Why only +/- 15% Fuel adjustment on 2.0?
 

1st I would like to say the Rtek 2.0 is a great tuning tool and the data logging functions are unbelievable. It is really a useful tuning tool. Especially with my Innovative Wideband 02 hooked up now. But I do have 1 complaint.

I was wondering why you are only allowed a 15% correction on fuel. My S-AFC has 50% fuel correction. I realize you dont want to push the injection duty cycle but 15% is not much room for adjustment. I really want to get rid of my S-AFC but with only 15% correction I still use my S-AFC to turn up fuel after my Rtek is maxed out.

I would like more freedom in fuel tuning.

ed

What RPM range is the 1st cell in the fuel map, it's not labled like the others, is it 2000-2500? If so I need to adjust my fuel all the way down to idle. These cars run too rich at idle stock.

i was thinking the same thing so i asked "turbo2ltr"

How much adjustability is in the Stage 2.0?
Fuel correction is +/- 15% duty cycle at 100 points. This adjustment is on top of the correction made automatically when you slelect other than stock injector presets. i.e. When you select an preset that has 720cc injectors, the ECU removes ~25% from the duty cycle to compensate for the larger injectors. Then you also have the +/- 15% in the fuel correction map for a total adjustment range of 40%.

AND

"The safc doesn't really adjust % fuel, it adjusts amount of ariflow. Since it doesn't know the max airflow, it is impossible to put a % on the number..."

Thats wrong. It does trick the ECU airflow signal, but it is an exact % correction in fuel. Ihave mapped out the entire map with an S-AFC many times.

Also if you set the injector size as 4X720cc as I have. Then you only have 15% correction. If you pick 550 instead (with 720's in the car) and then you have 40% correction it defeats the purpose of being able to pick your injector size. You then have to go in and remap the entire fuel map to compensate for it not pulling out fuel for the 720's.

And if you pick 550 and really have 720's you only have 15% correction which is not enough correction to make the AFR correct under normal cruising situations. 720 are more than 15% bigger than 550's and the stock map is rich at idle and other low load situations. For example with just a S-AFC at idle you need to pull out around 33% fuel to get a 13.6 AFR at idle.

O. I was just relating what he told me. I have no experience with rtek2.0. I had the safc (just sold it for rtek 2.0) and I just leaned out low map (lowest I could go on idle was 17% before it wanted to die, I guess cuz I still have stock injectors). I'm gonna be buying bigger size 2ndarys like 880cc but I'm afraid rtek 2.0 won't be able to lean them out for cruis conditions.

I have been informed that the newer SAFCs do know the max airflow and therefore have a somewhat accurate relationship between the percentage of change and the actual change. The 1st and 2nd gen AFCs did not have this. In order to give a value a percentage label, you must know the maximum or it is impossible to calculate. (50% of what?) The AFC did not know the max airflow signal for any given car so the % value was a guess at best. And if you think about it, how can the AFC possibly actually add 50% more airflow unless the airflow is at or below half the max value of the sensor? If it's above it, it's just running up agaist the ECU/sensor limit. IMO, its just a number.

In any case, edomund, you are misunderstanding.
No matter what, the Rtek Fuel Correction table only has +/- 15% injector duty cycle adjustment range. *Where* that adjustment range is, is the difference. If you have 720s, and select 720 from the presets, then the ECU *already* removed ~25% duty cycle. (25% that you would have to have used the AFC to remove just to get back to stock) At this point from an actual duty cycle point of view, the Rtek's adjustment range would be comparable to -40 to -10 on the AFC. If you need to move that window up in the scale, choose 550s.

I can tell I am not doing a good job at explaining so heres a picture.
http://www.pocketlogger.com/images/adjustment_scale.gif

A note for xboxthug13b: The secondaries are not used during cruising
(closed loop operation) so no need to worry about this. The secondaries
will only come on when the ECU is open loop (ignoring the O2 sensor).

That's a great diagram! I see an addition to the manual.

