Is it possible to turn off the turbo via a controller?

[leon cupra r]

to clarify,

i DID NOT, and never have said that you are always running some boost. That is total cr@p.
i do not want to be associated with such comments, in fact i replied to muttley stating that he has missunderstood the theory behind turbos making an engine more efficient.
Similair to that an engine is more efficient when it is accelerating slightly rather than at a constant speed. Some people think this means its using less fuel, but this is incorrect. Its more efficient in that the output is greater in proportion to input. (ie the power output/fuel is greater) but this is not to say its a more efficient way to drive. In order to make this work for you it would require that you slowely accelerate, then coast then accelerate then coast, which is how they drive on ultra fuel efficient runs for records etc, but its not how you should drive on the road.

Turbos were originally designed for efficiency, but thats not to say when on boost you will get better mpg, in fact quite the opposite as it allows you to run a smaller engine for 95% of the time but have the power when needed of a larger engine. (eg overtaking)


and finally, "disconnecting / turning off the N75 will increase efficiency"... well not directly. It will not increase the efficiency of the engine, but it will effect how you use the engine as it will limit how much boost you have available. You can do exactly the same thing by modifying how hard you press the accelerator and so its really for people that have no control over their right foot
As ibizacupra has said, like for like driving, eg cruising there will be no difference.
(although i will conceed that anyone who has or has used a boost guage will have a better understanding of how and when boost comes in)

Think you've hit the nail on the head there andy - people getting confused with using less fuel and being more energy efficient. Nicely explained!

The TDi letters in his signature suggests diesel rather than petrol...

Haha at least one of us is awake today matey!



Still wondering if anyone has tried leaving N75 disconnected for a while and if you get an EML?

I'm seriously considering trying to wire a switch to it in the dash so can drive normally with it disconnected and flick the switch when I fancy a bit of spirited driving!

 

[ChrisGTL]

What is this turbo you mention?

 

[ibizacupra]

is it safe to do so then bill? not going to throw EML after a while?

it will throw a light immediately the n75 is electrically not there.
as I said however to cruising it will make no difference at all, as you are not on boost anyhows..
Cruise control is nice for taking the temptation for more throttle away.. set it and leave it if your journeys have straight roads

 

[ibizacupra]

to clarify,

i DID NOT, and never have said that you are always running some boost. That is total cr@p.
i do not want to be associated with such comments, in fact i replied to muttley stating that he has missunderstood the theory behind turbos making an engine more efficient.
Similair to that an engine is more efficient when it is accelerating slightly rather than at a constant speed. Some people think this means its using less fuel, but this is incorrect. Its more efficient in that the output is greater in proportion to input. (ie the power output/fuel is greater) but this is not to say its a more efficient way to drive. In order to make this work for you it would require that you slowely accelerate, then coast then accelerate then coast, which is how they drive on ultra fuel efficient runs for records etc, but its not how you should drive on the road.

Turbos were originally designed for efficiency, but thats not to say when on boost you will get better mpg, in fact quite the opposite as it allows you to run a smaller engine for 95% of the time but have the power when needed of a larger engine. (eg overtaking)
/QUOTE]

"Fuel Efficiency" would better describe one from the other

 

[leon cupra r]

OK so in my boredom today I decided to wire up a switch to the N75, and am now dead chuffed with it! planning on leaving it switched off most of the time - it still feels quick enough, and will still outpace most standard cars, but just means you can be that much more heavy footed without having a major effect on fuel consumption! and no EML.... yet, anyway!

Then the switch is always there whenever you need a quick frap round country lanes etc! - almost like having a NOS switch! haha


Tell you what though, its a bloody ballache trying to get anything through the bulkhead into the cabin on these cars aint it?!?! had nearly the whole drivers side of the dash apart before I could see the cables coming through!!

 

[LEE69]

Should have followed "how to install a boost gauge", my hose just fell through

 

[leon cupra r]

Should have followed "how to install a boost gauge", my hose just fell through

Yeah I did mate, but the hole you push it through is so 'deep' into the dash (i.e. away from the face of the dash, towards the engine) that I couldnt see it (looking from the side, where the fuses usually sit)

Eventually got upside down looking up from the footwell and just about saw enough of it to grab!

compared to the other cheapo cars (rover 25, escort, old astra, *cough* ford ka) I've had with their shabby build quality where you've only got to get the cable etc through 1 inch worth of metal, carpets, plastic, getting to it in the leon was a right pain in the arse! Worth it in the end though!

