Here's a question for you tuner guys. I have an 07 RG with closed loop FI. Why would I want to install a PC that eliminates the O2 sensors. It seems that changing the stock O2 sensors for wideband ones and getting a tuner that can use the wideband O2 sensors would be the way to go. Since I do a lot of touring it seems like the closed loop system would keep the A/F ratio where I want it regardless of whether I'm in the mountains or at the bottom of Death Valley.

 

Wouldn't call myself a "tuner guy" but it's been my "area" here recently so I'll give it a shot...

The factory closed loop EFI system targets an ARF of about 14.6 in the lower RPM and cruising ranges. Above a certain RPM and throttle position your factory EFI system will go into open loop mode which no longer utilizes the O2 sensors. When in open loop your motor is operating soley of the inherent map in the ECM which is also very lean. Lean is hot and it robs you of engine performance....loss of HP/TQ.

Since your question refers to PC's...

The PCV without the autotune (from Fuel Moto) does eliminate the use of O2 sensors (open loop), but it also gives you a better tune by changing the fuel maps. Adding more fuel based on throttle position and RPM will bring the AFR's down into the 13.8-13 range which will improve performance and bring down operating temperatures. It will also (with the right map) compensate for any modifications you have made or will make (exhaust, intake, cams, heads, etc). Quite simply it gives you the tune Harley would have liked to...but couldn't due to EPA regs.

The Autotune with wideband O2 sensors (closed loop) does all of the above except it keeps the bike in closed loop throughout the RPM/TPS range. It makes adjustments (trims) to the fuel table constantly while you ride...improving the tune. It also allows you to adjust the target AFR's in any throttle position and RPM. This allows you to adjust your basemap for optimal MPG or performance. Making performance modifications is also simplified because you don't have to worry about finding a perfect match basemap as the system will tune itself to the target AFR's as long as your basemap is fairly close (timing needs to be on target). Jamie at Fuel Moto can get you close enough for autotune to do the rest if your build doesn't match anything he has on file for basemaps.

If you prefer, but unecessary, PCV with or without autotune may be dyno tuned and a custom map developed for your bike. I do not recommend this because Jamie's maps are close enough as is.

As far as touring anywhere you want (elevation/humidity/etc) this capability for adjustment is resident in other sensors and remains functional with or without PCV or O2 sensors. Disabling the O2 sensors or going to wideband O2 sensors will not affect this as compensating for elevation, humidity, barometric pressure is accomplished through sensors such as the MAP (manifold air pressure) sensor which remain operational with the PCV.

So..."Tuner Guys"....how'd I do?

 

09StreetGlider:

Thanks for a response that I could understand. I appreciate you taking the time to teach me something.

 

Anyone else have a comment?

 

same here 09stg...i been reading all about PCV since i now want one. I think since u dont need the o2 sensor now to go with Tru Duals.. still winter here and alot of snow.. so saving up my $$ before i go on a spending spree and learning about PC at same time. Jamie also has been great supporting everyones questions.. 09STG.. my guess is once Fuel Moto programs PCV to my spec, how much of a difference would having the auto tune be vs not haveing it ? thats what i would like to know. yes AT keeps reading the AFR and keeps adjusting till smooths out the AFR line, but say after 2 months of riding, and the AT has set its values, how much would it make a difference haveing the AT if you dont do any more Mods to the bike ?

 

My situation is a little odd in this respect as Jamie didn't have a map specifically for my build at the time...and I didn't want to wait. I have 09 103" without cams. The basemap he sent me was for a similar 08 build done with the PC III and transfered to the PCV format.

At first, when I couldn't figure out why my AT was working (my fault not the AT) the map felt spot on by seat of the pants. However, once the AT was working I did see some significant trims in the AT "Trims" tables. Then the ride smothed out even more. I would not say the AT was necessary even for me, but it does make the "canned" map more fine tuned for your specific bike. Now that I have accepted the trims I am seeing very insignificant trims in the AT from day to day...like + or - 1 to 3 or so. I can not tell a difference between these trims by the seat of my pants.

I do like to tinker with things so I have really enjoyed the AT kit as it has given me much to play with and make AFR adjustments. For the map I'm running now (adapted from Jamie's original using AT) I'm running AFR's ranging from 14.4 in cruise to 12.9 in WOT and the AT has made all the necessary adjustments to the fuel tables in order to do this smoothly. I choose to accept the trims to the fuel tables just in case there is ever a problem with the AT kit...that way the bikes tune is already fully maximized for my bike and I can just keep going without any ill effects. When I spoke to Chris at DynoJet he told me this was a good choice and if I wanted I could tune my bike the way I wanted, then remove it and put plugs in the O2 bungs and tune another bike with the AT kit as long as it had a PCV. I am choosing to keep the AT installed because I like knowing it is always there making the fine tune adjustments as I ride.

What PCV and AT does not do for you is timing adjustments...so you need to know what you are doing (which I don't) here and be very careful if you make adjustments to the timing tables. I have not heard any knocking or pinging so I have not had the need to make adjustments in the timing area.

