This is JMO on this subject, I will have poeple here pissed at me or saying I have no idea what I'm talking about but let me say that I have tuned cars (race and street) for many years and also work on and repair many EFI systems. So read into this for what it's worth. The only observation I have here is that if you use the factory O2's to tune with won't you get the same 14.5-14.7 AFR? Narrow band sensors only can read .5 v either way of that. So we are talking approx 14.0-15.0 AFR. Now with cams and compression increases thats not a good AFR to be running on. I have a SERT and have done the tunning myself without a dyno so far, however I am going to have it run and test the AFR at the pipe to make sure it is close or right on and then adjust from there. My other question is if the bike is tuned on a dyno and they test doing a full wide open throttle thru the rpm range to approx 6000 rpm, now that would make any O2 equiped bike run it in open loop as full throttle postion triggers the ECM to open loop and sets the AFR to the map settings installed there, so cruising down the road in closed loop did that tune help you at all? Common sense tells me no. So unless the map is set so it is open loop at those speeds and throttle postion you will be running at the factory 14.5-14.7 AFR. What I am saying is that when a tunner set the map it is more of a SWAG (scientific wild *** guess) then fact. Most dyno's can't duplicate road conditions of everyday riding. Now I have thrown out all what people thought about tunning. The best way to tune a bike is with an AFR recorder reading the throttle postion,load , and the Afr thru the driving condtions. IMO the rest is just reading HP. The TTS and SERT will allow you to tune the whole package well, and you need some understanding to do it right.

 

When VTuning with the TTS, you create a calibration that has 14.6 in nearly all the AFR cells. This allows the ECM to recieve data in all these areas from the O2 sensors. Using the SEPST, you check the Smart Tune box and it uploads a special calibration that has nearly all the cells in the AFR table set to 14.6.

When you complete the VTune or Smart Tune process, you should be able to set the values in the AFR table where ever you want them and get what you expect to get.

I run a custom calibration that is 100% open loop. Some tune by staying in closed loop and adjusting the CLBS to get the desired AFR where they want it.

 

I too run a 100% open loop calibration, before I did the motor work I ran a smart tune and reset the tables and was not all that happy with it. It ran ok so I went to custom maps and worked much better. there are many ways to skin the cat. Sorry I was just ranting it happens sometimes when you have a bad day, have a few drinks and write on the board...

 

I live in Baytown and would like to get my bike tuned. Can you give my Wolfgang's number and address?

 

I understand the range to be around 14.2-15.1.

I'm not arguing with you but I don't know why CR's or a cam change would negate the value of the NB O2 sensors. In reality they do very little beyond acting as switches to keep AFR's at stoich (in stock form) to meet EPA requirements. They will work in the above AFR range, but not above about 50% TP, so to get AFR's correct above that point will require either a dyno-tune or guesswork using Smart Tune or some other algorithmic method to establish AFR's while in open-loop mode with absolutely no feedback. I would like for a user of TTS or similar flash-based tuner, using NB O2 sensors or running open-loop, how you can gather accurate AFR values without feedback. TIA for anyone willing to help.

There is a competent new player in the flash-based-tuner market, but since the OP's inquiry is limited to TTS and SEPST I will refrain from comment on it here.

 

I know this particular issue is a few months old but since you mentioned it and I'm in the market, can you share some information on the new flashed-based-tuner??

Would appreciate it as I'm in the process of doing some upgrades and a tuner is one of them. I've been leaning towards the TTS based on what most everyone seems to prefer but my service folks aren't familiar with it and are pushing me towards a TMAX.

I'd appreciate any info you can pass along.

 

I think the discussion is how "best" to hit an AFR target across all engine operating ranges and in a varriable street environment. The consensus is that, if you realy want 99% and know you have it, there is nothing like properly calibrated dyno equipment for gathereing accurate AFR info accross all rpms and operating ranges and then a competent tuner to set things spot on. Otherwise lifes a compromise, and you may be kidding yourself to believe otherwise.

In spite of vendor marketing, it is impossible to gather "accurate" AFR readings in the HD engine using the so called WB systems available to the consumer. These products may provide readings, but the resulting AFR is set with arguably the same accuracy as the educated guess systems, and degrade as the sensor wears.

I don't think you will find a TTS user that understands the tool that will claim you gather accurate AFR values outside the stock O2 sensor range. Most understand that the TTS kits does not gather AFR information directly, its just an easy term for reference. TTS, and others, gather the amount of correction the ECU needs to maintain Stoic plus your offset for the operating ranges used (which gets correlated to VE tables). The ECU uses these derived table values plus your desired AFR and timing numbers to squirt fuel and light off the spark. Its more complicated, sure, but the vendor claims of within 5% of optimum tune is an conservative estimate based on vast user experience and of independently conducted fly off testing. Considering all the other variables that effect street tune, 95% is excellent for the street. A DIYer using a broadband sensor (so called wide band) on the street to get closer than 95% is pure marketing, but you will find many here drinking that coolaid.

As far as hitting and AFR target, under typical conditions, the ECU adapts the engine tune parameters based on closed loop O2 sensor information, and then carries the adjustments into the open loop operating area, getting you very close to your desired AFR in all the power ranges. Many here choose to run completely open loop, however, to minimize this ECU adaptation.

...later

 

Here's my opinion. If you have a bike that is an older model, then TMax is ok for sure. But... if your bike is new or just a few years old... I would NOT do a TMax. Here's why. There are different types of fuel injection. There is Alpha-n; there is Speed Density; and then there is Speed Density with MAF sensors.

The last is whats on our cars and trucks; the Speed Density is on our bikes, and Aplha-n is what TMax is. All goobly gook except for this.....

Speed Density measures the load placed on the engine, using the MAP sensor (manifold pressure), and adjusts the timing to suit. It even pulls timing if needed to help stop ping. Alpha-n (Tmax) is pure map based (not to be confused with MAP), and the map in a Alpha-n is based upon throttle position instead of the load. Doesn't matter if uphill or downhill, the timing stays the same if the throttle doesn't move.

The Tmax works fairly well, but why downgrade a newer bike. Find a different dealer.

I like TTS because I am used to it and understand how to tune with it, but in reality, I think all three flash based tuners are ok. Some are easier to use than others.

What year bike? What mods? These two questions can define the answer further.

 

Pulled the plug on a PC V and basically a stage 1 upgrade with an S&S 557 Cam. Hope I made the right decision but seems like a lot of folks were using it or the TTS.