Piggy back tuning box, has anyone installed one?

[shanek]

Hello all,

New to the forum and I was just wondering if anyone on here can provide any info for me.

I recently upgraded from a APR stage 1 tuned C7 S6 Avant to a new C7 RS6 PE and although the RS is miles faster than my old S6, I am already looking for a little more power to enjoy while driving about. As the car is new I don't really want to go down the remap route yet as this will put a TD1 flag on my car.
Has anyone on here installed a DTUK or a Racechip tuning box? If so, have you had any noticeable difference in performance?

I have contacted DTUK and they are still developing their RS6 PE box but info from anyone with a standard RS6 who installed it would be just as useful.

I look forward to hearing your views on this as I'm a bit torn.

[pez81]

Nice purchase. When you say miles faster is it that much faster than your stage 1 s6. Don't Apr quote 580bhp.

[rtd]

ABT and MTM also do them

[Leo-RS]

No, no, no, no, no

Not acceptable on an £80k+ car.

DTUK type boxes work by manipulation of the boost sensors, example below...

Standard ECU boost pressure = 1.2bar
Manipulated DTUK boost pressure = 0.9bar
Corrected manipulated ECU boost pressure = 1.2bar
Real boost pressure = 1.5bar

Your ECU will be reading 1.2bar in the tables but the turbo will be pushing 1.5 bar in reality. Now this is all very well and good in extracting more horsepower but unless you understand what's happening in the background then I would strongly advise against going down this path. The engineers at Audi have fine tuned the engine and written boost fuel and ignition tables for 1.2 bar of boost pressure. If you up the boost pressure, you need to make finely tuned adjustments to the other fuelling and timing tables too. Why? Well, cast your minds back to your physics lessons, an increase in pressure = an increase in temperature. In this case, the most important aspect of safe and reliable horsepower is controlling your EGT's. Run them too hot and you will begin to melt things.

The piggyback DTUK type boxes rely on the inbuilt ECU safety features to protect the engine hardware. They do this by recognising an over temp and going into a limp home protection mode. Essentially this means that boost and ignition is pulled back and the fuel mixture is richened until a point where EGT's are back within normal range.

For example, 1.2 bar standard map may see a peak of 950c EGT, this is finely controlled so that the inbuilt protection measures do not ever go into a protection mode. If you now ask 1.5 bar from the turbo (but still have 1.2 bar written fuel and ignition tables) things are going to get hot, very hot. You may run the turbo up to 1050c before the inbuilt protection measures kick in and then start to go into protection mode. When the ECU goes into protection mode, it richens the fuel mixture substantially in order to cool everything back down. (You would likely get a rev limitation and the car would run poorly during this time)

In summary, DTUK type boxes run lean due to the fact they run off of standard fuel and ignition maps (but manipulated boost) Lean means hot.

Now for the odd blast here and there, they are fine. You generally only drive hard for a few seconds on the road before coming off throttle and slowing down (giving the turbo time to cool). However, if you were to run a tuning box at a track or on a vmax type run then you would likely run into protection issues at some point. 9 times out of 10, the standard protection measures will catch it all in time but you're always running that risk, you'll always be over temping and you'll always be reliant on the inbuilt EGT protection trigger protection.

Now compare that to a properly tuned car with properly written fuel and ignition tables. The horsepower is more reliable and repeatable with the protection measures never breached. A piggyback 'tuned' car may produce a good run on a dyno of say 675hp (ONCE) run it a 2nd time and that will drop to 650, run it a 3rd time and that will drop to 625 and so on and on, eventually it will hit protection and not even pull standard horsepower. Now run the properly tuned car back to back in the same manner and you would likely consistently pull 700hp run after run after run.

That's the difference between a DTUK type car and say an MRC or APR type car. in addition to that, a properly tuned car will remove the 155/174/189 speed restrictions. A piggyback car will not.

I run a DTUK box on a £30k Audi S3 a couple of years ago and had no issues at all, the only reason I run the box was because at that point in time there were no other options. The ECU hadn't been cracked by any of the mainstream tuners. I have good experience with Vagcom logging so I'm familiar with how it all works in the background. I always had sustainability in the back of my mind, if I was on the throttle 15-20secs accelerating, I would back off and allow for cooling down time before going at it again. I was able to see how hot and how lean I was running things from the tables I was recording. I only ever hit limp mode twice during my time with a tuning box and that was after back to back dragstrip runs. I was mindful though and always knew when to back off.

