Compound turbocharging: Tell me how it works?

[boomerkk]

Was idly browsing and saw this:

http://www.boostlogic.com/xcart/product.php?produc...

I know the Mkiv supra used sequential turbocharging, which from my simple understanding is when 1 turbo spins first and the other spins a bit later.

Usually twin turbo cars have turbos that spin together.

Can someone explain to me how compound turbos work?

What about the Veyron, how does the 4 turbos work? Are they all the same size and spin together?

[boomerkk]

Thanks!

But this compound system looks like a different kettle of fish?

[boomerkk]

Trommel said:

Compound turbocharging is not at all the same thing as sequential turbocharging.

In compound turbocharging, one turbo blows into the intake of another turbo.

Thanks! That helps a bit. What are the benefits and drawbacks?

[boomerkk]

Thanks. Seems like the best thing since sliced bread.

The supra boys stateside have got their knickers in a spin about it

http://www.supraforums.com/forum/showthread.php?t=...

Impressive results tho:

Torque (ftlbs)
compound....Normal setup
310..............195 (3000rpm)
400..............225 (3500rpm)
520..............275 (4000rpm)
550..............400 (4500rpm)
560..............550 (5000rpm)


Horsepower
compound....Normal setup
170..............120 (3000rpm)
260..............150 (3500rpm)
390..............210 (4000rpm)
480..............340 (4500rpm)
540..............530 (5000rpm)

[boomerkk]

Gazboy, u mentioned some people use a gt28 to replace the stock set-up but still run sequentially (one of the special characteristics of the Supra I reckon)...

Is this the cutting edge:
https://www.speedforsale.com/supraparts/speed-sale...

Looks very well developed, and value for money too.

[boomerkk]

Gazboy said:

I was interested in the Speed4Sale set up when I heard someone was experimenting with the set up with GT2510s (similar size) and emailed TDI to quote an estimate for them, the fuel hardware and engine management to run it but they never returned my email, as it was unproven I didn't chase them and last year started thinking about running Disco Potatoes in parallel with custom fabricated 3>1 x2 manifolds & 2>1 boost pipes into a SMIC but ended up selling the car before starting this project. Three guys in the states are going through with it though.

Why Gt25s? Do you expect the 28s to be too laggy?