Re-map or tuning box? 2.0hdi

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wellad
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Re: Re-map or tuning box? 2.0hdi

Post by wellad »

Northern_Mike wrote:I don't have a trip computer. It's measured from tank to tank. Sorry to upset your little theory, but it gives an increase of about 5mpg with the box on, every time.

I imagine this is because I can use a higher gear than I could before i.e. I can happily potter along at 30mph in 4th or 40mph in 5th on a light throttle, whereas before I could not, so the engine would be revving harder thus using more fuel. You're not taking all the variables into account.
Your light throttle in 4th and 5th scenario is exactly the same as using slightly more throttle without the tuning box. I'd guess that it would actually be more efficient doing this without the tuning box, as the ECU would be aware of the actual injected quantity, and adjust the timing, pre injection and rail pressure to give the most efficient bang. I'm interested in how you think adding more fuel could possibly make the engine more efficient.
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Northern_Mike

Re: Re-map or tuning box? 2.0hdi

Post by Northern_Mike »

wellad wrote:
Northern_Mike wrote:I don't have a trip computer. It's measured from tank to tank. Sorry to upset your little theory, but it gives an increase of about 5mpg with the box on, every time.

I imagine this is because I can use a higher gear than I could before i.e. I can happily potter along at 30mph in 4th or 40mph in 5th on a light throttle, whereas before I could not, so the engine would be revving harder thus using more fuel. You're not taking all the variables into account.
Your light throttle in 4th and 5th scenario is exactly the same as using slightly more throttle without the tuning box.
No it's not because the engine won't pull at 30mph in 4th without the box. It simply bogs down. Same at 40mph in 4th.

Now if you're going to tell me the engine is going to be more efficient running at higher revs with a wider throttle opening. ....
Like I said, you're not taking all the variables into account.

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Re: Re-map or tuning box? 2.0hdi

Post by wellad »

Do you not see that by increasing rail pressure, the tuning box is essentially just increasing the throttle? The box hasn't altered the gearing, there's no reason for it to bog down in the same gear and same road speed without it. I never claimed it would be more efficient to drop a gear, I don't know where you're getting that from. And there is only one variable changed, that's the thing, all the box does is alter the rail pressure. So does pushing the throttle down further. 30 mph in 4th is ~1450 RPM by my calculations, so you're very much exaggerating if you claim it's bogging down at 1450 RPM, or you have an engine issue.

Look at it this way. If a £0.70 potentiometer can give you 5 extra MPG regardless of an increase in power, which results in less emissions, why would Citroen not have done this? It's a no-brainer for them. Don't get me wrong, I've no doubt that the tuning boxes increase power, but that's all they do. If you adjust your driving style without the box I've no doubt you'd see the same MPG.
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Re: Re-map or tuning box? 2.0hdi

Post by jotto »

Thanks for all the replies....I hope I havent opened a can of worms.
I know there are some boxes available that simply force the car to inject more fuel thus giving the illusion of more power but with more smoke and less mpg. Some of the boxes do look a lot more advanced, as has been mentioned with micro processor control but I have no idea if these are just and advanced set up of the old potentiometer.

Having read some reviews on Steves work, Im very tempted to try a remap. The car is otherwise stock so it should provide a bit more power as well as taking all other ECU factors in to consideration. Will get her serviced then contact Steve for some advice.

Thanks all.
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Re: Re-map or tuning box? 2.0hdi

Post by jgra1 »

my comment.. as per my earlier post, and agreeing with Mike, the car is driveable with the box in a way that is impossible without.. it just has a lot more torque and pulls in gears that I cant comprehend now.. so I spend more time, maybe being lazy, but using that torque whereas now, on my hilly twisty commute, its all gear changes, lots of throttle or I bog down...

so.. the day to day reality is the car is a lot better with the box, and the economy hasn't suffered.. I just don't measure it well enough to be 100% on that, but the extra power is worth any loss in fuel, if in fact there is one.

sorry.. grouchy as I have just burst a brand new tyre on a brand new pothole in a dark forest with no phone signal, and the silly wheel brace is chocolate.. thanik goodness Hondas have 19mm whel nuts and for triangles and reflective jackets :)
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Re: Re-map or tuning box? 2.0hdi

Post by taffy »

so buy a box but a good one?
like £50+?
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Re: Re-map or tuning box? 2.0hdi