There are some advances in piggyback boxes for sure where they start manipulating fuelling and timing sensors too but these will never be as good or as safe as a properly tuned car.

The whole TD1 thing is a huge scaremongering tactic used by these companies to sell their products. They preach on the warranty safe aspect but in reality, tuning boxes can be traced back too. Once removed from my S3, I had a few sensor out of limit messages on the boost sensors, going deeper I'm sure the Audi boffins would be able to determine max stored values too.

MRC for example can reset the flash counters and remove all traces of TD1. I just last week had my ECU restored back to factory and all traces removed. I live the opposite end of the country too and the turnaround time was a couple of days in the post, saved me the long drive back down to them. ECU can be removed from the car within 30secs, it's just held in by two snap back plugs in the scuttle panel, you don't even need tools to remove.

On an £80k+ car, my advice would be to do things proper, not half hearted.

Just my tuppence worth anyway.

[shanek]

Nice purchase. When you say miles faster is it that much faster than your stage 1 s6. Don't Apr quote 580bhp.

I had the S6 rolling roaded after the remap and i was getting 560bhp/560lbft at the crank and due to the smaller turbos the initial torque buildup on the S6 was noticeable compared to the RS6 however, its the top end where the difference was really noticeable. Above 4000rpm the RS6 PE engine revs so much better and keeps going all the way to the redline. The rolling road figures for the RS6 was 615bhp/560lbft at the crank but these headline figures don't do the difference justice as its the area under the graph that makes the real difference in feel and the RS6 had bags more due to its better higher end breath-ability. During the run, apparently there was a vibration coming through the rollers indicating some tyre slip or roller issue just after 6000rpm that meant max power figures weren't fully reached but 615+bhp standard with only 3,000 miles on the engine I was pretty happy with.

Leo-RS, I fully understand what you are saying and if I was to put a box on, the car would be straight onto the rolling road to check Air-Fuel Ratio to ensure its not running too lean and melting pistons etc. If it was the box would be straight off and sent back.
From what I have read, the Racechips unit also plugs into fuel and ignition sensors indicating that they may change/alter these too. They also offer a 2 year Engine/Transmission warranty should anything go wrong.

[W8PMC]

No, no, no, no, no

Not acceptable on an £80k+ car.

DTUK type boxes work by manipulation of the boost sensors, example below...

Standard ECU boost pressure = 1.2bar
Manipulated DTUK boost pressure = 0.9bar
Corrected manipulated ECU boost pressure = 1.2bar
Real boost pressure = 1.5bar

Your ECU will be reading 1.2bar in the tables but the turbo will be pushing 1.5 bar in reality. Now this is all very well and good in extracting more horsepower but unless you understand what's happening in the background then I would strongly advise against going down this path. The engineers at Audi have fine tuned the engine and written boost fuel and ignition tables for 1.2 bar of boost pressure. If you up the boost pressure, you need to make finely tuned adjustments to the other fuelling and timing tables too. Why? Well, cast your minds back to your physics lessons, an increase in pressure = an increase in temperature. In this case, the most important aspect of safe and reliable horsepower is controlling your EGT's. Run them too hot and you will begin to melt things.

The piggyback DTUK type boxes rely on the inbuilt ECU safety features to protect the engine hardware. They do this by recognising an over temp and going into a limp home protection mode. Essentially this means that boost and ignition is pulled back and the fuel mixture is richened until a point where EGT's are back within normal range.

For example, 1.2 bar standard map may see a peak of 950c EGT, this is finely controlled so that the inbuilt protection measures do not ever go into a protection mode. If you now ask 1.5 bar from the turbo (but still have 1.2 bar written fuel and ignition tables) things are going to get hot, very hot. You may run the turbo up to 1050c before the inbuilt protection measures kick in and then start to go into protection mode. When the ECU goes into protection mode, it richens the fuel mixture substantially in order to cool everything back down. (You would likely get a rev limitation and the car would run poorly during this time)

In summary, DTUK type boxes run lean due to the fact they run off of standard fuel and ignition maps (but manipulated boost) Lean means hot.

