I brought a tuning box a few months ago. When I fitted it, it didn't work so I sent it back. They tested it and it was working fine, so I tried it again, but it wouldn't make my car any quicker.

So I thought I'd just go for a remap. Had this done and again no difference in power. My car has plenty of power and seems quick, so it not losing lots of power. I dont think, I just don't understand why the tuning box and remap won't increase bhp?

5 Answers 5


Remaps are often not about significantly increasing the top-end power, but changing the shape of the power and torque curves to suit the intended use of the car.

A normal road car, such as your mondeo, will be tuned to suit the average road driver - it will idle nicely at rest, and pull fairly smoothly through the lower end of the range, and will be fairly frugal with fuel. A competition car, on the other hand, will have a different set of requirements - they won't be concerned with idling or economy, so will tune it to get the best acceleration possible - matching the torque curve to the gearset as much as possible.

A lot of it therefore depends on what you want by 'quicker' - making a car get a better time over a quarter mile at your local drag strip is very different from cutting a few seconds off your lap time at Spa, or a forest stage...

I'd agree with jzd, think about the balance. If you're after a fast road car, tyres, brakes and suspension bushes make far more difference than small power increases. For that matter, so does getting a bit of professional driver training (which has the added advantage of being fun!)


Without other modifications the typical increases in power from tuning adjustments/remaps will not be that noticeable because they are small increases. If you are putting the car on a dyno then you should be able to see some effect, but just driving the car around you would not likely be able to detect much of a change.

If you are looking to increase your power, look at what mods can make significant impact without breaking your budget. This normally means actual hard part changes, but tuning is important to keep up with as you are moding the car.

Also, continue to think about keeping everything in balance: You don't want a car with high HP and poor brakes, or upgrades that don't deal with bottlenecks.


I would suggest taking the car to a workshop and having them put it on a dyno. First without the chip and then with it. If there's no difference, the chip is faulty.

If you had a remap of your current ECU, it should still be illuminating to compare your dyno graph to that from a standard car. You should be able to acquire a dyno graph from Ford or one of their dealers.

My guess is that the tune was so mild that you don't even notice, or the technician didn't understand your requirements and mapped your car to be more fuel-efficient, but also more tardy.


The Ford Mondeo has plenty of power as it comes out of the factory. The specification of the vehicle would have been tested over thousands of miles under many and varied conditions. All of this means that your Mondeo is at its optimal best. Fuel economy, power, noise, and emissions are all at their optimal best. If you were to buy and use a piggy back box, or were to have a re-map, and your engine was to blow or you became involved in an accident which could be shown to be caused by the alteration, who would be responsible? Your insurance company would not want to know if you had not declared the mods to them. If you did declare them the insurance would in all proberbility decline cover. To modify your vehicle for power or anything else would involve a host of adaptations, as outlined by jzd, and it would end up not entitled/legal to be on the road.

  • So why do so many people remmap there cars if they dont gain any power ect. I told my insurance about the remap they were fine I want more power out my car so I thought remmap would be best option as I read the tunning boxes damage u car. The guy who remmap my car said I would gain between 30 and 35 bhp but there seems to be no difference I thought there might of been something wrong with car that stopping it from producing more power thought it could be something with the fuel ect cause thats how the tunning boxes work. I thought someone else might of had same problem.
    – Ben Wiley
    Dec 3, 2013 at 2:25
  • Without a print out of the 'before and after' from a dyno for your car it would be very difficult to say what power increase has been achieved exactly. You have exactly to duplicate the two test conditions. Dec 3, 2013 at 17:03
  • So thee no way to tell if my ecu is mapped or tell any gain without being on a dyno rolling road? I pretty sure I should tell when my car has a extra 30 0r more bhp as so many people say how much responsive and acceleration is loads better. Can there be somthing stopping it like dirty feulfilter a boost leak.
    – Ben Wiley
    Dec 4, 2013 at 19:48
  • My car just seems the same as before I had the remap and was hoping there was a reason why it not producing better acceleration ect I thought it could be something like fuel filter or something not working right do many people say the car is much faster ect with remap if this is the gain I get well its a waste of money I pretty sure it sould be better then this
    – Ben Wiley
    Dec 5, 2013 at 1:26
  • Put the car on a dyno and see if anything changed. Jan 17, 2014 at 10:06

trying to get more power out of an engine is forced to put more tension on crankshaft,pistons bearings and clutch, the engine is only tested to run on original specifications properly,john.ps buy a car with a larger engine ,less fatigue?

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .