Bryans12v

Any Injector size upgrades for the 12v A4 ..?

MikTip

<center><img src="http://www.rceng.com/formula-1.gif"></center><p>17.25 lb/hr injectors are required for an 6 cylinder engine producing a maximum horsepower of 230.

This calculation assumes a duty cycle of 100% and 0.45 BSFC for normally aspirated engines.

Flow rate (lbs/hr) = Max Hp x BSFC / no. injectors x duty cycle

BSFC = 0.45 - 0.55 for naturally aspirated engines. 0.55 - 0.65 for forced induction engines

Conversion from lbs/hr to cc/min = lbs/hr x 10.515

Simplified max Hp x 1.807 (nat) Simplified max Hp x 2.136 (turbo)<ul><li><a href="http://www.rceng.com/technical.htm">http://www.rceng.com/technical.htm</a</li></ul>

Bryans12v

Which ones would best comply to us ?

MikTip

You cant just add a set of higher flow injectors.

They are controlled by the ECU, and have very specific voltages & duty cycles they operate under. The ECU follows the info on the MAP of the EPROM(chip). Too much fuel(rich) condition, and the ECU will lean the engine back towards the normal, in order to meet emissions. To install higher flow injectors, you need to alter the ECU programming, and or MAF sensor.

The purpose of changing the MAF calibration for use with larger injector sizes is to make the computer think that less air is actually entering the engine. By doing this, you are making the computer reduce the duration of time that it is opening the fuel injectors at a given air flow rate. The larger the injector that is used, the more the voltage is dropped, and in return, the shorter the time the injectors are pulsed by the computer. This "tricking" of the computer is how a MAF allows the use a larger fuel injector than what originally came on your vehicle from the factory. The only way that you can calibrate a meter for larger injectors is to reduce the output voltage, and ALL aftermarket air meters use this method to "trick" the computer. The most important thing to consider is that changing the calibration for larger injectors must reduce the voltage to the proper level for the ideal air/fuel ratio.

Another possible fix, is increase the fuel pressure at the injector head. Higher pressure usually translates to more fuel. But only until the ECU senses the rich condition and changes the injector duty cycle to compensate. Additional mods needed here too.

A "chip" often changes many of these parameters
to allow for larger injectors, etc......
However, many hours of testing and dyno work needs to be done to find the "ideal" set up for specific makes and models. Ideal to the fact such a chip will be marketable, meet emissions, and actually increase performance. The limiting factor is the "meeting emissions" rule. Especially in this day & age of annual inspections of our cars.

APR has a chip which has 3 "modes", switch able by the driver. A ton of R&D has gone into their setup, for they have the market.

No one makes any sort of upgrade for the 12V V6, because in its "stock" form, a chip wouldn't add anything. Modify the engine with cams, ported & polished, etc.... then a chip is desirable, to ensure you get the most from your mods.

Everybody wants the "quick fix" to performance. Its not ever that easy. Lots of R&D required. Time, money & effort. Those who know the info don't let it out, because they are trying to earn compensation for all their efforts.

Old saying: "Ya got to pay to play"

Bryans12v

I was wondering about this because,...

When it comes time for the group to fork over the 15k for Jets product, I want to make this as prductive for me as possible. Since they are doing the bending of all parameters for us.
Which are the following few that i know of...

1. Fuel Map
2. Injector Pulse timing
3. Ignition Map
4. Variable intake man. timing
5. Variable Valve timing

All are going to be remmaped to fit the mods of my car. Now, I was wondering if it was possible for me to up my injector size for them to compensate for.I would love to do this if the price is right. You know what its like to own a 12v, not much to do. Is this a possibility?

Mike O.

...all you need to do is make a MAF housing (not the element itself) that is the same percentage larger than the injector is over stock. 15% larger injector = 15% larger MAF housing that the stock element will fit into.

Ford guys have been doing this for years. You buy the 30lb injectors with the larger MAF and use the stock ECU.

Mike O.

MikTip

My MAF has been modified, as are my injectors, ECU
and fueling system.

My Audi has been extensively run on several dyno's
to fine tune it all.

Looks like GIAC did all the work for you?

I bet your still running the stock MAF?

What works on a Ford doesnt mean it works on an Audi.

What works on an A4 1.8T wont work on an Audi V6
12v.

But, you probably already know all this......

Mike O.

...but you probably already know that.

Have I done this on my Audi? No need because I haven't hit the limit on the MAF yet (my T3/T04E will however) Has anyone else? Yup - APR has to on its 3+ kit for the non-DBW and 3 kit fot the NB 1.8T.

What's really interesting is how you've modified the Hitachi ECU. If you have indeed modified it and not just replaced it with something from Electromotive (or someone else) then I am indeed impressed. From the way you describe things, it must be great to work with a chip that only has one map that is in closed loop mode all the time and even reads the 02 sensor at WOT to back down fuel injector timing. That Hitachi ECU sure is something.

Oh, where did you get onto an AWD dyno? I've been looking for one but there are only about six in the US available for public use right now. Can you help me with this?

After we're done with this subject I'll just stay out of your way when you post. Your understanding of tuning is obviously more advanced than mine. I will stand back and try to learn from one with such wisdom.

But you probably already know all this......

MikTip

I'm not "competing" here. I'm trying to point out that "performance" on these Audi's is not always very simple. Especially on the Audi V6 12V's. Which the original post was about. You have any experience with the V6 12V?

