Does anyone else find the turbo a bit laggy?

[instigator]

thanks for the explination

and thats exacly the same as he was saying.
and thats just the point i was trying to make, i don't think my car was dealing with that verry well...
it was a serious diffrence and really noticeable while he was stock.
now with IC he runs smoother as before, sounds normal to me?
but thats the opposit of what you guys are saying...

so i guess there are limitations for the ECU to correct ignition etc..?
when it gets TO hot, he maybe can't correct it any more and it is running trough its limits??

ps: it is hard for me to explain so i hope you understand what i mean

[DNA Tuning]

Of course there will still be noticeable differences in power on a hot day, but not as obvious as after getting a remap. The ECU won't just limitlessly increase boost to try and normalize the performance as issues like knock and excessive exhaust temperatures may result, but it will to some extent to reduce the difference.

Here is a nice excerpt; the description is for the Bosch ME7.1 ECU, which means the feature was already implemented in older VAG vehicles. The 9N3 Polo GTI 1.8T runs an ME7.5 system, which isn't very recent either (old 1.8T Audi S3 already started using ME7.5), but nonetheless also utilizes this load-based engine management system, including this boost compensation feature.

IAT effect on requested boost
ME7.1 will adjust the specified load limit depending on IATs. As IAT's go up, ME7.1 brings the max boost up a bit so that the driver can't tell that the car is slow in hot weather. It can do this because the stock boost curve is relatively conservative, and there is plenty of headroom. At some point, if IATs go high enough, max specified load is pulled to prevent knock:

KFTARX - IAT correction for maximum specified load

However, if you are running a lot of boost, and always want maximum performance, there is no point in increasing boost when it is hot, let alone reducing boost when it is cold. Also, as IATs rise, even with a perfectly flat KFTARX and LDIATA (see below), you will see more requested boost because the ECU knows that a higher P/R is required for a given cylinder fill (PV=nRT for you thermodynamics nerds out there).

It is unknown if there is a table for that calculation. To compensate, you may want to taper KFTARX across the board as IATs rise to keep your requested boost sane. In particular, be aware that the maximum requested boost is slightly above the maximum MAP reading. Readers who understand PIDs should recognize that really bad things happen when the measured output cannot reach the setpoint...

[kaanage]

Readers who understand PIDs should recognize that really bad things happen when the measured output cannot reach the setpoint...

That's GOLD

[instigator]

now thats a good explenation, thanks for that!
but honestly i have to say, i know my way around tuning stuff, but when it comes to the ECU, specially the terms you use... it's latin for me bro

but i understand where you getting to.

maybe a bit out of the context here but you seem to know alot from ECU and mapping etc...
so i have a question for you.
my polo is going to get custom remapped somewhere in March.
this will be done by a guy who seems to know his stuff also.
alot of people recommended him to me as he only does VAG cars.
only problem is, he is going to remap my car on th eroad, not on a dyno.
is it possible to custom tune my carwithout getting it on dyno?
if so, how will he know when he is reaching limit's and how does the finetuning work if you don't see any numbers??

would appriciate it if you help me out with this as i'm not sure about this...

[DNA Tuning]

is it possible to custom tune my carwithout getting it on dyno?
if so, how will he know when he is reaching limit's and how does the finetuning work if you don't see any numbers??

Just to clarify, I am not a "tuner" for DNA Tuning; I am a dealer who has had extensive experience in ECU tuning and standalone/piggyback work, but I do not write tunes for DNA.

As for road vs dyno tune, to some extent, getting it tuned on the road is possible. It is made alot easier with an uncongested stretch of road that "allows" a full 3rd gear (or higher) pull from idle revs to redline.

Having personally done a few custom tunes, I can tell you that getting it done on the road can be tedious. However, a tune on the road can be close to as good as a dyno tune; it really depends on how many parts you have changed on your car. For me, most of the custom tunes that I have done have simply required a few % changes in primary fuelling, etc.

However, if you have changed MAF, fuelling, and internals, just as an example, it is difficult to "road tune" these drastic changes; it is still possible, but would take many many revisions before a healthy running tune is achieved. A dyno would allow much quicker generation of maps and to iron out flat spots or spikes in boost, etc. Ideally, your tuner would need to have access to a tuning package that allows realtime changes of parameters or else it would be tedious and time consuming to be constantly remapping the ECU for every small change.

