02 Sensor bypass

Anyone have success making up a diy o2 sensor bypass for their 1250 ??
(.o0 Read online that it needs a 330 ohm 1/4 watt resister..)

Nevermind, have sourced a ready made one from abroad.
$27 Australian delivered

Here's the link: http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=260724291976&ssPageName=STRK:MEWAX:IT

Note, haven’t purchased off this seller before nor tried out the product so I can't recommend yet.
Will provide update when goods received, installed and tried it out.

Cheers,
Mars

I confess I'm bewildered by this EFI system and the various mods that can be done to it.

What is the advantage to bypassing the O2 sensor - I understand the ECU gets input from the O2 sensor to keep the air/fuel ratio within parameters.
Does bypassing the O2 sensor help address the lean condition thatI understand the system has from the factory ?

It seems that the best compliment reviewers give to EFI systems is that they are as good as a well set up carb bike. If that is the case I guess the only reason manufacturers use EFI is to meet emission standards seemingly at the sacrifice of low revs running - or am I completely missing the point?

Glenn.

Above ,+ me.

Guys, I’ve sourced the following from Dobeck Perf. themselves to help clarify this subject:

Your bike is equipped with a narrow-band O2 sensor. For part of the drive cycle your bike's ECU will function in closed-loop mode. During this time, the ECU is taking the O2 sensor readings to help make fine tune adjustments to make the bike run 14.7:1 AFR. This is occurring in the drive cycle from which we define as the CRUISE zone. 80% of the time when riding your bike you are within this part of the drive cycle.
The problem with running 14.7:1 AFR is that it is not always the best performance. A lot of vehicles respond better to say a 13.5:1 AFR. However, if we were to try and adjust an O2 equipped bike when it is operating in closed loop mode a sort of tug-of-war begins to happen which results in poor drivability. This is caused by TFI (or other) unit trying to add fuel to the stock curve, the ECU recognizes this from the O2 sensor and pulls it right back out. Without bypassing the O2 sensor signal, you can not run a richer AFR.

Should note that I’m not performing o2 Sensor bypass mod in isolation rather, I’m combining this with various mods including airbox, tfi, pipe and K&N filter. May do the PAIR mod while I’m there if I have time.

As for question on why do manufacturer bring them out like this?
IMO, there are two main reasons.
1. Regulatory emission controls and
2. Fuel Economy. (I’m regularly getting 300+ out of a 1250cc motorcycle– Gus has got well over 400klm’s!)

Hope this helps.

doesn't the seller of the TFI send a O2 bypass as part of the kit?






Fi is a great thing as it can make the engine run and perform at it's best/optimum at all times regardless of (most) environmental conditions without the need for human (the owner/driver) input. This is the big drawcard for Fi IMHO.
With the right knowledge and hardware/software it's also easier to modify the engine for better outputs for the majority of people as a lot of systems are plug and play.
How many shops do you see now that will not go near a carbed bike or car because the skills needed to tune an engine properly are almost dead in the general auto industry (there are specialists out there) or it involves a lot of time and parts so in most cases is not commercially viable compared to Fi

One of my early introductions to the wonders of Fi was with a CAT diesel engine. In the past to increase output of the engine (lets say a 50hp increase) involved anything up to two days of mechanical work. With Fi and the right gear it took about 15 mins and you didn't even get your hand dirty.

I purchased unit seperatly.
Hence, wont recieve the special D.W settings but will start with the TFI reconmended settings that come with unit till opportunity presents itself.

D.P 1250 settings look to be:
Green: 2
Yellow: 1
Red: 2
RPM:5800

To be honest, cant confirm if there is a difference between the D.P and D.W settings but assume there is.

Thanks for that explanation.Is there any differance between TFI and a power commander in what they do ,or are they just different makes.

Yes and No. All (including the Healtech FI tuner pro and BAZZAZ) will permit you to modify the ECU's fuel map; the difference is in the amount of modification that is possible and other features such as support for quick shifters etc. Basically, the TFI is a low cost (comparatively) solution that will work if the engine is not too heavily modified, (think cams and porting).

