EFI University

[Tomak]

The documentation that I have is not very good. Been tuning a few of these, so I need to know more:.

Main Fuel Number. From what Link told a friend of mine, this is a peak calculated pulsewidth at 0 MGP.

1) Why MGP? The software says it is baro compensated, but I did not see a table, is this simply part of the fuel calculation in the background?

2) Also, most basemaps guys are showing up with have MGP as the load scale for fuel. Again, no baro correction table that I see. I have been switching this to MAP to avoid issues, so is baro ignored in this mode? Can someone fill me in. Or is my MAP gonna go to shit if they go to sea level, and the ecu adds 12% fuel for baro (I'm typically at 89kpa ambient)? If I leave the table as MGP, will this in fact work if the customer travels down in elevation?

3) Main fuel table. So, once we set our main fuel number, what does the main fuel table represent? Anyone know the actual formula for the fuel calculation? Why do people hate traditional VE?

4) I have trouble logging with this ecu. By accident, I found that if you have a table open, like the fuel table and try to log, nothing happens, close the fuel table, and it starts. Anyone else?

5) Seems the rev limiter is some sort of soft touch, or anticipatory deal. I set it to 8000, and the engine drops power roughly 300 rpm before. I do not see this documented, and tried various modes (fuel, ignition, rotary all with similar results. To rev clean to 8000, I have to set the rev limiter well above that).

6) The software is very similar to Haltech, with some distinct advantages (ie, change table axis without shutting engine off), but lots of disadvantages ("store" fucntion required etc.... but the biggest PITA....

Is there a way to not display every damned damned parameter? You know, how the Haltech only displays the active ones? Seems a royal pain to have to click every branch, and tree to make sure you don't have something on that should be off?

7) These guys wont allow new dealers in Canada, and I refuse to buy a unit from a competitor. Bad enough I have to fix their work. Anyone wanna sell me Link or Vipec at dealer cost?
_________________
www.Dynomotive.ca
AEM Factory Trained, Accel EMIC, Haltech Trained, Advanced GM EFI, Diablo CMR Mopar Dealer, SCT TUner - Viper/SRT10, Delta Force Dealer.
Analog DD 450
Mustang MD250 - gone but not forgotten.

[daveh]

Master fuel use this as a main scaler to get sufficent resolution of the main fuel map.
The maths behind it if you really want are
Base pulse width=master x map/100 x %VE/100
so at map reading of 100kpa and a value of 100% then what the master number is would be the inj ms with no other corrections in place.

The ecu has a baro sensor fitted to the board
so when selecting MGP you are applying baro correction
when you select map you are only applying map correction
Manifold Gauge Pressure(MGP)=MAP-BAP

Rev limit depends on how you set it up are you using the advance mode or the default either case the limit number is the Hard limit (highest rpm you want the engine to go to) a soft cut is in effect before this value if you use advanced mode then you can dictate this as well as the cut percent

I find the software easy to use it really depends on what you get used to the screen can be setup to show what you want open a tab and setup the gauges how you want and what values and tables you want save that page and it will always be there.

failing that hit the f12 key and see what going on with what in the runtime tabs

What firmware and software version are you running as i have never experienced the logging issues that you have?

Hope that helps somewhat
if you want give me an email or ring and i can go online to your computer and run you through it a bit
Regards
Dave
www.dtechmotorsport.com
dave@dtechmotorsport.com

[Tomak]

Thanks Dave, great info.

Vipec I tuned 2 nights ago, I was having the logging issue, so I updated my software AND ecu firmware to whatever was the latest on their site. Still did it. Ie, you are on the main fuel map, click start log, and it runs for a second but stops. Close the fuel map, and all is well. This was an S14 Sr20. Right after the update also is when the rev limiter started to pull timing and kill power early, not in advance mode. I am almost positive prior to my software update, it was fine. This is where it got frustrating opening every item on the "tree" searching for something that may have caused it.

