What concerns me (technical)

[9Hooker]

Gents,
What concerns me at this point is that looking at chips it seems (correct me if I'm wrong) some companies don't really dial in air/fuel ratios as well as they probably should. I've seen graphs of one chip that went from 13.5:1 (too lean) to 8:1 (too rich)! You would think this would be better ironed out. This leads me to think that given a dyno with a wideband O2 sensor, software programmable via laptop, and some time, I could dial in a safe but aggressive fuel map "better" than what's out there. As for boost however, I've got a thing to learn. All I ever knew was an external wastegate with boost pneumatic boost control. I think I can manage if given a good piece of software. It seems the only place that comes to Motec, Haltech, or Electromotive's TEC-II (or even the import VAFC/SAFC of yore) is Revo... and I don't even know what I can control with that thing. The website is vague.

Can someone help me out or put this (mis)conception to bed?

Also, MAF sensor? Really? We're still using these things? Not taking into account air densities/temps? Holy fuel nightmare when the weather changes. (again, correct me if I'm wrong)

/rant

[Hyphy]

I don't know what kind of answer you are looking for, so i can't really do my part and try (key word) to help you.

[9Hooker]

gotcha... more of a rant than anything.

Will the revo give me the opportunity to get on the dyno and make changes myself? All of the other products on the market do not to my knowledge. Once you install it/get it flashed, that's all she wrote, set it and forget it. I would like to install the performance parts I want, jump on the dyno, and get it tuned to my specs/my parts. Unfortunately one size does NOT fit all.

[Grishbok]

unitronic will do a custom tune for you, you might have to pay a pretty penny, but itll be custom specific to your car.

[chaos2984]

for starters 13.5 to one is not that lean buddy. 12.5:1 is Stociemetric. Cars now days with factory widebands go all the way to about 17 18:1 if not higher when your crusing on the hwy for fuel milage. And your not gonna hurt the car. Now 8:1 is rich but not overly to rich. You need a very rich mixture when you punch the gas.

And what are you talking about Maf's are the way to go. Speed density is so old technology. Maf's work so efficently they meter how much air you pull in. and they use a intake air temp sensor so they can caculate speed density of the air. Caculating it is more efficent than trying to mesaure it like how some old school cars did with Vane meters and such.

[Mike@APR]

Gents,
What concerns me at this point is that looking at chips it seems (correct me if I'm wrong) some companies don't really dial in air/fuel ratios as well as they probably should. I've seen graphs of one chip that went from 13.5:1 (too lean) to 8:1 (too rich)! You would think this would be better ironed out. This leads me to think that given a dyno with a wideband O2 sensor, software programmable via laptop, and some time, I could dial in a safe but aggressive fuel map "better" than what's out there. As for boost however, I've got a thing to learn. All I ever knew was an external wastegate with boost pneumatic boost control. I think I can manage if given a good piece of software. It seems the only place that comes to Motec, Haltech, or Electromotive's TEC-II (or even the import VAFC/SAFC of yore) is Revo... and I don't even know what I can control with that thing. The website is vague.

Can someone help me out or put this (mis)conception to bed?

Also, MAF sensor? Really? We're still using these things? Not taking into account air densities/temps? Holy fuel nightmare when the weather changes. (again, correct me if I'm wrong)

/rant


Customers who are not tuning these cars often think the same way you do. However, let me be the first to say there is a lot more to it than you think. First of all, most people have some pre-conceived notion of what is lean or rich. At APR, we set our air fuel ratios based on actual street and dyno tuning but not to some fixed value that the customer may or may not agree with.

The standard Air-Fuel ratio while at wide-open throttle is setup for good power and torque. However, we also setup a strategy to taper fuel in as a cooling strategy for the Exhaust Gas Temperatures (EGT). Since we work with OEM hardware companies, our APR hardware, and the ECU tuning all under one roof, we setup our air-fuel ratios to protect the components from a temperature that would be dangerous to the longevity of the vehicle hardware given the actual specs for the hardware. We often install a pre-turbine thermocouple on test vehicles to measure Exhaust Gas Temperatures in real time.