By the way, I can remember how much fun I had pulling out the carbs in my GSX1100 to re-jet them (not), the novelty wears off pretty soon after you have done a few times and the jetting is still not right

From Healtech FAQ's: "What about modules like the TFI or Juice box ?
These have two major flaws. For one: can’t subtract fuel. All bikes (either
with stock or racing exhaust) require fuel subtraction at many places of the
fuel map. (You don’t have to believe this, just put your bike on a dyno and
get the AFR logged at various load conditions.) Without the ability to
subtract fuel, the engine will not get the optimal AF ratio.
The second problem is that it’s not a map-based module and only allows
adjustment for 3 ranges (Low, Mid and High). You can make certain areas
better but hurt other areas at the same time. Fuel injectors are not like
carburators. The AFR changes rapidly depending on actual TPS/RPM and
only a true map-based module can fix all ranges. (Again, if you put your bike 9/9
on dyno and look at the AFR charts you’ll understand that it is just not
possible to get the fueling right by turning 3 screws on a module.)"

As per Dobeck performance opinion

More info if you click here :-P

gus wrote:Thanks for that explanation.Is there any differance between TFI and a power commander in what they do ,or are they just different makes.

Gus I believe the power commander has increments of 200rpm in it's maps. As stated it can also deal with quick shifters and timing devices

The details can be found here onthe internets http://www.powercommander.com/powercommander/default.aspx

I know people who are happy with both units.
Most of the time, the problem is that the engine doesn't receive enough fuel so the TFI is spot on 90% of the time, if it's set up ok.
The PC has more adjustments, but is that really a good thing? More adjustments means more things can screw up.
The TFI adjusts fuel level by looking at how quickly the engine revs pick up vs throttle. It gives fuel according to engine load.
The PC has maps tuned in that match tps and rev. It's better in many ways but a lot more expensive to get set up. Setting the bike for tps and rev has drawbacks too. The Dynojet system can't tell if your at 5000 rpm in 4th gear climbing a hill or if your on a flat surface at the same rev and tps; the engine loads are different yet tps and revs might be the same.
Also Mark Dobeck of TFI fame, actually was the founder of Dynojet and sold the company.

I got the TFI box and am going to install it this weekend. I hope I don't end up eating my words!

Could we hope for a ride it,then install it ,then ride it again report.This could be interesting .

No prob Gus. I might take a video camera with me and do some accel runs before and after. I'm not too fussed about getting dyno numbers or anything like that. I'll be able to tell if there's an improvement, when I crack the throttle and she's able to haul my fat 100kg arse into the air!

I didn't notice a major increase in grunt ...just a lot smoother running.

Dale reakoned don't muck around with the stage 1.rip out the secondaries & use his stage 2 settings.

As far as the TFI v PC. it's a matter of choice & ease of use. Dobecks' no idiot, so he would have a good idea of what works & doesn't!

geekay007 wrote:.....Dynojet system can't tell if your at 5000 rpm in 4th gear climbing a hill or if your on a flat surface at the same rev and tps; the engine loads are different yet tps and revs might be the same.

...actually it can, that's why TPS is used is an input, i.e. if the trottle angle is 10% then you are on the flat and if it's 90% then you are climbing a hill, towing a trailer, two-up with a cyclonic headwind etc....

I think I'll try the stage 2 settings when I get a new pipe. At this stage I'm tossing between a yoshi pipe (too expensive) or just ordering one from the states ( might be a lot chepaer with the plummeting US dollar). I'm just hoping to have a better breathing donk at this stage as the big girl sounds asthmatic up top.

I always thought Dynojet only use Alpha-N to adjust the fuel curve.

Check this out.
http://www.bayareamotorsport.com/alphan.html

In particular:

"The answer, in a crude sense, is that you "train" the computer what to do in a given situation (on the dyno). For every possible combination of throttle position and rpm, the tuner determines the appropriate ignition timing and fuel delivery to yield max power but not incur detonation. The computer just remembers all this (in the form of maps which are stored on a chip), and when it sees a certain combination of rpm and throttle position in the field, it just says "what did they tell me to do in this situation?" and does that.
So now throttle position and RPM are the two dominant input parameters to the engine computer. This is where the Alpha-N name derives from. Alpha for the angle of the throttle plates and N for RPM. "

The key words being "train the computer" and "every possible combination", that process is time consuming and for all practical purposes impossible. Still the PC is a good unit.

