Let the tinkering begin...

**twincamsham** · 08-03-2009, 01:15 PM

Interesting work your doing there
Im a big van of the new generation diesels myself -How much better can it get than to drive hard all day and come home with over half a tank left!

However to realise potential gains you may have freed up i would strongly recomend getting it remaped or fittting a decent tuning box,
It will literally be like driving a different car- you wont know yourself and every drive becomes a blast !

I realise your concerns about reliablity etc but people have been tuning the Tdi since its introduction back in the early 90s, Practically every tdi in germany and the uK has been tuned at present. i have not heard of anyone actually breaking an engine yet albeit unless through no servicing and sheer abuse. the power is of course harder on gearboxes etc,

As for Warranty , well if theres a problem and Vw start to get smart arses ,Tell them you have no idea what there talking about,Chip tuning? its all undetectable once removed and anyway i dont think it will send vw bankrupt to fix your car.

A car is not for life so why not tune it and enjoy it all right now!, Let her idle after every hard run and in my experience of tuned tdi you will never have a problem.
Synchromesh wear,Low compression etc prob wont show up for a good 12-15 years and by that time it will probably be sitting in the corner of some sales lot out the marooka magic mile with a great big "Air,Steer,Rego,diesel" banner draped across its ferocious QLD sun faded bonnet!!

**Greg Roles** · 08-03-2009, 02:27 PM

Appreciate the input Sham, and a tune will happen, but the day my tinkering is complete, my car tuned, and it runs as best it can, well, I'll probably be bored. For me it's much more about the messing around that the drag strip, I'd be the perfect race team mechanic.

**gldgti** · 08-03-2009, 03:09 PM

Originally Posted by cogdoc

I'd be the perfect race team mechanic.

c'mon mate, you dont work THAT fast

**POLARBEAR666** · 08-03-2009, 05:55 PM

Originally Posted by benno

Hey Greg and anyone else reading - do you think it's feasible to reroute the factory external temp sensor - the one that displays on the MFD - to indicate other things? I'm thinking intercooler temperature, in conjunction with a waterspray kit...

No, the car is taking readings from multiple locations. Most boost sensors are also temperature sensors and the car is taking readings from all of them. If one gives a reading that is substantially out of normal ranges , the car will just take averages or use another sensors reading as a fallback.

So if you could work out which sensor the car ULTIMATELY would use. then you could possibly move one sensor that is a fallback for temperature to another location. But you would need to know exactly what each sensor is doing to work it out. I wouldn't want to move a sensor that measures both boost and temp as who knows how the car uses that boost signal?????

Too hard.

**gldgti** · 08-03-2009, 09:44 PM

Originally Posted by POLARBEAR666

No, the car is taking readings from multiple locations. Most boost sensors are also temperature sensors and the car is taking readings from all of them. If one gives a reading that is substantially out of normal ranges , the car will just take averages or use another sensors reading as a fallback.

So if you could work out which sensor the car ULTIMATELY would use. then you could possibly move one sensor that is a fallback for temperature to another location. But you would need to know exactly what each sensor is doing to work it out. I wouldn't want to move a sensor that measures both boost and temp as who knows how the car uses that boost signal?????

Too hard.

why, oh why, would VW go to the trouble of taking these multiple sensor readings of boost and temperature for the intake air? this theory makes no sense to me - have you anything to back this up with (i'm not trying to contradict you, it just sounds unlikely to me).

i can think of no good reason, apart from redundancy, to place multiple sensors along the intake tract as you are suggesting... there are far too many possibilities for discrepancies to appear between the data for each one to be able to use all of the data together to work out some kind of optimum value.

MORE TO THE POINT -

i believe what the orignal question was posing was "can i move the external temp sensor to the IC to tell me what temp it is?". and my answer to that qn would be "why not?".

**POLARBEAR666** · 08-03-2009, 09:52 PM

I wouldn't fiddle with the external sensor either as you don't know whether the computer uses it to compensate for fuelling. Eg if external says its -10 maybe fuelling is changed. Or if its over 40c etc.

There are 3 temperature sensors on the 1.4 TSI's intake system and 1 is the main one with the others providing redundancy it seems. Not sure about the 2.0. But VAG definitely has the technology to know if you mess around with the sensors.

**gldgti** · 09-03-2009, 06:43 AM

good info - but remember that the TSI engine has a 2 stage compressor setup (so 2 stages of pressure increase) so it needs every single one there... in going towards the engine, the first 2 are needed to control what the supercharger is doing, and the 3rd would be used for mixture determination.... i see no redundancy in that circuit.

on the other hand, the diesel needs no mixture control (although it has it anyway probably to reduce smoke a little) and as such needs fewer sensors.