The ECU has multiple fueling strategies for numerous conditions. So if you are expecting to see a fixed air-fuel ratio at all times, you might be dissapointed by an APR tune. The Air-Fuel Ratio varies for a given load but there are also component protection strategies that come into play as well. However, this is also true of the OEM engine calibration. We are setting up the Air-Fuel Ratio thinking about: power, torque, drivability, proper exhaust-gas temperatures, fuel system hardware limitations, hardware longevity, various enviromental effects, and fuel mileage.

I am writing this to give you an idea of what you may see from APR. I cannot speak for other tuners in the industry but this is our philosophy. I hope you take my words in a positive manner as I don't mean to downplay your knowledge or your desire to tune your own car. However, I wanted to point out that if you are not getting real time data from the ECU as well as other external measurement probes including a properly mounted Thermocouple, you may not have all the data you need to set the AFR. In addition, without proper access to all of the strategies within the ECU, you could be setting up a fixed AFR that doesn't work in some conditions and fails to utilize the best of what Bosch Motronic has to offer.

Just my $0.02.

BTW: I love technical discussions like this. I wish we had more discussions like this on the forums so keep it coming.

[Michael N]

Get Revo you can adjust the Timing Fuel and Boost. APR is just for the name not for performance TRUST ME! there a great company and do make great products and have been around since the flinstone era but go with Revo!!

[Mike@APR]

Get Revo you can adjust the Timing Fuel and Boost. APR is just for the name not for performance TRUST ME! there a great company and do make great products and have been around since the flinstone era but go with Revo!!

I came on here with a detailed technical explanation and you come on here and say TRUST ME!. How can I compete with that? [:D]

[wayneB7]

Get Revo you can adjust the Timing Fuel and Boost. APR is just for the name not for performance TRUST ME! there a great company and do make great products and have been around since the flinstone era but go with Revo!!

Maybe they have been around for a long time because of responsible engineering philosophy, that does not end up causing engine failure trends.

Thanks to posters like Mike@apr, I felt much more comfortable going with APR as opposed to going with some other tuner who is not around to explain exactly how their product works.

[ZEM930]

Some people are so rude! Awesome explanation Mike. Thank you!!!

[audidrver]

BTW: I love technical discussions like this. I wish we had more discussions like this on the forums so keep it coming.

x2

[9Hooker]

for starters 13.5 to one is not that lean buddy. 12.5:1 is Stociemetric.

you're wrong, 14.7:1 is. you're off on your assessment. 8:1 is too rich, and 13.5:1 is probably still too lean for FI. I believe (it's been a few years, like 7) when I was tuning NA motors I was using 13.1:1, 8-10 psi in a high compression motor that wasn't build for FI, 10.5:1.. these are rough numbers and my head is fuzzy. a couple of run on the dyno and I'll be able to get them more sorted out.

Mike@APR, I'm not saying you don't have a good product, at least in my little experience in days bust countless hours of off time here on the forums have shown... one that, if what I'm thinking of fails, will be the first place I turn for a plug + play solution.

I agree completely with what you are saying here including your methods and reasoning. However, one tuning program cannot expect to be the optimal for each person's setup. If person X has only a moderately larger exhaust, the tuning program will be different than person Y who has a 4" exhaust, K&N, test pipe, higher compression pistons (stock turbo). What I'm saying is that as many dimensions of testing and analysis goes into your chip or anyone else, it's not tailored to user's setup.

What car(s) exactly did you tune your program to then so maybe I can make a more informed decision as to whether or not I want to tweak my own or use off the shelf.

[JRMSLINEA4]

Also, MAF sensor? Really? We're still using these things? Not taking into account air densities/temps? Holy fuel nightmare when the weather changes. (again, correct me if I'm wrong)

/rantThis part you are wrong, MAF is better than "speed density" if thats what you are refering to. MAF takes into account air densities and temps better. Speed density looks at all the engine sensors then does a "guess" at what table to go with. On a street car you want a MAF on a big turbo race car making 500+hp the MAF becomes a restriction and you will want to change over to speed density.

[JRMSLINEA4]

you're wrong, 14.7:1 is. you're off on your assessment. 8:1 is too rich, and 13.5:1 is probably still too lean for FI. I believe (it's been a few years, like 7) when I was tuning NA motors I was using 13.1:1, 8-10 psi in a high compression motor that wasn't build for FI, 10.5:1.. these are rough numbers and my head is fuzzy. a couple of run on the dyno and I'll be able to get them more sorted out. Your correct 14:7:1 is Stociemetric.(not spelled correct)I understand what you are saying about N/A motors but "turbocharged" and "supercharged" motors are tuned different than N/A motors.