This car, rev limit set to 8000, got to 7700, then a drop in power, and a hick-up. Both log and dyno rpm confirm the 7700. I bumped the rev limit to 8500, and it pulled to 8000, where I let of, clean run.

Last night was a Link G4 Atom. S13 SR20. I am not 100% sure on the version, but it did the same thing with the logging, so I did not bother to update. Rev limiter was also on fuel cut, not advanced, and it too dropped timing right before the redline, and the car did not reach its 7000 rpm redline. Got to 6650 or so, did the saemt hing as above. This car had mechanical issues (ecu voltage suppply was 12.4 volts, voltage at injectors was 13.8 volts). Seems common on Nissan's, seeing this quite often. It also had no IAT, and the MAF was still installed, and his wideband was not wired to the ECU. I suggested he "fix" all the issues, and we will try again.
_________________
www.Dynomotive.ca
AEM Factory Trained, Accel EMIC, Haltech Trained, Advanced GM EFI, Diablo CMR Mopar Dealer, SCT TUner - Viper/SRT10, Delta Force Dealer.
Analog DD 450
Mustang MD250 - gone but not forgotten.

[EFMotor]

You are right about the rev/map limiter. In default mode (not advanced) the rev limiter actually starts 500rpm before the set rpm. This is no problem when you know about it, but I imagine it can really be frustrating when you don't.

I'm also experiencing the same problem with the pc logging. I always switch to the logging page before starting the logging to be sure that it actually starts.

[Tomak]

interesting "glitch"....

If you get the "main fuel number" right, the fuel table is basically a VE table.

Most turbo cars have been easy to tune, no problems.

Last night, a rank little 13:1 compressions, 11,000 rpm NA 4 cylinder.

Wanted "about" 109 in the fuel table at peak VE. Guess what, Link tables wont let you go more than 100.

Sooo, you need to "fudge" the main number, or add a multiplier or some other thingy to do get enough fuel into it.

At the end of the day, I guess it doesn't matter, 2x2 is 4, so is 1x4, but being a Ford tuner as well, we just tend to do things "by the book".

I really like this ecu/software though. to bad they have no warehouse or true distributors in Canada.... probably why they are fairly rare here compared to aem, haltech, bs3, fast etc
_________________
www.Dynomotive.ca
AEM Factory Trained, Accel EMIC, Haltech Trained, Advanced GM EFI, Diablo CMR Mopar Dealer, SCT TUner - Viper/SRT10, Delta Force Dealer.
Analog DD 450
Mustang MD250 - gone but not forgotten.

[RH9]

Hi , i am new to this forum , I intend to tune the car myself as we dont have any certified tuners in our country. I have chosen Link G4 plugin as the ECU that i shall be putting in my 2jz swapped Rx7, hence i am trying to learn and get used to the functions of LINK. I have a few questions that i would like to put up.

1. There is an option in Link which is called OVER RUN FUEL CUT and Over RUN DEACTIVATION TABLE.. How exactly this table works ? when does it gets activated and how to set it up properly ? The RPM values are put against ECT C. It isnt clear in the help file.

2. Similarly for RPM LIMIT TABLE . The Limit is ECT C against RPM. Again the question is what is hard cut limit ? because at different temps there are different RPM set .. So how it works ? suppose if i start putting 8000 RPM from 20C till 110C and then reduce it what will happen.

3. OPEN LOOP TARGET AFR table , when does this table gets utilised ?

Kindly elaborate these options keeping in view i am new to this side.
Thanks.

