TFI vs. downloads? confused.

Discussion in 'Engine, Fuel and Exhaust' started by jonny oz, Apr 21, 2009.

  1. jonny oz

    jonny oz Member

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    Hi, All,
    I've been researching the TFI - looks like a great product. I have a couple questions here:
    The TFI website has some suggested settings for various engine configs - it lists settings with and without a stage2 download, and the pot settings are lower for the bike with the download. This is where I'm confused.I thought the whole point of an aftermarket fueler is to eliminate the need for a dealer download? It seems that with a stage 2 download, the fueler doesn't need to modify the fuel delivery as much?
    I was similarly confused when looking at the canned maps at the Dynojet website - they have maps for the power commander for stock ecu, stage 1, stage 2. Why would you buy an aftermarket EFI controller AND pay for a dealer download? this isn't making sense to me.

    I'm changing my pipes from v&h big radius to the straight shot hi lo's. I'm hoping the swap won't need a different map, but worried that it might. I'm considering buying a TFI to be sure it'll run nicely. Right now I have the pipes, Ness big sucker, PC3 with a canned map for my setup. How do I know if I have a stock or stage 1 ecu?? will that info show up on my computer when I hook it up to the PC3? I know I could just trial and error my way to a nice fuel curve with the TFI, but I'd like to get a handle on what's happening before I dive in.

    Also, my plan in the next couple of years is to build my engine to 95" or 98", get a nice street port on the heads, and put in Andrews 37 grind conversion cams. Will the regular TFI (vs. the high output/high HP model) work okay for this build? The site says it'll work for 95", various head ports, and "mild cams." Would the 37 be considered "mild" in this application?

    Thanks very much for any help.

    Jon.
     
  2. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Jon,

    It would NOT make sense to do that. But many folks (me included) have done a Stage 1 upgrade and then paid the Dealership for the canned 1450 Stage 1 download. The Dealership will do NOTHING but download the new map to the ECM, and then back it out. Maybe the more diligent wrenches that care about what they are doing (or just want a smoke break) will tool it around the block, but probably not. The standard 1450 Stage 1 is just that. Remaps back to the EPA compliant lean condition compensating (with more gas) for increased huff and puff.

    So if those of us that have done that then change things further (like cams, head work, more CIs, etc.) we have to go back to the Dealership for another down load, or buy a fueler like TFI. But we already have the 1450 Stage 1 download in the ECM. So TFI gives us some alternative starting points knowing that lots of folks have had various download BEFORE we came to our senses!!

    TQ
     
  3. jonny oz

    jonny oz Member

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    oooookaay, now I get it. I was not thinking about it that way. thanks for clearing that up!

    Anyone know if the regular TFI unit will work for my anticipated Andrews 37/95"/port job? Thanks again!
     
  4. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Give Chris a call at Dobeck and discuss your current set up and what you are planning to do. Here is the info and includes a toll free number:

    TFI Discounted - Harley Davidson Community

    TQ
     
  5. The4opps1

    The4opps1 Junior Member

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    A few times on this forum, I have mentioned that I recently did a roller chain conversion to my TC88 and added a set of Andrews 26N cams, a big sucker air cleaner, a TFI, to the set of V&H slip ons that I had on the bike. Can't say enough about the TFI unit. SImple, accurate, and best of all, the folks at Dobeck, particularly Chris, are there to help you. In the 2000 to 4000 RPM range, the bike simply comes alive. If you decide to go with a TFI unit, I think you will be happy.
     
  6. Caper

    Caper Active Member

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    Good advice there.
    Strictly a novice's approach here...but forget for a moment your bike is EFI,so you have a carbed bike with a stock ignition module.
    You plan on upgrades... a breather and pipes you'd only need to rejet, a bolt in mild duration cam rejet again,(TFI) Then when you put a longer duration cam and bump compression and have the heads flowed, you'll probably want to raise the rev limit to take advantage of the headwork and you'll need the timing advance curve adjusted so you don't get the pings.(New Ign Module)
    The TFI will fill the bill nicely until you get to the point where a stock advance and rev limit won't do for what you've put into it.
     
  7. jonny oz

    jonny oz Member

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    thanks again for all the replies.
    I have NEVER hit the stock rev limiter in my 3 years on this bike, and do not plan on doing so in the future, so a rev extend feature doesn't interest me.
    As far as I know, the 95", street port, 37 cam job will not require ignition advance? If I'm wrong please let me know!
     
  8. Caper

    Caper Active Member

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    Don't know the answer to that, but that's why TQuentin1's advice is good, give Doebeck a call, tell him what you're doing and they could probably tell you if the fueler is enough.
    Let us know what you find out. If you can do those mods with just a fueler I may do my own similiar build sooner rather than later.
     
  9. Bud White

    Bud White Well-Known Member Retired Moderators

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    I dont think you will need anytimeing done but riding it will be the only way to be sure