Big Dog's Factory Stock Fuel Injection (S&S VFI)

[Corey]

I have the S&S Dual Runner 600 cam and V&H Big Radious exhaust. I installed the S&S VFI module and it worked flawlessly. I collapsed a rod and the module instantly learned when the valve shut and quit sending fuel to that cylinder. When it was repaired the module re learned the instantly and it ran better than ever. The check engine light was on because it was way out if parameters so all we had to do was plug in the PC with the S&S free software and clear the code. So simple and no searching for a competent dealership that can access the Big Dog software. I don't know what a dealer would of charged but the way I see it I'm way ahead of the game money wise. I recommend this upgrade to anyone with a factory module.

 

[Stimey131]

I've been considering changing my 07-Mastiff over to EFI and would like a ball park figure of the cost? Now I have done more performance work than just air cleaner and pipes, I've also had 40 thousandths taken off the bottom of my cyclinders, 600 cam, and a TH ASM-5012 ignition upgrade, and my heads done also, so my question is with these upgrades if I install the S&S VFI will the system set a base map to handle my performance work then work as normal making the fine tune adjustments it needs. My previous bike was a Harley that was EFi and it just seemed to always run smoother without any fluctuations in performance due to fuel problems.

Another Question, will I have to purchase a new exhaust because of the O2 sensor. Also if someone could give me a breakdown of everything I need to get to make the swap I would really apreciate it.

 

[erldawg]

I've been considering changing my 07-Mastiff over to EFI and would like a ball park figure of the cost? Now I have done more performance work than just air cleaner and pipes, I've also had 40 thousandths taken off the bottom of my cyclinders, 600 cam, and a TH ASM-5012 ignition upgrade, and my heads done also, so my question is with these upgrades if I install the S&S VFI will the system set a base map to handle my performance work then work as normal making the fine tune adjustments it needs. My previous bike was a Harley that was EFi and it just seemed to always run smoother without any fluctuations in performance due to fuel problems.

Another Question, will I have to purchase a new exhaust because of the O2 sensor. Also if someone could give me a breakdown of everything I need to get to make the swap I would really apreciate it.

This is a first... In my opinion cost prohibitive. Re-wire the bike, new intake and throttle body, new fuel tank w fuel pump, new EHC or wire plus or PDM, VFI module and all the sensors. Good news all you have to do with the exhaust is add bungs for the O2 sensors, the least of your worries. At this point your up over 2k. I'd rather spend the cash on an open primary

 

[Kiwirider]

This was a really good read. Thanks for taking time to write it.

 

[Sven]

1-wire 02 = Narrow band body.
This is heated by the gas exhaust. As the temp inside begins to heat up the inner core, it sends in the samples in a resistance mode of communication of numbers. If you WOT the throttle open, this sends in a cooler sample. The 02 cools down, lowers the temp, changes the resistance output = Lean out the lead foot.

Multi-wire 02 = Wide band sensor body.
This has a self contained heater core. This has the ability to sample faster since it can heat itself up before then engine does. There are no faster engines per say. The V-8's rpm has not changed much. Racing V-12's and below can spin up to 16,000 rpm, if not up to 23,000 on some engines.

It still means, it means nothing to a millisecond. Catching up to those rpms is child's play in the FI world.

 

[frazicl]

I just joined this Forum because I was desperately searching the Internet for any SSCycle VFI info I could find and hit on this discussion. This is by far the best and longest thread of VFI info I've ever found when it comes to VFI, and even though I don't ride a BDm I no longer feel like a red headed step child when it comes to owning a VFI based EFI bike. After being totally fed up with the HD's MM&ECU, I converted my 2K RK to SSCycle's Closed Loop Kit featuring VFI a few years ago. I studied both Zippers setup and SSCycle's and I wouldn't throw either away, but chose SSCycle only because I was one of the Bleeding Edge adopters of VFI (1st year) years before and I had to give up on it due to lack of any available way to tame (tune) it. I had a horrible idling problem, but outside of idling, the VFI opened my eyes to what power I had locked up in my engine. My bike ran like scalded dog. I felt torque with every slight movement of the throttle. So years later I figured it only got better and more support spread around the country.

So while I was converting, I gutted the entire MM system and replaced it with the SSC Manifold, Single Bore ThrottleBody, Teardrop Air Cleaner and of course the VFI. I had to have bungs added to my D&D 2-1 Fatcat to take the sensors.

So I know the discussion is more on the sensor types, so if I'm out of line and you feel my questions may highjack the thread, please tell me so. It's not my intention.
After a long run of pure clean idling and awesome throttle response, smooth operation, and absolutely no backfiring or decel Pop, my bike's Idle started to act up. Given, nothing's changed other than gasoline. I'm going through basic troubleshooting and of course the Sensor questions pops up. Can the failing or faulty sensors cause symptoms like idle dropping low to shutting off at lights, then when running hard and stopping having a high idle followed my popping until the bike is restarted again?

If my question better fits another existing EFI problems troubleshooting thread, please point me away. I'm going through the process of elimination and this is one stop. Thanks and once again for saying "VFI" more times in one thread than I've found on the entire Internet!

 

[Sven]

Can the failing or faulty sensors cause symptoms like idle dropping low to shutting off at lights, then when running hard and stopping having a high idle followed my popping until the bike is restarted again?

Sensors are self diagnosing. In other words, if the sensor fails, a code sets. It is more a redundant map. If the intake manifold sensor is adjustable, like a harley's VOES, I'd try that for the idle problem or high speed surge. Totally experimental in that tuning dept. Also, I'd see if there are any Q&A's on the S&S site about any idle issues?

 

[frazicl]

Thanks Sven, thought I'd come back and let folks know that with Protune and a tech that knew how to read the guage's tea leafs, he tracked down my idling issues to the Throttle Position Sensor going bad. The TPS voltage was jumping all over the place, but yet no DTC. Told me that my symptoms made it suspect over the IAC (which I thought it might be) before he saw the gauges while bike was running, which confirmed it. Just FYI. I'll move this off of this thread now since it's certainly doesn't belong, but wanted to come back and thank you all for letting me barge in. The VFI and O2 band discussion is far more interesting.

 

[agourabob]

I posted this elsewhere on the board, hope it helps.

Bob

I have been troubleshooting a Bulldog that quits when hot. We spent considerable time on it yesterday and determined that temperature (330) was shutting down the EFI computer and when we cooled down the sensor it would start again. The question was, is it the sensor or is it running too hot.

I called S&S today, they were great. The tech support person I spoke too thought that 330 would be the limit on temperature for this engine. He felt the existing non programmable EFI module was causing the bike to run too lean (EPA) and is not re programmable.

They sell an off road module replacement and have a bunch of them. They retail for $355 and come programmed for BD engines, I believe plug and play.

The data below is subject to confirmation, but the module number for the 07 EFI bulldog is 55-50-29. Only sold by S&S dealers, not the factory and should be plug and play. I would think this is an extremely valuable asset for this bike and should be kept in mind while they are available.

Hope this helps more guys with similar problems.

Bob