[Chb04]

Get Revo you can adjust the Timing Fuel and Boost. APR is just for the name not for performance TRUST ME! there a great company and do make great products and have been around since the flinstone era but go with Revo!!

"DUDE" Your mom just called asked me to tell you to return her car and that if you have nothing nice to say then say nothing at all! [:/]

SORRY! had to say something can't stand thoughtless verbal puke.

[9Hooker]

I agree. FI applications desire a richer fuel mixture for cooling, not necessarily for extra fuel/air reactions. cooler temps, better burn, etc, and so... more power and definite safety buffer.

Here's one graph on AFR on a chipped a4. This is AFTER the cat, still doesn't look right to me. No offense to 034 motorsport here, I'm grabbing any graphs I can to illustrate my point.

http://www.034motorsport.com/images/Laszlo/Dyno/B7_A4_FSI_AFR_Comparison.jpg

now have a look at the boost sine wave @ 2200rpm and 5500rpm. If boost is ECU controlled, why is there what looks like a sine wave where the other ups and downs in boost don't look anything like it.
http://www.034motorsport.com/images/Laszlo/Dyno/B7_A4_FSI_Boost_Comparison.jpg

[JRMSLINEA4]

I agree. FI applications desire a richer fuel mixture for cooling, not necessarily for extra fuel/air reactions. cooler temps, better burn, etc, and so... more power and definite safety buffer.

Here's one graph on AFR on a chipped a4. This is AFTER the cat, but doesn't look right to me. Also "stock" boost on a 2.0T is "not" 14 pounds of boost,more like 10-12psi.

http://www.034motorsport.com/images/Laszlo/Dyno/B7_A4_FSI_AFR_Comparison.jpgWhat that really shows is how "rich" the factory sets up cars to be on the safe side. Also "stock" boost on a 2.0T is 10-12psi not even close to 1 bar.

[9Hooker]

Also of note, without seeing graphs on how the final map came out like it did, I'm just making assumptions. It may be 100% correct in that's the best AFR setting for that application. However, my experience tells me the curve shouldn't have as much magnitude.

[JRMSLINEA4]

Check out this old post. The best info I have seen on this site about reflashing a B7. http://www.audizine.com/forum/showthread.php?t=85612&highlight=apr+dyno

[Mike@APR]

Mike@APR, I'm not saying you don't have a good product, at least in my little experience in days bust countless hours of off time here on the forums have shown... one that, if what I'm thinking of fails, will be the first place I turn for a plug + play solution.

I agree completely with what you are saying here including your methods and reasoning. However, one tuning program cannot expect to be the optimal for each person's setup. If person X has only a moderately larger exhaust, the tuning program will be different than person Y who has a 4" exhaust, K&N, test pipe, higher compression pistons (stock turbo). What I'm saying is that as many dimensions of testing and analysis goes into your chip or anyone else, it's not tailored to user's setup.

What car(s) exactly did you tune your program to then so maybe I can make a more informed decision as to whether or not I want to tweak my own or use off the shelf.


Of course if you change your car drastically such as a compression ratio change or a different turbo, you can't expect a calibration meant for stock hardware to compensate for this. However, that's why we offer software packages starting with a Stage 1 chip, Stage 2 with Exhaust, Stage 2+ with Exhaust and Fuel Pump, K04, and Stage 3. We tune all of these stages on the cars that you drive with our hardware packages. We don't just guess what the exhaust will do or what the turbo will do.

Now, let's get back to a more resonable argument where we fix the hardware but discuss your concerns about optimization of the Air-Fuel Ratio. Given the Bosch Motronic fuel strategies, we are already varying the air-fuel ratio for a given engine load. Or more simply said, based on your right foot and the torque demaned of the engine. That's the normal strategy that is in place to vary the air-fuel ratio.