Other than the convenience and time-efficiency of dyno tuning, there's not a whole lot more information that a dyno tune can provide other than the torque being generated; this will allow fine tuning of open throttle AFR to maximize the last few horsepower, and also provide fine tuning of the ignition timing; and as mentioned, it is also useful for ironing out small flat spots or spikes.

However, the dyno will not simulate real world conditions such as elevation, humidity, sudden transient loading, and characteristics of air flow through the front end of the car (big effect on intercooling). These require on road tuning; to put the vehicle in these particular scenarios, carry out data logs, and to make changes accordingly.

If your tuner has a systematic method of road tuning that he has used many times with success, I think your car should be in good hands. A dyno will inevitably be required when chasing the last few horsepower, mainly in tweaking the AFR and ignition timing but you can get close to the full potential from a decent road tune. At the end of the day, there is alot of information that the onboard data logging systems can provide, such as MAF, boost pressure, IAT, RPM, O2 voltage, Knock Voltage/Correction Factor, Injector Duration/Duty Cycle, etc. the only number it's missing is the real torque being generated.

[instigator]

Thank you verry verry much for youre info.
that is just about all i needed to hear.

about my car, it has a few mods but not alot, regular stuff like Milltek exhaust, K&N filter, Seat sport intercooler, Turbotip and throtlle body hose, diverter valve.
but still has stock internals, turbo etc... so nothing major.
i guess this will be do-able for him to tune my car on the road?

the tuner himself basicly said the same thing as you,
he has onboard data logging and he assured me that he will see all the info he will need,
on that part i was a bit sceptic...
i asumed that you allways needed a dyno to perfectly see improvement on a car etc.
and like i said, quit a few people recommended him to me.
Minhea in France and MRC in U.K. also recommend him and they say he is one of the better custom tuners for VAG related cars in Belgium.
i have seen cars he mapped and they drove verry well.
so on that point, i do think he knows his job.
only thing that held me back was the issue about the dyno.

the reason i do want to try him is because he made me a verry good price wich is hard to resist for custom remap.
but that was also the reason i wanted to double check if what he was saying is correct,
and not some false truth to quicly tune my car and get easy money.
because he can tell me about data logging all day long and i still won't know if what he is saying is true or not.
there are still alot of bad tuners around... and you can't see or know that for sure unless you know what he is talking about.
but as he is saying basicly the same things to me as you did (unless you also lie ),
i don't see any problems why i won't get my car tuned by him

so thanks again for sharing your wisdom!

[VW Central]

So Melbournians: Today as you all know it was 40C. Now be honest who was heatsoaked? Summer 2009 my car was terrible in the heat. I am now prepared for all conditions, with my FMIC and water methanol spraying at 10psi

Just thought I'd post to hear your experiences..

[hazrd]

Today was F$cked to say the least

Fuel consumption through the city was 16.2, boost was all over the place, not a happy car lol

[instigator]

F*ck that... 40C°
guess you guys have summer over there??

over here in Belgium it is still winter, last couple of days it was freezing and today it was 2 - 3C° or so.
last night it got to -8C°
not bad for the car at all, but i was freezing my nuts off

what is the coldest temp you guys reach in Australia?

[Gti Dave]

Yeah fuel consumption was crazy but not as bad as your Adam. It was hovering around 10-12l/100km according to the computer and only after a easy drive with cruise control on the freeway did it go down to 9l/100km which is still higher than usual (7.8-8.5l/100km average). But car was fine and didn't suffer too much in terms of power output. Love the Forge FMIC. Maybe the OTA has made a difference too? Don't really know as I havent driven in such hot weather for a while now. I usually hide away at home or enjoy a read and ice coffee at borders under the cool conditions of the air con in shopping centres

[break]

what is the coldest temp you guys reach in Australia?

Really depends where in Australia.

Being a large country in terms of land size, we have a number of climates depending on your location.

The southern parts of Australia easily get down to around (and occasionally below) freezing during the middle of winter. While we don't get snowing in major cities, there are a number of snow fields in mountain locations around Australia's southern half.

The nothern half of the country varies from dessert in the central parts (which get down below freezing at night, and up to 40 degrees c during the day), to sub-tropical (5-35 degree's, typically... average being around the 25-26 degree mark) and tropical weather (basically two seasons, wet season, and dry season. Very hot... usually ~30 degree's and high humidity of around 80-90%)

[instigator]

ok, thanks for the info mate!
i think Aus. is 200 times bigger as belgium
if a small cloud comes in from France or Germany into Belgium, we are covered in 1 big cloud