Tuning boxes, quick question.

A19quattro

A19quattro

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I saw one of these, not for my car second hand an a well known auction site and for much cheapness. I watched it and it never really got many more bids, so I thought if I could find one for my car, it would be a cheaper way of getting a bit more power. I have had the car for 5 years and about the only thing I haven't done is tune it. I wasn't actually going to bother but it's got uprated suspension and brakes so maybe would make it a more rounded package when I do decide to sell.
So I have loked on and off fora few weeks now and not really seen anything. I strayed into new boxes and some actually seem quite cheap. My car is a 2005 A3 TDI 140 quattro, so the ECU plug is the big round one like the 1.9 tdis used to be. I saw loads with smaller rectangular plugs and initially thought they must be to CR engines but some I have since found are for the pd but instead of plugging in to the ECU, they plug into the Temp sensor at the front of the engine.
Does this mean they are in effect just the old style "Resistor mod" boxes (fool the engine into thinking it.s colder and so it adds more fuel), which were always cheap anyway or are they OK? I am not a big fan of tuning boxes but any advice would be welcome, cheers :)
 
Yep bang on mate. Pd engines mean each injector is it's own hp pump so all they can mess with is the coolant temp sensor or the inlet air temp. It's just a resistor mod.

On a common rail they can jack up the rail pressure giving a bigger bang which in turn causes more boost from increased exhaust velocity at the turbo.
 
Is that all any of the boxes do anyway or are some different.
We had a Tune-it Pd box years ago on a Fabia TDI, I wasn't keen as it messed up the acceleration curve, made it more jerky to drive, you were never sure what it was going to do, if that makes sense.
 
Alot of tuning boxes are rubbish from the info I’ve seen from them.
I were watching a video the other day of someone explaining how they work. They plug into one or two sensors and then the ‘tuning box’ gives the sensors false readings by giving the sensors incorrect voltages therefore making the ecu think the car needs to work harder which maybe gets you a slight increase in performance at the expense of the car getting false readings. No tuning is involved at all as the ecu isn’t modified in anyway unless it plugs into the obd port like with a remap.

If anyone is considering one of these that can have a remap then I don’t understand why when you could get a proper remap for a similar price. Do some quick research online and read a few forum posts about them and I’m sure you’ll realise how poor some of them are.

Apparently when cars are put on a dyno with a tuning box they show very little gains.
 
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Oh you can get gains by using a tuning box on a cr alright, but it's a rough cut. They could push up the rail pressure to insane levels but it's an "all across the rpm range" increase. Mapping does the same but with some intelligence.

On a TDi you can only increase fuel pressure and injector duration (injected volume), boost increase happens naturally after that. There is no other way to increase power on a TDi. Mapping does exactly that too but taking rpm and smoke maps into account.

CR tuning boxes do the same thing but with no finesse and it will smoke like feck under load at low rpm. Dpf soot levels will shoot up and egt increases at higher rpm so tuning boxes are crap but so is a cheap remap.

Pd engines are different in that a tuning box can only mess with the temp sensors and only a remap can alter the fuel pressure.

In short, so called tuning boxes are crap as are cheap generic remaps.

Quality remaps that have been extensively tested on a particular engine will be many times dearer than a box from eBay. If a remap costs the same as a tuning box, it won't be any better.
 
The box I followed was £15 :whistle2:
The one was had probably cost as much as a remap and came from a VW specialist who claimed to have tweaked the tuning it gave to make it better. We took it back to him twice to get it re-tweaked and it was a bit better but never something I would like to live with daily. I wouldn't be surprisedacually if he was Bs ing us, it's a long time ago and the box long gone though, you hope to live and learn though.
 
I'd avoid it and get a quality map, if it sounds too good to be true....etc
 
ScottyP45 said:
Oh you can get gains by using a tuning box on a cr alright, but it's a rough cut. They could push up the rail pressure to insane levels but it's an "all across the rpm range" increase. Mapping does the same but with some intelligence.

On a TDi you can only increase fuel pressure and injector duration (injected volume), boost increase happens naturally after that. There is no other way to increase power on a TDi. Mapping does exactly that too but taking rpm and smoke maps into account.

CR tuning boxes do the same thing but with no finesse and it will smoke like feck under load at low rpm. Dpf soot levels will shoot up and egt increases at higher rpm so tuning boxes are **** but so is a cheap remap.

Pd engines are different in that a tuning box can only mess with the temp sensors and only a remap can alter the fuel pressure.

In short, so called tuning boxes are **** as are cheap generic remaps.

Quality remaps that have been extensively tested on a particular engine will be many times dearer than a box from eBay. If a remap costs the same as a tuning box, it won't be any better.
Click to expand...

Just done a quick google search for tuning box prices.
A DTUK tuning box for an A3 170 tdi Quattro (which is what I have) is £399.95 and apparently takes it up to 220 bhp(which will be a load of bulls**t).
I got a custom remap where I can feel the difference is night and day and it’s completely smoke free. I also have a dyno print to show that after the map it made 212bhp whereas before it was 168 bhp and that cost me £250.
That is exactly why I said I don’t see why anyone would bother with a tuning box if they had the option of a remap or tuning box.
 
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