[RH9]

[supercharged88]

Over run fuel cut deactivates the fuel injectors on decel.
It is active when the TPS Threshold values is below the set point, normally 1% and below the rpm setpoint in the table.
RPM Limit table is the engine rpm limit you wish to run for a given engine temp.
For example you may only wish for the engine to rev to 5000 rpm if the coolant temp is only 40 deg celcius.
At low temps you would obviously run lower rpm limit values and increase the rpm limit values towards operating temp.
EG: at 20 deg rpm limit maybe 4500 rpm, at 40 degrees 5000 rpm at 80 degrees 7500 rpm.
When the engine heads towards over heating eg 110 degress celcius you would also normally lower the rev limit value, eg 4500 rpm.
Hard limit is an option in the Advanced Mode of limiters.
I never use Hard Limits with forced induction engines, soft limit only.
Some people use hard limits with launch control options.
OPEN LOOP TARGET AFR.
This must be set to ON for tuning.
With this turned on the QUICK TUNE FUNCTION can operate and the Main Fuel Table can be tuned automatically by the software, using the Target Air Fuel Table and you also require a Wide band Air Fuel Meter.
The Target Air Fuel Table is also used for Mixture Map Tuning and Maths Key tuning, when tuning off the data logs.
Also with this option set to on,
As long as the engines fuel table has been tuned correctly,
You can go to the Target Air Fuel Table and change the values in the target table and the software will change the fuel table value at that given load point or points.
EG if you tuned the engine for 12.7 :1 at a certain load value say 4500 rpm and 150 kpa but you wish to have 12.5:1,
You simply change the Air Fuel Ratio value in the target table to 12,5 :1 at the load point or points you want the change to occur.
The software does the rest, you do not require an Air Fuel Meter for this to happen.
However it is good practice to recheck the Air Fuel Ratio with a wideband on completion.
Hope this helps.

[RH9]

[RH9]

Any one ?

[Turboivo]

[RH9]

[Turboivo]

[RH9]

Lets suppose the ECT is 40 and i have set RPM 5000 against it .. I suddenly floor the throttle at that temp the car will hit the limiter at 5000 ? what if i want to set rev limit 8000 RPM starting from 30C to 100C and then decrease.. Is there any harm in doing this ?

OK now there is a confusion between AFR TARGET TABLE and OPEN LOOP AFR TARGET TABLE.

AFR TARGET table is the table which is used by QUICK TUNE option to tune the car nearest to the AFR given in the table, for that we have to tune particular cells holding the RPM steady which can only be done at DYNO jets. This wont be applicable for road tuning, if so then how ? Am i Correct ? and
OPEN LOOP AFR TARGET TABLE -- What i understand from this and the help file is you can change the AFR of the Fuel table by giving values in this table . Software will directly alter the values .. is it so ?


Can any one explain this ?

[supercharged88]

Running an engine to 8000 rpm at only 30 deg C is not really advisable.
The engine should be allowed to reach operating temperature before revving it that hard.
That is why you have adjustable rev limits for given engine temps.
At the end of the day, it is your engine so if you wish to rev it to 8000 rpm at 30 deg C, then that is your call.
The Target Air Fuel table and Open Loop Target Air fuel table,
The Target Air fuel Table is the Actual Table where you set the values you wish to run for that particular Load point.
EG 12.5 : 1 at 4500 rpm and 150 Kpa.
Open Loop AFR Target Table, this is the OPTION setting only.
By selecting ON in the software, this allows the Target table to be used for tuning.
If you DO NOT turn this option ON then the Target Table will be ignored.
The Target table and Open Loop Target Table are the same thing.
There are just different ways of using it.
Quick tune, Maths key tune and Mixture Map tuning from data logs all use the Target Air Fuel Table values as their source for calculating the fuel cell number required to run the correct Target A/F ratio.
Yes, once the engine has been correctly tuned to the Target A/F Ratio, then you can alter the A/F ratio of the engine at a given load point by simply changing that A/F Ratio value in the Target Table.
As i posted previously.
If the engine was tuned to say 12.0:1 at 5000 rpm and 150 Kpa but you decide you wish to run 12.5:1 at that load value, then simply change that load point in the Target Air Fuel Table to 12.5:1.
The ECU will apply the mathmatics to the corresponding cell value and change it to the number required to achieve the new Target Value.

[RH9]

clarified.

[boca juniors]

good thread to get some information on this EMS since we are going to be tuning one in the near future.
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Corr Performance Tuning