Tunit Diesel Performance

[JohnI.Stephen]

Yes, we discussed this about a year ago, so apologies to those for whom this post is a dÇjÖ vu. However, since this company (Tunit diesel performance) is a regular advertiser in the CC Magazine, I daresay some of you will have seen it, and possibly even made enquiries / bought their product.

I have a 2005 KIA Sorrento with its meagre 138 bhp. KIA have just released their new Sorrento with around 168 bph (from the same 2.5 diesel engine!). Tunit assure me that I will get at least 160bhp and are now willing to offer the product on a try before you buy basis; i.e. they fit the unit (20 mins they say), and then you go for a 30 min test drive. Whilst I am sure that this test would be 'solo', I am assured that the performance improvement (increased torque especially) will be immediately felt but, if I am not impressed then they will remove the unit and all I pay is the fitting / unfitting charge (£35).

Whilst the standard Sorrento is 'fine' when towing, I am very conscious that there is zero power in reserve. It would be nice to being able to tow at (just under) 60 mph on motorways and remain in 5th without the box clicking down the moment we hit even a slight incline. So have any on you tried this; what do you think?

John

PS Fully aware about i) insurance company needs to be informed and ii) potential warranty issues

 

[CliveV]

Hi John

I am no expert on "re-chipping" but my son is well into such things as part of his work. From what I have read and discussed with my son, the old way of doing it was to actually take out the original chip and plug in a new one.

But like all things - this has moved on a bit. Now, as I understand it most modern engine ECU can be reprogrammed.

Thus the idea of replacing or adding on something to a modern car like the Sorrento is frowned upon by people like my son who is well into all this technical stuff.

His advice is to use a Kia upgrade if their is one, or simply go to an expert and get them to advise you on your upgrade options that could well be there already, but just need to be turned on as it were.

I think the removal charge says it all as it indicates a "bolt on go faster goody" - which is all a bit "Halfords" in my sons vocabulary.

Very much yesterday's way of doing it.

 

[spj]

Hi John,

I had an Audi A4 2.5tdi quattro 180bhp [2003] and bought a Tunit box, this gave 210bhp and 295lbs of torque at 1400rpm which I pulled our 1400kg van once to Cornwall and twice to Scotland with. The worst we got slowed down on the A30 or the motorways was 54mph with the cruise control set at 60 and never had to drop out of 6th gear.

Before the box was fitted the car was very smooth but felt a little sluggish, my previous Passat 130tdi felt more responsive, but with the Tunit on the mid range torque and acceleration reminded me of a Subaru Impreza Turbo I had before although from standing the Audi was slower but mid range was similar.

I now have a Mercedes ML270CDI auto with a DTUK tuning box [

 

[JohnI.Stephen]

Hi John,

I had an Audi A4 2.5tdi quattro 180bhp [2003] and bought a Tunit box, this gave 210bhp and 295lbs of torque at 1400rpm which I pulled our 1400kg van once to Cornwall and twice to Scotland with. The worst we got slowed down on the A30 or the motorways was 54mph with the cruise control set at 60 and never had to drop out of 6th gear.

Before the box was fitted the car was very smooth but felt a little sluggish, my previous Passat 130tdi felt more responsive, but with the Tunit on the mid range torque and acceleration reminded me of a Subaru Impreza Turbo I had before although from standing the Audi was slower but mid range was similar.

I now have a Mercedes ML270CDI auto with a DTUK tuning box [

 

[rob_jax]

Hi John,

I think "spj" has quite nicely illustrated the difference between a "Plug-in box" and a "remap of the ECU".

Plug-In Box:

Easily transferable between identical cars.

Adjusts the signals from the car ECU by feeding in a false reading from one parameter - usually results in an ECU signal to increase the fuel flow to the engine.

ECU Remap:

Needs a diagnostic lead and laptop computer to install / remove the tuning package.

Should be cheaper - as it is "just" a software remap - no real hardware to buy - but these are often optimised for each engine - so some labour to pay for.

The ECU remap reads all the sensors from the engine - so the effects of a cold or hot engine, air flow, crankshaft position, automatic gearbox, fuel, and so on are all taken into account.