Post by Northern_Mike »

jgra1 wrote:my comment.. as per my earlier post, and agreeing with Mike, the car is driveable with the box in a way that is impossible without.. it just has a lot more torque and pulls in gears that I cant comprehend now.. so I spend more time, maybe being lazy, but using that torque whereas now, on my hilly twisty commute, its all gear changes, lots of throttle or I bog down...
Yes, this is my point. For a given engine speed, at a given throttle position, I'm sure the box does inject a bit more fuel, though not a lot - it's a pressure difference mainly. However, this doesn't take into account the extra torque and how the engine pulls, so you don't need to use the same throttle, gear and revs as you would do without it, hence fuel is saved. The Berlingo will happily potter along at 30mph in 4th with barely any accelerator at all, whereas it either bogged down or needed 3rd before.
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Re: Re-map or tuning box? 2.0hdi

Post by taffy »

so as its injecting at a higher pressure it produces better combustion with a better spray pattern in respect to normal values of given revs maybe
like a week spark and a strong spark on a petrol
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Re: Re-map or tuning box? 2.0hdi

Post by vborovic »

I'm thinking of finding a more expensive box solution for my car, since the ECU remaps range from 700-900€ ... which is slightly more money then I'd invest in this area ... but found Pro (as in you can tweak many parameters yourself) tuning boxes at around 250-450€ ... some of which connect to 3 car components (fuel intake, turbo output and air intake) ... and on paper provide up to 33% power increase ... I will at a certain point get something, if for nothing else to test the self chip tuning method by myself, and, if it won't work, off it goes ... while looking t ECU remaps, I've also found out that there are offers for ECU programming of the maximum speed limit ... now, I know this is done to the higher end cars that are digitally blocked to 250 km/h max (and actually have power to go far beyond that), but some respectable tuners offer this for the Citroens as well ... my car does max 210-215 km/h ... which is according to the specs ... so, what can still be configured to bump the speed limit higher, if the car isn't "limited" digitally, but by the sheer remaining power to drive it even faster? The ECU remap and ECU speed limit are two different procedures being on offer btw ...
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Re: Re-map or tuning box? 2.0hdi

Post by taffy »

be great to see 200hp out of urs with a box! keep us posted!
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Re: Re-map or tuning box? 2.0hdi

Post by vborovic »

Well, I wouldn't know for sure about the final results without a dyno test, which are scarce in Croatia ... but, the feel of the drive, and the acceleration definitely must be felt, if the torque rises 20-25% on paper ... :D ...
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Re: Re-map or tuning box? 2.0hdi

Post by taffy »

just burn everyone of the lights for us wont you :)
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Re: Re-map or tuning box? 2.0hdi

Post by Peter.N. »

I put a tuning box on my 2.2 Hdi C5 to try and improve the abysmal fuel consumption, it didn't make any difference but it went like a train but as that wasn't the object of the exercise I took it off again, sold the car and bought a 2.0. which gave about 30% better fuel consumption.

I believe the box works by fooling the ECU into believing the fuel pressure is lower than it actually is, so it increases it.

Peter
Northern_Mike

Re: Re-map or tuning box? 2.0hdi

Post by Northern_Mike »

wellad wrote:Do you not see that by increasing rail pressure, the tuning box is essentially just increasing the throttle? The box hasn't altered the gearing, there's no reason for it to bog down in the same gear and same road speed without it.
The engine does not have enough power or torque without the box to potter along at 30 in 4th. With the box, it does.

How hard is that for you to understand? There's guys on the Berlingoforum who've dynoed the same box - without the box, 89BHP, 155lb/ft. With box, 107bhp, 186lb/ft.

Is that really so difficult?
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Re: Re-map or tuning box? 2.0hdi

Post by vborovic »

In my case, if I would get 200 BHP out of a chip box, I wouldn't mind having the same or even slightly larger consumption (currently 6.4 l/100 km average, after 7000 km) ... up to 7-7,5 would be just fine for me, knowing I had 30% extra power ... there are chip boxes that actually lower consumption by a whole liter, maybe a bit more, but the car becomes slower and unresponsive ... for the people who don't care about that, just to lower the fuel costs, this is great (compared to the factory setting) ... but, it should be a given that you can't reach higher output without increasing the inputs ...
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