I'm considering a digital tuning box for my Octy 2.0 Tdi PD.

Current possibilities are a Tunit box or a Dragon one.

The Dragon ones are considerably cheaper (especially with some good prices at the moment in their Ebay shop), although the Tunit ones seem to have more features including the facility to be lap-top tuned.

I have seem mention of a new Dragon design, so I have emailed them to find out what exactly is available, and whether the units they currently have on Ebay are an older design.

Both come with 3 year warranty, and a "money back if you dont like it" type guarantee.

I've done some research on here, and there are plenty of people who seem to say "I have type x and it works well" etc.

The main question I have though is whether anyone has tried both types and has opinions on which is best, or comparisons with any other digital tuning boxes.

I've pretty much decided I don't want a remap, so please keep the discussion to tuning boxes only.

:bump:

Anyone?

The dragon box will be fine. Both boxes do the same thing - increase fuelling. If the tunit box is better I doubt it is

Would the fact that the Tunit box is laptop tuneable not make it the finer tool? I wonder if it would be able to give results more akin to a re-flashed ecu? I

i had a dragon on my vrs. cant go wrong mate. get one ordered!

Would the fact that the Tunit box is laptop tuneable not make it the finer tool? I wonder if it would be able to give results more akin to a re-flashed ecu? I

The laptop tunability option of the tunit adds further to the cost and essentially allows different amounts of fuelling enrichment at different points in the rev range. This will not give greater power but will give you the option to change the shape of the power curve to your preferences.

Ultimate power/Torque isn

It sounds like you need a slight fuelling increase at low to medium revs and a larger increase at high revs. The tunit box will be able to do this and if what I read is correct so will the latest Dragon boxes. Sarah or Dragon will be able to give you info on each system respectively.

It sounds like you need a slight fuelling increase at low to medium revs and a larger increase at high revs. The tunit box will be able to do this and if what I read is correct so will the latest Dragon boxes. Sarah or Dragon will be able to give you info on each system respectively.

Thanks. Andy 2407 is awaiting a reply from Dragon still I think. I will wait and see what they say to him.

Dragon service and after care is brilliant, not quick but they mean what they say ....if you don't like it they will refund

Dragon service and after care is brilliant, not quick but they mean what they say ....if you don't like it they will refund

That is what you get with Tunit too.

I have seen this in action and it impressed me to the point that I want one.

Craig.....It is not all about overfuelling to get the power.Overfuelling will cause masses of black smoke and Tunit guarantee that this will NOT happen , so it cannot just be about fuel

Sarah

What are the prices of these things?

That is what you get with Tunit too.

I have seen this in action and it impressed me to the point that I want one.

Craig.....It is not all about overfuelling to get the power.Overfuelling will cause masses of black smoke and Tunit guarantee that this will NOT happen , so it cannot just be about fuel

Sarah

Sarah, as far as I am aware these devices only alter fuelling levels. This is done by altering the signals to the injectors. To many this is part of the attraction as the turbo is not put under extra stress. As standard diesels run with quite a lot of excess air and there is potential to increase the fuelling (within reason) to give more power without substantial increases in smoke.

Hi Craig

This is not a tool to alter the fueling to achieve the bhp gains

It does not fool anything.

It is along the same lines as a remap.

It is more inteligent than just doing that.

If it was like that I would go for a 25p resister.

But it is not!

Tunit guarantee that it will NOT give you black smoke (the main sign for overfuelling)

The one that we had on our rolling rod smoked less than standard , so I dont think that you can put it in the same catagory as that!

The Tunits are £398.00 + VAT about the same as a remap , but it can be transferred on to another VAG PD engine too , so if god forbid you think of selling your car , you can take it off to transfer it.

If your car is still in warranty it can be removed in about 10 to 15 mins , so then there is NOTHING for the dealers to find.

Ooops am I bad Skoda UK read this

Sarah

I've had a few dragon boxes over the years and they are indeed very good for after sales care.

