Turbo cut in?

[POPEYE]

Johnsiddle turbo prob made me think! and not sure how to pharse it but is there a particular reason the turbo cuts in at about 2000+rpm? is the cut in time adjustable? has anyone done it? mine crawls up the road but when it reaches around 2000 odd rpm the turbo comes on and theres a marked increase in power, i've often wondered why it dose'nt come on earlier (cold engine) when it seems to need the extra boost, cheers

[RodLeach]

Johnsiddle turbo prob made me think! and not sure how to pharse it but is there a particular reason the turbo cuts in at about 2000+rpm? is the cut in time adjustable? has anyone done it? mine crawls up the road but when it reaches around 2000 odd rpm the turbo comes on and theres a marked increase in power, i've often wondered why it dose'nt come on earlier (cold engine) when it seems to need the extra boost, cheers

It's basically down to compression mate.

The exhaust gases need to be pumped out at whatever pressure in order to spin the turbo over enough to make a positive induction.

The turbo is always spinning but it needs those gases to get it to really spin up... i would guess that at around 2000rpm there is enough exhaust gas to get the turbo going.

[gwh200]

mine comes on acroos the rev range from 1000 to 2000 rpm. it comes on at 1000 rpm when im trundling along at 40 mph

[POPEYE]

Right!! cheers Rod, pity it's not possible to get it going manually when it's cold,
oh well just a thought

[POPEYE]

mine comes on acroos the rev range from 1000 to 2000 rpm. it comes on at 1000 rpm when im trundling along at 40 mph

Yeah mine does that to, when it's got going, it's just that first trundel up our road when cold that it takes 200 + revs for it to come on, fine when its off and rolling

[gwh200]

even when cold it comes on about 1500 rpm ian.......i just reckon they are all a bit different.

[Sancho]

I guess the more worn the turbo, the more it'll take to get it going?

If you want it to work across the revs, you're going to need a supercharger.

[shirlster]

I guess the more worn the turbo, the more it'll take to get it going?

If you want it to work across the revs, you're going to need a supercharger.

or bolt a smaller turbo on to feed the bigger turbo.

[POPEYE]

or bolt a smaller turbo on to feed the bigger turbo.

Aye! thats a plan or a very powerfull electric fan, suppose sticking the hair dryer up it wont do the trick?
anyway speaking as a rate payer and a thicko, is the turbo powered? it cant just rely on exhaust can it? how's it powered?

and congratulations on your reuniteion (getting back together) with stienhauser

[RodLeach]

is the turbo powered? it cant just rely on exhaust can it? how's it powered?

It's just off the exhaust mate.

Its like a small fan attached to another small fan an when the exhaust gases make one spin like feck the other one pulls/blows/sucks (whatever one...) the air into the engine.

A supercharger works the same but rahter then exhaust gases its run off the engine so its always conducting a positive charge of air.

[shirlster]

Aye! thats a plan or a very powerfull electric fan, suppose sticking the hair dryer up it wont do the trick?
anyway speaking as a rate payer and a thicko, is the turbo powered? it cant just rely on exhaust can it? how's it powered?

and congratulations on your reuniteion (getting back together) with stienhauser

there is two sets of turbines in the turbo.one at each end of the shaft.the shaft floats on a film of oil under pressure from the engine.the exhaust turbine is spun up using the exhaust gases.this in turns spools up the other turbine blade on the intake side,so the faster the turbo turns the more air goes into the engine.in simple laymans terms

[POPEYE]

Right! that would account for it running (pulling) a little better since i fitted the 3" exhaust then, did'nt think it were much different at first but it's definatly better, starts better to, it's just the slow crawl at first thats annoying,

[gwh200]

Right! that would account for it running (pulling) a little better since i fitted the 3" exhaust then, did'nt think it were much different at first but it's definatly better, starts better to, it's just the slow crawl at first thats annoying,

i got that all the way up to its 60 mph cruising (ie flat out) speed ian !!

[shirlster]

Right! that would account for it running (pulling) a little better since i fitted the 3" exhaust then, did'nt think it were much different at first but it's definatly better, starts better to, it's just the slow crawl at first thats annoying,

yep basically as with any performance tuning the quicker you can get the fuel and air mixture in and exhaust gases out the better,more responsive your engine will be.