Slip on mufflers

Discussion in 'Engine, Fuel and Exhaust' started by biscuit, Dec 11, 2007.

  1. biscuit

    biscuit Junior Member

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    Hey Glider,does the TFI really work?Is it really as simple as adjusting 3 or 4 little trimpots with catchy lights?

    With the addition of a TFI unit will the engine run better/cooler/smoother etc---?The only info i know about these is via good ole George on the instructional DVD clip.Not to denigrate George,but HOW will a TFI improve my bike?
    If i put one on a standard 2008 FLSTN what could i expect?If i put a stage one air filter and slip-ons on the same bike,what then could i expect?


    Can of worms.

    thanks. Ride safe
     
  2. glider

    glider Veteran Member

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    I've used many of them and the install couldn't be easier. The thing I like most is the simplicity of the unit and no computer needed. There are many that go the PC III or SERT route but they require a lot more work/tuning than the TFI does. It's true that they also get a tiny bit more out of the bike as far as power but these are Harleys , not crotch rockets. There is custom mapping available with the other units and dyno time which can run into quite a few $$ but what you get from the custom maps with the dyno runs in my opinion isn't needed on a street bike or worth the additional expense for what you get.

    The addition of the stage 1 and slipons will add about 10-12 HP on the 96 engine and the TFI will make it run a bit better/cooler/smoother too. The key is not to over do it with the settings. Richer settings than needed will give you soggy throttle response.

    There also is an option when buying a TFI to keep the 02 sensors or eliminate them and use the unit to trim the fuel curve to where you want it. I chose to eliminate them because the 02 sensors will lean things out again. The elimination is done with plug in resisters to bypass the 02 sensors after they are unplugged near the sensors, very easy to do.

    The extra fuel added with the TFI seems to do the trick as far as power , cooling the engine down a bit and it runs noticeably better.

    There's very little chance of messing up the settings with the 4 pots for adjustment. I would imagine that if you put the bike on a dyno and sniffed the exhaust for mixture that the other units would be closer, but for a street bike I think the TFI is hard to beat. JMHO.

    I have the TFI and stage 1 on my 07 RKC and it runs real well.
     
    Last edited: Dec 11, 2007
  3. Not Very PC

    Not Very PC R.I.P

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    I've done a bunch of Dyno runs with about any tuner on the market and for a air-cleaner & pipe swap The TFI is so close to "Tuned" Tuners that no one will ever know the difference. Unless your going to a wild build the TFI is the way to go.
     
  4. biscuit

    biscuit Junior Member

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    Thanks very much to both of you (GLIDER & NVPC) for your quick replies.Even though delivery date of my bike grows longer with each day,i'm trying to put all the info togethor b4 i get it.

    regards nick h. Ride safe
     
  5. biscuit

    biscuit Junior Member

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    Hey Glider,it's me again.Are you sick of Queenslanders yet?

    Another question please---What is the Thundermax EFI control module with Auto Tune and Wide Band O2 sensors?

    How does it work?Does it work any better especially with Wide Band sensors to cover a greater range of RPM'S and fuel deliveries?Ive heard that the TFI can make things a LITTLE rich and by using none or narrow band O2 sensors the adjusted fuel delivery is at a 'set' ammount.

    Ive read things and absorbed your comments about the TFI and i like what i hear,but now i'd like some non biased info on the T/MAX.I imagine it costs a fair ammount more but my bike is going to cost me almost as much as my first house was to build 25 years ago!So i want it right.

    Will it work BETTER than than the TFI all round(fuel delivery that's adjusted by Wide Band sensors)or is it the same?If it comes pre-mapped it appears no dyno tuning is neccessary(like the TFI).I'm not after big numbers in HPor TQ,just the best running V-Twin i can get.

    I've not seen much technical info on the T/MAX and any you can furnish will be my early XMAS prezzie.And if it's good,i'll send you a pineapple for XMAS!!


    Thanks again. NICK H.:bigsmiley11:
     
  6. glider

    glider Veteran Member

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    Nick

    These two units are at different ends of the spectrum. The T Max is what I call the ultimate as far as tuning. it eliminates the dyno tuning and is an active tuner that will adjust as you ride once the correct base map is loaded. It takes about 500 miles of riding to completely tune the map.

    The TFI is just a fuel enrichment device and no more. It will add what you tell it to add.It doesn't require dyno tuning unless you wish to do it and isn't adjusting the ignition curve. Price comparison is wide, $200-$300 for the TFI and $700-$800 for the T max.

    The T Max is new to the market and it's reliability will be known after a few years whereas the TFI has been around quite a while and has been proven to be reliable.

    Wallet thickness is what should be used in making a logical decision but one more thing here is that there isn't going to be a HUGE difference between units as far as the way the bike runs. The T Max no doubt will dial things in better and more completely but for a price.

    As with any tuner, if dyno pulls are needed, the question arises of how good the dyno and operator are. There are some great tuners around, but then again there are some that are not so good too. The TFI usually doesn't result in dyno time where the T Max doesn't need it either.

    If what you are looking for is the best running V Twin like you say, then I would go with the T Max over the TFI. Like mentioned, there will not be a huge difference between the final results of the two units, but it may be enough to justify the difference for you.

    Big thing to consider is a breakdown on the road and resulting trip to the dealers. The TFI can be removed without a trace and the T Max is an ECM replacement so the dealer will not be able to work with it and possibly will start the "voided warranty" song.



    Depends on how far you wish to go.:s
     
    Last edited: Dec 13, 2007
  7. tlyoungb

    tlyoungb Junior Member

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    Hey Glider,

    So if you are sitting in traffic for an extended amout of time, will the TFI adjust the mixture to richen it so the engine will run cooler.

    I don't have anything attached to mine right now. Mine is all stock. I have read though that even the stock ECM (I guess that is what you call it) will do some adjusting of the mixture if the engine temp gets hotter. Is that correct?

    Tim
     
  8. Flashback

    Flashback Active Member

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    the T max it's supposed to help keep it from getting there in the first place by constantly reading and adjusting unlike the stock ecm that goes from 14.7 down to 12.0 if it senses overheating (to little to late imo) optimal for street riding should be around 13.5 to 13.0. I believe the TFI just operates in the ranges you set for the different range lvl's ( idle, low range, mid-range, high)There's also a couple companies that now manufacture WBo2 sensors now that are compatible with the harley ecm and programable from I believe 10.0 to 20.0 the ones i was looking at ran around 450.00 for the pair. they also made an easy in-line pluggable that will drop it from 14.7 to 14.2 and ran about 75 bucks.
     
  9. glider

    glider Veteran Member

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    The TFI only does what it's programmed to do and doesn't have the capabilities to change the mixture on its own. The ECM will go into a mode if the temps rise to a pre determined/programmed temp. that will cut out one cylinder on some bikes and will cool things down a bit. The new bikes are user programmed for this mode but the older ones have to have a download at the dealer to do this. It's usually a one time free download that can be removed if you don't like it.
     
  10. Flashback

    Flashback Active Member

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