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Questions on TFI

I know you're high on this unit and sell it on every post you can, and that's fine. What I don't like about it is that it's guess work at best. Install it and mess with the settings until it either feels better or sounds better (RPM). Increase the pots to hold the injectors open a little longer. I've yet been able to find an explanation of how to richen up the idle.

Like you said "anyone that knows basics about tuning can set the TFI up where the bike runs the best without using sniffers etc to test AFR." Anyone thats been around tuning bikes for a while wouldn't rely on sound to tune a bike either. Get it in the ballpark, maybe. Tune, not likely. Plugs will tell a little, but not truly reliable in giving a visual of lean/rich based on color. So, back to relying on how it feels and sounds, but not knowing for sure if it's running the way it should. If just getting it close it acceptable, then maybe this unit has some merit. I guess that's up to each person to decide if... close enough...is good enough.

I just don't see the sense in spending 20k on a bike and then relying on a unit that's set up based on feel and sound, which by the way, could very well be different from what you hear and feel compared to what I hear and feel (same bike). Now, if this unit told me somehow that my bike was running xAFR at idle, xAFR at low speed, xAFR at cruise and xAFR when I cranked the throttle...then I'd be okay with that. But this unit tells me nothing. I'm just not really thrilled about the guesswork, or the "it feels better, it must be okay" approach.


To each his own.
 
Everything I found says the ECM will set up at 12:1 if the sensors are disconnected. Going from 14.7 to 14.5 sounds a little flaky.


that's if their disconnected, ie, no voltage, there is a voltage reading with the bypass therefore the ECU only disregards the info as unreliable and the rest of the system functions are monitored (temp, rpm, air flow, throttle position), and adjusted for. the ECU knows that they are in operating range so applies the AFR as such, not a cold temp or start up value.
 
Everything I found says the ECM will set up at 12:1 if the sensors are disconnected. Going from 14.7 to 14.5 sounds a little flaky.

I know you're high on this unit and sell it on every post you can, and that's fine. What I don't like about it is that it's guess work at best. Install it and mess with the settings until it either feels better or sounds better (RPM). Increase the pots to hold the injectors open a little longer. I've yet been able to find an explanation of how to richen up the idle.

Like you said "anyone that knows basics about tuning can set the TFI up where the bike runs the best without using sniffers etc to test AFR." Anyone thats been around tuning bikes for a while wouldn't rely on sound to tune a bike either. Get it in the ballpark, maybe. Tune, not likely. Plugs will tell a little, but not truly reliable in giving a visual of lean/rich based on color. So, back to relying on how it feels and sounds, but not knowing for sure if it's running the way it should. If just getting it close it acceptable, then maybe this unit has some merit. I guess that's up to each person to decide if... close enough...is good enough.

I just don't see the sense in spending 20k on a bike and then relying on a unit that's set up based on feel and sound, which by the way, could very well be different from what you hear and feel compared to what I hear and feel (same bike). Now, if this unit told me somehow that my bike was running xAFR at idle, xAFR at low speed, xAFR at cruise and xAFR when I cranked the throttle...then I'd be okay with that. But this unit tells me nothing. I'm just not really thrilled about the guesswork, or the "it feels better, it must be okay" approach.



Morn'n slimjim47,

Hope your day has gotten off to a great start.

Last summer/fall I read all the posts here and on several other boards about the TFI. Yea, it was toted here a lot. Not planning any major motor work and only wanting a little better throttle response, less heat and to stop a lot of the backfiring I elected to install the TFI. To tune I started with the suggested settings and then went from there with suggestions from this board. Then I used sound, smell, sight (plugs/exhaust) and "my seat of the pants dyno". To say the least, I was very surprised with the increased performance the TFI provided. It really is a very simple unit with a BIG BANG.

There are a lot of units out there that require a computer to tune and you can get lots of "numbers". Just whatever your wallet can handle.

TFI....$250.00....couple hours most....BIG SMILE!

ride safe
 
Everything I found says the ECM will set up at 12:1 if the sensors are disconnected. Going from 14.7 to 14.5 sounds a little flaky.


that's if their disconnected, ie, no voltage, there is a voltage reading with the bypass therefore the ECU only disregards the info as unreliable and the rest of the system functions are monitored (temp, rpm, air flow, throttle position), and adjusted for. the ECU knows that they are in operating range so applies the AFR as such, not a cold temp or start up value.

Do you know what that voltage is with the sensors out and the resitors in? To go from 14:7 to 14:5 the resistors would be taking very little voltage away.

I guess what I'd like to see is some numbers. I'm assuming these units have been dyno'd during testing. I tried searching for some kind of numbers that show stock versus TFI installed. Granted, it doesn't seem to give the flexibility to tweak smaller RPM ranges, but it would be interesting to see some stock versus TFI installed numbers (at the recommended settings) across an RPM band.
 
I seem to be late to the party, but here is my perspective on this subject.

Without any sort of fueler or more sophisticated manager, I would have NO ability to adjust the bike on my own. My bike is an older unit and does not have the Oxy sensors.

When I did my Stage 1, I then took the bike to HD for what turned out to be a standard 1450 Stage 1 download. No dino, no confirmation of the performance, in fact no "numbers" at all except for the approximate $200.00 numbers on the bill. So after that expenditure, I have nothing to show for it except the receipt and the hope that the download will be good enough.

