4x4

on twin turbo cars do the turbos come on boost at the same time or small one first and then big one takes over?

reason i got wondering was because i was thinking of the buggati eb110 and veyron which have 4 turbos so anyone know how those work aswel

joshF

littile one first then big one takes over.

dunno bout how 4 work lol

Porkie

iTrader: (1)

Not true. Depends on car. Skylines for example both work exactly the same time. Porsche 959 has sequential Turbos though...

4x4

would that be the same with diesel bmw twin turbo like 535D?

cjwood555

I was under the impression that the 535 uses the first turbo to power the second? I.e inlet turbo 1 -> compressor outlet 1 -> inlet turbo 2 -> compressor outlet 2 -> intake

Chris

4x4

what would be a better system?

joshF

what i thought is the smaller turbo comes on boost lower down the revs then the big one takes over at higher rpm

i could be wrong?

4x4

i think that is one way twins T's work but from what PORKIE said, on some cars the turbos come on together

jammy86

There are different types of setups.

seqential where they are all the same size and just get fed to the num of cyl/num of turbo's.

compound, where one feeds the other then they all feed the intake.

and there might even be a few setups out there where the small one takes off early, then it gets bypassed when the big one is up and running. If this setup is about i'd imagine its for some truck engine.

JAmes.

4x4

so on skylines where both turbos come on together is it a matter of turbo running 3cyls each

4x4

found this if it got anyone thinking.

http://en.wikipedia.org/wiki/Twin-turbo

zippyobrien

iTrader: (2)

each turbo on a skyline is fed by 3 cylinders, then the charged ar is feed into the intercooler, so both turbos feed the same inter cooler (like a noble) then they go to the plenumn

Fil

both mine work exactly the same both @ 10psi so a grand total of 10psi

messcortmk6

it depends, on a car where there is a bigger and smaller one they work at different RPM. if theyre the same size they come on together.

for example on the toyota supra the small turbo kicks in for low end boost then when the turbo is at its peak meaning its boost is no longer increasing the second one will be kicking in to a high RPM.

therefore with the big/small set up you have a very large boost range and lots of power.

PeterD

so why do folk change the supra to single turbo then

genuine question by the way

Stavros

woweee, some right old bullshit being said here

right, you got twin turbos that spool at same time, like Skyline, BMW335 (i think???) etc etc.
TBH theres not a huge amount of reason for this on a non-v engine these days, a well specced split pulse manifold and turbo would be just as good.
Pretty sure thats why the XR6turbo uses a GT40 rather than twins.

then you got sequential twins that are identical size but dont get the flow to both till high revs, like RX7s and Supras.

then you got twins where there is 1 big and 1 small, sometimes 2nd activated by a valve, sometimes not, think Legacy Twin turbos and BMW diesel twin turbos (i think???) are different sizes, dunno the exact setup the aformentioned cars use tho.

finally you got compound charging, turbos blowing in to turbos, like dumped saff and loads of mega boost diesel engines, these have different ssized turbos too.

reason people change to singles is the reality is a well designed single setup is hardly any less responsive (in modded car terms), a lot simpler, and a lot easy to get how you want it.

getting big power from the stock supra or RX7 setup is nigh on impossible, would need a complete re-design as the stock parts cant do mega power, so its massivley simpler to go to a single, lots of gains and very little losses.

messcortmk6

they change it to a single massive one because they can get a fuck load more power out of them.
im not to sure but i thong the twin turbo ones are the better ones to make into a single massive conversion.

dojj

iTrader: (3)

my only experience is from the tt twin turbo'd sierra and they were one turbo per pank, fed through each bank, sent through an intercooler which was mixed, then seperated into each bank again to go in

this way even if one was a blowing slightly less than the other you would still have equal pressure across both banks