How did he adjust your throttle? Can you tell if your throttle is not opening all the without the computer? Can you look into throttle body to see if the butterfly is not all the way open, with car off while some one steps on the gas? What "pins" is he talking about and were do they go? It would be so great to find an extra 10 HP that I did not know I was missing. As for the Chip tuning as I have said in the past, it's not brain surgery, with the correct knowledge any one can do it, I do wonder how he can get fuel/timing curve correct without a Lambda sensor?

Phil,<p>I have seen the software they use to "tune" the chips. Let me tell you, it's pretty close to brain surgery. It's very complex. It doesn't look like one of those programs where you just sort of wing it until you figure it out. <p>Mike

The customary way to alter the throttle is to look at the open cross-section... if there are nuts or screws, machine them down. Make the butterfly's circular component cross-section as close to invisible as possible... and the valve componentry as close to two-dimensional as possible. Any interference around the stainless valve plate can be removed through throttle modification.<p>This is machine work discussed above, not electronics.<p>Cameron<br>

this has nothing to do with the post Damon made about a guy he met who claimed 90% of the A4's he works on had throttles that did not open all the way. He told him this after putting his car on his laptop and checking throttle perameters and found his also was not opening all the way, or so he claimed.

Have you met or talked to any of the major Chip tuners? Are you telling me that there are not at least 30 guys who post here that could not learn how to tune a chip? Again it is not brain surgery, and with the right knowledge any smart person with interest can learn how to do it, for God sakes most of you who work with computers have done more dificult programs at work!!! I am well aware you do not wing it, I am well aware of whats involved, any complex thing can be learned if you want to learn it other wise how did frank or Ivor, or Joe learn it?

I was pointing out that throttle opening has many physical factors that affect flow, and is not simply a variable in a program hidden in the ECU. Throttles are routinely altered, both from a programming standpoint and from a mechanical/machining standpoint... but people should realize that, unlike valve timing and dynamic fuel injection formulae, overall throttle opening is something that can be changed both mechanically and digitally.<p>Cameron<br>

The overall engine programming is extremely complex....allowing an engine computer to adapt to various sensors & actuators as they age isn't cake with multiple nested control loops.<p>However, "tuning" the program for more power isn't as hard because you're just adjusting parameters & curves. With a dyno, you can adjust, test, adjust, test, etc. Still not easy, but not as hard as designing from scratch.<p>steve

This is how the computer knows what position the throttle is actually in...it doesn't measure pedal position...that's a cable connection.<p>The TPS on some cars (notoriously, Fords...cuz I am familiar!) will not report WOT even when you're stomping the gas. The throttle IS wide open, but the TPS reports 90% or 95% of WOT...so the ECU only sends fuel for that much throttle.<p>I'm guessing that this guy is saying that you stomp the pedal to WOT, the TPS is telling the ECU (and his laptop) that you're at 90-95% throttle, and (in the A4, at least), the throttle valve itself may not be wide open (unlike the Ford example above). Somehow the "two pins" correct the problem?<p>steve

I think of myself as a fairly intelligent person. When I saw the software, it looks VERY involved. Also, you need to do very thorough testing (road & dyno), otherwise you won't know what the actual returns are. <p>The software looks very intimidating. There are long-term maps, short-term maps, partial-load low rpm maps, high-load low rpm maps, full-throttle maps, etc. They are all 3-D topographical maps that translate into long tables full of values. If you do anything it doesn't like, you'll set off an error code.<p>Also, dyno testing, adjusting, dyno testing, adjusting, etc. doesn't work very well. The dyno puts very minimal loads on the engine, which means that you don't get a chance to see many changes to be made in the high-load mapping areas.<p>If anyone wants to learn this software, they would need to dedicate a lot of time. Also, they would need to dedicate an extraordinary amount of time to research the effects that their changes had as far as power increases, possible detonation, power losses, too rich a mix, too lean a mix, etc.<p>All I am trying to get a across is that I don't think it's something you just sit down and learn in a few days. It's more complex than probably most people would think. That's why there are only a handful of folks doing it. <p>Actually, it's a little ironic that out of the two people I have met who are doing this stuff, one is pre-med, and the other holds a few advanced degrees in mathematics (and co-authored a famous equation). <p>Mike (not a chip tuning expert)

No one said you can sit down and learn this in a couple of days, but any one with a brain and a desire can learn how to do it. This is a fact proven because there are people doing it there for it can be done. I personally feel that many on this boaqrd have this capacity, if they wanted to devote the time. on the other hand those who feel it to hard for them, I really hope they do not try to learn it as they are bound not to succeed right from the start.

Phil,<p>After carefully reading my post, I have come to the conclusion that I really didn't have a point! ;-)<p>Actually, I was sort of in "discussion" mode, and was simply trying to give people a bit of an understanding of some of the aspects of chip tuning. You made the whole process sound a bit simplistic. I was merely playing devil's advocate after seeing how much time and effort is really involved.<p>Mike