Here's the actual data:
rpm inj duty cycle%
3440 55.56
3720 59.02
4000 64.60
4280 67.91
4560 73.64
4800 76.16
5080 83.48
5320 90.44
5560 94.52
5800 95.31
5920 97.29
6120 98.84

<img src="http://members.shaw.ca/dannykso/Injdutycycle.gif">

Want to level off around 12.0-12.5

what would happen if i switched to 225TT injectors?

wot. A chip must be programmed for a set injectors size. From you chart you need smaller injectors at the injector pulse your getting. What size injectors are you running now and have you logged what your getting for injector pulse?

At the end of the day you are right, the fuel map must be modified to get it right.
Rod

If so, this would be it:

<img src="http://members.shaw.ca/dannykso/vagdata.gif">

Duty cycle is kind of decieving, since as the RPMs rise, the same injector pulse at 3000 RPM will have half the duty cycle then at 6000 RPM.

Usually, anything over ~16ms is considered maxed out. The valves are only open for around 15ms at 6000 RPM, and even less as the RPMs go up.

What is your actual injector on-time?

<ul><li><a href="http://forums.audiworld.com/performance/msgs/60917.phtml">http://forums.audiworld.com/performance/msgs/60917.phtml</a</li></ul>

"The fuel injectors on the 2002 A4 flow 281cc@45psi. This will be the same pressure that the fuel injectors will see when the car is running 1bar boost pressure. In other words, the 2002 A4 injectors are only capable of delivering the same or less fuel under boost than the 1999.5-2000 Beetle! Yet, one company offers a 185-hp chip with a mandatory fuel system upgrade for the Beetle yet claims that no fuel system modications is necessary on their 217hp chip for the 2002 A4! How do you explain that? "

then max T = 120 / RPM

At 6000 RPM, max T = 20ms.

However, the duration on the camshaft (the degrees the intake valve is open) is usually between 250 and 270 degrees, depending on application.

So actual T = max T x 270 / 360 =&gt; 15 ms.

So, what good is an injector on-time of 20ms going to do if your valve is only open for 15ms?

IMHO, anything over ~15ms is considered maxed out (the max nonDBW on-time is 16.32ms)

after that point the car leaned out.

It's a 4 stroke motor, so after one full revolution of the camshaft (two of the crank) the cycles start over.

The Max time is T = 120/RPM

If the injector is open longer than that, it's going into the next cycle, which is not possible, so it will not add extra fuel.

sates for boost and vacuum whereas the returnless systems don't.

All I am saying is that my setup did not go lean till I hit the limit of the injector pulse readings.

A chip would lean it out in the right places and that will bring your injector pulse down a bit and give you more room for power.

vs the stock 02 sensor. It was not all that far off and it would not cause his readings to drop down to 10:1. Most of us have used the vag readings to see that we are running too rich (high .8's and even into the .9's) and knew it was way too rich. Once we got down to the mid .8's the power jumped up and most of the issues went away. Not all that hard to know your running rich, all you have to do is look at all the fuel on the back of the car. =P

he posted calculated A/F values, assumingly from MAF and injector on-time, which I don't trust.

I'm guessing its block 31?<ul><li><a href="http://www.ross-tech.com/vag-com/m_blocks/030-049.html">http://www.ross-tech.com/vag-com/m_blocks/030-049.html</a</li></ul>

Just make sure you log it with something that shows engine or throtle load, like block 002 or 003.

Will this let me lean out my mixture?<ul><li><a href="http://www.ecodetuning.com/revo/Lemmiwinks.exe">http://www.ecodetuning.com/revo/Lemmiwinks.exe</a</li></ul>

A car that is running too rich will make less power then a car that is tuned right. If the car is running too rich and your at your max on the injectors, then having it tuned correctly will allow for more air flow before your injectors max out again.

be no gain in hp?

I've been comparing the stock spec boost value at redline of VW 1.8Ts to my spec boost value, and notice that its higher on VWs..

Here is a 20th AE GTis stock 115 with mbc

LOG 115
Engine Engine Load Spec. Boost Actual Boost

/min % mbar mbar

3480 138.3 1650 1790
3960 137.6 1680 1830
4320 136.1 1690 1830
4680 136.1 1700 1830
5120 134.6 1730 1790
5480 136.1 1750 1760
5800 132.3 1690 1750
6080 129.3 1640 1710
6400 124.8 1620 1690

By 6400 its still requesting 0.62bar.

My stock 115 spec and actual; is no where near as high.hmm...i wonder if somethings wrong with my ecu..

3360 136.1 1600 1690
3600 150.4 1600 1860
3880 152.6 1570 1900
4160 151.1 1560 1860
4480 151.1 1550 1850
4720 151.1 1550 1810
5000 148.9 1550 1770
5240 145.9 1530 1720
5480 141.4 1510 1690
5680 138.3 1490 1650
5880 133.8 1490 1630
6080 130.1 1480 1610

So it can hold boost much longer.

You really need to do some block 031 runs to see if your running rich or not before you change anything.