Now for the odd blast here and there, they are fine. You generally only drive hard for a few seconds on the road before coming off throttle and slowing down (giving the turbo time to cool). However, if you were to run a tuning box at a track or on a vmax type run then you would likely run into protection issues at some point. 9 times out of 10, the standard protection measures will catch it all in time but you're always running that risk, you'll always be over temping and you'll always be reliant on the inbuilt EGT protection trigger protection.

Now compare that to a properly tuned car with properly written fuel and ignition tables. The horsepower is more reliable and repeatable with the protection measures never breached. A piggyback 'tuned' car may produce a good run on a dyno of say 675hp (ONCE) run it a 2nd time and that will drop to 650, run it a 3rd time and that will drop to 625 and so on and on, eventually it will hit protection and not even pull standard horsepower. Now run the properly tuned car back to back in the same manner and you would likely consistently pull 700hp run after run after run.

That's the difference between a DTUK type car and say an MRC or APR type car. in addition to that, a properly tuned car will remove the 155/174/189 speed restrictions. A piggyback car will not.

I run a DTUK box on a £30k Audi S3 a couple of years ago and had no issues at all, the only reason I run the box was because at that point in time there were no other options. The ECU hadn't been cracked by any of the mainstream tuners. I have good experience with Vagcom logging so I'm familiar with how it all works in the background. I always had sustainability in the back of my mind, if I was on the throttle 15-20secs accelerating, I would back off and allow for cooling down time before going at it again. I was able to see how hot and how lean I was running things from the tables I was recording. I only ever hit limp mode twice during my time with a tuning box and that was after back to back dragstrip runs. I was mindful though and always knew when to back off.

There are some advances in piggyback boxes for sure where they start manipulating fuelling and timing sensors too but these will never be as good or as safe as a properly tuned car.

The whole TD1 thing is a huge scaremongering tactic used by these companies to sell their products. They preach on the warranty safe aspect but in reality, tuning boxes can be traced back too. Once removed from my S3, I had a few sensor out of limit messages on the boost sensors, going deeper I'm sure the Audi boffins would be able to determine max stored values too.

MRC for example can reset the flash counters and remove all traces of TD1. I just last week had my ECU restored back to factory and all traces removed. I live the opposite end of the country too and the turnaround time was a couple of days in the post, saved me the long drive back down to them. ECU can be removed from the car within 30secs, it's just held in by two snap back plugs in the scuttle panel, you don't even need tools to remove.

On an £80k+ car, my advice would be to do things proper, not half hearted.

Just my tuppence worth anyway.

As above. I'd never consider a piggy back tune on any premium performance vehicle for all the above reasons.

Plenty of quality tuners offer a custom tune on C7 RS6's & given no 2 cars leave the factory with the exact same power/torque outputs, why would you want a tune that was not bespoke to your car as these tuning boxes use a generic code. I'd be paying MRC or DMS a visit as both offer a full insurance backed warranty & both have an excellent reputation in tuning premium vehicles. My personal preference would be DMS but due only to the fact they've tuned several of my cars & i've arranged group buys for both RS's & M's, they also now have a facility in the West Midlands as well as the South Coast. MRC however have a track record working on more Audi's as that's their sweet spot. Other tuners of course offer similar but with such a value of car i'd not be spending my money somewhere less well known that didn't offer a custom tune &/or an insurance backed warranty.

[robf]

That would leave only MRC. APR is just downloaded and installed.

Really interesting to read about the piggy backs, and yet MTM and ABT have solid reputations, charge quite a bit and take over the manufacturer's warranty. Are you sure they have got it so wrong?

[rtd]

The ABT box is supposedly a bit more advanced than the MTM, i have some info somewhere which I will try and dig out.

A custom tune is no guarantee of a safe map no matter who does it or what warranty they have which purports to back their work.

[W8PMC]

I don't think anyone's saying the Piggback tunes are the work of the devil & custom tunes the work of angels, but if only for the reason of NOT wanting to go down the 'generic' map route i'd be suggesting a custom tune from a reputable tuner over a 'generic' piggy back tune all day long.

