Correct me where I'm wrong:

All newer bikes now have 02 sensors in the pipes thatsend data back to the ECM that tell it how to adjust the fuel mixture based on what is coming through the exhaust, mostly for EPA purposes.

If I replace the ECM or install an OPEN LOOP add-on like the PCIII (not sure if the SERT is open or closed loop, can anyone comment?) I can elliminate the 02s and program the ECM to produce a fixed setting of the fuel mixture.

If I choose to go with a CLOSED LOOP system like the ThunderMax, I will retain the use of the O2s (replacing them with the wide-band type that come with the TMax), the Thundermax will get feedback data as does the stock ECM to dynamically tweak the fuel mixture on an as-needed basis.

Not looking to race, but to maximize performance (HP and torque), maintain a cool, smooth running engine, problem free, without having to repeatedly re-tweak the ECM map.

When the closed loop systems were first introduced, everyone cringed at the notion that the FEDs were forcing these as EPA devices that would bog down performance. (Not sure if this was true or not since I'm a new Harley owner as of this year). Has this been the case? If so, has it been compensated by the larger engines? Does the TMAx replacement ECM mitigate this issue (if there is one) and is this the better way to go than the open loop method? Is a SERT open or closed loop? How does wide-band compare to narrow?

Sorry for all of the questions, I think I'm getting this but would really appreciate the additional knowledge and advice from the experts on this forum.

 

Slowly starting to get a handle on this stuff myself and from what I've found is that open loop when tuned is good for the given conditions of temp, humidiy, and air pressure of that day. Change any of these the tuning is now no longer optimum. Closed loop will adjust to these changes and keep the bike tuned to those conditions. This means two things. The engine will run better in all conditions and at the same time will reduce smog, unless you are initially tuned too rich.Here's one example. Anopen loop is tuned on a cooler low humidity day and runs great. As the weather heats up and humidity climbs, you know those sweat your *** off days, the engine will run a lot richer than it should. The opposite would be true if tuned in hot humid conditions. Since weather in southern Ontario changes a lot, I went with the tmax closed loop to hopefully give me the best tune for the whole riding season.
Ron

 

The stock closed loop system is limited. It's only for part throttle cruise. But that's where you spend most of your time. The stock narrow band sensors only work in a very narrow band. The base map has to be pretty close to begin with. And the base map doesn't change on it's own, you need a SERT and a dyno.

Wide band, OTOH,senses and adjusts over a much broader range. Not just part throttle cruise, but also during acceleration and nearly WOT. It's also self tuning. It starts with a base map, then "learns" a new base map to make the adjustments off of. If you make a change like pipes and intake, it will learn a new base map.

IMO, the new wide band systems are far superior to anything else on the market.

 

I agree with bobcowan and rbabos, except I don't think the WB/CL systems available (T'Max, for one) are the best for everyone, nor are they the best bang for the buck. First, although open-loop will not tune A/F on the fly to the precision WB/CL will, the practical difference is nil since it does tailor A/F to different atmospheric and altitude differences. The MAP and other sensors on the bike are capable of making accurate adjustments on the fly. Second, a very efficient setup can be tailored using open-loop controllers like the PCIII, although it will not adjust to changing hardware like cams, head work, etc. Then again, no controller will do this effectively, even the T'Max.

Keep in mind that the NB/CL system used on a stock Harley regulates only a small range and isn't something one might want to retain in the interest of performance or cooling. With T'Max and SERT you can change the A/F from stock 14.7:1 down to as low as 14.2, which is useful but not essential IMO. I really don't think there are any important reasons to retain the stock CL functionality.

T'Max can make small adjustments on the fly as mentioned, but it does have its limitations. You must start with a close map of the configuration you have and give it time to auto-tune, reportedly around 100 miles. Slap a pair of cams on the bike, for example, and the T'Max will likely not auto-tune properly, so if a close map isn't available you'll need to perform a dyno tune like any other controller that lacks a good canned map.

After reading all the pros and cons over the years about these devices, I still think the PCIII is the best alternative for most people, purchased from a seller like Fuel Moto with a big library of maps based on dyno tunes at their facility. For about $300 you can have a controller that is tweakable using a computer and comes with a map for your hardware configuration (AC, exhaust, and engine mods). For people who plan on doing small and incremental changes to the engine/exhaust it may not be the best idea. But remember the limitation of the auto-tune controllers like the T'Max, so they aren't cure-alls.

