Twin Turbo Setup

[illusiVe]

just wondering, i could be wrong

why are twin turbo systems generally split with 3 cyl to each, rather than 6 going through 1 turbo 1st, then that gas going into the second turbo?

i mean in my book its doable...

and would mean u could run bigger turbos with half the ammount of lag, or half the lag of existing turbos..

Air comes out of all 6 cyl, enters turbo 1, turning compressor 1, exits turbo 1, enters turbo 2, turning compressor 2, exits into exhaust.

oh wait i think i figured it out........waste gate.....

but couldnt u basically remove the 1st turbos waste gate and the second one's wastegate regulate the flow?

Edited September 1, 2006 by illusiVe

[Topaz]

I may be wrong but doesnt the twin turbo RX7 have all into one turbo then the other setup?!?!

I know you say generally and the setup on the RX7 I remember seeing could have been modified that way.

[Mr. Oizo]

worst. idea. ever.

[dan_the_man]

u should make it tonight. add a little cocktail umbrella in for a bit of spice

[Sydneykid]

but couldnt u basically remove the 1st turbos waste gate and the second one's wastegate regulate the flow?

Nope, all the exhaust gas has to go though the first turbo ie no wastegate control on that turbo.

Take a look at the stupid exhaust manifold and complex plumbing on atwin turbo 13B or JZ.

It simply isn't worth the hassle.

cheers

[Topaz]

....complex plumbing on atwin turbo 13B....

I thought so....

20B top, 13B bottom....

Heres a bay shot with a normal-ish setup.

[GTRgeoff]

It's done in big installations where they can use multiple stage turbos and multiple stage intercooling. The wastegate gas goes straight into the next turbo, but by the tim you need to start doing that you go with an axial flow design. Just not necessary on a car to achieve that level of efficiency.

[slo-a31]

toyota uses a similar setup on their 1and 2jz's dont they?

[Ronin 09]

didn't Greddy / TRUST do some twin turbo'ed and supercharged R32 back in the 90s? it was metallic blue.

I have a magazine kicking around somewhere - the exhaust side is a mess of spaghetti polished pipework and blue vac lines...

Anyone got more info on it?

[discopotato03]

From what I can tell staged turbos particularly on a petrol engine are complex to package especially in todays "shrink fit" engine bays . Most Diesels get it easier because many are said to be free floating ie no wastegates and that eliminates lots of dramas .

I don't know for certain but I believe Nissan tried hard to make an efficient compact setup for the GTR's but thats not to say its not very involved on the exhaust side of the engine . To be fair they got low innertia turbo rotating groups (ceramic turbine /aluminium compressor) and double the wastegate area of your typical single turbocharger integral wastegate . In pure race terms Fred would probably have prefered to use a larger single but Group A didn't allow for that . You gotta feel sorry for the V8 brigade , at least they could lament that it took two hairdriers to beat the "iconic" bent 8 . I think the legacy of being beaten by one would have been terminal ...

Production turbochargers have come a long way since 1988 and many of the benefits (and this is my opinion only) of twins are just not there anymore . Toyota is a good example of staged twins (I think ?) and later a larger single on the 1J / 2JZGTE . Their marketing arm may not have been able to stensil TT on the side of some Supras but arguably a bit more capacity (3L) and one adequate turbo made the 2J a good road engine (as opposed to a homologation special engine) .

My vote goes to singles and todays production cars seem to be this way . There are a few examples of twins as in one per bank on a V6 or V8 ie TT VG30 and Audi's RS6 and for packaging reasons its way to go .

Cheers A .