Profitune Boxes

[pepper]

I'd been reading up on the threads about the profitune boxes on here and then spoke to a mechanic friend of mine, he warned me off them slightly saying that what they do is send a false signal from the engine temperature sensor which makes the CPU think the engines still cold so adds extra fuel.

He says there have been problems with them sending too much fuel into the cylinders which remains unburnt and leaks down past the rings and into the sump watering the oil down.

So watch your oil levels if they're increasing try turning the dial down on the little box.

[clartsonly]

it wouldn't surprise me... which is why they only improve fuel consumption if you drive carefully.. I will check my oil etc - it is still fun to floor it occasionally and surprise the cars trying to out accelerate you up a hill..

but you have to give a little to get a little... speak to the millions of people with 5% quicker PC's after a little alterations

[pepper]

It hasn't stopped me thinking about trying one. He just gave me a few caveats to be aware of so thought I'd mention it on here.

[Murphwiz]

Pepper, your mechanic is thinking of the ones you get on ebay for a fiver, a 3p resistor to fool the fuel injection into operating cold start program!
These are bad, very bad, massive overfueling will occur.

The Diesel ones are a little different, they interupt the rail pressure signal, telling ecu different (lower pressure) so you are actually rasing fuel pressure, at 1300bar thats quite an achievement!!
So each duty cycle of the injector will squirt in a bit more fuel due to higher pressure, ok if used sesnibly.. if the pressure is to high, expect a hole in the psiton, or similar failure!

[pepper]

Cheers Murph, sounds about right and all the positive comments from the people who use them on here helps towards the decision too.

[seacam]

Hi Clartsonly,

On your Profitune box, what setting did you finaly settle on?
Seacam

[seacam]

Hi Murphwiz,

Explain not being sensible, now I'm worried.
Seacam

[clartsonly]

I think it is on A. I assume driving hard constantly will cause problems eventually. a bit like the V8 interceptor you should only have your superchargers running for a short while.