To the OP, if your goal is for cooling, performance, and reliability you may need to go no further than the above suggestion. OTOH if you're like me and want all of the above plus good gas mileage you will need to take further steps. Canned maps from sellers like Fuel Moto prioritize cooling and performance at the expense of mileage. If mileage is important to you, you can start by adding an oil cooler with thermostat and use synthetic oil, both of which will allow you to safely lean the mixture in the cruise range, which if not overdone will not hurt performance at all. Relying on one map is a compromise proposition where you weigh cooling and mileage. Another option is to have more than one map available, e.g. the PCIII's multifunction hub and map switch option (HUB002), which will allow you to switch between two maps on the fly. I have one map I run that provides a lean A/F in the cruise range, yet allows maximum performance once RPM's and throttle position exceed this range. This is a good map for 99% of my riding, and I've done this by leaning the cruise range (1-3k @ 0-20% TP), yet leaving values above this range alone. Map 2 is the original map tuned for optimum cooling, so if I get into slow-moving traffic in mid-summer I'll switch to it on the fly, which overcomes Map 1's limitation of remaining lean in the low-end. To my knowledge you don't have this flexibility with any other controller on the market.

 

[8D]
Check out this site. http://www.nightrider.com/biketech/h...erformance.htm

 

Checked out the NightRider web site. Outstanding source of information.

Thanks

 

iClick, you are a very knowledgableand an experienced road warrior. It's great to have you on these boards. Based on the information you've provided (Although I don't know what ALL the acronyms stand for), I will probably stick with my decision to go with the ThunderMax unit.

Don't want to use a SERT and rely on MOCO Dyno tuning.

Don't want to use a PCIII and risk carbon build up with an open loop system, not to mention reduced fuel economy. (If this was an older bike without O2s I would probably go this route.)

Don't want something that will be too complicated to calibrate and fine tune.

Don't want to keep having to putz around with it. (I understand it may require several initial attempts to get it right, but once that's been established, that's it.)

I do want an intellegent system that will monitor and make adjustments accordingly, utilizing wide band sensors that provide feedback at broader ranges.

Don't care about the cost.

Don't care about overkill if I don't go to Stage 2 or 3.

Don't care about getting racing type performance, just want the bike to run correctly; strong, cool, with excellent performance and throttle response, consistently.

I do care about when the Thundermax for 08 Touring will be available, I'm guessing Feb-Mar. And also somewhat concerned about the Bub 7 pipes that I bought which utilize a crossover pipe, and if there will be a specific TMax map available for the x-over version, since this is not a conventional true-dual type configuration. Therefore I would tend to believe that it would require a modified map or better yet, TMax should provide a map for both Bub 7 types. (Nothing is ever easy)

 

Jsans, with all of your "don't wants", there is really only one tuner out there that fits the bill. The Terminal Velocity II Alpha N system.

It takes about an hour to install. It hooks up to the front and rear O2 sensors, the Throttle Position sensor, the crank position sensor, and of course it needs a positive power supply as well as a negative power hook up.

It achieves hooking up by running a wire to the rear O2 sensor with a male and female HD coupler. You unhook the rear coupler (about six inches from the sensor). Then plug the male HD connector into the female TVII connector, and the female HD connector into the male TVII connector, thus running a loop through the Terminal Velocity box which mounts on top of the stock ECU. Your other connections are similiar. It's really not difficult to install it.

Once installed you turn on the power and check the LED light on the unit to make sure it is functioning properly. When you start the bike the check engine light will come on twice. The first time it comes on to show an initial check of the HD system. The second time it comes on is to show a check of the TVII. Then you start the Bike. The LED will go through a sequence of blinks to tell you its working properly. Now all you have to do is to ride the Bike any wheres from 50 to 75 miles and the unit automatically adjusts itself to your bike.

Thats it. No maps to mess with. No laptop needed. No pots to adjust. No Dyno time required. You will never have to mess with your bike again.

I installed mine when the bike was stock. Within 50 miles I could feel the bike was running smoother, felt better throttle response, accelerates quicker, and the fuel mileage improved. The inside of my Rush mufflers has a very slight tint of charcoal grey, no heavy deposit.

Later on I installed an RK3909 K&N air kit. I simply rode the bike for about an hour and it tuned itself up with the air cleaner. My fuel mileage is typically in the mid 40's.

It doesn't get any easier than this.


https://www.hdforums.com/m_2617839/tm.htm

 

Wow, sounds like a winner. Curious as to what the differences from the TMAx are. Doesn't it require you do do wire splicing to install and does it use the existing stock sensors?

 

The older model required spilcing. The new ones are plug and play. Really quite simple.

Yes, it uses the stock sensors (front and rear).

You can find them on Ebay for about $395.00.