The ECU remap should offer better fuel consumption (doesn't just increase fuelling), lower emissions (same comment) and possibly better torque or bhp.

At the end of the day, both systems will increase torque, bhp and remember that more power means you burn more fuel. But many people find that the more powerful engine allows them to drive more efficiently - and by not using all the new found power actually reduce fuel consumption.

The factory upgrade for my Mercedes C270 CDI is a remap - the engine stills stay Euro III compliant - and I'd recommend the remap as the "more complete" solution.

Robert

 

[JohnI.Stephen]

Hi John,

I think "spj" has quite nicely illustrated the difference between a "Plug-in box" and a "remap of the ECU".

Plug-In Box:

Easily transferable between identical cars.

Adjusts the signals from the car ECU by feeding in a false reading from one parameter - usually results in an ECU signal to increase the fuel flow to the engine.

ECU Remap:

Needs a diagnostic lead and laptop computer to install / remove the tuning package.

Should be cheaper - as it is "just" a software remap - no real hardware to buy - but these are often optimised for each engine - so some labour to pay for.

The ECU remap reads all the sensors from the engine - so the effects of a cold or hot engine, air flow, crankshaft position, automatic gearbox, fuel, and so on are all taken into account.

The ECU remap should offer better fuel consumption (doesn't just increase fuelling), lower emissions (same comment) and possibly better torque or bhp.

At the end of the day, both systems will increase torque, bhp and remember that more power means you burn more fuel. But many people find that the more powerful engine allows them to drive more efficiently - and by not using all the new found power actually reduce fuel consumption.

The factory upgrade for my Mercedes C270 CDI is a remap - the engine stills stay Euro III compliant - and I'd recommend the remap as the "more complete" solution.

Robert

Thanks Robert; I would be happy with the simpler 'box' solution as it appears to be easy, fast and, according to the vendors (in this case DT UK), there are some 28 different 'maps' to select from, each of which will offer a slightly altered combination of bhp, torque and mpg. What appears to be clear though is that the extra 25-30% in power is very noticeable and I haven't read any feedback from customers who say that they are only mildly satisfied with the result.

I am surprsied that more caravaners haven't appeared to have gone this route; perhaps we are a more cautious bunch in general?!

John

 

[Geordie]

is this type of modification likely to be found if a vehicle was in the dealers for a service. I ask, because I was thinking about this chipping, but am concerned with my car under warranty it will show up next time my car is in the garage for any number of reasons .

 

[WatsonJohnG]

7 years or so I had 2 cars chipped by a firm in Blackpool who re-write the chip and so there is no external mod to be seen.

Oddly enough I found no need to chip the 1st X-trail so Nissan increased the power on the first upgrade !!

I was told that it would cost

 

[JohnI.Stephen]

Hello Geordie; thsi si what I have read and been told. The 'plug and play' box could be spotted by a service engineer. I ahve been convinced that, it's easier to simply remove it (15 minds) and the car will revert to 'normal'.

Nice to read that you too have done this John (G); for around

 

[CliveV]

From what I understand removing the unit will not fool the dealership as the cars ECU will register that it has been tamperred with.

So there goes your factory warrenty!

Far best to use a Kia approved upgrade.

 

[JohnI.Stephen]

Thanks Clive; I'll check that out. My understand is that there is zero tampering with the car's ECU which is very diffrent from the chip re-mapping. The box 'simply' intercepts the signals from/ to the ECU and provides an alternative signal. When removed, it's situation normal.

I shall ask KIA though; no harm in that. Thanks

John

 

[Litespeed]

If your vehicle is still under the Manufacturers Warranty and suffers a fault, the vehicle manufacturer / dealer can only refuse to cover the repair / item if it can be directly attributed to the power upgrade. ie (in simple terms)if the power the engine is producing exceeds the the torque a driveshaft was designed to take. But even then the dealer must prove that this has caused the fault.

Our company has fitted approx 500 power upgrades to all makes of vehicle and can honestly say not one fault has been caused by the fitting of the box.

