That's a mouthful .... I push the gas pedal & expect it to work better after $3-5K - pretty simple.

 

In the end, that's all I want. I am leaning to the FVD piggyback since it's cheaper than GIAC and looks like I can add stuff and it will recognize the addition without having to be told about it which the GIAC cannot do.

 

I feel like I am back at engineering school, anyone care to do some analysis using triple integrals of revolution

wrs is spot on though as far as the electronics data and signal processing go, whether you have a control system added on or within the ECU it is really achieving the same thing at a digital level.

BTW AWE - is your 650S with exhaust quicker to say 150 mph than your 991 Turbo S with GIAC tune and AWE exhaust. I would be fascinated to know

 

Alex here... GIAC is a great company that we use regularly for many different tuning applications - the Level1tec tuning "ECU Piggyback" that we used on our 991 Turbo S was chosen for a couple of reasons -






1) The system auto calibrates - important for climate/fueling and some hardware changes.
2) Can be installed by customer if so desired and removed for vehicle sale.
3) Non detectable and bypassed for factory software updates and warranty issues.
4) We have the actual hardware/software for advanced tuning and diagnosis of the Level1tec Piggybacks - that gives our customers complete support for any upgrading (vehicle hardware) and diagnostics - this is paramount for the end user - also we are working as we speak on blue tooth and map switching.


We could go on and on about "piggy backs" vs. flashing, but the thing to remember here is that both avenues work and work very well - there are many tuning companies that make excellent products and deserve to get credit for their accomplishments - we use many different tuning companies for our projects (Level1tec/Protomotive/GIAC/SCT/HP Tuner/Cobb/Electromotive/Motec/AEM), and there are many more out there - the Level1tec kit that we assembled for the 991 Turbo S works as you can see from the dyno charts that we posted The car was delivered the customer and when he got home (after a long back road drive) his text to me was "HOLY CRAP!!!" That is the most important result.... a happy customer
Got to get back to work - this was a fun thread!!
Alex

 

 

Hey guys, I am the happy customer Alex is referring to. I wouldn't pretend to understand the fine details of this tuning package, but suffice to say, MaxRPM and this kit has transformed what I thought was a perfect machine. My TurboS is stupidly fast. The acceleration is so rapid and so linear, it's really amazing. Alex had tuned my previous 996TT and it was a handful, but this new car and this performance kit put it in a whole different playing field. Thanks again Alex, you never disappoint 😎

 

Our software will recognize upgrades such as exhaust systems and allow for more power to be made when exhaust gas temperatures are reduced. We're really able to push the envelope with intercoolers added to the mix as well. What we're doing in these "stage 2" test files, a piggy back simply cannot "recognize" and adjust.

 

Alex has a great history for taking care of his customers and we wish him luck with his new product. However, piggybacks backs are neither new, nor revolutionary in the Porsche market. They have a detailed history in the Cayenne and Panamera markets and have been closely compared with flash tuning there. These real world results are easily searched.

 

I see what you are saying, but with your background I am sure you know that you are referencing a pretty extreme piggy back system, the likes of which the market will probably never see. You are describing a piggy back that would change every input and output to and from the ECU, PDK and potentially PSM (if you wanted to change a speed governor). The designer of such a piggyback would also need to fully understand how their changes interacted with all the tables in the effected controllers.

Changing the MAP signal into the ECU will affect far more than a higher flow vane position. This piggyback may be more than one signal change, but we need to start somewhere. The one change actually affects quite a few tables that as a calibrator you would not want so affected or compromised. Lowering the boost signal will change the computers request for fuel delivery, timing, reactivity to knock, etc. There is a reason that calibrators choose to pay more attention to knock, lower timing and increase fuel as boost goes up. Unfortunately, lowering the value from the boost sensor sends (indirectly) all these requests in the opposite direction per how they are mapped in the DME. A calibrator with access to modifying the DME can choose to raise boost and lower timing and or the AFR to prevent detonation. A calibrator can also choose to leave the knock tables to react to the knock sensors at a given condition as they were intended to. Of course this is moot if the DME simply throws a code and puts the car in limp mode because it sees that the boost value is not a reasonable one. Perhaps the intake air temperature is too high for the boost and throttle position.... well the intake temperature sensor can be fooled too, but this opens another Pandora's box of potential issues.

 

You are over complicating the problem I think. The issue is to map the response of the car with the ECU over a range of operating conditions and sensor inputs and it only needs to be the group of sensor inputs that control what you are looking to change at the output. Before the piggyback is ever programmed it acts as a pass through and data collector during the test runs. The closed loop response of the system is measured under different performance regimes and with this data an I/O map of inputs to outputs can be created for a given performance profile. Now it is possible to begin to make modifications to the appropriate inputs by applying a filter to them. This is simply another control box in front of the ECU. The final result is a new closed loop response from the car. The closed loop response now includes the piggyback and the ECU. What is going on in the ECU doesn't matter since you already have mapped / estimated the transfer function of the car with the ECU. Now you have created a new transfer function with the addition of the piggyback in the loop.

It's exactly how you design a control for a system with unknown parameters. You model the transfer function and apply a control according to how well the system response fits the model. When the control fails certain criteria, a new model is generated and a new control is designed. This is called an adaptive control system and they are fairly common in autos and airplanes I believe. Of course it may be the case that instead of a new model being generated it may be selected from a group of models and the appropriate control subsequently applied until the control criteria are satisfied.

I don't know for sure if this is what the piggyback people are doing but I suspect that it is close to this in practice. It might be more hit and miss and there might not be as much real control system analysis involved but I suspect that the net effect is the same.

 

Thanks for the kind words Todd - I had a hard time giving your car back!!!!

 

This is assuming that changing one sensor input affects only that input, which is certainly not true with any of the new ECU's. There are so many checks and adaptations within the ECU that half the battle of making more power is finding the correlations between them. There is simply no way a piggyback can do this (short of actually making a slave ECU), and as such you will always be sacrificing power and more importantly safety.

 

No it doesn't assume this at all.


This is called mapping the transfer function. It doesn't matter what the ECU is doing internally, it is a black box and it responds to inputs with a specific output that is being tracked. In this case the output is torque and horsepower at the wheels. The ECU doesn't measure them as much as it makes sure that limits on exhaust temp, AFR and rev limits are kept within operational constraints imposed by the designers. The control on AFR, exhaust temp and rev limits are based on boost, fuel flow, timing and pressure differential to name a few that I can think of but that is probably not an exhaustive list. The control response can be modified by attenuation of the measured parameters. So as long as the modification of the measured parameters doesn't cause the critical limits to be exceeded, a new response is created and the car generates more power but within the design limits.

Now if the operational window limits can be expanded in the ECU by changing tables then a flash could potentially do more than a piggy back. However, if the flash modifies what the designers have deemed to be operational limits then I think that it wouldn't be hard to prove the flash was responsible for a failure if such a result was the outcome. Thus, I doubt that anyone doing flash tunes would be messing with the imposed design limitations. OCICBW............

 

Some folks love to baffle laymen with a sprinkling of tech terminology, fairy dust and misnomer, but this is great reading, thanks wrs!

 

Austin! more importantly, when is Champion releasing better intercoolers and stage 2 be ready for release? what kind of numbers should we expect to see as well...(exhaust, plenum, intercoolers, stage 2=?