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Hondata S300 & Tuning Stuff

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G'day mates :)

Good to be back again in this forum again. Anyways, i have been reading a fair amount of topics in HT, Hondata's forum and the "helpful" Help section in the software about the S300. There are a few things i need some clarification:

1. Here i quote from the Help section " Open loop (closed loop disabled) - This setting disabled closed loop. Disable closed loop while tuning. Otherwise the ECU will adjust the air/fuel ratio resulting in an inconsistent air/fuel ratio."

In what setups would the Open Loop be switched on full time? Semi street/track cars? Full time track cars?

2. Would putting the wide band sensor near the extractor (drill another hole) give more accurate readings than the typical exhaust bung setup?

3. I have not used AEM wide band kit before and i was advised to give it a try as i do not need to calibrate as much as the Innovate? Anyone has any experiences on both before?

4. In fuel/ignition map adjustments in the Hondata S300, there will be at least 2-4 blinking cursors following the map. May i know if any changes need to be done on other values,surrounding the blinking cursors also to ensure no sudden spike/dip?

5. What are the main sensors or key points should i be observing closely during datalog analysis in the S300?

Thanks guys.


1. Some Honda tuners feel closed loop is not needed if the car is tuned "properly" but if fuel efficiency is the key then enable it. But know how to use it, if you rely on the sensor to correct the tune and it goes bad than your car might run bad. Good way to do it is set your fuel table area of where the closed loop works about 4% richer of what you want. This way the sensor only leans the car during closed loop from an already rich state. This give you a safety margin in case the sensor fails, the car will run little rich but safe.

Another reason why you will disable it is when the car does not have its own sensor, ex you tuned it using the dyno WB.

2. Install the sensor following the instructions provided. Installing it closer to the collector wont make much difference because you are collecting the air/fuel ratio AVERAGE of ALL the cylinders combined.

3. I personally do not like the AEM units much, they tend to be problematic with ground offset when hooking it up to ECU analog input. That is my experience and maybe others feel otherwise. Innovate units are pretty decent and just because you have to calibrate them does not mean they are worse. Actually a lot of lab equipment needs to be calibrated so I think its false to think AEM would be better than those. Innovate allows you to connect your laptop thru their serial plug so you can log exact values on your laptop with no voltage differantial messing it up. AEM UEGO lets you as well but not out of the box (you need to source your own cable and use hyperterminal)

4. The Live tracing icon lets you know what cell or combination of cells the s300 is using. the darker ones are closer to the current cell its using to calculate the timing or INJ PW. The lighter nearby cells are interpolated. This lets you make sure that your not adjusting one cell to make a change but that you might have to make adjustments to neighboring cells as well, to achieve a smooth table and smooth running engine.

5. Everyone has their preference but I would assume RPM, MAP, IAT, ECT, TPS, LAMBDA (AFR), INJ PW

The AEM uego (controller in their gauge) was the worst wideband I've ever used. The readings were anywere but correct, so I ditched the unit and replaced it with an Innovate LC-2 product.

Later, my action got backed up, by a couple of customer cars that were using the AEM unit - the readings were all over the place compared to our dyno WB and an Innovate LM-2 unit.

Hey Tommy, howzit goin?

1. In which option listed in the close loop tab or scenario i should be disabling the o2 heater check box at all?

4. By editing the neighbouring cells, say if you look emtirely on a particular row, wouldn't it best to also adjust

the entire row together on the X-axis (RPM)? I am using the 2d method and somehow or rather i feel compel

to move them up an down just to avoid the gaps between the lines. What's your advice on this?




As for me so far so good with the LM-2. I haven't tried AEM nor i have friends using them to give me a review on it.

Thanks for the update.


1. I generally don't use Close Loop operation on my Hondata tuned vehicles. I did once and it was a pain in the ass (most likely because I couldn't get the car on the dyno to retune it from the previous tuners horrible job)

2. I run my WB 18" away from the collector at a 15 deg. angle as per PLX installation instructions.

3. I have never used a AEM uego, I don't like them. I've had friends who've had them, though. I've used PLX for the last 4 years and haven't had a single issue. No voltage offset corrections as long as you cut the D14 resistor inside the Honda ECU (for more accurate data logs) and ground the PLX module at the thermostat housing with the ECU.

4. the blinking is because the ECU uses fuel values from its neighbor cells and interpolates it. If you notice your load cells are wide and your RPM index is by 500 rpm. anything in between will use close by cells to get a value from.

5. I use RPM, gear, MAP, IAT, ECT, Ethanol Content, Inj. PW, Inj. Duty, Ign, and a few others. I like to know whats going on everywhere.


1. Yes you disable the O2 heater anytime you are not running the OEM o2 sensor.

2. In 2d mode you strive to have the lines nice and smooth and not overlap eachother, this method of looking at the map is always good to see if previous tuner just started bashing numbers in there. Although if the car is tuned for ITBS Alpha N style it will look a little bit different to regular style tuning.

red96turbols - I never had to many issues with closed loop enabled but I use voltage target not lambda value. My question for you is, which D14 input resistor are you talking about? I know for D10 ELD input to be used for a wideband you need to remove two resistors R136 and R138 but never heard of doing it on D14.

Hello Red96turbols,

Noted and thanks for the reply.

Hello Tommy,

Yeap, i do notice the difference between the non-alpha-n and alpha-n

tables. I took note on the ITB helpfile on the Hondata page.

By the way, i was reading in the other thread on overlay


And this is something i have not done. So far this is the closest mini-tutorial

i came across and just need some pointers/tips if i were to do it on the S300




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