I have one fitted to my Espace that lifts the power from 175 to 204 bhp.

A word of warning is to watch out for upgrades offering huge increases in power as these can cause serious stress and failure to the powertrain on your vehicle.

The manufacturer we deal with only make boxes that conform to all manufacturers tolerances.

 

[Litespeed]

If your vehicle is still under the Manufacturers Warranty and suffers a fault, the vehicle manufacturer / dealer can only refuse to cover the repair / item if it can be directly attributed to the power upgrade. ie (in simple terms)if the power the engine is producing exceeds the the torque a driveshaft was designed to take. But even then the dealer must prove that this has caused the fault.

Our company has fitted approx 500 power upgrades to all makes of vehicle and can honestly say not one fault has been caused by the fitting of the box.

I have one fitted to my Espace that lifts the power from 175 to 204 bhp.

A word of warning is to watch out for upgrades offering huge increases in power as these can cause serious stress and failure to the powertrain on your vehicle.

The manufacturer we deal with only make boxes that conform to all manufacturers tolerances.

Hi John,

Ive checked the spec and it will lift the power on your Sorento from 138bhp to 169bhp.

 

[spj]

Hi John,

The ECU does have a fault memory but will only register an actual 'fault' A remap or tuning box will not be stored as a fault.

The only time they could cause a fault to be stored is if the turbo overboosts but tuning boxes and chips etc wont cause this at normal settings, some like DTUK and Tunit can be laptop tuned for more power but the standard upgrade should be enough with no risk of faults. As for whether the transmission etc can take the extra torque, has the new more powerfull Sorento got the same gearbox? I doubt the transfer box or diffs are any different and the Sorento looks a substantial enough vehicle with good build quality and the transmission on most 4x4s is pretty good. They also fit a 3.5 V6 petrol to it which has more bhp but I am unsure of the torque figures. Another advantage of the box over a remap is that they can go on another car or be sold on when you change car. It takes about 10 minuites to remove from my ML270 but most of that is removing and refitting the engine cover, this leaves no trace at all as my car is still under warranty. Also a remap could be lost if the ECU failed, and if under warranty would be sent back to the manufacurer and possibly detected which would void any warranty if not an aproved upgrade, a replacement chip would be more obvious if anyone had cause to open the ECU.

 

[354]

Why not just buy a vehicle with sufficient power or a caravan suitable for the tow vehicle?

 

[AlfromYC]

You can never have to much of a good thing!

 

[JohnI.Stephen]

An update if I may. Two weeks ago I had a TUNIT box fitted to the Sorento and I was really expecting little 'obvious' difference (hence why I was so keen to be assured that there was a full refund if I wasn't happy). I have been assured that the very minimum increase is from 138-168bhp and that this it's likely to be 8-10bhp more. So what's the difference on the road? Well, slipping into 'D'rive you feel it the moment you start off. The engine now revs freely and has a real desire to 'get up and go'. The torque is greatly improved with mid-range acceleration being substantially improved. In practice, all this means that the performance is both much greater but also delivered more easily and more smothly. Fuel consumption has improved from 26 - 30mpg solo; which is very impressive.

On Saturday 23rd I shall hitch up the Bailey Senator and tow to the Lake District. My plan is to set the cruise to 56mph and just hold all the way (M25, M40, M42, M6 (M6 Toll) and then A66 to Keswick). I anticipate a pleasant surprise at the pumps. But I shall update you all upon our return.

John

 

[Andy_5039823]

An update if I may. Two weeks ago I had a TUNIT box fitted to the Sorento and I was really expecting little 'obvious' difference (hence why I was so keen to be assured that there was a full refund if I wasn't happy). I have been assured that the very minimum increase is from 138-168bhp and that this it's likely to be 8-10bhp more. So what's the difference on the road? Well, slipping into 'D'rive you feel it the moment you start off. The engine now revs freely and has a real desire to 'get up and go'. The torque is greatly improved with mid-range acceleration being substantially improved. In practice, all this means that the performance is both much greater but also delivered more easily and more smothly. Fuel consumption has improved from 26 - 30mpg solo; which is very impressive.

