Hi Greg,

Most auto manufacturers are harder on "programmer box"/piggyback users because they're not actual calibrations and literally leave the ECU blindfolded. That said, they do put code in there to detect increases in output with them. So despite removing them, there are traces in the memory that the box was used (think logged over rev hours that everyone talks about with Carreras).

In terms of your experience, you have a TDI, I believe. The ability to make power on the TDI is a bit more simplified considering you can simply add fuel and gain power without an increase in boost. We've had quite a few customers switch from piggybacks due to the issues that I outlined (it's the very reason I am aware of the issues) on the petrol turbos.

 

Thanks Austin! The misinformation on this subject is truly amazing. Thanks for clarifying....

 

The only thing you got right in that response is that I have a direct injection turbo diesel. Other than that, your knowledge of what you call "piggybacks" is clearly limited.
1. I drive a 2013 Porsche Cayenne Diesel, have never owned a turbo charged gasoline engine. My comments and discussions are strictly limited to diesel related matters. My opening post simply expressed amazement at the confounding price difference between Vivid's box and mine, given that they are of similar design and concept.
2. Because of my geographical location, I use two servicing Porsche dealers. Both were informed up front that I have a tuner box installed after the ECU. I opened the hook, pointed out the device, explained to them what it was and how it worked. Neither have a problem with it, and both have conducted all service procedures with the box intact.
3. My box does not "simply add fuel to gain power". It increases the fuel pressure at the common rail, and increases turbo boost pressure at the boost sensor. With higher fuel pressure, I get more power with LESS fuel. Increased turbo boost pressure adds to the equation, but within a safe +3 psi limit. More horsepower and torque moving the same vehicle then naturally results in improved fuel economy.
4. My box does not "leave the ECU blind". There is constant two-way communication - through the tuning box - between the fuel rail and the ECU and between the boost sensor and the ECU. This is clearly documentable at the OBD2 port.

I have not once demeaned a single GIAC-related person, place, or thing during this entire exchange. The only thing that may have been construed as less than positive was that I- when my Porsche was new - I considered and quickly rejected the ECU flash solution because of the cost. Yet you persist in criticizing my non-GIAC solution without even understanding what they do or how they work. Well, mine at least. It's fine that you use these forums to promote your products and services. But it may be helpful to your success in the long run, if you were a little more considerate (and understanding) of other members choices. Self-promotion is an admirable goal, but I do not consider demeaning alternatives is an admirable method to achieve it.

//greg//

 

Please be aware, I am not taking any shots at you, customers asked for educational information and I am simply providing that. If I see something that I know is inconsistent, I will set that information straight. Contrary to what you might believe, I have a wide knowledge of piggyback tuners that reaches far beyond my years here at GIAC across multiple makes and models. The first one I ever used was about 16 years ago.

I wasn't stating that your box simply did that, I was using that as a basic example of something you can do on a diesel engine to increase power, that doesn't necessarily carry over to petrol engine, all else the same. As for #4, you're grossly mistaken. A piggyback tuner box by design contains a series of resistors that are placed between a specific sensor and the ECU itself. This resistance falsifies a reading input to the ECU (since it is unable to change actual requests). For example, most piggyback boost logs we see show that the ECU believes the engine is only making 1-2 psi of boost pressure. Because it sees this as an under boost condition, it will compensate adding more turbo duty cycle. This means that the car can be making 16-18 psi compared the 1-2 psi it believes it makes. Moving into the blindness part, there are a series of overboost corrections (amongst other things) that the ECU can make under high stress situations. When the ECU believes that it is only making 1-2 psi, all of those safeties are rendered useless. Moving into why power corrects down, the Cayenne Turbo ECU has set torque request that can't be directly altered via sensor input. If the boost is above stock, the ECU will log higher torque value and seek other avenues to pull the power down (pull timing, richen the mixture, close throttle, trigger limp mode). These torque values (and other information) are stored in memory in the ECU and can be used in the event of catastrophic failures to show that the vehicle has been modified.

Now, some piggybacks have the ability to extrapolate the inputs they receive for datalogging purposes before it is inputted into the ECU. This is very different than what you would see if you were logging with a PIWIS or a durametric which just pulls information from the ECU.

Again, none of this information is a dig at you, or your tuner, it's a simple explanation of what they do.