The second strategy that kicks in is based on Exhaust Gas Temperatures. So let's say for arguments sake that your new exhaust forces a change in the Exhaust Gas Temperatures AND load (for arguments sake). You might think that the APR chip for exhaust is not optimized for your particular exhaust. However, since the load has changed, the ECU will move to a slightly different part of the fuel map to adjust the AFR accordingly. As far as the second strategy, if the EGT's are now different as a result of the new exhaust system, the fueling will be adjusted accordingly. The temperature that the turbo can withstand does not change so if the critical temperature is approaching, the EGT fueling strategy will start to taper in regardless of what brand of exhaust you decided to purchase.

So at this point, you may be saying, "with all of these compensations in place, it appears that the system is pretty robust for the most part but it just doesn't seem optimized to my setup." So, let's discuss. Let's say that you make a file for your car on the dyno that is perfectly dialed in. Timing is right where you want it. Boost is just how you like it. AFR is just where you like it. Everything is optimized for the most power and best use of your hardware. Well, what happens when you leave the dyno facility? The conditions are now totally different. Let's say for argument's sake that you live in a world where the ambient conditions don't change that much and are pretty much just like your dyno day. However, one day you are on the other side of town and you start running out of gas. You end up having to stop by a pretty shady gas station to pick up some 93 octane. The quality of this gas is not just like the one you tuned on during your dyno day. So now your timing pull due to knock events is pushing past the precise limits you set on the dyno. Your EGT's get hotter as a result but you've dialed in your "perfect" AFR which is now no longer applicable. See what I'm getting at here?

You cannot tune a car to the ragged edge for a single condition or single environment. You must provide the system with a proper baseline that allows for compensations and variations. In addition, you must properly tune the compensations to deal with these issues. We do all of this at APR. This is not to say others don't but I can't speak for them. We tune compensations for knock sensor activity, compensations for changes in coolant temp, compensations for changes in ambient temp, changes in altitude, etc, etc. If you ignore all of this and set the car up at the ragged edge, you are doing yourself and your new hardware a disservice. Unless you plan on getting on the dyno all the time or logging the car all the time, you need to leave some headroom in the system and you need to properly tune the compensation portions in the ECU to use this headroom appropriately when needed. Bosch Motronic is very well setup and is very smart and can deal with lots of situations. I would rather use this than to dumb it down like some of the "tuner" style standalone's would. Not to mention, you have to be experienced and smart to know how to use Motronic properly. It takes most people quite some time to become comfortable with it AFTER they are very knowledgeable about the physics of automotive combustion and the science behind it. As an analogy, anyone can take a knob and turn it up to 11, but few people take the time to know what the signal-to-noise ratio is at this level? Makes sense?

None of what I am saying here is meant to make you think that either I or APR is perfect. However, I am saying that we put a lot of effort into engineering the best products for the Audi market and we do our homework.

[Mike@APR]

now have a look at the boost sine wave @ 2200rpm and 5500rpm. If boost is ECU controlled, why is there what looks like a sine wave where the other ups and downs in boost don't look anything like it.
http://www.034motorsport.com/images/Laszlo/Dyno/B7_A4_FSI_Boost_Comparison.jpg

Boost is N75 controlled by a PID loop. This is not a manual boost controller. Not to mention, if you can record boost with a very high resolution, you will see natural pressure fluctuations in the system. You have to work with the PID loop to dampen out the oscillations but still allow the appropriate response and feel to the driver. There are many components to boost control in Bosch Motronic but they all go toward properly tuning the PID control loop. If anyone has questions about PID control, type it into Wikipedia.

[Auditude2.0T]

Big thumbs up the APR!! They do unbelievable things and mike has an enormous amount of knowledge about these cars.. Mike and APR #1 product and customer service

[9Hooker]

Mike, thanks for the great response. I'm relieved to know now not only what you do (not hanging on the ragged edge like I would ought to do) but the reason for doing it. In years past, manufacturers would put out a product where they turn the dial to 11 without the whys and wherefores.

Also, for electronic boost control... the PID scheme makes sense to me completely. You make a correction, then a correction for the correction, then a correction for that, etc.

[Charles]

If there's one thing you can rely on, it's a well thought out and executed product from APR. Those guys cover every base.

[JRMSLINEA4]

If there's one thing you can rely on, it's a well thought out and executed product from APR. Those guys cover every base.+1[drive]

[elwigglero]

I'm sold...Waiting patiently for the summer sale announcement from APR.