-Henrik

I under stand all that. I probably didn't explain it well either. I know there is only 15% correction and that if you choose 550 and have 720's it's move the scale.

My problem is, I need more adjustment than just 15%. Is there anyway you can upgrade the program with a patch or something to add more correction %. 15% is not very much at all.

Also if I change the preset to 550 and have 720's it will run rich in all situations except under hard boost. To me that defeats the purpose of being able to select your injector size and have the rtek map out the fuel map. If I choose 550 then I won't even have enough adjustment to lean it out at idle and cruising.

please help I love the Rtek and data logging functions and want to keep the rtek, but without more correction range it is useless to me.
ed

edomund, do you have any logs and saved maps that you can send to us so that we can see what you're running into so that we can figure out how to best address the issue? Yes an upgrades are certainly possible, but we need to see feedback so we know what the best plan of attack is.

O I see. I guess 15% still isn't enough for some people that run bigger size like 950cc and more.
I see the great service you guys are givin, it gives me confidence in buying your product knowing that if if I ever have a problem you guys won't turn your back on me. Ima upgrade mines this week:)

I will second the notion that the service is second to none. Henrik and turbo2lltr are great to deal with. they are responsive and throughly understand the products. Super product!
My response is to edomund. I am certainly not an expert on tuning however I do collect a lot of data. Many times my interpertations are wrong but that's the benfit of forums where all can see it. I have an Rtek 2.0 set at 550/550 with 720 secondaries. I don't think I'm too rich in other than full boost conditions. For instance, I tracked fuel mileage over two months and averaged ~17 MPG (more or less normal driving) My best evidence is found in a chart that I posted under stories. It a data log of 30 minutes on a road race course. Unlike a 20 second pull on a dyno, the chart is thousands of data points. Road course's are all types of driving. Can't always take cornors at full throttle. I use lambda but's is easy to convert to AFR if needed. I think if you click on the thumbnail it will become large enough to read. Granted some of the conditions are likely too rich for maximium performance but others seem OK. Again I'm not an expert - just offering observations. Lastly even with the car running rich I was able to outrun many other cars over 8 driving sessions spaced over 4 days.(i.e. not a fluke happening) This seems to indicate to me that the motor is tolerant of rich mixtures and that I'm making good power.

-Hughes

Thank you for the input, but I think your tuning is far from ideal. I always tune with a wideband and want my AFR spot on. I dont care about fuel milage or anything, only AFR. With your car too rich you will not be making optimal power and lean you blow an apex seal due to detonation. I also dont care about judging my car by outrunning other cars, I want to pull every pony out of my setup safely.

My problem is I am running a BNR TO4 60-1 compressor trim hybrid turbo. My turbo at say 10PSI is pushing a greater voloume of air (CFM) than a stock turbo at 10PSI. Therefore I run leaner than a stock turbo at stock fuel maps that are intended for a stock turbo trim. That is why I have larger injectors.

However with the Rtek when I set my 720's as 720's it leans -25% right away (which is perfect for cruising and low load situations). Then if I max out the fuel at +15% (for boosting situations) I am still running -10% fuel. This setting would be like running my AFC at -10% (-10% of what the stock ECU would deliver with a 720cc injector not being leaned out) which is way too lean for my high horsepower application.

Agreed

Possibly. Remember there is an airflow meter that will actually measure the increase in air volume and make fueling changes accordingly. RX7s are not speed densitiy, so it can deal with increased air volumes somewhat. What boost levels are you running?

There are several options that we could impliment but we would like to see some logs and maps to see which option would adequately address your issue as I'm sure others might run into the same situation.

hughes was a beta tester for the 2.0 and has been running his for quite some time. He provided extremely detailed and methodic information regarding tuning and using the 2.0 to us. Everyone is entitled to their opion and I respect that, but don't be too fast to dismiss what he has to say.

BTW I agree that Rtek customer service is second to none. I made a seperate thread saying so. It's awesome that they are willing to help me get my car setup correctly. I really do appreciate their willingness to upgrade and tweak the program that is great.

turbo2ltr I will post some of my logs. How do I get the log files off my Palm onto the PL java viewer program. I have the PL Java program running but can't figure out how to get the files off my Palm.