 

Yet again you are responding outside of the parameters of the post you're addressing. I clearly said I'm a diesel-only guy, and that all my points and counterpoints are relative to turbo diesel tuning boxes. I won't argue that engine faults - minor and major - are quite likely an issue with generic boxes. My DIESEL tuning box is far from generic, to the point where programming contains mapping applicable to not only specific makes/models/engines, but factory ECU mapping differences as well. Please believe me, this individualized mapping approach has proven quite effective at eliminating any/all faults and - especially - limp mode.

As far as my being "grossly mistaken", I have an iOS wireless monitor permanently plugged into my OBD2 port. It doesn't have any problem seeing modified rail pressure and boost sensor data from the ECU. For example; I also clearly stated that my box adds no more than 3 PSI to that sent from the ECU. To amplify, feedback thru the box tells the ECU that boost pressure is output plus (up to) 3 psi (depending upon driver input). If you have a problem with this, I can only suggest that you approach the folks who actually designed my box. If it carries any import at all, I recently assisted the manufacturer in finalizing the NA-spec mapping for their Cayenne Diesel V6 box. They don't seem to share your issues regarding the ECU understanding what the tuner box is doing. I'm thinking it would probably be less stressful for all, than watching a gasoline tuner guy try to out-counterpoint a diesel tuner guy.

//greg//

 

I didn't gather that Austin was making claims related to YOUR specific piggyback, but the merits of how they operate in general. There is really only one way they work, which is exactly what Austin outlined. The fact of the matter is that they do operate via falsified signals, as that is simply the only way you can work from OUTSIDE the ECU.

Additionally, the points made regarding diesel tuning versus petrol tuning are valid, as the architecture of a diesel engine (air supply vs. fuel supply) naturally makes for different methods of producing more power. Besides arguing about the engineering behind a piggyback module, you are really comparing apples to oranges when you are trying to compare diesel tuning practices to petrol. On a diesel engine, the throttle controls fuel while on a petrol engine the throttle controls airflow. Adding more fuel is going to produce more power, based on the design of the engine (there is no device to regulate airflow, the engine can essentially use as much air as it needs). This is not the same as a petrol engine, where you need to directly increase airflow (through hardware, boost, etc.) to produce power.

Also, increasing fuel pressure is going to give you more fuel given the same injector on-time.

 

Yes sir, I understand. But please realize that I did not instigate this thing. Vivid Racing inappropriately posted what amounted to advertising in the wrong forum location. It was in fact a gasoline engine related advertisement. I responded with sheer astonishment at the fact he was trying to get six times the price for a box that did little more than one I had on my Cayenne Diesel. Vivid Racing thread was subsequently relocated to the appropriate forum location (classifieds)

GIAC entered a subsequent discussion with a rather cleverly disguised promotion of their own. And actually, I did feel that he lumped my box in with his generic criticisms. During the back and forth, I never once disabused the notion that an ECU flash is a good thing. I simply defended a previously established position that I felt I had at least proportionately as good performance and fuel economy increases with my tuner box. Despite allowing that diesel and gasoline tuning have operable differences, I'm not the one with an agenda here.


//greg//

 

Again, if you're comparing your diesel performance with GIAC's petrol tune, a few points need to be made. Unlike petrol engines, diesel engines are not as susceptible to air fuel ratios. Because there is no device to meter airflow, the cylinders will always be filled. Because of this, your fuel input (controlled by the pedal) becomes the main way to control power. Unlike gasoline engines, diesel engines can run very lean or very rich without adverse effects. So by changing fuel output, you can experience better performance and economy with a larger margin for error than with a gasoline engine that mixes the fuel and air charge in a pre-determined ratio.

As you mentioned, one of the main ways the piggyback module will increase power is through rail pressure (on a diesel engine). The module will add a resistor in-line with the rail pressure sensor. What this does is allow the ECU to control rail pressure, but the kicker is that it will not SEE the true rail pressure. Why does it do this? Well, since you cannot directly alter rail pressure from outside the ECU, the module will feed the ECU a signal that the rail pressure is lower than it actually is. When the ECU sees this, it will make a corresponding increase to the rail pressure, thus producing more fuel. An additional benefit to this is that the factory checks and safeties are bypassed, as the ECU believes that the rail pressure is in spec, and thus sees no reason to make any corrections.

