keman

I know exactly what you're talking about.

In fact it's rather entertaining to get on it at low rpm when it's cold, accelerate fairly hard, grab the next gear and short shift it, accelerating fairly hard again. I easily get up to 60 mph this way with hardly taking it past 3500 rpm .. .all the while the car is acting like a 60's musclecar.

It does NOT do this when warmed up. In fact it only does it for about a minute on my car.

WHATEVER the cause ... the chip makers should figure out a way to make it do it all the time.

And as for our engines running so lean? Heh. Sure can't tell by the mileage I get. Lean? You've gotta be joking. If it's running lean, and it's only 4.2 liters .. where the hell is all the gas going??? *looks for holes in fuel tank*

There's 4.3L V6 GMC trucks that get better mileage than this ...

- Keman

SleepingTalon

Actually, Im not so sure there's any timing change at all for the flashes for pump gas. I've never asked, but I wouldnt be suprised if they left the lower airflow tables alone, and just leaned it out a little bit on the highest airflow map. For the high octane flashes Im sure they threw some timing at the car, but I dont think they did that for the pump gas flash. Then again, I really dont know the knock threshold on this car and how leniant the ECU is in relation to timing advance, with a leaner fuel mixture on pump gas. I would love to see some of the logs from a bone stock car just to see how aggressive Audi was in setting it up. Im gonna hook the WB up next week and see what my car does during cold start and after its out of the warm up enrichment tables. I've also noticed the drastic performance difference during cold starts, but I really think that it's more related to the motor being shoe-horned under the hood, and it creating a lot of heat after the cars been driven for awhile. What I wouldn't give to be able to log this car! LOL

beaudawg

The aftermarket programs adjust both timing and fuel. Most of the lower mid-range gains (torque) are made by adding timing, while the high rpm (hp) gains are primarily made by leaning the AF mixture. And yes, this is for pump gas programs.

I've seen the tables.

gregmag

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SleepingTalon

I dont have a flash on my S, nor have I driven in a chipped/flashed S4 yet, so I was just assuming. Can you get a copy of the tables in an Excel spreadsheet? I'd really like to see them. How much timing advance is there at the top of the powerband? How many airflow tables are there in the ecu? Was there adjustment on the lower airflow maps? Also, do you know what the knock voltage was at for the tables you saw for pump gas? Just curious...Sorry to bombard you with questions, it's just that I've been wanting to see some logs for this car, and you're the first person I've spoken to that's seen them. Im just trying figure out as much as I can about the ecu in this car. I saw above you had a UTEC in your STI, so you have some experience tuning, so I figured you could let me in on some different things. BTW, I tune cars for a living (UTEC, AEM, MOTEC, DSMLink, Uberdata, and all the old piggyback stuff from the first AFC, to VPC's), so I plan on experimenting a little bit with this car. I just dont have that much backround info on some of "inner workings" so to speak. Any info you have would be greatly appreciated, and if you do have those tables in Excel, even better! Feel free to check out our shop sites, we're one shop now, thanks again!
www.batlground.com
www.twistedtuning.net

keman

This is why you get a lot more crud on your tailpipes and it isn't smog legal. I'm familiar with the process of getting C.A.R.B. certification, but this goes much further than that, ie: performance != emissions .. they're kinda at polar opposites.

Rich is good ...

beaudawg

I saw it with my own eyes on dyno. A rich top end does bad things for power.

I also did a bit of fine tuning on the UTEC program for my STi, and the same thing was done there.

beaudawg

What I saw was shared with me as tuning was being done (not necessarily on my car). I know I was told the knock sensor voltage as well, but can't remember it for sure. IIRC, I want to say 20V was a real knock, but anything up to that point was just noise.

SleepingTalon

Actually, it depends on if the car is boosted or not. When I tune boosted cars, I always leave the top end pretty fat. The reason I do this is because if I tune at a higher boost level, say 20psi, and set the fuel for that boost level, if the customer decides he wants to run less boost, say 14psi, the car will go lean up top. For that reason alone, I leave it rich up top on boosted cars. N/A is completely different. All the N/A cars have a sweet spot for where they have their best power curve, maybe not peak power, but just the curve. Honda's are particularly picky about the timing, specific A/F, and where you engage the HI/LO cam crossover points, for it's powerband to be optimal. Im really wanting to do a lot of ecu tuning with the S, I think there's a lot to be had (maybe not on pump gas, but on race fuel) with some good, innovative tuning. I would love to see more low end torque, so when I do tap into the tuning side of it, that's where Im gonna give most of my attention to. Just trying to gather as much info about what the ecu is doing on it's factory airflow tables before I start changing things. If anyone does have some of the factory numbers, I would really like to take a look at them.

beaudawg

Once you get into it, you'll see the big torque gains are in the lower mid-range, with gains of over 20 ftlbs possible on pump gas. Now, PEAK gains are less than that, but as they say, it's the area under the curve that is important, not so much the peak numbers.

Have fun.