Just curious. I have my opinions, but want to hear yours. What is the reasoning?


David

 

my GUESS is single/twin doesn't matter. reasoning, eventually it's just compressed air going in, don't matter how it gets compressed.

 

The one that puts out less efficient boost or more heat under the hood.

 

exactly

 

i would *say* that these^ opinions are spot on. i would also dare to say, from seeing things like this, that a set of overworked twind would be more debitrimental to an engine, where a single COULD be, but operates in a more efficient area, and has more of a range of efficiency and would theoretically [if properly tuned] be more encouraging of longer life...

 

I just thought the twins cause too much heat. heat is the worst enemy to an engine.

 

Stock twins are hot and too cramped, i would much rather have a single.


It is less complicated and retains less heat in the engine bay.. And the stock twins efficancy isn't that great above stock..


-Zach

 

everything being equal, i say it doesn't matter. of course if the twins run hotter than the single the single is better, and vice versa. so the question should be which is more efficient/cooler, single or twin

 

oh, and it probably should be claried, stock twins vs aftermarket single or aftermarket twins vs aftermarket single.

 

ZB,

heat is what i am referring to in the overworked twins department...

louis

 

Your right foot.

 

what about two big singles, haven't people done that before?

 

yes people have done that. but its pointless unless its a drag car.

 

i've got another question on turbo's, why are the stock ones on the bottom of the engine bay, and when people upgrade or modify they put them at the top? is it just cuz its easier?

 

Just thought I'd bring up a point here. Don't know if anyone considered this, by introducing more air (single turbo) and fuel, one tend to create a larger, more powerful combustion. All things being equal (ie compression, rotor configuration, housing construction etc.), a bigger explosion will cause more stress on the engine, unless some one is going to tell me that the physical laws do not apply to rototry engines.

 

you could potentially just turn down the boost on a single to make it match the twins' max output. Then the turbine is running at a higher efficency and a lower boost than designed maximums; I.E. the turbo will not get as hot at the same boost level and the engine stress will be reduced concurrently... but then why the single turbo.. seems like an expensive way to reduce heat.

 

WRONG, people don't do it because it is more expensive..

In other countrys people do it all the time. And with success...


Stop making **** up.

 

Dude, you don't know what you're talking about. Slowly back away from the definitive statements.

 

um, no..


2 turbos are not worthless, and are not only done on drag cars..


The reason people do not do it is because of cost..


-Zach

 

Oh lord. The original question is, "what about two big singles, hasn't anyone done that before?" The issue is not cost, the original reply is correct. A turbo (or turbos) need to be sized correctly for the engine, too small of a turbo and it will be out of it's efficiency range and possibly overspin, too large of a turbo and the engine will not be able to spool it quickly (or possibly at all), hence the statement that two BIG turbos would only work well in a drag application. But what do I know? I'm only a mechanical engineer that performs analysis on turbomachinery for a living.

 

Well, since he didn't clarify what BIG ment , then who's to say?


But why would you size turbos to small or to big? When someone say's to big sized turbos, i would think they mean one of the singles that are discussed on the forum.

So yes two T78 turbos would be too big.. and would not even work on a drag car with out nitrous.


But two S5 turbos run as twins can yeild like ~500RWHP.. but would still not be a very good match because their A/Rs are to big.. Something around .54 would probably be good.

There is also a TD07 and an Apexi twin kit, that would be considered big, but is not considered a drag turbo kit.

So, we will call this a misunderstanding since no one classified what BIG means.

But a twin setup with two single turbos is not worthless, but costs are prohibitive.


-Zach

 

Of course, with two appropriately sized turbos it would work quite well. It clearly is only a misunderstanding. I think that both myself and the person who originally answered the question saw the words "big single turbos" and assumed that the person was just inexperienced and thinking that "more is better", hence my views.

 

It's all good..


JoeD is know for posting stuff like that though.. I should have read more carefully though..


-Zach

 

yes, i'm inexperienced, i'm 16 and this is my first car, thats why i ask questions...
i'm not a mechanical engineer and i've never built engines, but i want to learn and i'm very interested in this stuff. I didn't assume that bigger was better, however, I remember seeing a pic of some guy who had put two singles on his engine and I was wondering what was wrong with that and why I had not seen it since.