. You may have a combination of parts & settings that are different from norm. But there is one thing I can tell you with 99% certainty. From the factory, the Front cylinder is set up Map wise to run leaner than the Rear. If the dyno sheets reflect rear cylinder A/F ratio's,, the front is even Leaner than the numbers printed for the rear cylinder which is already lean.

 

[spelasr]

I appreciate the input you offer and your calculations. I am not a tech or anything like that just a rider who wrenches his own and does his own maintenance most of the time.

Please explain this to me since you seem to posses a lot of knowledge on the subject. I am almost convinced (again) why is it that the Fuel Air mixture gets closer to the Seemingly perfect 13 to 1 as the rpms increase and the Power and torque peak out. As I look at the Dyno Sheet it starts out right at 14 to 1 when getting on the throttle and decrease as it goes along to 5500 rpm where it settles at around 13.2 to 1 at around that 5500 rpm range.

I do think I can get more out of the bike but, I am still just undecided. Seems to me that if it works why try and fix it.

 

[Hoople]

Seemingly perfect 13 to 1 as the rpms increase.

13 to 1 is only perfect for a given engine load and RPM. Don't look at A/F ratio as being a fixed value or number. A/F ratio needs to be changed primarily due to engine LOAD. Of course, air density or how much 02 is packed in a cubic foot of air, air temperature, or how much humidity is displacing 02 are all other important reasons but lets say all factors being perfect, the amount of engine LOAD is the number 1 factor.

So lets say that: Idle has basically "no load". Cruising at 50 mph with a steady grip is "medium load". And Quarter mile WOT throttle is "Maximum load".
The A/F ratio is dynamically changing all the time as you transition from 1 mode to the next.
When you look at a given A/F map for a cylinder, it is a function of LOAD vs RPM. You can look at the graph and say "at 2850 RPM with an engine load of 50% I want my A/F to be THIS value" On a factory map there are 170 cells or fields that you can define what the A/F is. There are 10 choices for engine load and 17 different RPM's. What your seeing is a change in cell value as RPM increases.
There is no 1 seemingly perfect A/F. Perfect can actually be from 12.5 to 14.6. It just depends on the conditions at a given moment.

 

[fatboyben]

I would say to tune for sure. I bought a fuel pak compared to taking it to harley shop only because I know me and that someday I will make another pipe, intake,(edit) who knows what I will change again. Just my 2 cents.

 

[spelasr]

Holy (EDITED), I guess I do have a lot more to learn about all of this, and I thought I was being smart. I guess I was wrong and man enough to admit it. What to do, what to do. I guess basically it depends on the riding conditions and how a person rides thier bike anyway. I remember HD trying to scare me though by saying that I can burn up those exhaust valves in a little as 2500 miles well, 17K miles later still running strong. Maybe my bike is just built closer to the HD factory specs as it should be and can tolerate more changes, Who knows for sure. At least that is what my local stealer is leading me to beleive anyway. I am thinking about upgading to a new Street Glide soon anyway and will probably do things a little different.

Thanks again for the lesson, You must be a Dyno Tech or something. Maybe an HD Mechanic who knows but, your input is appreciated.

Thanks,
Ray

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[Hoople]

It was not suppose to hit you like a ton of Bricks Ray. Next time say Holy Smokes. Sorry about that.

 

[glider]

It was not suppose to hit you like a ton of Bricks Ray. Next time say Holy Smokes. Sorry about that.

Language is not allowed on the forum, sometimes it hits you like a brick and other times it will remove your account.
There's no benefit at all to using language to express a thought.

 

[Crocker]

I run a RB lsr 2-1 on my 07 SG, and they are not a easy pipe to tune , they are no canned maps that I no of for any tuners that are on the market for RB, this is what makes it a hard pipe to tune , and what you want to due is call back RB and speak to them, I know somtimes they are hard to deal with but it is his design and he will set you on the rite track, .he is not a fan of most things on the market and he will tell you when running his exhaust what he would do .He will set you straight. and I mean set you staight.if you spoke already with him not his wife .then you know his personality ,but he does know how to get the best performance out of his exhaust even though he is a bit pompass .Soo bottom line is no canned map means extra dyno time to get things rite , I have tryed to use some canned 2-1 maps and build from there ,but really need to build one from scratch for best results.these pipes are built like no others and take a lot of tweeks , if you can find someone who already has gone through this with a RB exhaust with your build and tuner you choose. then try to start from there then have a dyno done.

 

[spelasr]

OK, I am back now after my temp suspension. Sorry that I used that word and will try to refrain myself. Did not realize that such a mild work would be taken as foul language. OK, well anyway, I am trding in my FXST today for a new 2010 SG and will probably do the tuning and power upgrades much differently on this one. I know a lot has changed for 2010 and I will be doing much research. For now, she will just have to be stock for a while. I will enjoy the music on the road though. Picking her up around 2PM today.