Hey guys!
I'm new here but I've been following the forum for a while. I bought a 2013 Fiesta EcoBoost 100 hp some months ago. This small engine is so great but has very long gears and a little bit more torque on low revs could be helpful during an overtake. I saw that on the Bluefin website there are the power curves of both the 100 and 125 hp model and they have more or less the same power output after mapping but a there is a huge difference on the torque curve. I think the main difference between the two is the overboost feature that is not available on the 100 hp one. Does someone know if it is possible to flash the 125 hp firmware to enable the overboost feature (or at leat a way to have the same torque of the 125 hp)?

I have seen some remapping for the 100ps version to raise the HP figure to 125 or even 135 ps , but engine longevity remains a question , I have seen reports that some components are different , the turbo may be or the cylinder head gasket , do your homework good before attempting that remap 🙂 

mine is equipped with the 6 speed traditional automatic gearbox , and its very torquey at low revs , I have no issues in overtaking at all , its the 100 ps version

Thank you. Yes, longevity is another concern that I have. I read some threads in this forum of people with the bluefin remap and despite someone have had problems with the gearbox no one seems to have problems with the engine itself. Am I wrong? Actually I looked for a while about the engine differences but it's very difficult to have a clear answer of this question. I think the gear ratio in the automatic transmission is a little bit better than the manual one so there might be a difference in the engine responsiveness. At the end the engine is brilliant but I'm looking for a little bit of torque on the low revs like the 125 models seems to have.

Put bluefin on my 100hp focus, was on for 4.5 years and 50k miles. No issues and drove like a 2 litre car . 

This is great and very encouraging! Did you notice an increase in torque in low revs?

Iirc there is a difference in the engine between the 100ps and 125ps models (but isn't between 125 and 140 - main difference there is gearing ratios and stock map).  I'd suggest not trying to get overboost enabled on 100ps; if bluefin thought it was safe to do they would have done it and just had one map rather than different ones for 100 and 125ps. Mountune also don't offer MP135 or MR165 for the 100ps model, so there's another indicator to be careful. 

Good point. You almost convinced me 🙂 The right way seems Bluefin. Last doubt, I've found in the Pumaspeed website the "125 OEM upgrade kit" for the 100ps model. Have any of you ever tried this Kit? It seems more or less what I was looking for but no reviews online. This kit attracts me because it should be less stressful than the Bluefin one but I don't know if this kit is just the map from the 125 model or it contains the entire firmware. If it were only the map could be useless and maybe also dangerous for the engine.

Pumaspeed 125 OEM upgrade kit: Their website says it’s just the single tune file (map). 

Early 100Ps models had a lower spec turbo but, from what I’ve read, Ford included the same turbo on their 125PS models sometime in 2015. The 140PS has the higher end turbo, thicker head gasket and 140 map as well as lower final drive ratio.  

Many tuners map both 100 and 125 the same with the same results. Others differ in final performance.

I’ve had the Bluefin tune on my 125PS 6DCT for about 25,000 km and still performing well. I wouldn’t worry about longevity provided you drive with some mechanical sympathy, change the oil to the schedule with the correct oil, and check your coolant levels regularly. Coolant loss is what kills these engines quickly and permanently. 

Ok, so that upgrade kit is not what I was looking for. Reading online I've found more or less what you have found about the engine differences, so thanks for the confirmation.

I'll go with Bluefin, then. Thank you all guys!