Triple carbs and triple turbos?

[Anonymous]

I was installing my fathers old tri-carb head on my brother's '81 Fairmont coupe and we (brother and I) were talking about my plans to turbo my Mustang. He brought up a hypothetical question that I have thought about for awhile: "Could we put three turbos on this?"

Any suggestions on how to do this? Hypothetically of course!

 

[jwhoss76]

Well, in theory I suppose you could fab up some custom exhaust and a scratch built intake. You'll probably do alot of trial and error before it works right. I actually was thinking about it myself but I decided that if doable it would be very costly. And it would take quite some time to accomplish. This is not acceptable for me as this is my daily driver. I'd love to see one done though. It would spool up a heck of alot faster than one big turbo.

 

[MustangSix]

While it would certainly be impressive looking, it flies in the face of the engineering priciple of "add Simplicity".

 

[XFlow_Fairlane]

wrong a single big turbo would spool faster. the three turbos would have more rotating mass for the same given exhaust energy. also smaller turbos have a more narrow efficency range. I was thinking of going the tripower single turbo route maybe

nick

 

[rbohm]

8) two small turbos with wastegates or pop off valves would be better system than three.

 

[Hot 6t Falcon]

Check out this six. It was on the cover of Hot Rod in May 1960. I know it's not a turbo, but it would be the way to hook up one turbo to three carbs.

Good Luck

 

[Anonymous]

We knew it wouldn't be simple to do and not as satisfying performance wise, but he thought it would have a better "wow" factor when it hits the local shows. IMO I think it's got enough with just the tri-carb setup and the fact that it has a black interior with bucket seats.

Dennis, that setup is interesting. One thing I would change is the log design, probably make more of a header type design with modified valves that open the turbo flow to the outer carbs when they open up.

My brother wants to run nitrous to defeat lag and we think that just having it in the center carb would be enough or would running smaller nozzles on all three be better?

 

[jwhoss76]

Turbos lag that's all there is to it. The bigger the turbo the longer the lag time but when it hits watch out. My apologies to 62fairlane170 but one big turbo can't spool up as fast as two samller ones, the big turbo has too much rotational weight. One pound of rotating weight is equivalent to almost 500 pounds of dead weight when calculating for axle strength, so the same theory applies. the smaller turbos are lighter hence they spool up faster.
Real World Example: I know a couple of guys running the same 3 liter MRbitchy engine, one in a 3000GT with twin turbos, the other in an Eclipse with one huge turbo. Now the 3000GT will smoke the other guy in the 1/8 mile cause the little turbos spool faster, but in the longer runs the Eclipse will flat stomp the 3000GT. Once that monster of a turbo finally spools up that is. Import are fine as long as you build them for performance and not like rice. Keep the rice on your plate not on the street.

 

[CobraSix]

John is right,

One large turbo spools up slower then a small one.

A nice practice with twin turbos is to use a small and large one together. Sequential is nice. Reduces lag time but still gives you big boost.

Slade

 

[jwhoss76]

Big and little turbos?? Now you got me thinking Slade. and that's usually a bad thing. I spend alot of money just thinking.

 

[Anonymous]

How would you set up a sequential twin turbo system like Slade suggested?

I spend alot of money just thinking.

I've got the same problem.

 

[Anonymous]

I think that is what Toyota used on the late model Supra.

John

 

[StrangeRanger]

Idon't think he's talking about sequential turbos, rather 2 in parallel. One spools up a lot faster but stalls at fairly low engine RPM by which time the other one is on stream. It would take some careful balancing of boost curves/maps but it could work.

Don't know about the Supra but the last RX-7s used the sequential turbo strategy.

 

[sefus]

sequentials are a really neat idea, they are used on the cars that are commonly refered to as 'twin turbos' like the supras and 3kgts, the problem is that after a time the smaller one becomes a restriction to the larger. that is when you are making big power though. for our sixes the sequentials would work as well as they do on the mitsu's if you could ever get them tuned well enough to work with each other. keep it simple, we flow just enough air to spool one single, around the T-3 size. there's no point doing anything else inless youve got too much money and even more time.