Tuning Tdi Power Output

[b318isp]

I'm sure this has been covered before, but I looked thru' 25 pages of forum listings and tried a search (which is faulty - webmaster???) so - anyone any experience of the different boxes/chips?

 

There seems to be many out there, from

[Guest nimrod]

Add the name SAIntruder to your search parameters! SA's opinion of these so called tuning devices are quite well known! :(

[Guest SA Intruder]

Infamy at last.

 

Tuning or kidology - the automotive world equivalent of Derren Brown.

 

I have an interesting piece (probably as long as my Superchips tome) to add to the site regarding VAG (and others) "special" preparation of Press vehicles....

[GaryM]

Infamy at last.

 

Tuning or kidology - the automotive world equivalent of Derren Brown.

 

I have an interesting piece (probably as long as my Superchips tome) to add to the site regarding VAG (and others) "special" preparation of Press vehicles....

Read many of your posts and you obvoiusly know youre stuff but why are you so against chipping?

 

Many of the points are spot on! But it is exactly because the manufacture has to cater for things like, running in different conditions, hot, cold, low altitude, high altitude, poor gas, good gas, emmison regs etc that your so called laptop oki has the scope to tune your motor to suit our climate, driving conditions etc. Sure there are some cowboys out there,

[Guest SA Intruder]

Of course it is perfectly valid to know of others' experience.

 

However, most of the chips or tuning boxes use psychology to manipulate the chip buyer into believing that they have better driveability (hence the Derren Brown comment).

 

Most tuning boxes simply extend the duration of the injection period crudely. They are not calibrated in any way and simply add about 5% duration, and some unwanted retardation due to the inherent delay they introduce. Since diesel power is controlled primarily by fuel quantity in the prescence of sufficient air, then for a given throttle pedal angle, you get more fuel and hence the engine feels more lively - kidology. You do get slightly more power at full throttle...about 5%. But you lose much in emissions and economy due to the blunt way these things work.

 

In much the same way, the chip (or more accurately the download to EEPROM) fools the driver by scaling the gas pedal differently - again. For a given pedal travel, the ECU is kidded into "believing" that the pedal has travelled much further, and thus you appear to be getting more power and the car appears more lively. There is some scope for the chip offering to slightly modify the duration and turbo boost, but it is very minor. At full throttle, some chips literally hold the injectors open in an attempt to dump fuel and raise power. It doesn't really work, and you get clouds of smoke.

 

The 115 and 130 and 150ps VAG PD diesels use specific injector nozzle sizes. There are limits to the amount of fuel these can pass in a given time - the injection period has to be finite to avoid massive soot production. Therefore, increasing power is ONLY possible within small limits until the next nozzle size is necessary - this is a purely physical constraint and cannot be overcome in any other way.

 

Petrol engines are a different ball-game altogether - but I am going on and on!

 

At the end of the day, it's up to the individual, of course.

[b318isp]

I was similarily sceptical when I got my first Superchip for my (petrol) BMW and insisted on a before-and-after rolling road printout. The company tried to charge me for this but I refused to pay - saying that it was up to them to justify the value of the upgrade. They eventually agreed.

 

The chip did a few things, it helped low power a bit which reduced the inclination of the car to stall when slow starting from a stop (heavy traffic). Secondly it increased the rev limiter increasing average power. Thirdly it increased power at the top 1000rpm of the rev band. After having it installed for 4 years now, I feel it was very worthwhile but I struggle to see how they justify the costs.

 

If anyone is interested I have some details here:

 

http://www.esatclear.ie/~bpurcell/318isdri...ing_performance

 

 

 

A good friend of mine paid top dollars for a Van Aaken chip for his BMW 320d and it really flies afterwards.

 

As SA intruder says, the TDi engines can be tuned to feel livelier by adding a bit more fuel across the board which can fool a person into thinking the car is faster. This better throttle response can be desireable in a flat car - but as he suggests, doesn't ultimately improve performance. I don't know if the TDi's have a WOT sensor, as this could be useful in triggering an increase in fuelling when it is needed most, e.g. when overtaking - but detail knowledge of the operation of a particular box/chip is required.

 

Typically fuel injectors will be rated 20-30% below their peak flow (possibly to account for partial blockage due to gunking up). On that basis, a similar lesser proportional increase in power may be reasonable to expect. Furthermore, turbo behaviour can also be controlled - but I don't think that is so common. If I could get 20% more power (or even broaden the power peak) I would be very happy!

[Richmond]

Tuning or kidology - the automotive world equivalent of Derren Brown.

Who's Derren Brown?

[GaryM]

Like b318isp I too got a before and after printout on the rolling road and the there were definate improvements. Rolling roads are a whole nother topic as they very rarely simulate real conditions calibrated or not. The best way to use them is for the before and after printouts. At least you know wether you are gaining power or losing it.

 

I rekon you need at least a 10bhp for most people to feel the difference on a normal road car and as I said both the straight petrol chips I have did not give me that feel of loads of power. However on paper I had gained 8bhp and drivability was definatley better. It was not kidology or the like.

 

And as I said it is all the compromises that the manufacture has to make to meet emmisons, long term reliabilty, etc., etc. that gives the window for the chippers to do thier stuff. A great example is the new mini one and the cooper. They both use exactly the same engine yet one give 90bhp and the other 115. The difference is all in the ECU (chip). Buy and mini one spend a few quid with superchips and walk away with a mini cooper!

 

Please lets hear from a few that have had the chips fitted to understand the real life results...