A negative effect of this false rail pressure is that the ECU thinks it is calling for a given quantity of fuel, while the actual quantity is greater. What this does is produce a false MPG reading, as the ECU says, "Hey, I'm making specified torque with only xxxx bar of rail pressure." In reality, the engine is using more fuel, the ECU just doesn't see it. So while the economy certainly can increase (and many times will, due to the reasons outlined previously), these increases are typically overstated by the vehicle's trip computer.

I hope you don't take this as an attack on your tuning preference, as I am simply outlining the metrics of how these modules work while also explaining the reasons that you cannot compare them to their petrol counter parts.

 

Again, what is so hard to understand about my position? The metrics of how gasoline versus diesel tuning modules work was never my top concern. From the very onset, my only point was that a 6x price differential between the Vivid Racing gasoline tuning box and my Bluespark diesel tuning box was disproportionate. I questioned how VR could justify charging so much.

GIAC/Authur is the one who injected ECU remapping into a tuning box thread. Not once did I suggest that there was anything wrong with ECU remapping, but he persisted in making me defend tuning boxes. As he currently understands them that is. Apparently there's a niche in the tuning box community that's escaped his 16 years experience.

As such, I simply took exception to his assuming that my tuning box deserves to be lumped in with his bias against the tuning box approach in general. I had no interest in bumping heads regarding ECU remapping versus tuning boxes. Like I said; self-promotion by virtue of demeaning the competition is not what I consider an admirable business practice.

The fact that you sell GIAC services notwithstanding, I like your website. And that your forum approach to self-promotion is in a way that I can appreciate; subtle.

//greg//

 

The impression I got from the OP was that this thread was about any tuning option for the CTT.

I agree with your view that the box options for the Porsche Turbos seem way over priced when you look at similar options for similar motors. For example Burger Tuning offers a $599 option for BMW's 550 which is a 4.4l TT V8. I accept, of course, that there are differences between the motors, but $1400 worth? Though it could be an issue of volume as there seem to be less people tuning their Porsches compared to BMWs (though I don't know how big the tuning crowd is for their big engines, it's the 135/335/535 crowd I'm familiar with).

As far as the back and forth between you and Austin, I don't think Austin has responded in any way I wouldn't have expected or find particularly unprofessional. He does ECU tunes (and by all regards the best for Porsches) and is understandably biased in that regard, but I don't think he has been unreasonably so and has just laid out the information about how they generally work.

No matter how you cut it though, an ECU tune (at least a good one) has the ability to do far more than a box can. The main benefits of the boxes are that they are (usually) significantly cheaper and a user installable option. Each has their pluses and minuses and the answer depends on what you are trying to accomplish with the tune (and in the Porsche world apparently the available options).

Unfortunately figuring out what is snake oil and what is real is the problem in either case and to that end Austin and Emmanuele have offered very detailed information about how ECU tuning is done in general and without directly attacking any competitor's product have made (in my opinion) a compelling argument for the GIAC tune

As I said before, normally I wouldn't go for an ECU tune as boxes give the best bang for the buck for the level I'm concerned about. In this space, however, given that there is no proven box option (or even one at a reasonable price) I'd go with the GIAC tune based on Austin's reputation if I somehow felt 500/500 wasn't enough for me already

 

After your defense of Austin, I reviewed the thread from the top. I now see that it was Emmanuel Design that actually instigated the GIAC promotion. Reading between the lines it would seem dissenting opinions caused a back channel communication asking GIAC to come to the rescue. From that perspective, I was indeed unduly harsh on GIAC. As a board sponsor, I guess self-promotion by ED should not be unexpected. Apology extended to GIAC for the misplaced dissent.

//greg//

 

I for one am impressed that GIAC came on here to give as much information as they did. Considering another vendor was trying to sell us their solution for 2K and provided no info or supporting test data is unbelievable. I guess the saying a sucker born every minute could not be more true. I encourage anyone who is about to spend considerable $$$ on a vendor to google them and read reviews. What you see may change your mind......

 

Hello gents!

I went to the GIAC site and there was no price for 958TT ECU flash. Can anybody here just post the price please?

ALSO, I came across a SOFTRONIC reseller https://soulpp.com/product/porsche-9...nic-ecu-tunes/ where they list an ECU update for $1395 - has anybody used them before? I did for my 996TT a few years back and it was a nice tune.

Your responses will be greatly appreciated!

 

woud be nice for other vendors to chime in about their tune like GIAC did. Makes me lean towards GIAC for my Cayenne turbo tune.

 

Why are you thinking GIAC considering that the Softronic tune *I think* is so much cheaper?