On Saturday 23rd I shall hitch up the Bailey Senator and tow to the Lake District. My plan is to set the cruise to 56mph and just hold all the way (M25, M40, M42, M6 (M6 Toll) and then A66 to Keswick). I anticipate a pleasant surprise at the pumps. But I shall update you all upon our return.

John

John - how did your towing trip/subsequent usage go/going?

Andy

 

[Andy_5039823]

John, how did your towing trip go? Are you still very pleased? Better towing economy?

Andy

 

[Pelyma1]

Be careful with plug in boxes. They work by fooling the cars ECU, they give it false readings, most just up the fuel and turbo pressures. To do the job properly and safely an ECU reprogramme is needed, which in an ideal world would be rolling road tested. Turbo Chip and JE Engineering are big in the Land Rover market, the former would probably be a good bet for a Kia.

 

[JohnI.Stephen]

I'm glad you asked about this. As many of you know, I will readily enthuse over things - provided they work. In this case, I had some problems with a happy ending.

The TUNIT box was fitted to the Sorento (with 7,500 miles following its first service). The mechanic set it to a high'ish setting to impress me; I was impressed ! I then asked if I could set it higher; I did. All was fine for 24 hours and then the car stalled on a steep hill (as I was flooring it to test the huge performance gain!). The net result was that after a return to the dealers (twice more in fact) it was established that the kit was faulty / wrongly programmed. So, I never did get to test it towing up to the Lake District in late September as the unit was disabled.

The dealer swapped the unit for one that he "guaranteed" was OK (as it had come from another 4x4). The mechanic set the unit to medium i.e. balance between increased torque at low revs and bhp. I was delighted and really hammered it for one week; perfect. I upped the power (each notch is approx 4bhp) to 6, then 7 and now 8 (max is 9). The car behaves perfectly and will easily return 30mph solo. Already it's returning 27mpg when I am purposely 'stress' testing it! But it's really solid.

So, when I go up to Cambridgeshire next Friday morning, I shall reduce the bhp / torque setting down from 8 to 4, as this will give me maximum low end torque and still a healthy 168 bhp (up from 138).

The point to note about this is that whilst I did experience a problem, the dealer assured me that this is a first (and hopefully his last) problem like this. With my current unit I can believe it; and the difference it makes is truly awesome; not just slight; it's huge; like having at least 50% extra power and response.

I rest my case M'Lud.

John

 

[JohnI.Stephen]

I'm glad you asked about this. As many of you know, I will readily enthuse over things - provided they work. In this case, I had some problems with a happy ending.

The TUNIT box was fitted to the Sorento (with 7,500 miles following its first service). The mechanic set it to a high'ish setting to impress me; I was impressed ! I then asked if I could set it higher; I did. All was fine for 24 hours and then the car stalled on a steep hill (as I was flooring it to test the huge performance gain!). The net result was that after a return to the dealers (twice more in fact) it was established that the kit was faulty / wrongly programmed. So, I never did get to test it towing up to the Lake District in late September as the unit was disabled.

The dealer swapped the unit for one that he "guaranteed" was OK (as it had come from another 4x4). The mechanic set the unit to medium i.e. balance between increased torque at low revs and bhp. I was delighted and really hammered it for one week; perfect. I upped the power (each notch is approx 4bhp) to 6, then 7 and now 8 (max is 9). The car behaves perfectly and will easily return 30mph solo. Already it's returning 27mpg when I am purposely 'stress' testing it! But it's really solid.

So, when I go up to Cambridgeshire next Friday morning, I shall reduce the bhp / torque setting down from 8 to 4, as this will give me maximum low end torque and still a healthy 168 bhp (up from 138).

The point to note about this is that whilst I did experience a problem, the dealer assured me that this is a first (and hopefully his last) problem like this. With my current unit I can believe it; and the difference it makes is truly awesome; not just slight; it's huge; like having at least 50% extra power and response.

I rest my case M'Lud.

John

I shall be twoing my Senator Oklahoma next Friday and not driving solo !