Of course it's each to their own as to how much they want to spend & what they feel is good value & most who have tuned forge an allegiance to one particular tuner, so nothing surprising in that, but as Leo said above the piggy back tunes do not offer anonymity regardless of what the websites may say & given the price of them is creeping ever closer to what you'd pay a reputable tuner for a custom tune i'd say it's becoming a bit of a no brainer.

Yes when Custom tunes were well over £1000 & these plug ins are a couple of hundred ££ then value can be perceived, but that's no longer the case as far as i can see. The ability to fine tune the code to a particular car or a customers specific requirements as well as a strong reputation & insurance backed guarantee are worth an extra few hundred ££'s as far as i'm concerned.

[chunky79]

There's a DMS opening up in West Bromwich, next door to Ramus Porsche. Not sure if they are linked to the other ones?

[wildbore]

It's good that a thread like this comes along every so often. It reminds me why it's a false economy to save a few bob by buying used....

[Leo-RS]

Ah there's some slight confusion here..

Custom tune would be MRC, basically a map from scratch. Mine took the best part of a day on the dyno to perfect for example with perhaps 20 odd dyno runs from start to finish fine tuning each time. This is usually referred too as a Stage 2 type tune which is fully customised to the car. With the RS6 specifically, the guys at MRC told me that the RS6 engine was very random and unpredictable to tune, what works on 1 16 plate RS6 may not work on another 16 plate RS6 and hence why each car needed a lot of time and attention. Usually a Stage 1 tune would be a generic type file, upload the file, do a dyno run and check all is good and then on your way. An hour or 2 max. As above though, particularly with the RS6 they have to fully customise each car every time. MRC might generic tune other cars though with a master Stage 1 type file template, it all depends on the car and how sensitive it is to tuning.

A generic Stage 1 tune would be something like APR or Revo, you go to a garage somewhere that are authorised Revo/APR dealers and then they load in a generic tune and then off you go. There will generally be an on road test to make sure everything is running sweet, you pay your money and off you go. This map has initially had a lot of R&D, in the case for APR, a few months testing in the states for example. Lots of fine tweaking in between until they have a finished file. That file is then the generic file and uploaded as a Stage 1 to the rest of the world. (See my point above though about no two cars being the same, even more pertinent with the very sensitive RS6's according to MRC)

Piggyback is a secondary ECU type box that will have specific maps loaded into then. As well as tuning for increased boost, they will also have fuel and timing maps written into them to keep them running well and making reliable horsepower) - A few German tuners use these types of boxes, ABT/MTM etc.

Then there are tuning boxes like what was originally being talked of in this thread, they are a half hearted cheaper effort to the piggyback ECU. They manipulate the boost sensors and rely upon the standard ECU to do the corrections to keep them safe.

4 very different options there.

[robf]

Interesting, thanks.

I'm still of the mindset that the car doesn't need any more performance.

I've been driving another car lately and getting back into the RS6 it feels like a rocketship again!

If you get used to 600bhp, then you'll get used to 700bhp. I therefore find difficulty in understand how people will ever be satisifed. It would probably be cheaper and more exciting to put some Nankangs on your wheels instead. I've been driving around with virtually bald tyres the last couple of weeks (Michelins on order!) and taming it in this weather is pretty challenging!

[Leo-RS]

Rob, 100% spot on.

I had my ECU restored back to stock and with the original 560hp the car was more driveable. I was able to launch it properly and I was able to use full acceleration in 1st and 2nd gear without the excessive amounts of torque steer and traction issues the Stage 2 car had

I would say that this is down to the time of the year though which makes low end traction difficult. Most of these issues not applicable once it warms up around April/May time

I actually think the PE 605hp is the sweet spot for a road going car. My Stage 2 car was too much for current conditions that it was just damn right dangerous. I only really noticed this when going back to the original 560 from the 700+ it once had and found it more planted at the lower output.

Although don't get me wrong, the tuned car was phenomenal in 3rd gear upwards with a night and day difference to standard but by that time though, you're already breaking speed limits.

[W8PMC]

There's a DMS opening up in West Bromwich, next door to Ramus Porsche. Not sure if they are linked to the other ones?

That will be their new West Midlands site.