jimbo1111

If I understand this correct. When the throttle hits 66% or the klr senses 1 bar boost the klr sends a signal to the dme to go to the wot map. 1 d. When that occurs the boost created by the turbo also raises fp in the regulator for additional fueling.
It is impossible to have 3 different fuel settings in one chip for wot. You would need 3 dme's to do that. The fueling needs in wot have to be different for every injector setting. Tomas seems to have the best interpretation. You would need a custom chip for every injector used because scaling back fuel is linear and would put the maf voltage output to high to make up for the scaling back of the injectors. This will max out the maf to soon.

fast951

Then use the correct size MAF.

jimbo1111

Your correct john but when you go larger the lookup points on the chip for timing will change for part throttle maps. Is this something we have to live with?

fast951

No, it's not something we have to live with. That's why we use the correct MAF transfer function on the chip...

Mikeaagesen

Jimbo, I think you just need a simpler explanation of the injectors. Now, feel free for anyone to correct me if I'm wrong, but here is how I see how injectors/Duty cycles work. Lets say that 36 pound injectors flow exactly that. When they are flowing 36 pounds they are at 100 percent duty cycle. Now, the larger injectors (55's) can do the exact same thing. They can flow 36 pounds but at a lesser duty cycle. So when you need more fuel up top you add more fuel,with a chip or fuel controller of some sort, which will make the duty cycle of the 55 pound injector go up and you will get more fuel. So what I'm trying to say is that the stock ones have to try really hard to make 36 pounds and the 55s can flow the same amount without trying very hard. When called upon, they can try harder and make the extra fuel up top because they have the ability to flow more. This is only how I see how it works. I am by no means an expert with fuel and tuning by any means. I hope this will clear some things up.

jimbo1111

What your saying doesn't make sense John. I have logged in and out voltage from my piggy back. The piggy back has a transfer function built in. The voltage is within .2 volts of each other. maf to afm signals are very close. They were designed to be. You will still be maxing out the maf whether the transfer is done on a chip or on the piggy back when you scale back the injectors. I choose to leave my injectors not scaled back because they will function like 55 lb injectors and not 36 lb. I have the benefit of scaling back the part throttle with the piggy back and have all the fuel I need up top. The maf meter will not max out premature as with your setup. Why should I detune a meter that is capable of 600 HP and has excellent resolution and replace it with a meter capable of 800 hp and lose the resolution at part throttle?

fast951

Jimbo, which part does not make sense? It's not that difficult, once you get the concept all of the pieces fall in place...

jimbo1111

There is only so much you can do with a 0 to 5 volt signal. 5 volts is all the dme can read for max out put. Anyway you cut it your fooling it into believing that it sees the same cfm that the afm maxes out at. Beyond that it's a fueling issue.

fast951

If you use a good MAF curve, and code the transfer function on the chip for it, you will not be fooling the DME at all.. Based on a voltage, a certain curve equates to a pre-defined air flow. Then you calculate the amount of fuel you need based on the desired AFR..
With the MAF chips, you are able to tune a car, change a MAF (to a different calibration), change the transfer function on the chip and the car will remain in tune.


Now use AFM chip with a MAF then yes, you are fooling the DME.. and that's when you encounter all sort of limitations...

jimbo1111

So you are saying that you code the chip with the characteristics of a particular maf meter. cfm to voltage. Then you setup a fuel map for it. If your getting 2.0 with a afm then with a larger maf you get 1.2 per say. You will give the same fuel at a lesser voltage to match the maf output. Sounds good but you still need a specific map for it. For a specific injector. The fqs will still not work for a larger injectors.

fast951

awilson40

I feel your Pain

jimbo1111

awilson40, you still have it wrong in your post above. I don't know why your so happy.

John lets assume that the above is correct. Your still using a piggy back for control of the fuel. The PG that you use has a conversion from maf to afm. So you are using a amf signal to send to the dme. Basically all you have done is made a custom chip for your setup.

awilson40

I dont think so Tim...er...Jim
I have a great Idea...how bout you apply your theories in designing a kit to put the other vendors to shame

fast951

You just don't get it!!! Do you? I give up, one LAST TIME....

The PB I use is not used to convert AFM to MAF like signal... The DME reads and understands the MAF signal... The PB is used for fine tuning only!!!!!!! I explained this to you MANY times, come on...

Look at this image. It's the software I use to setup the transfer function for a particular MAF. Each MAF has a unique transfer function. Also notice the transfer function the the stock AFM (VAF)...