If you wanted to, and you did not plan on making any more mods, you could tune the bike with AT and accept the changes to the fuel tables and then remove it. Then you could either sell it to a buddy, tune another PCV equipped ride, or put it on the shelf for future use...just in case.

 

09StreetGlider and iclick have the market cornered on smarts, let me tell you. Anything I could add to his comments would muddy the waters, but I will say this...
I just put a PCV on my '07 UC, and the differences - especially in the first 3-4 gears - are, well, astounding. The bike leaps ahead now. No hesitation. It says "LET'S GO!" now instead of "huh?" when you twist the throttle.
How's that for some awesome technical language!!!

 

Tony (09Streetglide) will tell you he's not a "tuner guy," but he just wrote a good explanation. As an certified PC hacker (self-appointed) working toward tuner status, I'll try to do the same even though our take on things is about the same, and will try not to be too redundant.

First, the narrow-band O2 sensors on a stock bike are in place primarily for one purpose, to meet EPA regulations. They work in a narrow range, around 50% TP (throttle position) except when cold, and in that range your AFR's are a fixed 14.6:1. This is called "stoichiometric" (or stoich), and this AFR works well for engines that sustain a relatively constant and predictable internal temperature. The air-cooled HD does not and thus stoich is acceptable only when moving fast enough to keep the engine cool. When the going gets slow in hot weather things start to break down, not usually mechanically but in terms of efficiency and heat generation. The narrow-band sensors can also only adjust in a narrow AFR band, from about 14.2 to 15.1 (or whereabouts).

It is a little-known fact that the Dephi EFI on modern Harleys ('02 and later) work very well in varied conditions without the O2 sensors. With a MAP sensor (manifold and admospheric pressure) and two temperature sensors (intake air and front head) it is able to adapt to any environmental conditions, compensating for altitude, air density, temperature, etc. For the past two years I've used a PCIII in open-loop mode and have toured in low as well as high altitudes without any problems, and even gas mileage has remained constant.

The PCV uses O2-sensor eliminators which send a fixed signal to the ECU that all is well and to use the EFI values written in the EPROM. This is still too lean for efficient operation, which is near stoich if left unaltered. The PCV will allow fuel adjustment in 250 areas of the map, and when tuned on a like bike with like equipment will perform well on a bike located in another part of the country. The key is to get a good tune, and that's where Fuel Moto comes in. You can read the numerous testimonials here by doing a search.

The Auto-Tune kit for the PCV is just another step toward owner-tunability, but is unnecessary for most riders. It is ideal for someone who plans on doing incremental changes to his configuration and doesn't want to do dyno tunes between each one of them, as well as someone like me who likes to tinker with AFR's for optimal gas mileage. You can do the latter with the PCV alone (no AT), but the AT takes the guesswork out of the equation. With AT instead of specifying percent changes for AFR's written in the PCV base map you can specify target AFR's (e.g. "14.1" would be an AFR of 14.1:1) and it will tune on the fly regardless of the equipment installed. BTW, the PCV with Auto-Tune uses wide-band O2 sensors which work throughout the RPM/TP range and can adjust AFR's from about 11 to 16:1, which is much more than the usable range.

I've been using the PCV with Auto-Tune now for about six weeks and it is working very well for me, tuning constantly to maintain the AFR's I've specified. But like I said the AT kit is not necessary for most riders and the PCV alone will work very well. If you decide to buy one from Fuel Moto, tell them you want their "mileage map," which will contain leaner values in the cruise range. If you have an oil cooler and know how to interpret feedback from your bike that it is getting too hot or detonating, you can lean these values even more in the interest of gas mileage. I did this and if you don't alter the values >40% TP you shouldn't notice any degradation of performance as you roll-on the throttle.

 

I'm seeing almost no trims in the portions of the tables that I have not altered. This testifies to the accuracy of the Fuel Moto base map for my bike. There is considerable change in the cruise range since I've changed the target AFR's in that area, and that's expected.

Tony and I differ a bit in our approaches here. He equalizes the base map by doing the "accept trims" function, but I leave the original Fuel Moto map in place and let AT trim to my specifications. Since I'm only changing the targets in the cruise range, leaner for better mileage, I can switch to the base map on the fly using an on-off switch I've installed in my fairing insert cap. This is a valuable feature, IMO, as you can lean it up for mileage and switch to the richer base map at any time, like when caught in heavy traffic in hot weather.

Last summer I played around with advancing the timing in the cruise range, but that was a failure. Any change upward (advanced) caused detonation, so I'm now using the values originally in the base map. Fuel Moto has specified the best values already so for this aspect of the adjustability I would advice everyone to just leave it alone, assuming you have a good tune to begin with.

You could almost go into the tuning business. This is no joke. The problem is that a good auto-tune for the entire map will take time as you move from different RPM's and TP's as you ride, so I don't know how practical this would be.

 

Again more excellent information. Since I have ordered my PCV from FuelMoto and waiting on it to arrive and a rereading and subscribing to many of these threads. Thanks for all the good info.