PDA

View Full Version : TUNIT engine management ?



Beemer
30-12-2013, 22:14
Ever since I bought our latest m/h with a TUNIT box already fitted, I have wanted to test it somehow, to find out what difference it makes.
Last weekend I decide to have a look at the box and see what setting it is on and then change the setting to see if there is any difference.
I noticed that the TUNIT box was set up to number 5 on the tuning dial so I recorded 60mph (indicated on speedo) at 2600 revs, and 70mph at 3000 revs. I then changed the setting to 1 on the dial and recorded exactly the same, then to 9 on the dial and... er..exactly the same!!!!

Is my test not a good test or do I have a dummy TUNIT box fitted?
I sort of expected to see a drop and a rise in the revs for each setting... or should I look for something else?
The cables to the box disappear behind the engine so are difficult to follow to see where they go.

sparrks
30-12-2013, 22:23
Ever since I bought our latest m/h with a TUNIT box already fitted, I have wanted to test it somehow, to find out what difference it makes.
Last weekend I decide to have a look at the box and see what setting it is on and then change the setting to see if there is any difference.
I noticed that the TUNIT box was set up to number 5 on the tuning dial so I recorded 60mph (indicated on speedo) at 2600 revs, and 70mph at 3000 revs. I then changed the setting to 1 on the dial and recorded exactly the same, then to 9 on the dial and... er..exactly the same!!!!

Is my test not a good test or do I have a dummy TUNIT box fitted?
I sort of expected to see a drop and a rise in the revs for each setting... or should I look for something else?
The cables to the box disappear behind the engine so are difficult to follow to see where they go.

You would need to change the gearing for that to change.

maingate
30-12-2013, 22:24
The result is bound to be identical.

The difference is in how long it took to reach those speeds and how much fuel you used doing it.

If you want a comparison, find a long hill and do the test again.

BTW, your van is quite low geared.

At 56 mph, my revs are 2000.

sparrks
30-12-2013, 22:25
A better test would to try it up a steep hill in various gears on No 1 setting and then change the settings to 5 and see what it goes up the hill like after changing the settings.

Beemer
30-12-2013, 22:32
Thanks for prompt replies....
I have a local hill that would be just the ticket for these tests..
Another question...
Would I expect a better pull up the hill, with more fuel usage on number 9 or 1?

thanks again.
Dave

sparrks
30-12-2013, 22:40
Thanks for prompt replies....
I have a local hill that would be just the ticket for these tests..
Another question...
Would I expect a better pull up the hill, with more fuel usage on number 9 or 1?

thanks again.
Dave

Don't know I haven't got one.

However with the economy setting the engine would be less responsive than on the power setting when the engine's increased torque should become more noticable as it powers it's way up the hill.

sparrks
30-12-2013, 22:44
The result is bound to be identical.

The difference is in how long it took to reach those speeds and how much fuel you used doing it.

If you want a comparison, find a long hill and do the test again.

BTW, your van is quite low geared.

At 56 mph, my revs are 2000.

The overall gearing on the van will play it's part in the economy of the van.

Mine is 3000rpm at 90mph so rarely goes over 2500rpm on the motorway.

tugair
30-12-2013, 22:45
You don't get anything for nothing in this life, (unless you are an MP or MEP!)

Improved performance. I.e. more power, normally comes at a cost in fuel and a long term reduction in potential engine life. However, if you also drive in max economy mode and if the Mhome is not driven correctly with enough rev's. I.e. it labours, then you are likely to get the same result (but without the power)!

Basically, if you are travelling fully loaded and feel as though you need more power, in a hilly area, for example, then it might be worthwhile changing the setting.........

Wooie1958
31-12-2013, 06:23
Tunit Diesel Performance - Diesel Tuning with Over 2000 Applications (http://www.tunit.co.uk/product/productrange.php?action=V-CR)

" Tuning Modules " like yours work by increasing or decreasing the BHP and or Torque by varying amounts.

They have nothing to do with the Gearing.

Number 5 is the " default setting " and gives slightly more BHP and Torque so it improves economy when driven sensibly.

What you will find is that if you turn it up to Number 9 you will have a lot more BHP and Torque at the expense of economy.

The increases will take you up the hill quicker and easier without have to work the engine as hard i.e. having to putting your foot to the floor.



This is a short simplified version so before the usual suspects start pulling it to pieces ..................... don `t bother !

David & Ann
31-12-2013, 07:30
I had a Tunit installed in my MH 3/4 years ago. I tested it after installation up the cliffs where I live. This particular cliff, you need 2nd gear to get to the top. It breezed up it on 3rd and I managed 4th so I am quite pleased with the job done. Normal engine is 128 JTD with Tunit I get 150BHP. My setting is on 7. He had first tried it on 5 took it for a run and came back to set it on 7. A Tunit gives you more power, in my case does NOT reduce fuel consumption, does not make you MH go any faster on top gear, but it DOES go faster from gear 1 to 5 with more power.

Wooie1958
31-12-2013, 07:40
I`ve had this one fitted for 5 years now :- Energy Tuning UK (http://energy-tuning.co.uk/tuningbox.php)

I bought it originally when i was towing as i wanted more Torque.

I don`t tow anymore but i still keep the box on the same settings and find it`s a much more relaxed drive with less gear changing.

I have noticed slightly improved economy of around 3 - 4 MPG.

maingate
31-12-2013, 08:43
A RHD 2.8JTD is 127 BHP. Each jumper setting increases this by about 5 BHP.

The extra power means you get from stationary to 5th gear quicker and may use less fuel doing so. Retaining a higher gear for longer (as long as the engine is not labouring) should result in a slight fuel economy, probably not enough to notice on my 5 ton van.

1807truckman
31-12-2013, 16:06
Hi, I haven't got a Tunit box but something similar (not sure of the make), I have a Hymer on a 5 tonne Merc chassis and I am now getting 28 mpg with the box connected and 23/24 mpg without, that is running at a true 60 mph on the motorway and showing 2750 rpm, the van came with the box already fitted and initially I was getting 23mpg with the box connected and 19 mpg without, now that the van is nicely run in the mpg has improved ( it's taken five years to get to this stage 50,000 miles, in previous vans I would have reached that mileage in 2 1/2 years ), with the box connected it makes for a more relaxed drive.

Kindest regards

graham


CLICK HERE TO REMOVE THESE ADVERTS