QuadTurboPrius

I am wondering about the possible bad-side-effects of installing ether an ECU reflash or piggy-back-style tuner (like RaceChip) when the car could also have something like a reflashed TCU from Eurocharged.

Are the potentially negative interactions in this scenario? It seems like the TCU and ECU should behave as a black-boxes to each other -- i.e. the TCU is fooling around with clutch pressures and such, while the ECU does similar isolated things with spark timings, but when these systems talk to each other it would just be "hey, shift to 4th gear" not "hey, shift to 4th gear with [x] pressure" or whatever...

I'm just not aware enough of how these systems might interact to give the chance of a problem scenario... or even if this is a ECU flash vs piggyback style question... maybe any ECU and TCU flash scenario must always be carefully matched?

Anyone care to educate me?

PeterUbers

My $0.02

i have ec and ams ecu's, edok tcu tune, and once I had my tcu tune (already had the ams 93 and ec40 e tune) I had my ecu's reprogrammed by each vendor to account for the tcu tune - they had to consider the torque tables (how much torque allowed per gear)

ams really dialed in my 93 and 100 octane tunes after I had my black boost and tcu tune with the car on their dyno. I'm a big fan of a great tuner and his custom dyno tune

5soko

Not advisable to run a piggyback with a TCU tune. The Tq tables and values will be skewed and you will have problems right away, or long term wear.

QuadTurboPrius

Thanks for chiming in!

Does this apply to an ECU (not piggyback) tune which isn't at all aware of the TCU update? Say, from a different company, etc...?

If so, can you describe the technical difference as to why it would matter (flash vs piggy)?

JettaRed

iTrader: (1)

Why don't you call Eurocharged and whatever ECU tuner you plan to use? You're asking the wrong folks.

QuadTurboPrius

I did - and they have no obligation (or conclusive ability) to tell me if their work conflicts with someone else's. It comes down to what the technical reality is vs what any party's willingness to speak with legal exposure is.

I will indemnify any party who offers an opinion here on the matter... but even then there is the matter of IP exposure. So, it might be a hard question to get any authority to respond to.

...I just don't want my **** to blow up when I try a 0-60 run now and then. But, in the legalistic environment we're in, maybe that just has to be done blind.

PeterUbers

Why not get an ecu and tcu tune from EC?

QuadTurboPrius

I still may - but I like the idea of being able to adjust things via an app, as well as the ease of install/removal without sourcing another ECU. @kennyd 's video on this topic was very persuasive.

PeterUbers

oh yeah no one is modding actual ecu's anymore I dont think - they're at least handhelds like mygenius.

i guess my point is that if both software packages are sourced from ec, they are appropriately configured to understand each other / ecu tune likes the tcu tune

QuadTurboPrius

Don't you have a spare ECU so that you can swap between stock and non-stock any time you want? That's all I meant... not that it would be required to do that.

Yep, the EC all-the-way is definitely the theoretically best option to ensure that all the systems work together as intended... but the RaceChip 1) makes similar gain promises, 2) easy-ish to install/remove, 3) configurable as I drive (this part would be awesome). Kenny's video really lays that out well... being able to react to external temps that could make bleeding-edge performance a risk to the engine is a great feature.

So, in a world where it doesn't break things and does what it claims, the RaceChip seems like it has an edge.

QuadTurboPrius

I meant @kenneyd above... Kenney - do (or did) you have a TCU tune when you made that video while using the RaceChip?

PeterUbers

yep I have four ecu's: stock, ec e40, ams 93, and ams100... still discoverable by times/dates encoded in the stock ecu when it lost power etc and when it regained power etc among I'm sure lots of other bits of digital residue that it was pulled from the car.

i did it back in the day when you had to crack open the ecu to program it

Piggy backs were a decent theoretical advantage in that they prevented residue of a tune (car under warranty, able to deceive the dealer) .. which isn't really the case. But they have their disadvantages and the case for and against piggy back concept is well laid out on YT

kenneyd

I did not, and I would also advise against it unless they could somehow custom Tailor the TCU tune for the piggyback which is unlikely.

The reasoning is related to how the piggyback works opposed to the ECU tune.

If you notice in my video, the piggyback was actually faster 0 to 60 and 8th mile I believe, while the ECU tune was much faster in the 60 to 130.
My hypothesis is while the Euro charge tune likely makes more power on a dyno, the reason the piggyback tune was faster down low was because it's essentially bypassing the TCU nannies.
the TCU is working in conjunction with the ecu, limiting the power in first second and third gear. Even if the ECU is tuned, the TCU is still overriding the map values and can limit the horsepower.

However with the piggyback tune, cleverly fools the sensors and is able to command more fuel and boost without the TCU knowing.

Totally making up these numbers but to illustrate, if stock boost is max 14 psi (however less in one two and three) ECU tune will tune it to 18 PSI... But then the TCU still limits it to like 14 and first, 15 and second, 16 and 3rd, 18 PSI in the rest of the gears.
With the piggyback tune, the ECU is commanding for example 11 in first, 12 and second, 13 and 3rd, and 14 PSI in the rest of the gears however the piggyback takes that 11, 12, 13, 14 PSI actual and tells the ECU that it's only 8, 9, 11 PSI and so the ECU closes the wastegate a little bit more and has a bit more fuel up to water ever the limit if the race chip is... Maybe 16psi the whole time

So essentially what a TCU tune does besides upping the trans pressure a little bit, it allows more boost in first second and third. So if one was to combine a piggyback with a tcu, you might get quite a bit more boost in first second third without the added trans pressure to prevent slip.

Long ramble, hopefully this illustrates what I'm talking about
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QuadTurboPrius

Yeah, that makes sense. Thanks for taking the time to explain!

.... and keep the videos coming, they're great!