Your statement "...all you need to do is make a MAF housing (not the element itself) that is the same percentage larger than the injector is over stock. 15% larger injector = 15% larger MAF housing that the stock element will fit into.
Ford guys have been doing this for years. You buy the 30lb injectors with the larger MAF and use the stock ECU"

This will not work on an Audi V6 12V.

How do I know? I've actually tried it on my V6!
I had C&L Performance custom build me a MAF! Then the MAF had to be recalibrated, and the largest injectors I could run were 23lb. Which made car fail emissions and trashed the cats while testing.

To date, there is no "chip" available for the Audi V6 12V's here in the US. Several companies are "working" on them, so we wait.

Your experience appears to be with the 1.8T. Very "impressive" Audi! However, very different animal from the 12V V6. You do your own mods & repairs?

Again, I'm not trying to compete, just point out the fact of what works on one type of Audi may not work on the other. I don't recommend mods to others for which I have not tried and tested, or
others have tried and tested in real world situations.

That's what I know.

Mike O.

"Looks like GIAC did all the work for you?"
You bet. I give him the data logs and he modifies the tables.

"My MAF has been modified, as are my injectors, ECU and fueling system."
How has your ECU been modified? I'd love to know about your success with the Hitachi system.

"My Audi has been extensively run on several dyno's to fine tune it all."
Again, where did you find an AWD dyno? Can you post the data sheet from any of the dyno runs, because I sure am interested in seeing what success you've had with the 12V.


"To install higher flow injectors, you need to alter the ECU programming, and or MAF sensor."
Wow, you debate me on a point you made first. That's interesting.

"The only way that you can calibrate a meter for larger injectors is to reduce the output voltage, and ALL aftermarket air meters use this method to "trick" the computer."
WRONG - Maybe all aftermarket MAFs for the 12V (but you already said there wasn't one available so you had one custom made). Most aftermarket MAFs actually are nothing more than a larger housing that the stock MAF element (i.e., hotwire) is mounted into. The concept is not to reduce the voltage but to leave it alone. Allow the MAF to flow a higher volume for a given reduction in element voltage (which is how the MAF reads airflow) by changing the overall volume of the MAF housing. The ECU then tells the injector to pulse at, let's say 14ms, but it is actually telling a larger injector to pulse at 14ms which is how you are adding the requisite amount of fuel to achieve a stioch mixture. Did you indeed have a custom housing made or did C&L just add on the resistors?

"Another possible fix, is increase the fuel pressure at the injector head. Higher pressure usually translates to more fuel. But only until the ECU senses the rich condition and changes the injector duty cycle to compensate."
I'll combine that one with...
"I had C&L Performance custom build me a MAF! Then the MAF had to be recalibrated, and the largest injectors I could run were 23lb. Which made car fail emissions and trashed the cats while testing."
Well, if the ECU senses the rich condition and changes the injector duty cycle (it's actually called a pulse and it's measured in ms not as a %) then how did you trash your cats while testing? I also find it curious that you had a MAF custom made BEFORE you chose your injector size.

Now, what do I know about tuning a 12V? Nada. What do I know about tuning in general? I'll leave that up to my cohorts on this board to answer.

Now if you want some basic technical advice, I'll give it to you. Most ECUs (at least for VAGs, BMWs and Hondas) have at least two and most likely three distinct fuel/ignition maps on the EEPROM. In the case of two maps, they are part throttle and WOT. Three maps adds an idle map that takes into account added idle burdens such as A/C and electrical demands and can adjust for that. The part throttle map operates in a closed loop mode where it is getting feedback from the 02 sensor to determine if fuel/ignition timing needs to be added or deleted (most ECUs can only reduce injector and spark timing however). Every WOT map I've heard of, on the other hand, is an open loop map. It does not care what the 02 sees because it should be seeing rich. The goal of a WOT map is to produce a slightly rich mixture to keep EGTs reasonable.

Understanding that the only way to get more power is to get more air and fuel into the combustion chamber should lead you to your answer. The ECU cannot let more air in at WOT. At WOT, the ECU simply refers to the MAF number and then looks for the corresponding fuel and spark timing which will first make the mixture ~13.5:1 and the spark advance about 17 degrees or so. These values were programmed in after hundreds of hours of engine stand dyno work.

Reprogramming the ECU to increase the MAF table is going to be a nightmare because you are going to have to start from scratch on everything else. Knowing little about the 12V, aside from the fact that the Hitachi ECU is next to impossible to crack, I'd say that the best bet is to go with a matched MAF housing and injectors. There are several reasons for this over the resistor method of recalibrating a MAF. First, it will be linear, whereas a resistor is not. If your resistor takes away 0.015volts it is plain to see that 0.015 at idle makes a hell of a lot more difference than 0.015 at WOT. Secondly, each MAF has a specific voltage range that is is designed to operate over. For example, my MAF will read at values over 210grams but it is no longer linear because the voltage has dropped below it's operating range. To make a long story short, you can't program beyond that range effectively.

My recommendation, therefore, is:
Pick an injector 20% larger than your stock injector (make sure it is a Bosch and not an RC).
Design a MAF housing that will accept the stock element that is 20% larger than stock.
Install plugs that are one or two heat ranges hotter (get another degree of advance)
Install an adjustable FPR so you can fine tune the fueling after datalogging the 02 and knock sensors.

Enough,
Mike O.