Hey Everyone,

Closing S4peeds was kind enough to swap cars with me for an entire week, and let me try out his demo AmD chip. Note that this was my suggestion, b/c I couldn't do it with my car since I'm in a buyback negotiation with AoA. The simple answer is the thing is fantastic.

I'll cut to the chase; the less important thing to me is the thing most of you care about - the power.

The difference is startling. I've driven chipped & stock 1.8T's, and I can say that by the seat-of-my-pants dyno, this chip adds more torque across the rev range than a 1.8T chip does (in absolute terms, not in percentage).

It made a difference every time I drove the car, and I did not ever spend a single instant wondering "is there more power here than before?" Note that this was version 3.0 of their software, which purportedly has significant gains since the dyno charts were produced for older versions of their code.

I personally always feel like my car is "holding back" at lower RPMs. Somewhere in my brain, there is a process that thinks it knows how much torque an engine "should be putting out" at various RPMs in proportion to how much it puts out at it's peak, and I feel that at 1500 - 2000 RPMs, the stock S4 comes up ridiculously short for a 306 lb-ft 4.2l V8, and that from 2000-2800, it still comes up disappointingly short - not just compared to the number Audi advertises, but to what I actually feel from 4000-6500.

With the AmD chip, I can say that not only do you get noticeably more from 4000 to 7000, but that below 4000, you get *a lot* more, and more importantly, it "feels proportional." CS's car did not feel like it was holding back above 1800. Below 1800 is still unimpressive, but not embarrassing like it used to be.

That brings me to another interesting point: Fuel economy. I can't say that it's changed either way when I maintain my driving style and compared to my own car, but what I can say is there is enough more power from 1800 to 3500 that I am willing to stay in higher gears much more often, and as a result *I* get 2-3 mpg better fuel economy when I'm doing this. That is still less than those of you who are driving around at 1300 RPMs of course.

Perhaps the most interesting thing I can say is that his car was simply a lot more fun to drive. The power delivery "made sense". What I mean by that is:

a) you get as much as you think you ought to be able to get, wherever you are in the rev band, and
b) it is consistent and predictable; once you get used to how much you get for a given pedal position and rev range, you always get that - so you can learn to use it more effectively.

I feel my own car doesn't always give me the same amount, it's like I have to hunt around for the right pedal position, or need to depress it at a certain rate, or I don't get the same amount of power as I did other times. CS's car however, really felt exactly like I always expected mine would feel before I took delivery.

The number of times I hit the gas in my car, and think "Wow this engine is magnificent" is only 15-20% (i.e. when I hit it at >3800).

In CS's car, it was about 95% of the time - I'm really serious, I would just run down the street to go to the store not even really meaning to drive "enthusiastically," and end up thinking "yow!" Everything I already knew about driving high performance cars kinda came back to me as I started to let go of all the second-guessing I've built up over the last 8 months.

Now that brings me to the issue that is more near and dear to my heart; driveability.

AmD has made a couple significant improvements, pretty much all in the area of predictability. I don't have this on authority from them, I can only tell you that I found that after 2 days of driving his car, I learned what to expect, and then that's what I got
about 98% of the time.

In my car it took me four months to learn what to expect, and then I would only get that about 75% of the time. The remaining 2% isn't AmD's fault, it's just a function of an existing flaw in the factory software that they haven't fixed (whether they've tried or not, I don't know). So the major improvements in DBW behavior are:

1) when I ask for more, I get about as much more as I wanted, and
2) when I ask for less, I get about as much less as I wanted.
3) Power delivery is consistent across the rev band - it always seems to make sense how much power you are getting in differing varieties of conditions (RPMs, gear, pedal height, incline).

The second one is something we've called "throttle over-run" or "lift-throttle acceleration" in previous discussions. This effect is pretty much gone, I think I noticed a really miner, like 1/5th of a second of post lift push once or twice, but it's not something I would have noticed if I didn't already know what to look for.

The one thing I didn't get to the point where I was able to be totally consistent at was from-idle revving. This has nothing to do with AmD, it is simply a remnant of the stock programming being too sensitive at the top of the pedal range. I do believe the AMD software is more consistent and predictable here too, it's just that it is still the
case that a couple millimetres difference in pedal position seems to be translated into huge differences in RPMs.

Also, now that the amount of torque available down there is higher, the effect is slightly magnified. I made significant improvements while I had the car in accurately revving for quick launches without over-doing it. I still wasn't perfect at it, but I can honestly say that when I got it wrong, I knew it was me being off by a couple of millimetres, not me being dead-on and the software just making a different decision that particular time. But alas when it happened, I was still off by 1500+ RPMs.

The other big thing that I don't believe AmD has addressed yet is the delay when coasting at idle. They actually may have made some changes b/c I can say that the amount of delay seemed to be consistent as opposed to random in my car. I think I was learning how to predict it, but it still was more than any logical delay I could make sense of, so that aspect of driving was still frustrating, albeit less so.

So the effect of all of this is that while the car is still hard to drive if you aren't used to it, it can now be learned very quickly, and is much more satisfying both out of the gate, and once you have learned it.

AmD's original claim as to how they could get so much power from an NA engine seems to be spot on - after driving CS's car, the most accurate description I can give of the factory chip is that Audi is deliberately cheating us power-wise, and not doing a very good job of hiding it at that.

I'm really anxious to hear what the AmD engineers have to say about these last two features, b/c if they can bring the same improvements to these issues as they have to everything else, this will be an out of the park home-run. As it is, it is at least a bases-loaded double ;-)

 

I think more so coming from you,which we all know have had "issues" and rightfully so regarding the S4 & power delivery.

well said & done, I can't say it doesn't make me curious......

 

Is it an engine reliability factor?

Nice write-up by the way.

 

Not a ecu swap but a ecu flash through the VAG port.

Thanks
Matt

 

anytime you step outside the bounds of what a manufacturer has designed as OEM specs that ANYTHING above and beyond that is "subject" to decreased reliability.

just as a general piece of information, to think otherwise would be naive

 

Take your pick. All the S4 needed was a higher hp number than the M3. And they likely wanted it less than the S6 or S8.

 

Sounds like you should keep your car and do the v 3.0 chip!

 

Dyno plots to come....finally!

 

Are you going to get the graphs for hp & torque at the wheel?

 

they're considering doing a switch thing like APR does. AmD is confident enough that other tuners aren't going to be able to match their power gains that they are encrypting the code on the chip & doing some other stunts to prevent someone from downloading it right out of the car.