Closed Loop EFI Systems

[jpotts]

Hi Mike,

I'm looking for your input on aftermarket closed loop EFI systems. First I'd like to provide a little background before I get to my question. I hope you can bear with me:

I have an '02 FLSTFI modified with a SE Stage I kit and Samson "Short Slasher" pipes. I made these mods when new and ran it this way for about a year and a half before installing a Power Commander III on it. I had the PC III dyno tuned at Latus.

Over the past year I've noticed some problems that I think (hope) have to do with the PC III and believe it may need to be re-mapped. I came to this conclusion after lots of test-riding where I determined a *very* noticable drop in torque at around 2800-3000 rpm which tends to show up while accelerating through the 40% throttle mark. The affect of this drop is strong enough that if I hit this point with any load on the engine (such as even a slight incline) I have to shift down from 5th to 3rd to work past it. I've managed to eliminate most (but definitely not all) of this by modifying the fuel table around this area to bring it closer to the "base line".

In addition to fixing this problem, I plan on swapping out pipes and do some performance work like a 95" upgrade with something like the Edelbrock 95-Inch Twin Cam Performer RPM Power Package or the S&S Hot Set-up kit. These will likely be done in seperate steps which means I'll have several dyno-tunes in my future if I keep the PC III. I'd like to find a solution, if possible, to eliminate the need for continual re-mappings. This got me looking at the closed loop systems currently on the market.

THE QUESTION: (finally!)

Do you have experience with any of the aftermarket closed loop EFI systems out there that you can provide info on?

I've been looking at two diffent options (are there any more?):
- Terry Component's Terminal Velocity II
- Daytona Twin Tec's TCFI Gen II Fuel Injection Controller with the WEGO IID dual channel wide-band oxygen sensor

The Terminal Velocity II definitely has a more attactive price and, according to their website, adjusts to all the changes I plan on making to my bike without a re-map. Unfortunately I've been unable to find much of any independent statements that back up this claim. Do you know if this holds true? Can I really just install this component and not have to worry about dyno time?

Are these closed looped systems worth it? Would I be better off staying with the PC III?

Also of great importance to me is reliability. I've been averaging 10,000+ a year thus far and spend a couple weeks each year on the road--far away from home. I'd love to find something that just "works" and doesn't need to be fiddled with ... and won't break.

Any help you can provide will be greatly appreciated.

Thanks!

[heritage]

The Harley Zone forum has several people using the Terry Components product and are happy with results.Especially with fuel mileage.I would also like to get Mikes' imput.Latus dynoed my bike last November and I was pleased (05'FLSTCI) @ 95hp/105tq.But am looking at differant pipes now.Would definitly be nice to change parts and have the ECM figure the correct AFR without dynoing.The Terminal Velosity II was around $500 +.

[Mike]

I waited to reply because I wanted to do a little homework on this. I must confess that we do not have a great deal of experiance with the aftermarket closed loop systems. It's difficult to be expert at all the stuff out and the new things coming online. I can say that the Terry Comp. unit seems to be the most popular and is getting good reviews. It seems to be the most adaptable. Most closed loop systems require base mapping to be within 80% of the correct values required with the closed loop portion then fine tuning the remaining 20%. This traditionally had to do with the narrow band O2 sensors range (about 20%!). Wide band O2's offer more range and with software able to dynamically recalibrate as the sensors shift mapping the ranging problem is less of an issue (just takes more time for the computer to fully map/learn the new values under all conditions, then shift the map to the new values to free up sensor range, then continue finer tuning from there [I'm theorizing]. This can be 4-20 hours of riding time, the bike will run "funny" until this process is complete). The Daytona unit requires the 80% map first which may require dyno time to achieve if a base map is not available. They recommend removing the O2's once the "learning" mode is complete unless changes are made to the bike (worried about the sensors degrading over time giving false feedback). This is also true of the S&S system but they recommend leaving the O2's in place. My feeling is that if we have to dyno for the 80%, then why not dyno for the full 100% range and thus eleminate the need for the O2's (if the mapping is correct there will be nothing for the O2's to adjust for other than minor enviromental changes). This is the approach most O.E.'s use and hence the "closed loop" feature is only active during cruise and idle which will not help changes affecting WOT. Closed loop is all the rage right now and we'll be seeing more systems come to market. The cool thing is that, if these systems really can account for the range changes we see with exhaust, motor size, etc., then you will be able to make such changes without the need to dyno/remap evertime one is made. This allows for your motor to grow as you can afford at a much lower overall cost. The caveate is that I'm still a little skeptical of that ability, but welcome it if it can. The funny thing is that, in time, we may see the O2's go away with fuel/ignition mapping done entirely by knock sensor feedback (S&S IST ignition is a foray into this technology/stratigy). The reliability question remains but this technology has been used for years in the car industry and should be pretty robust, but cars do not see the kinds of stress that are common on motorcycles (esp. H-D's). The $500.00 price of the Terry units also make me a little skeptical about it's longevity. Power Commanders early on had reliability problems due almost entirely to the need to purchase the least expensive component parts available (small company at the time). The new USB versions are extremely reliable because Dynojet learned from this and can now afford the capital to purchase more reliable components. Lets hope Terry does not have to learn this same lesson, at our expense! Do not know if this helps with your decision, but thank you for the chance to fire up some sleeping brain cells. I'll be continuing to monitor and learn more about these systems and hope to have more learned and complete info. as we have the opportunities to investigate these.
Regards, Mike

[jpotts]

Thanks, Mike, for the thorough and frank response.

