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twin turbo


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TT on an L-series is worthless for anything other then a novelty.

 

So getting quicker respons is worthless!?

 

I´ve gone from one turbo to twin on my L28, and though the respons was rather quick on my "single" installation, the twins where noticebly quicker!

The best way to feed a turbo (on a 4-stroke engine) is with the exhaust from 3 cylinders with evenly spread ignition sequence (that is 240 degrees apart).

You can achive that with (on a 6-cylinder) twin turbos or with one turbo with twin entries.

 

Here´s some pics of my twinturbo-arrangement:

http://speedfreak.nu/forums/gallery2.php?g2_itemId=38685

http://speedfreak.nu/forums/gallery2.php?g2_itemId=38678

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"Quicker Response" as opposed to what? A misapplied single?

 

There is no reason twins are more responsive that a properly sized single.

 

The largest reason for twins in the past was compressor flow. To get comparable flow and lower spool, you had to have two smaller compressors with relatively large compressor sections. With the advances in wheel design, and materials advancements twins really are superflous. They have to be very well applied, and even then it's likely a wash when you consider potential failure points compared with a proper single.

 

Really 'quicker response' is a theoretical argument, and then only really proven by using turbocharger tachometers, and sophisticated instrumentation... practical application will show there is no real discernable difference with the current generation of turbochargers. It really is more for novelty these days than any practical application argument.

 

If a single can give me 17psi boost at 1700 rpms and 21psi by 2000, pull hard to a power peak at 5800rpms (around 350HP) you will be hard pressed to give me a practical example of twins beating that power under the curve. And that was old tech, without a hybrid compressor section. Were I to make that same build today, and actually port the head and use a cam the power point would be even higher. I have learned a lot since I built that one in 1986... using 1983 OEM technology. Today's turbo technology would improve on that response by a considerable margin.

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"Quicker Response" as opposed to what? A misapplied single?

 

There is no reason twins are more responsive that a properly sized single.

 

The largest reason for twins in the past was compressor flow. To get comparable flow and lower spool, you had to have two smaller compressors with relatively large compressor sections. With the advances in wheel design, and materials advancements twins really are superflous. They have to be very well applied, and even then it's likely a wash when you consider potential failure points compared with a proper single.

 

Really 'quicker response' is a theoretical argument, and then only really proven by using turbocharger tachometers, and sophisticated instrumentation... practical application will show there is no real discernable difference with the current generation of turbochargers. It really is more for novelty these days than any practical application argument.

 

If a single can give me 17psi boost at 1700 rpms and 21psi by 2000, pull hard to a power peak at 5800rpms (around 350HP) you will be hard pressed to give me a practical example of twins beating that power under the curve. And that was old tech, without a hybrid compressor section. Were I to make that same build today, and actually port the head and use a cam the power point would be even higher. I have learned a lot since I built that one in 1986... using 1983 OEM technology. Today's turbo technology would improve on that response by a considerable margin.

 

Curses. TonyD again with the quick right answer.

 

Quick Q, I've always understood it that, relative to the size of compressors used in the engines at hand (I have no idea how this would relate to industrial size compressors or the larger industrial turbos) that a larger turbo is usually more efficient than a smaller turbo. I've also been of the belief that the idea that smaller twins are better than singles is falty as even though it takes less energy to get a turbo spooled if it's smaller, it's also only receiving half the energy of a single larger turbo and that even though the pieces/parts are lighter the total sum of rotating mass between the two smaller turbos is actually not all that different from the one larger turbo, perhaps even higher. Is there any validity to this?

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I have gone for twin turbo set up simply for the nostalgic point of view and for the wow factor, and it was a little more challenging then fitting a single turbo. I know it may not be the most efficient but I like it.

 

thats why I was thinking of doing it, and still might?

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