Hi Guys,
Quick update: Brought bike up to Stage 1 mods over the weekend. (still waiting on o2 bypass..)

Skill level required: Low - need to work a spanner, a screw driver, a drill, read instructions and use tape/cable ties

1. Airbox mod #1 - Snorkel removed
2. Airbox mod #2 -new whole drilled (aka stage 1)
3. K&N re-installed
4. PAIR block mod - Easy and worthwhile mod, popcorn machine now decommissioned
>> http://www.twtex.com/forums/showthread.php?p=799456
5. TFI installed - Easy install, dobeck settings used.
>> http://www.dobeckperformance.com/instructions/2023ST.pdf
6. Givi Topbox installed. (39lt - brand new off Ebay including all brackets etc..for $200)
Looks like a descent piece of kit. Got well into 6th gear (...kph's) and hasn't fallen off, which is nice.

So, how she go??
Really happy with these mods. Would of liked to get the o2 bypass on but she hasn't arrived.
A marked improvement in throttle smoothness felt. The exhaust popping from the Leo Vince has now vanished completely & this could contribute to the smoothness being felt. A healthy power increase felt from 4.5k onwards felt which while not the main motivator, is most welcome.

Finally, after recently turning 40, the Givi now cements my enthusiastic entry to midlife-crisis kingdom. Next marker, 50 but doubt I can wait that long before celebrating with an Airhawk 2.. maybe 45..

Let you all know when the o2 sensor is on and do a comparo.

Safe riding,
Mars

Flame me all you want... but... I use my Bandit for commuting, so fuel economy is (sort of) important for me. I'm getting pretty close to the best case advertised 5.5l/100k at the moment, how much do these mods effect that economy?

Mars, I also did the stage 1 Mods this weekend including the oxygen bypass. I still have the stock exhaust can.

I haven't had an opportunity to take her for a long run yet.
So far it looks good. Sounds a lot better, pulls better at moderate to large throttle settings. I suspect a tiny drop off in grunt below 4000rpm, but I had a chance to give it 70% throttle in 1st and 2nd gears and it definitely pulls better.

Clayton, I don't think this is going to improve my fuel economy at all, I have a heavy right wrist. After all PC and TFI boxes add extra fuel most of the time. However the engine breathes better and it seems to spool up quicker, so at low throttle settings this may improve your fuel economy slightly. In standard trim I was getting around 14.5 km/L and you're getting over 18km/L. If it's fuel economy you're after, I'd leave the bike alone and just use premium fuel.

o2 sensor bypass still not arrived... Been 2 weeks and Greece is 13,592km's away (as the crow flies) from OZ..... Will sit tight

I feel for you Mars, you're dealing with GPT (Greek People's Time). I should know, I'm Greek.

sorry to hear that G.K ..only kidding

Seriously, If it doesnt arrive by Monday, may need you to PM me how to say "hurry the f... up in greek"

Hmm, probably didn't understand all of the explanations posted above but am contemplating an O2 sensor eliminator, eg

http://www.ebay.com.au/itm/Oxygen-Sensor-O2-Eliminator-GSXR-HAYABUSA-BKing-BANDIT-1250s-GSX-R-M50-VZ800-C50-/370568128525?pt=AU_Motorcycle_Parts_Accessories&hash=item564794e80d

I guess my question is: Is it just a waste of money if simply installed with a R77 can and no other mods? Would it have any noticeable effect?

That's a bit pricey there Ewok. The benefits of a sensor bypass, as I understand it, will be seen when you add a PC III or TFi box. I'm not sure if you'll notice it with the R77 can alone. Before I did the stage 2 mods, I had a Delkevic can and a TRE. The bike felt much better in the lower gears and breathed better. So my advice is get a TRE instead of the bypass.

http://www.ebay.com.au/itm/TRE-BANDIT-GSF1250-GSF650-GSF-650-1250-/290654097845?pt=UK_Motorcycle_Parts&hash=item43ac5591b5

Just be warned, if you own a GSX1250FA or any other bike with a digital gear display, it won't show you the gears properly. It will keep reading 5, as it sets the ignition map to that of 5th gear.