The boxes aren't a bad price either, you can get a digital one for under £300

The jumper pin adjustment is usually more than sufficient for most peoples requirements.

I have no doubt that these devices work and give good gains. They alter the signals from the ecu relating to fuelling and nothing else. The resistor type mods increase fuelling everywhere and can give error codes and idle problems. The digital boxes still increase the fuelling but are rather more sophisticated in how they do it, the basic principle is the same though. I have had a look at the tunit site and they confirm my thinking:-

"All Tunits are specifically designed to achieve enhanced diesel performance by modifying the fuel injection parameters and only by the careful interplay of these values and characteristics can the optimum performance of your engine be achieved. The turbo boost pressure is not directly altered (on turbo models) by the Tunit and is only increased via the natural increase in exhaust gases provided by the increased performance."

As for the mention of exhaust gases increasing boost ...hmmmm, I'm not sold on that one. There will be increased exhaust gases for sure and this will increase spool up speed and give better response. The actual maximum boost pressure is requested (and monitored) by the ecu though. Surely if the ecu sees a higher than expected MAF value it will chop things back?

Craig

My mates dragon box is very unrefined around the 1750rpm mark as the unit comes into play, plus it's very smokey! :thumbdwn:

A remap maybe a better solution, if the money is available...

I agree with what you say, I think the Tunit boxes are more or less the same as Dragon boxes in that they fudge the fuelling of the engine to throw more diesel in the cylinders.

Isn't a waste gate there to regulate turbo boost pressure at X psi? no tuning box will alter that value. And don't forget most modern diesels have variable geometry turbos controlled by the ECU.

I think the appeal of the tuning boxes is the simplicity and easy of removal for certain situations. A remap can complicate things on the warranty front can it not?

What are the prices of these things?

As Sarah has mentioned, the price of the Tunit is

I

Dragon have done a lot of work on their new boxes and now supply a USB-key with a "map" on it. This basically allows control of the voltage across the sensor for specific revs. I do not believe laptop tuning is going to buy you big gains on a tuning box and I certainly wouldn't pay an extra 200 quid for that capability.

At the end of the day, they both fool a sensor and change the voltage across it.

Chris

I

Not sure if I understand you so please ignore this if it doesn't make sense, but the way the box works is one plug will plug into the sensor, and the other plug plugs into the plug that came off the sensor, so the box is after the sensor (to modify fuelling) and sending the new signals via the original plug.

The only thing a tuning box can do is modify the fuelling by fooling the ECU by changing the output of a sensor. I certainly wouldn't pay remap prices for something which did that

Btw, Dragon's e-bay shop is here with their new style boxes

Chris

Thanks Chris, but I think I am still a little in the dark. When you say one pair of leads are intercepting the readings from the sensor, which sensor are you referring to? I was under the impression that the

I'm not sure the exact sensor that is used on the PD (the cheaper boxes plug into the fuel temperature sensor), but it will be whichever one is used to control the fuel pump.

It uses a single wire to the tuning box, the tuning box then munges the voltage, and the output signal is then fed back out to where the old sensor plugged in. It can only affect the voltage output by the sensor and the knock on effect of that is that the car puts more fuel in. I can't see how it can vary the timing of injection (which isn't really a big factor in a diesel?) and it can only adjust the amount of fuel being injected at particular rpm's.

Remapping the ECU means that you can directly affect the amount of fuel being injected and the boost being held, rather than relying on fooling sensors to indirectly increase fuelling.

As I said, the tuning box is very good at what it does, and produces effective results, but for the price of a Tunit, I'd seriously be looking at remaps....

Chris

Remapping the ECU means that you can directly affect the amount of fuel being injected and the boost being held, rather than relying on fooling sensors to indirectly increase fuelling.

As I said, the tuning box is very good at what it does, and produces effective results, but for the price of a Tunit, I'd seriously be looking at remaps....

Chris

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