Just gotta decide where to put the switch now, I'm not overly keen on starting to drill holes in the dash to slot it in somewhere to be honest!

 

[LEE69]

Put it in one of the "compartments" in the lower dash?

 

[leon cupra r]

Put it in one of the "compartments" in the lower dash?

Yeah I was thinking about that, at the moment, on the one under the headlight switch I have a 4way cigarette lighter (for satnav phone charger etc) that fits in there perfectly (wedges in with the power cable down the side to hold it solidly so didn't have to screw it down or anything permenant)...


I have got the cable for the switch at the moment coming out on top of the dash, near the circular vent for demisting drivers window, but could easily be re-router under the steering wheel towards the centre console and stuck down there somewhere I suppose...

for the time being, I am just wedging it in between the door and the dash when I close the door! haha - holds it nicely in place ready to use, but not really a long term solution lol

 

[leon cupra r]

Managed to sort it - the switch wedges in between the centre tunnel the gearstick sits on, and the centre console to the right and below the climate control unit - to the right of the fag ligher cover / ashtray when its dropped down. Will leave it there for now so I don't make any permanent damage to the interior!

 

[Steely]

im quite interested in how youve done this, any pics of what youve actually switched and how?

cheers!

 

[leon cupra r]

I don't have any pictures but I will see what I can do mate, its really simple - just cut the wire to the N75 and wire a switch inbetween on a long cable through the bulkhead to the dashboard somewhere!

Ill see if i can find a camera for ya...

 

[Steely]

Ah right ive not actually gone to have a look at the plug to the n75 to see how many wires it is, so im understanding its a 2 wire sensor, if i put a switchable link on either of the wires it'll break the conection- Ie not allow the N75 to activate

i know it sounds black and white, just wan to be 100% sure on what you've done,


still no EML i take it?


cheers for the help!

 

[ibizacupra]

EML should come on if N75 is open circuit.. (I think)

 

[Murdered LCR]

I've got the solution for you take ur maf off throw various nuts and bolts down the tip go for a nice hack this should then smash all yours blades out of the turbo so it's empty thus making no boost ,

 

[HallycupraR]

Yea clarkson Drove the Audi A8 twin turbo?? to scotland and drove the jag from some where abroad to blackppol for the lights turn on as i recall

 

[J-DUB]

You should sell your car whats the point having it if your going to drive it like a Gay??

If you want fuel economy by a Disease-ILL!

 

[Muttley]

By switching off the N75, you are disabling the wastegate actuation and not the turbo. The default wastegate positition is open, so you are throwing away boost except at max revs.

You have NOT switched it off

Soooooo the turbo is still producing backpressure in the exhaust manifold and degrading your engine performance there. But you are not getting any meaningful boost until the revs approach maxium

Tell me, what is your fuel economy like with the N75 deactivated? Better or worse?

 

[leon cupra r]

Ah right ive not actually gone to have a look at the plug to the n75 to see how many wires it is, so im understanding its a 2 wire sensor, if i put a switchable link on either of the wires it'll break the conection- Ie not allow the N75 to activate

i know it sounds black and white, just wan to be 100% sure on what you've done,


still no EML i take it?


cheers for the help!

Yep, two wires to N75, so put switch on either one. Wires are very short mind, I had to cut away at some of the plastic sheath to expose more wire to fit into a connector block.

EML should come on if N75 is open circuit.. (I think)

Hasnt done yet Bill, think I've probably done about 10 miles with it off so far....

I've got the solution for you take ur maf off throw various nuts and bolts down the tip go for a nice hack this should then smash all yours blades out of the turbo so it's empty thus making no boost ,

Thought about it.......

You should sell your car whats the point having it if your going to drive it like a Gay??

If you want fuel economy by a Disease-ILL!

Thats the whole point having the switch there - so I can still give it the beans when there's an empty road / need to overtake etc

By switching off the N75, you are disabling the wastegate actuation and not the turbo. The default wastegate positition is open, so you are throwing away boost except at max revs.

You have NOT switched it off

Soooooo the turbo is still producing backpressure in the exhaust manifold and degrading your engine performance there. But you are not getting any meaningful boost until the revs approach maxium

Tell me, what is your fuel economy like with the N75 deactivated? Better or worse?

Economy is improved. Still plenty of boost, 6th gear used to see 9.5mpg, now off top of me head its around 15/16.......

Still drives like a quick car, just dont have to be as delicate with the throttle to do sensible speeds! I really do like having it to be honest!

 

[jgy6000]

6th gear used to see 9.5mpg, now off top of me head its around 15/16.......
!

huh?