I posted this in the C-Max forum, but it's probably of more use here....

I was always reasonably happy with the performance of our 2005 1.6TDCi C-Max until we got a 2.0TDCi S-Max with the 140hp engine. Even though it's a much heavier car, and the family (plus associated clobber) is getting so big (we've almost out-grown the C-Max), the performance of the S-Max has been fantastic!

Unfortunately, my wife usually gets the S-Max for ferrying everyone around, while I drive to work in the C-Max, which I still enjoy, but it seemed a little under-powered now. So I finally gave in to a temptation I've had for a couple of years now and got a tuning box!

I considered a 'proper' ECU remap, but reputable engineers are a bit thin on the ground here in western Ireland and after a bad experience trying to arrange it, I instead decided to go for this tuning box: http://www.chipexpress.com/

It sounded much more sophisticated (and expensive) than the many cheap analogue boxes around which simply dump more fuel into the injectors. The Chip Express unit is electronic and continually monitors ECU signals, revs, throttle changes etc. and adjusts injection accordingly, in what sounds like a similar way to what an ECU remap achieves.

It works out about a similar cost to a remap, but of course is easily removable at any time. The purchase was quick and easy (I did it on eBay where they had a "Submit Best Offer" deal and I saved 40 quid! ) and it was delivered to Ireland in 2 days in very professional looking packaging with easy to follow instructions. "ENOUGH ALREADY", I hear you cry, "What's it like?"

Well, it was different than I expected...
I kind of thought I'd subtly feel a bit more torque and faster acceleration, but when the turbo kicked in, engine acceleration was noticeably more rapid straight away. I've got used to diesel engines revving up kind of slowly and tend to rely more on the torque, but now it spins up much faster between 2000 and 3,500 revs! Acceleration is therefore definitely better, which is especially useful when overtaking.

So I expected it to feel like the S-Max, which pulls like a train and you can feel the tyres squirming at times, but instead it was more like a petrol car's free-er acceleration - above 2000 rpm anyway. At lower revs before the turbo kicks in, you can feel more subtle improvements in torque, which I presume is where you'd get improved mpg due to being able to change up a gear at slower speeds than before. But it's early days on that front yet, and it remains to be seen if mpg improves by my careful management of gear changes at lower revs when in competition with me flooring it regularly to enjoy the extra thrust available!

So I'm happy with the results so far, with no noticeable sooty exhaust. I estimate power has gone up by 20 to around 130bhp, with torque gaining a similar percentage. That's on supplied settings - it's possible to switch them up 2 or 3 notches, which should take power up to similar levels to the 2.0TDCI. But I'll keep it standard for a while before trying that out.

In Summary - highly recommended as a 'proper' box alternative to a remap for anyone looking for a bit more oomph who are beyond their warranty period.

Interesting read Gwyn,

Thanks for the review. Keep us posted on the mpg figures as that's where my interest is and most people seem to talk about the power more than the economics.

Ascii

It's usually a while before folk get around to trying out for efficiency. I don't think my box is hugely more efficient than before, if not the same to be honest, but the smoothness of delivery is far better than before and makes it worthwhile alone.

It seems to get rid of that horrible diesel knock/clatter at lower revs, which is quite nice when pottering about town in 3rd etc.

That's a good point - mine does that too!
I think it's the extra torque at low revs that means the engine doesn't struggle (I'm guessing that's what the knocking indicates) when you potter around town in a high gear (I often use 4th).

I suspect that's where the extra mpg would come from. I could have pottered around in the same high gear and got better economy before the upgrade, but the knocking discourages it somewhat...

I can't see how mpg can improve once on the open road at a constant 60mph in 5th gear at 2,500rpm when I presume the tuning box will be injecting more fuel in for more power+torque than before at that given mph/revs. Unless at constant speeds the box doesn't necessarily use more fuel, only when accelerating?

The knocking sound isn't the engine struggling, rather a characteristic of diesels themselves working on compression rather than spark plugs - that's the noise I'm describing. By altering the fuel timings, I believe that the clattering spanners noise is eradicated, because the fuel timing is retarded (shot in and combusts slightly later), when the previous cylinder is at a different point in its stroke (usually later and closer to the lowest part of the engine and on its way back up).

However, put your foot down, and it will soon be loud again, lol. It's mainly at lower revs I notice this more relaxed sound, or driving in 5th at 40mph. Surprisingly quiet.

When I'm in 5th gear at 60mph though, my rev counter is slightly below 2000rpm - figures that the 1.8 diesel requires fewer revs than the 1.6 at that speed I suppose.

Though I can almost guarantee this with most tuning boxes: shove them on the highest setting, and all is rosy for most every-day driving. Go past 3500rpm, and they tend to cause the engine management to come on and warn you. It's not going to cause any damage in reality, but nobody wants that. I tried a few well-known brands (coming to the conclusion that the innards are more or less the same for most, including the ROM), and all of them caused management to come on at some point when thrashing.

This is common to the MKII 1.8 engine specifically though, as it has more torque than the MKI as stock. The guy who I spoke to about a particular box, said that similar stories occurred with the 1.6 and 2.0 with high settings, particularly with newer and 'tighter' engines. He said that a knackered or high miles older engine would happily go on higher settings, as torque/bhp was likely to have already been lost in the first place.

Though I care not for the power really, as I would have kept my 170; I prefer masquerading in a less-noisy 1.8 TDCi, which is far more pleasing than booting a diesel engine about

So what brands are there out there for good tuning boxes? and what were the ones you tried silver?

I got mine from http://www.chipexpress.com/
Fast, efficient service, and I've been happy with it after 7 weeks of use.

It's hard to say whether my mpg has improved all that much. Just going by the trip computer, it's definitely no worse than before, but I tend to watch the readout like a hawk now, while I only checked it occasionally before. It's hard to keep tabs on it because on the one day a week my wife has the car, the reading seems to go south by up to 10%

I'd say economy is a little improved, mainly as I can comfortably drive around at 60kph in 5th gear, which was a struggle before. With more noticeable advantages of the the smoother (and faster) acceleration, plus better overtaking performance, I'm happy with the results!

After sampling a good few, I found that the Vector tuning box was the best value. Identical performance (and nigh-on identical innards) to one of the 'top brands' in the UK, but only £150-200 instead of £350-£400.

Well after 6 months using my tuning box with no problems, recently I'm seeing black smoke from the exhaust under hard acceleration for some reason. Any ideas why this can happen?

Also, in recent weeks, the narrow flat spot around 1700rpm (a common trait of the 1.6 TDCi) seems to have widened up the rev range - sometimes noticeable even when the turbo has kicked in. It's still only occasional, but is more intrusive now. I wonder though if that's down to the cold weather?

I will try disconnecting the tuning box and seeing if there is any difference.

Check your air filter straight away - it's not the cause of all those issues (of course), but after having mine replaced, it drives far better. The old one was disgusting and the Ford guy even commented how bad it was.

Disconnected the tuning box and the flat spot is still noticeable - it almost feels like a misfire at times. I also noticed that the indicated mpg has gone up more than 10% in recent weeks too. Maybe it is the air filter - it's due a service, so I'll get it checked out.

More worryingly, whilst under the bonnet yesterday, I noticed a crack in a pipe and a little bit of an oily mess around it. I'm not sure what the pipe's for - it's quite wide (about 2 inch diameter) and goes in to (out of?) the top front of the engine from somewhere down below. I will get that sorted at the service too.