You've got it.

The "14.6" value is a place-holder and not a real AFR. It means "make closed-loop work here".

The actual AFR in use is then tweaked with the CLB tables. Which is actually a fairly crummy way to adjust the AFR for closed-loop and the functionality is changed for later versions of the ECU so you can enter the desired closed-loop AFR straight in the AFR tables.

The adjustment is down to about 14.25:1 when you set the max possible bias of 800mV in the Super Tuner software. This is on the edge of the bias you can apply to this type of narrowband sensor, beyond this the sensor is working outside its possible range and its output will be indeterminate and not useful. So, you can't take it beyond the working range but personally I think even 800mV is too much because that's the limit for new sensors and is beyond the limit for sensors a few K miles old. I wouldn't take the CLBs above 780mV.

 

I was/am curious to know if my stock map has the same CLB as the tuned map.
My map used for the Dealer tune is 176AE106.

 

Nobody asked for your opinion. Did they?

 

I don't believe you can get the stock map off a bike. You need to upload one to the SEPST first before you can do anything. I'm sure someone will correct me if I'm wrong but I'm fairly sure that is correct.

 

Truk, I think Bingee got it figured out but at least I understood his comment the wrong way first.
Bingee, we are all here to learn and I guess Truk wanted to point out that your post seemed to have a logic error - as you were referring to increased air. Only reading your answer twice I realised you meant that the tune before increased VE had more air and higher AFR thus I believe we all violently agree how the ECM and smart tune works.

So to be absolutely clear to the rest of the audience, the amount of air that gets into the chamber is always constant given equal conditions. If one increases VE then ECM squirts more fuel to maintain what's set in the AFR table and thus it is the amount of fuel that is increased and engine runs richer.

VE lets ECM to know how much air is entering the chamber and as said before, ECM does not have sensors to measure it and therefore we need to find the right values to the VE table for the specific engine. Based on the VE set value and other sensor inputs ECM calculates how much fuel to squirt in order to hit the AFR target set in the AFR table. And as said numerous times before, the step one is to get the VE's just right by smart tuning or dyno.

What happens in smart tuning is that the engine is put to closed loop, that is, the AFR table is filled with 14.6, which is the value the narrowband O2 exhaust sensors can measure, and CLB table is set to 700mV. Then while driving, the real O2 data is gathered which the smart tune software in PC uses to calculate how much the VE's were off. Despite of its name, Smart tuning is not very smart, as it requires several (tens of) rounds of "reflash-drive-calculate" so instead of smart it is tedious and error prone while a proper tuner finds out the VE's with a wideband sensor on a dyno.
Finally, only after the VE tables are correct, one can set the AFR table and expect the ECM to follow.

As Christmas is nigh, I would like to extend my gratitude to strokerjlk for a premium HD tuner to be active on this forum with the appropriate tone for us who are still on our early parts of the tuning journey -- and to Truk who I know will leave no stone unturned to find out more about getting his engine perform perfectly and sharing his DIY knowledge with the rest of us.

Merry christmas to all and may Santa bring strokerjlk better dyno interface software for SEPST and for the rest of us cheap plug-in wideband sensors along with new ECM software.

 

This thread is more opinionated than fact.

If it came down to who to listen to truk would be top of the list.

Now that's my opinion. You didn't ask for it either.

 

No I didn't ask for it. And, frankly, I don't care what it is. But if that's how you get your kicks. Go ahead. Knock yourself out.

 

This is true, but I believe the actual use for the CLB is to make adjustments for the stoichoimetric value of various fuels or fuel blends. Many people do seem to use this to richen up closed loop values but I think it's better to set the CLBs according to the most common fuel/blend you'll use and tune your VE's.

 

I think are probably right.

The Super Tuner manual is a bit vague on it though (as always). It talks about about adjusting the AFR in closed loop to suit your needs (or some such) without really saying why you would do this - whether for tuning or for adjustment for fuels with different stoic.

I'm kinda OK with it though. I don't see much point in running closed-loop any richer than 14.25:1 (the max you can get with adjusting the CLB). I mean, why throw fuel at an engine when its cruising?

I tend to run a slightly smaller closed-loop range than Harley maps anyway and adjust the AFR with the AFR table. So never find the need to mess with the VE tables, which I am quite happy to get right with Smart tune once per set of pipes & A/C and then leave alone, as Harley recommend.

 

You just have to set the clb to how much of an offset you want from stoich, fuel doesn't matter. The clb value just sets the switching voltage. A clb of 778 will set the point at an afr of 14.45 for a fuel with a stoich of 14.68. If the fuel has a stoich of 14.3 the switch point will have an afr of 14.07. Both would be a lambda value of .984.