20psi at 2800 rpm's. 800rwhp. Compound turbos!

[tekdeus]

2JZ Twin Turbo Kit from Boost Logic

This might stir up some discussion. Wowzers!:aigo:
http://www.supraforums.com/forum/showthread.php?t=527336

 

[bountykilla0118]

that is gross!!!!!!!

 

[Piratetip]

Very nice indeed.

 

[dumbo]

Beautiful Work:love::love::love:

 

[adampecush]

pretty effective use of the fundamentals of gas compression. Lots of boost with a relatively low compressor speed. This has been done on diesels in the past with excellent results.

 

[Sawbladz]

Very badass! I love it when guys push the boundaries.

 

[arizzle]

thats soo sexy! i wanna see videos!

 

[got_boosted]

thats soo sexy! i wanna see videos!

+ 1

 

[figgie]

Thermodynamics and physics are infallible.

wonder when this thing reach critical velocity fo rthe first turbo.........

dyno graph looks good BUT how come they only posted to 5k RPM??

 

[92nsx]

Maybe it fell flat on it's face at 6K RPM :biglaugh:

 

[adampecush]

wonder when this thing reach critical velocity fo rthe first turbo.........

woudln't a properly sized wastegate take care of that?

 

[figgie]

well if they are not bypassing the samll turbo... correct.

Though from the picture they posted of the exhaust routing and the size, they should be able to bypass the small turbo at higher engine flow (measured as pressure). The problem with wastegates such as tial etc. They do not really need to open much at all to control the turbo. So that might be a stick point UNLESS they use a small pressure spring inside the wastegate to get a bigger opening.

So if the waste gate is say 20 psi. the smaller turbo can spin up to that and which at that point the gate starts to open. The thing is that my thermodynamics is saying that you will lose some energy in the process thereby making the big turbo even laggier, even with the pressure ratio being better.....

 

[adampecush]

So if the waste gate is say 20 psi. the smaller turbo can spin up to that and which at that point the gate starts to open. The thing is that my thermodynamics is saying that you will lose some energy in the process thereby making the big turbo even laggier, even with the pressure ratio being better.....

It will certainly be laggier...but your manifold pressure is still +20 psi irrespective of what the large turbo is doing. I'm sure it takes some tinkering with the sizing to avoid a dip in the boost vs rpm chart from this lag though.

 

[mdr40z]

sweet, I want one

 

[tekdeus]

It's interesting how all the exhaust is forced into the small turbo first, spooling it up very fast; but at the same time, the exhaust from the small turbo is spooling the big one, AND it is pulling air in through the large turbo, spooling it form both sides(maybe that would overcome the potential extra lag, Figgie?). Then on top of that, the small turbo is further compressing the already compressed air from the big turbo, hence compounding pressure. These guys have been R&D'ing it for a while, and I assume will have most trial and error issues out of the way soon.

That test was on a stock NA 2JZGE but with cams. 310 Torque at 3000 rpm, 520 tq at 4000. Imagine a stroker 3.4L TT 2J... Incredible!

 

[Frankenstien]

Insane.... I want one :evil2:

 

[figgie]

It will certainly be laggier...but your manifold pressure is still +20 psi irrespective of what the large turbo is doing. I'm sure it takes some tinkering with the sizing to avoid a dip in the boost vs rpm chart from this lag though.

well keep in mind though.

To get 20 psi by 2800 rpm will require a smallish turbo. GT30r tops with probably a GT28r doing the low duties.

GT35r will not, under any circumstance, flow that much at that RPM on the 7M. Hell i doubt it would do that on the 2jz either.

 

[NokaoiMK3]

pretty effective use of the fundamentals of gas compression. Lots of boost with a relatively low compressor speed. This has been done on diesels in the past with excellent results.

Yeah it has... I have seen some caterpillar diesal engines with almost the exact twin turbo set up... With one turbo feeding the other... Its a dam good idea... LIKE TO SEE VID!!:naughty:

 

[Breth]

So do i understand the system right?:

The first (small) turbo will set on (only as example) 10psi, then the first wastegate (from the smal turbo) will open and regulate only the first turbo-pressure, but will still feed the second (bigger) turbo (because the first wastegate-outlet goes in the turbine from the second turbo) till that second wastegate open at 20psi. ...........
So then you have a quick spool from 0-10psi, because the smaller turbo will spool up quick to the 10psi, and then you got the big one for big power.

Is that right?

And for what is the pop-off valve?
PS: Sorry about my english, im from switzerland, hope you understand what i mean.

Regards

 

[figgie]

So do i understand the system right?:

The first (small) turbo will set on (only as example) 10psi, then the first wastegate (from the smal turbo) will open and regulate only the first turbo-pressure, but will still feed the second (bigger) turbo (because the first wastegate-outlet goes in the turbine from the second turbo) till that second wastegate open at 20psi. ...........
So then you have a quick spool from 0-10psi, because the smaller turbo will spool up quick to the 10psi, and then you got the big one for big power.

Is that right?

And for what is the pop-off valve?
PS: Sorry about my english, im from switzerland, hope you understand what i mean.

Regards

let me make it as simple as possible

think of it this way, imagine the stock ct26 in that system. Good spool down low, good to about 14 psi. Comes online pretty quick. That would be the first turbo.

We know that the ct26 will NOT make 20 psi on our 7m and that it really chokes when it starts getting nearing redline. So if we were to pair that turbo up with a GT40r. Then we get the sppool of the ct26 down low and cut over to the GT40r on the upper rpm scale. This cut over is controlled by the waste gate of the smaller turbo. This still REQUIRES proper turbo sizing otherwise you will have a gap or way to much overlap.