its possible, but its stupid...on a 4 cylinder car, its much more efficient to run one big turbo than 2 small ones.

 

Im not a turbo guy, but im goin guess a twin turbo focus would be kinda pointless, a single turbo would be much more efficient. Im sure all the turbo guys will be on here soon explaining it alot better.

 

turbos work off the exhaust gas, and the time it takes for them to get into boost is related to the speed and heat of the exhaust gas pushed through them. two cylinders will take a significant time to spool up a relatively small turbo, and two of them would probably still not equal the flow in cfm as a single larger turbo with the same spool time.

it also would be considerably more costly, with all the additional plumbing required, plus the 2nd turbo, and in an engine bay where space is an issue, would be very difficult to route

 

well u could always use a relatively smaller turbo to spool up a bigger turbo ;p lots of $ for that setup tho i would imagine and i can only imagine the tuning required

 

like fat pat said, a true twin turbo setup would consist of two cylinders feeding one turbo and the other two cylinders feeding the second turbo. both turbos are the same trim levels, hence the term twin turbo. afaik, noone has ever attempted this on a focus and its a good bet noone ever will.

a second option is a dual sequential turbo setup. in this case, all 4 cylinders feed one small turbo to produce very low boost thresholds. after the engine is up in the revs, exchanging alot more gas, a second, larger turbo is activated in order to make the big boost numbers up top that the small turbo would be thermally ineffecient at.

f2 has built a car on this principle but there seems to be some doubt as to whether theyve gotten it to actually work. it would seem to me that if they had the first true, robust sequential turbo setup on a focus that theyd be rushing to the presses to get the word out. however, so far there havent been any dynos or video of the car getting flogged around a track. theres a difference between having the car idle or run at part throttle, and actually perform at its peak.

 

^^^ agreed the sequentail setup that F2 has produced is good thinking, but if it never works than it makes no difference. A sequential setup allows 100% of the exhaust gas to go to a smaller turbo at low rpms, then at blank rpms there is a valve that opens and allows the exhaust gas to flow to the larger turbo for the big end power. The compressed air from the turbos both go to the intake, not eachother. If you look closely at this pic of F2's setup, you can see that it is deff. a true sequential setup. Now the question is does it run?

 

That is a crazy set-up.

 

Can you say $$$$$$$$$$$$$$$$$$$$$$$$$$

 

That looks crazy

 

twin is not that bad of an idea. the big turbo takes more time to spool than the smaller two and still make aroud the same power as the big

 

forgot. yes it is possible.

 

can someone say shoe-horn?

 

thanx i just herd a rumor i was tryin to clear

 

bling bling too much money for any power u could possibly make!!

 

so we have aftermarket companies that dump that much money into a twin turbo setup . . . but nobody will develop an AWD kit for the focus? =/

disappointing.

 

well frankly its not about big power. if they just wanted big power theyd use the single huge turbo and let it take forever to spool up. the sequential is an attempt to provide a more refined powerband; so youre not running out of breath on just a small turbo, or sitting there waiting for a big single one to spool up.

 

Sequential would be good for a wider power band.
But when I saw this thread I was thinking of my neighbors Peterbuilt with Twin Turbos.
Exhaust feeds into #1 then #2 then out. Charge starts IIRC in #2 feeds into #1 then IC.
I may be wrong on on the plumbing but I know it runs both turbos at once.
And it makes crazy boost at low RPM! Like 35psi at 700 RPM.
This is on an engine with bucket sized pistons though.

 

Does anyone remember the turbo-sc setup? guy had a Focus with a turbo and sc both on the engine (looked badazzzz!). I think he was having major tuning issues with it, saw it like maybe a year or 2 ago.

 

I saw that Focus in the current Modified Magazine last night. It's a 2.3 Duratec engine in a Sedan. It has a complete F2 RS widebody kit. Looks pretty sweet in my opinion.

 

with the twincharge setup, he actually got it to work but then spun the bearing on the sc and scrapped the project. as far as the modified mag feature on the f2 car, thats just the sticking point for alot of us. alot of the cars that show up in those rags are major trailer queens. yea, the quality of that build is really nice, all that shiny steel, and that makes for great pictures in a magazine, or a piece of art to stand and admire. but lets see some art in motion. im more interested in whether it can actually realize the theories on which it was built then whether funkmaster flex came by their booth at sema cause it looked cool. maybe thats why im more of a grassroots motorsports guy then a max power guy

 

Has anyone ever seen a twin turbo svt is this even posible herd rumors

I have seen some 4 cyl cars use a sequential turbo setup, and some that do use twin turbos.

From my understanding, using a twin turbo setup can be effective when the need to manage bank pressures in pairs comes to call. I am by no means a tuner, but I would imagine that is huge headache to tune for especially in a MAF equipped vehicle. Maybe Tom could chime in on this thread his opinion would be good insight.

It is generally not a "street" setup but is in fact possible and has somewhat widespread usage in various motorsports. A setup like this on an SVT motor would be both impressive and VERY expensive.

-Technyne

 

Re: Re: Twin turbo

From my understanding, using a twin turbo setup can be effective when the need to manage bank pressures in pairs comes to call.

exactly. contrast a vg30dett with its separate intake manifolds, one for each bank of 3 cylinders and corresponding turbo, to a straight 6 2jzgte with sequential turbos, to, say, a standard ford small block v8 with a common intake manifold, two 4 banks in v configuration