Thread: TDV6 - SDV6 3.0L Power

Originally Posted by Firko

Gday All,


All we can see is different in the mapping has anyone else managed to get a tune done or have an explanation as to what the go is and how we go about upping the power.

I would also be keen to hear if someone has had a Roo Systems ECU remap.

[ame]https://www.youtube.com/watch?v=sgLF0crCwII[/ame]

Cheers
Craig

It always puzzled me as to how you get better economy with a tuning that increases power. To increase power you have to burn more fuel; you don't get something from nothing. If it is really that simple, car manufacturers would all be doing it.

I was always under the impression that the SDV6 had sequential turbo's where the TDV6 had a standard single turbo.

The only difference between TDV6 and SDV6 is the file that's loaded to the PCM. LR dealers can't/won't make this update for you, but there are people that can

Originally Posted by phl

It always puzzled me as to how you get better economy with a tuning that increases power. To increase power you have to burn more fuel; you don't get something from nothing. If it is really that simple, car manufacturers would all be doing it.

Hi Phl,

I agree, this claim (they never seem to back it with facts) has always seemed counter intuitive to me.

Having said that my brother bought a LC200 that came with a tuning module. He's taken it out as it went into limp mode a few times whe he gave it a boot full (the time it happened during a road train overtake was the final straw) and he says that his fuel use has gone up with it out......

Originally Posted by phl

It always puzzled me as to how you get better economy with a tuning that increases power. To increase power you have to burn more fuel; you don't get something from nothing. If it is really that simple, car manufacturers would all be doing it.

Standard nearly all vehicles run very rich, it helps them pass noise tests and puts less stress on the engine when a heavy right foot is used.

We also have a 6.2 litre HSV Senator and I know if I get it remapped by a recognised tuner then it gets about another 30 extra rear wheel kilowatts and the fuel economy improves, under normal driving, by about 1.5 to 2 litres per hundred.
It also resets the shift points in the auto and allows 100% full throttle in first gear. Standard no matter how hard you push the loud pedal when you take off you only get about 50% throttle and 80% in all other gears.
So a simple remap on a HSV makes huge gains in performance and fuel economy, while this might be more than the average remap will attain on most vehicles it shows how the manufacturers detune the vehicles off of the assembly line which in turn effects fuel economy.

Remapping is not the same as bolting on a piggy back fuel metering device, these are common in motorcycle road racing and give impressive results if used with a Dyno to reprogram it for maximum performance for that bike/pipe/cam timing/compression/fuel set up.
However most on here reckon that piggy back devices on every day drivers are problematic and no where near as good as remapping.

I have a fair bit of experience writing ECU maps for Saab turbo engines (petrol, not diesel) and you can indeed get better economy from an engine that is tuned.
This comes down to ignition timing in petrol and injection timing in diesels. To get more power, you advance the timing, which shifts the point that peak combustion occurs. If you change light duty throttle conditions to have more advanced timing, you get a longer burn which does increase EGTs. This is where you need to find the balance of ignition/injection timing, fuel quantity delivered (injector duration) and air mass.
For full throttle, max power, high revs, you are obviously using more fuel, but this condition is not where anyone really cares about fuel consumption, as you expect to use a lot when you floor it.

Originally Posted by TerryO

Standard nearly all vehicles run very rich, it helps them pass noise tests and puts less stress on the engine when a heavy right foot is used.

They usually run rich at WOT for engine protection etc and run lean for their closed loop (partial throttle) for anti-pollution control.... unless it's a VW Diesel, then it runs on 1 cylinder to pass the tests