Disappointing Dyno

[deevious]

Hello all,

Organised a dyno meet last saturday with some friends. It looked like it was going to be fun day with 3 DIY turbo'd MX5, an S13, Golf III GTi, a heavily worked Vectra turbo and Golf II G60 and off course 2 Leon Cupra4 TDi's. I was off course hoping to get close to my previous dyno result done at my tuner's (184bhp and 410Nm).
Unfortunately, despite a healthy looking cloud of black smoke, I got stuck far below the expected result. 'Only' 162bhp and 335Nm was achieved. What's worse though is the look of the graph. I have a picture, but due to computer problems I'm not yet able to add it here;
Basically what it does is power goes up then flattens out, goes up again, flattens out again, goes up once more and then reaches it's peak. Similar thing with the torque, goes up, drops down a bit, goes up again, drops down a bit again, then goes up again up to peak torque.
According to the techie who did the run this was a clear sign of my MAF sensor being on it's way out .... :mad:
Now I have to get a new one fitted and do another dyno run to make sure it's running the way it's supposed to be.
Does anybody have any good tips to avoid having to change the MAF sensor again in another 20.000km?

[DaveP]

The only thing I have read about that people believe shortens the MAF life are third party air filters.

[deevious]

Dave,

yeah, I've heard the same. That's why I'm sticking to my original one until someone comes out with a 'dry' filter that allows better airflow AND have better filtering... Until then, I hope I can keep on having it replaced under warranty.

[mik]

MAF cleaning techniques dicussed here (http://forums.tdiclub.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=17&t=002286) with lots of pictures here (http://forums.tdiclub.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=17&t=001565) :)

I believe MAF design on Leon is slightly different (not checked mine) but same cleaning principles should apply.

[prc]

The MAF design are different, but you should be able to use the same techniques. It's strange how some go quicker than others. A friend of mine with an A4 TDI was replacing his every 60000km due to problems. In the beeza I had mine replaced at 200K.

I would have expected the price to go down on the MAFs seeing that they have to be replaced often, but it doesn't seem to be the case.

[deevious]

Here's a pic of my rolling road graph. Looks like a camel:confused:

[deevious]

Cleaned the MAF yesterday. Pretty straightforward jobbie. The ring for the airhose is a pain in the **s though.
Result? It felt quicker again. 2nd and 3rd feel quite stunning.
To check my feeling I'll need to get it dynoed again though. Will keep you guys posted on the result.

[prc]

It's good to hear that the a basic cleaning (DYI) has such good results, even if it's "seat of your pants" results.