When Does The Turbo Kick In ????

[jamesm182]

Get a remap if you're unhappy with acceleration. Should help dramatically!

[ben1191]

lenny im sure they miss you too lol......

EMISSIONS & FUEL ECONOMY Urban MPG: 42.1 mpg Extra Urban MPG: 65.6 mpg

Combined MPG: 54.2 mpg

Fuel Tank (Litres): 53 litres

Emissions - CO2 (g/km): 137 g/km

Tank Range (miles): 632 miles

these having a laugh.......

When i first got the car i drove it like i cared for it,and easily attained 60+ from mine.now i tend to go a bit quick (not excdeeing speed limits though) but i still get 45-50 from it around town

[ben1191]

All points taken guys thankx a lot, however will remain unhappy wit the take off acceleration, its very slow to pick up speed..lol especially wen moving off from traffic lights or the roundabout I can never try to sneak into a medium gap between two cars approaching from the right coz its just too slow i need a big gap..lol, thankx anyway for all your comments.

need to get the hang of the clutch by sounds of it,i found the focus to have a stupid bite point myself and dont like it much.

[south_bound]

Great explanation FOCA, although some of it above my head this time of the evening...I won't let the details worry me too much in the way I drive. Just one more question though - driving at a constant speed, say 2000 to 2500rpm in top gear on the motorway, I asume the turbo is spinning and helping reduce strain on the engine, allowing to burn a little less fuel to maintain speed? At slower speeds, say 45-50mph on an A road, would it be better to drop down a gear to keep the turbo operating?

[FOCA]

Great explanation FOCA, although some of it above my head this time of the evening...I won't let the details worry me too much in the way I drive. Just one more question though - driving at a constant speed, say 2000 to 2500rpm in top gear on the motorway, I asume the turbo is spinning and helping reduce strain on the engine, allowing to burn a little less fuel to maintain speed? At slower speeds, say 45-50mph on an A road, would it be better to drop down a gear to keep the turbo operating?

There is no definitive answer - it depends on throttle position, load, exact speed, if there is an uphill or downhill incline etc, and the way the ECU, engine, turbo is set up

At tickover, very low speeds/ loads on a trailing throttle, (decelerating, with your foot off the throttle) downhill(when not accelerating) and before the turbo spools up - the engine runs like it was a non-turbo/ naturally asperated engine

in these conditions the turbo is not doing very much

when you open the throttle/ accelerate hard enough, the exhaust gasses will energise the turbo, the boost control system(s) allow the compressor to spin up, producing useful amounts of boost

the transition between the turbo not boosting (like an NA/ non turbo engine) and the turbo booosting is the BOOST THRESHHOLD

To see when the turbo is producing boost you really need a boost gauge

At the revs/ speeds you mention the turbo is probably producing some boost, increasing engine power

The great thing about a turbo is it increases engine power by harnessing the heat and pressure from the exhaust that would otherwise be wasted, that is how it can improve performance and economy

A turbo can increase back-pressure, as seen by the engine, so higher lift/ longer duration exhaust cam profiles can be used, without producing a midrange flatspot, (so when engine/ turbo are more integrated/ the engine designed for a turbo, further improvements can be made) good designer(s) can also reduce the amount of exhaust silencing required, (reducing weight/ improving flow) as the turbine does a great job of reducing exhaust noise

With the engine being designed at the outset for a turbo it becomes better integrated, and works better and makes it more difficult for tuners to increase power or actually improve anything past the initial remap, especially with the advances manufactures have made - that is one of the reasons we are seeing traditional modifications (K&N filter, bigger intercooler, hybrid turbo, etc) reducing power

Anyway the best way to find out when the turbo "kicks in" (and see how much boost is produced) is to fit a boost gauge