I'm thinking of building compound turbo system for my next engine update.
I have 2JZ-GE that will be updated with oil squirters, gte oilpump, h-profiles, homemade large plenum inlet ect.
My original plan was to use supercharger and turbo setup, but I have gotten a interested on compound turbo setup.
I allready have gathered information on the sizing of the turbos.
Most often people on different forums indicate that the correct sizing is High Pressure turbo compressor radius X 0.707 is the high pressure turbo radius.
Haven't found much information on how the size of the exhaushousing is calculated.
There is companies that sell the kits for cummins diesels. As an example I will take diesel power source kits.
they offer dps62 (62in/65out/12cm) or hx35 sized turbos for the high pressure turbo. on their kits they have S475 (75in/96/1.32 ar) as the large turbo (low pressure)
I have allready BW S300g (59mm in/74mm out/ 1.0 T3 exhaushousing ar from s200), hx55 holset with 71mm billett compersor and 77mm turbine in 22cm exhaushousing.
Boost control I planned on using greddy 50mm style gates, from biltema... I know this can prove to be a large mistake, but my friend has had loads of good to experience with them past decade. You wouldn't easily belive but he has one of the fastest roadcars here.
To prevent getting high exhaustpressures, I'm planning to plum the hotside this way.
EXAMPLE 1
With this way there is less exhaustflow that will bybass the high pressure turbo, that has to go true the gate that is named "v60".
If you compare the example 1 setup to example setup, there all of the exhaustflow has to go througth the HP turbo exhaushousing and wg.
EXAMPLE 2
Cold side is going to be coupled without the check valve directly from LP turbo to HP turbo...
Does anyone have experience how fast the small s300 or hx40 with small exhausthousing will spool on the 2JZ?
Or the hx55?
I was wondering allso if the is the HP turbo still too big for this kind application? Would It be better to go hx35 or hx30?
