Diesel tuning boxes

Third Opinion · 1 Nov 2012 at 20:16

Realistically what you guys think?

I have used 2 now. One for a Rover 75 with the BMW engine. The car was pathetic with it's 2 litre engine producing about 110bhp. I bought a box off a Rover/Mg tuning company and was amazed by the difference. The car became so powerful it was knackering the clutch.

Since then a friend has fitted one without the clutch knackering but with amazing results.

I was just given one that will fit my car but am thinking what is the downside. The MPG doesn't seem to be effected and both above passed MOT.

There must be a downside as they are so cheap (between 70-300 pounds) but I have not found it. Both cars have covered 30k plus with no problems.

Seems to good to be true, is there a downfall?

Phil W · 1 Nov 2012 at 20:28

They just up the air/fuel mix, nothing else. I had one on my Mondoe TDCi and got worried about the Injectors giving up so removed it after a few hundred miles. Actually performed pretty well, very little smoke (although i followed others advice and went with the most common setting).

My brother fitted one to his 306 HDi, it was ok on the lower settings but rubbish on the higher ones.

Westyfield2 · 2 Nov 2012 at 00:41

The downside is that they're normally just upping the air/fuel mix and don't really have all that much logic inside them. The better alternative is to remap your ECU, as that'll be reading all the sensors etc.

Brookert · 2 Nov 2012 at 01:12

Third Opinion said:
Realistically what you guys think?

I have used 2 now. One for a Rover 75 with the BMW engine. The car was pathetic with it's 2 litre engine producing about 110bhp. I bought a box off a Rover/Mg tuning company and was amazed by the difference. The car became so powerful it was knackering the clutch.

Since then a friend has fitted one without the clutch knackering but with amazing results.

I was just given one that will fit my car but am thinking what is the downside. The MPG doesn't seem to be effected and both above passed MOT.

There must be a downside as they are so cheap (between 70-300 pounds) but I have not found it. Both cars have covered 30k plus with no problems.

Seems to good to be true, is there a downfall?

They only 'knacker' a clutch if it didn't have much life left. Many people remap their cars to find the clutch slips, as the extra power is just too much for the old worn clutch.

mattyprice4004 · 2 Nov 2012 at 07:16

Having owned a couple of 75s and a ZT, I can honestly say you're lucky to have a working clutch anyway

If the clutch is dying you're either not driving properly or it's going of its own accord, I had my last 75 running around 170bhp with a SS exhaust, tuning box and remap on standard clutch and it was fine. Now that was fun for a bit of a lardy estate

They're either 114 or 131 as standard, which isnt really enough for the car.

rodenal · 2 Nov 2012 at 08:24

Tuning boxes are ok to get an idea of the difference a remap can make but they don't really compare to a properly written map in terms of power delivery or all round performance.

With regards to clutches well it depends on what the stock clutch can handle and how worn it already is as said above. Most vag's can handle a remap on the standard clutch without issue whereas most Honda diesels have a clutch made of chocolate which doesn't last long once the power is upped - in saying that mine is ok, but it's only a year old!

233 · 2 Nov 2012 at 08:28

remap is the best way to go tbh

don't have time to type up a full argument why but trust me it is (google tuning box vs remap for all the pros and cons)

nowt wrong with either though or if your a bit loopy both

mattyprice4004 · 2 Nov 2012 at 12:55

rodenal said:
Tuning boxes are ok to get an idea of the difference a remap can make but they don't really compare to a properly written map in terms of power delivery or all round performance.

With regards to clutches well it depends on what the stock clutch can handle and how worn it already is as said above. Most vag's can handle a remap on the standard clutch without issue whereas most Honda diesels have a clutch made of chocolate which doesn't last long once the power is upped - in saying that mine is ok, but it's only a year old!

The stock clutch is good for almost 200bhp, without some serious work a 75 CDTi won't really get there. A decent tuning box (Synergy 2A) and a remap would see around 175bhp, then you need a decat or SS exhaust, EGR removal, inlet manifold cleanout etc to see those last few ponies.

I had 320 lb/ft of torque and my clutch was still fine, around 12 months old Valeo if I remember correctly.

Delta12 said:
remap is the best way to go tbh

don't have time to type up a full argument why but trust me it is (google tuning box vs remap for all the pros and cons)

nowt wrong with either though or if your a bit loopy both

Both is brilliant, I preferred just the remap if I had to pick. Much more linear and 'original' feeling.