I appreciate the time you've taken to research this topic. If I decide to go this route I'll be sure to let you know how it works for me. Of course, you'll likely know anyways as I plan on taking my bike to Latus to have the work done that I cannot accomplish myself. There are HD shops much closer to me but you guys really seem to have your s#!t together when it comes to performance upgrades on EFI bikes.

Thanks again.

- Jessie

[Mike]

Thank you for the kind words!../images/emoticons/smile.gif

[heritage]

Just spent some time on the V-Twin Forum reading about Terry comp.Terminal Vel.II.There are over 100 threads on this item under v-twin mods.It's a single cylinder(rear)o2 unit so it makes a judgment for both cylinders based on the AFR in the rear cyl.The biggest problem that they are having is people buying the wrong unit for their build.ie.stock vs big bore.Also this unit gets spliced and soldered into your ECM .Not a plug and play.Most of the users are happy with it but the experianced wrenches trying it said a good tuner on the SERT is the way to go.I believe this is the reason they are interested in this unit is the problem of finding a tuner in Mikes' caliber.You also have to start with a good tune before using this unit.Anyway,thought this may help.

[Mike]

Thanks Heritage! Maybe us old guys are just slow to change (or want to wait and see before jumping in to something new) but I agree that, for now, a good SERT tune is going to be hard to beat.
Mike

[diesel_lv]

I'm not sure if any of you have checked these guys out. I'm sure a bit pricy but Their tech seems solid. http://www.rbracing-rsr.com/efiharley.htm

[REED]

I have been using the Daytona Twintec unit all last summer on my o6 Dyna 95 cid st6ock cams slip ons and screamin eagle A/C. I had the bore kit done initially at the dealer I purchased the bike from and had the flash file in the cpu. A short time later I decided to make a monster out of my little 95 and make it into a 131 however, there were many parts not yet available to make this combination. The first part that I aquired was was the Daytona Twin-tec. I decided to install it on my bike so that I could play around with it. The manuals for the unit are all on the internet at their site take a look at them and decide if you think you have the computer saavy to figure it all out (need lots of compiter saavy) the instructions are very good but they warn you several times that you really need to know your way around a computer as their te3ch support is for their product and not to teach you computers. I installed it on my bike and used one of the pre loaded files which put me right in the ball park all except for the vss sensor frequency so my speedo was out a bit. This setup ran great, the autotune took me a little while and a couple of trips into the computer to fill in some missed cells but wow does it ever work well, the bike goes like a raped ape for a 95 inch motor and my fuel economy is much better than I was getting with the motorcompany ecm. Their website does not suggest that you remove the wide band O2 sensors and the say that they have had very few failures. More than that I had not been on their website in the past 10 months so when I went I was surprized to learn that they had all the new updates to the software for the 07 models and that they had fixed a couple of glitches that they had in their programing, all of which can be flashed into their unit with a program called mega boot pro so I can make my year old setup the same as the current one. I am really looking forward to getting to work on my 131 build and using my BC Gerolamy setup and Daytona Twintec unit. The thing about the unit is the self programing feature as we do not have anyone with the experience and knowhow that mike has to rely upon aand mike is a little over 1000 miles from me, how3ever I think I will be able to drop in and see him this next summer and talki him into putting this thing on the dyno. Tom

[Mike]

Removing the O2's was based on a discussion I had with Daytona over a year ago and appears to be dated info. Apologies. Keep us posted on your 131 build results.
Mike

[cardboard]

I am suprised that nobody mention trying the Thundermax with auto tune !

[Mike]

The previous posts were several months old and the Autotune was just coming on-line. Reports have been favourable so far but we've not used that unit. At the risk of sticking my head in the sand, we'll likely stay with SERT as so far that has been able to satisfy anything we've built so far. We are just now starting a 131 Jims build with our t-body upgraded for the FBW on the 08's and this will also be using SERT. Which brings up another reason for us staying with SERT, the aftermarket systems will not be compatible with the new FBW ECM's and it's features and control, at least for now. It's going to take a LOT of research and rework for complete replacement systems to incorporate the 08 touring changes. Of course the Zippers/Thunderheart and Daytona guys are smart people and should not be underestimated.
Mike

[knuckleh47]

Check out the Master tune/Vtune program. It requires the use of a TTS MT7 calibration and a VTune DM3 data recording and combines the two generating a new MT7 calibration file with an optimized VE Table.
Note that VE tuning is only effective for AFR cells that are set to exactly 14.6 AFR value. For tuning purposes, the AFR can be temporarily set to 14.6 over a wide range of engine load. DataMaster-HD is used to collect VTune data while riding or dynoing the vehicle. The DataMaster VTune Data File and the associated MT7 calibration file are then processed by the VTune software. This process analyzes the data to generate a corrected VE table for the vehicle. This corrected table is automatically merged into the MT7 calibration file and saved as a new calibration file.The new "merged" MT7 calibration file is programmed back into the vehicle. This process is repeated several times, and each iteration will zero-in a little closer to the optimum VE table value. When the values do not change more than 5% between iterations, the optimum table has been generated. In our experience, this takes three iterations.
After the final iteration, the user must reset all AFR cell to the factory original values. This is required to prevent the vehicle from running too hot due to lean mixture operation.
Hope this helps--

[Mike]

Great explaination! We are now a Mastertune center.