Turbo's ?

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MuvverRussia said:
Uhh, why?

With a handful of exceptions, turbochargers only normally tend to work once you hit a certain rpm (2500-3000rpmish for a petrol car), as they need to spin up. That's why you get turbo lag.
Not stictly what turbo lag is.

MuvverRussia said:
I can't think of any time you'd want to have a switched turbocharger.
Winter.
 
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Pfft!! Turbos kicking in at 1800rpm for the win!

* if only it wasnt all over by 3800rpm!

meh!

Switchable uber power devices you could look at are N O S!

OMG N O S kicked in YO!
 
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you could make it bleed all the boost away if you really wanted to, then again the engine since its mapped for boost will be sluggish.

I can redline without boosting :p (although its painful)
 
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then again the engine since its mapped for boost will be sluggish.

Whilst this would be true for a standard vehicle, there are many ECUs out there now that can support multiple maps - so you could run a boosted one and a 'plain' one and just switch between the two when necessary :)
 
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agreed, the engine is set up to run with a turbo and if you're worried about mpg then get something less powerful.

Its like (I know its possible cause i've driven a chevy impala) getting a V6 and wanting to turn off half the cylinders.
 
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MuvverRussia said:
Uhh, why?

With a handful of exceptions, turbochargers only normally tend to work once you hit a certain rpm (2500-3000rpmish for a petrol car), as they need to spin up. That's why you get turbo lag.

I can't think of any time you'd want to have a switched turbocharger. If you want to drive economically, then just use less throttle.

It's easily done if you have the right software - an electronic boost controller (Audi TTs come with an easiily usable one...) mapped to a throttle position sensor and you can set it to 100% boost at full throttle, 50% at 75% throttle and zero at half throttle (with all interim measurements appropriately mapped)...Turns the engine into one which basically acts like a n/a lump...

paradigm said:
A switched supercharger would be far FAR easier to implement.

Oh dear god, no. This isn't Mad Max - clutch-controlled blowers are a pain in the Harris and eat components.

*n
 
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You can't turn off boost with an electronic controller. you will always run a minimum of actuator boost determined by the actuator spring.

VW N75 valves as fitted to the TT are fancy bleed valves
 
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Will Gill said:
disconnecting the actuator will disable the turbo, probably a complicated way to automate that with some funky stuff, but it would drive like a big lump of poo.
i don't know why, but i really wanted you to have factored into the above post somewhere the words "flux capacitor".

i'm having a bit of a "day"...sorry :D
 
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Hate said:
Its like (I know its possible cause i've driven a chevy impala) getting a V6 and wanting to turn off half the cylinders.
i drove a caddy a while back and i'm sure when cruising along the engine switches off 3 or 4 of the cylinders.

for the more technically minded (simon, johnnycoupe etc) i have a question.
in cases like this, is it always the same cylinders that are switched off or is the order rotated around all of them?
the reason i ask is, if it's always the same pots that are deactivated then doesn't it put a lot of unbalanced and undue stress on the crank?
 
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The_Dark_Side said:
i drove a caddy a while back and i'm sure when cruising along the engine switches off 3 or 4 of the cylinders.

for the more technically minded (simon, johnnycoupe etc) i have a question.
in cases like this, is it always the same cylinders that are switched off or is the order rotated around all of them?
the reason i ask is, if it's always the same pots that are deactivated then doesn't it put a lot of unbalanced and undue stress on the crank?

caddies have individually fed pistons, I remember reading that when they invented some made caddy powered armoured car, meant that even if 5 out of the 6 cylinders were knackered the car would still happily move - well it might not be happy but it wouldnt stop in a cloud of smoke.

(p.s. I tried to insert flux capicator here but thought I'd take you unawares at a later date :p)
 
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