I'm sure this has probably been covered in another area on the forum but I couldn't find much on it.

I currently have a Mondeo MK4 2.0 TDCI 140 and as usual I'm looking at upping the power/torque.

On my previous car (Focus 1.6 TDCI) I had a custom remap which I was quite impressed with (although a clogged DPF took away some of the benefits).

I was always under the impression that tuning boxes were a poor subsitute for a remap as most just fool the ECU. However recently I've been talking to a few people with different ones installed that highly recomment them.

One thing that's very appealling to me is the fact that they can be removed and reinstalled at any time.

This is one in particular I was looking at and is a digital tuning box as opposed to those cheap analogue ones with only resistors tricking the ECU

http://www.bluesparkautomotive.com/

What is the general opinion on using boxes like these?...I know it's a broad question as obviously some are far better than others, but then again the same can be said for a good remap against a poor one

And has anyone experience of using one or know anyone using one?

I've heard that for low down torque especially tuning boxes can often be better than a custom remap

Tuning boxes often cause over fuelling issues, I'd recommend a removable quality remap such as Bluefin.

Would love a Bluefin but they are extremely pricey!

The reason I was looking at that bluespark box in particular was the reason of over fueling which I did'nt want but this manufacture says "The default map provided on our tuning boxes increases torque without increasing maximum fuel pressure" which gave me the impression it wasn't going to use over fueling as it means for power gains...maybe I'm wrong?

They also offer a 28 day returns policy if you weren't happy with it which makes it quite tempting...provided it's reasonably safe and doesn't cause any issues with injectors etc