Jump forward a couple of years, and I am worried enough about my spring loaded tensioners that I feel I have to upgrade to the '07+ configuration in the cam chest. My bike is used for street riding as my daily commute vehicle weather permitting. I am not racing the bike or trying to impress anyone so I pick a mild up-grade cam set from Andrews. But I am changing things enough so that my previous download would probably need something more. Now my choice is to go back to HD and pay for another stock download that will get no dino time, no testing for performance and no numbers except for the dollars on the invoice.

I don't want to spend a few hundred dollars on a control module that then requires a few more hundred dollars on dino time so I can get some charts back and know what the numbers are (or at least were on that day given humidity, temperature and barametric pressure levels). Not important to me. But might be important to others. So be it.

So I picked the TFI that is easy to install, easy to set AND change as I see fit with no guessing on the right downloads or having to take it to the "experts" to map for me. Just a wee flat blade screw driver and voila'. Tweaked! Now if I decide to change something else. Have wee screw driver, will tweak!!

For those folks that are gonna race their bikes, race tuners. For those folks that want to program the ECM with downloads, Power Commander or equivalent. For those that want HD to do it, just need some money.

To each his own.

TQ
 
Do you know what that voltage is with the sensors out and the resitors in? To go from 14:7 to 14:5 the resistors would be taking very little voltage away.

I guess what I'd like to see is some numbers. I'm assuming these units have been dyno'd during testing. I tried searching for some kind of numbers that show stock versus TFI installed. Granted, it doesn't seem to give the flexibility to tweak smaller RPM ranges, but it would be interesting to see some stock versus TFI installed numbers (at the recommended settings) across an RPM band.

it doesn't matter what the voltage is because the outcome for the ECU is taking the o2 sensor out of the calculation of AFR with out disabling any other factor that the ECU controls. there is no voltage at the sensor because it is unplugged. the ECU doesn't know that it is unplugged and thinks it is not a viable reading to include in calculation. therefore the ECU defaults to a setting of about 14.5:1, still very lean. these values are programed in the map.
 
Tfi has 4 pots.

1. Pot one is low speed and will bleed into the high speed is this is the cut off...
2... Is pot number two. Pot 2 has to close down the low bleed into the high bleed and the next pot..
3... Is the accelerator pot.
4. Last pot runs the high speed or main jet where think the #1 pot is the low speed jet.


:newsmile049: I love Fuel Injection Pep Peer Mode and Meatballs.

If you are going to post information for members, find out the correct information before posting your gibberish or don't post anything.

Pot #1 Green Fuel Pot: (functions like a fuel mixture screw on a carburetor)
Adjusts for the motorcycle's fuel requirements during light load operation, from idle through legal highway cruising speeds and steady throttle, at or below the rpm set by your rpm set pot. We have found that manufacturers have generally leaned out the fuel mixtures for emissions to a specific rpm (see below). To set this pot, make sure the motorcycle is up to a full operating temperature, then while in neutral, pick a fast idle that is not easy to hold a steady rpm (V-twins 1800-2200 rpm and multiple cylinders 2500-3000 rpm), hold the throttle at that spot and then slowly and evenly turn the green pot clockwise from its minimum setting, while listening to the exhaust sound. You should hear the exhaust sound change form an irregular and uneven sound to an even and smooth one. You may also see an increase in rpm as you increase fuel, and if you continue to increase fuel past this point to where the revs start to fall back away, then you can stop and start returning the pot screw back to a point half way between where the exhaust note first smoothed out and the point where the highest rpm starts to fall away.

Pot #2 Yellow Fuel Pot: (functions like an accelerator pump)
This fuel adjustment adds fuel into the fuel map whenever the throttle is opened rapidly. This pot needs to be adjusted from test riding, by performing brisk roll-ons in a specific gear, and by always starting at the exact same rpm. Try one clock position increases between roll-on tests until you can't feel any more improvement, and then go back to the last setting that improvement was noticed. Some models won't require as much fuel as others, so while increasing the yellow by one clock position increments if the motorcycle starts to decrease in throttle response, then turn the yellow back one and a half clock positions

Pot #3 Red Fuel Pot: (functions like a main jet on a carburetor)
This fuel adjustment adds fuel under large load conditions and is generally required when either air intake or quality exhaust system changes occur. This addition happens automatically using our unique load sensing technology, and similar to the road test procedure listed above in yellow fuel, test riding while increasing red fuel will find an optimum setting.

Pot #4 RPM Switch Pot:
All (except Harley/Metric V-twins) Sets the rpm that the green fuel turns off. This adjustment is achieved by setting the pot to 4:30 o'clock for 600cc and above multi cylinder sport bikes. Each clock position of this pot equates to about 1000 rpm's, so 4,500 rpm's would be half way between 4 and 5 o'clock. Verify this setting by revving the bike in neutral and watching for the green light to go out at the chosen rpm.

All Harley and Metric V-twins Sets the rpm that the green and yellow fuel turns off and the red (main jet) turns on. This adjustment is achieved by setting the pot to about 70% of redline (for example a Harley-Davidson Roadking redline is 5800 rpm and 4000 is 70% of redline) which would be 4:00 o'clock. Verify this setting by revving the bike in neutral and watching for the green and yellow light to go out at the chosen rpm.
 
I have a 05 FLHR with true duels,air box and stage 1 download.
Is there a standerd setting for the Doback Tfi unit?:eam

Yes. It will be in the instructions that come with the unit. These are STARTING POINTS. You can optimize once you have installed and felt how the bike is doing. Also, you can call Dobeck and talk to Chris (George's replacement). Describe your set up and get his recommendation as a starting point.

TQ
 
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