The post above was actually being written and posted before your last post, so I do want to send some data logs.

I didn't mean to come off like that, sorry if I sounded condesending that wasn't my intention. I appreciate everyones input also thats the beauty of the forum.

As for the question about boost levels, I want to run around 15PSI for the track.

How to view the logs on a PC:

http://www.pocketlogger.com/index.ph...faq_gs_viewlog

Thank you

Can u post them on here if u don't mind? I would like to see a few maps to see more or else what they look like.

Yeah I will post them but I dont know how to set the Analog 1 correctly to show the AFR correctly on the PC PL Viewer. I read the instructions and it says there is a Wideband choice in the Preferences but my PL Viewer has no choice.
I have it correct on the Palm. I set my Wideband (it's fully programable) to:

0.00 volts = 8.98 AFR
4.98 volts = 17.98 AFR

Then I set the Palm RX7 Logger to the same and had it calculate the offset and it reads out very close.

You will need to go this link
http://pocketlogger.com/index.php?pid=utilities

Download the PC PL for the RX7. Save it as plviewer.jar if you let Windows name it, it will save as a Zip file. Once you down load it just double click on the file and it will open. Then DL the files I post and open them with the Pocket Logger Viewer program. To see more than the 2 maps (RPM & boost) just click the little map picture at the top left hand next to the time and under the file button. It will add another graph then you right click on the new graph and choose preferances then you choose what you want it to dislpay in the graph (AFR, coolant temp, etc)

It's a cool program.

Data Log Maps
 

Here are few of my maps I logged today. The AFR is too rich around 4000-4800. I need to lean it out a bit there. It's in the 9's.

Keep in mind these maps are with my S-AFC at +50% on fuel at 3500RPM-7000RPM. And the Rtek is at +15% in the same RPM range at 4PSI and above.

Before the Rtek leaned them out (setting it for 720's) I had the S-AFC tuned to +25% under boost.

Set up the WB scale from Preferences-> Custom Sensors in the viewer. You'll need to reload the log for the changes to take effect.

Also a known issue is the "AFC boost index" and "AFC RPM index" labels are swapped.

Unfortunately logs with your AFC still connectetd won't do us much good.

I know it will be a pain, but to get useful data for us, lower your boost, remove the AFC and take some logs. With the AFC still in the circuit, we can't truly see what is going on, or how much more adjustment you really need.

Right now your logs look good. I'd be really curious to see what effect just removing the AFC would have with everything the same...but I suppose I wouldn't recomend it without lowering the boost first to be safe. If the lower boost is OK, raise up the boost a little until you see the AFR start to dip (with the fuel corrections maxed at +15.)

Thats what I figured, the logs are not much good with the afc helping. I have logged with the S-AFC zeroed out and it was lean with the boost down at stock levels. I will do some more runs with the AFC zeroed out and the boost down at stock Waste Gate levels (no boost controller).

I found the analog input 1 setup, but I don't understand how to set it up. Where do I enter the volts and correspoding AFR? I tried entering them in both ways, logger value as the volts (my WB outputs) and maps to as the volts value. Could you help me out with setting it up correctly?

BTW I really appreciate the product support I have received.

Thanks
Ed

Preferences->Custom Sensors-> Analog Input 1

You should see this:
http://www.pocketlogger.com/xd9/prefs.jpg

Fill in the numbers.

The value on the left is not in volts, it's in raw A/D value. (I'll have this changed so you can enter volts.) For now, to convert your volts to the number you should put in, multiply by 51.

0 * 51=0
4.98 * 51 = 254

Low boost data logs
 

Here are some data logs with no corrections from the S-AFC. The Rtek is at +15% across the board under boost. This is also with no boost controller so the boost is around 7 PSI. I could not log much data time because it was so lean.

Thanks
Ed

Thank you for explaining the sensor setup the above post was written while you were posting. That makes sense I'll try it.

ed