Question: Compound turbo pressure ratios?

[BHoward6.6]

What is the ideal compound turbo pressure ratios?
Lets say I have a 483 and a 4094avnt with a total boost of 50psi, and 25psi from the 483.
At sea level that gives a overall P/R of 4.4,
Primary P/R of 2.7
Secondary P/R of 1.6
For daily driving, towing and racing, is there a perfect P/R the two turbo's?
I would think the closer the P/R's are the better.

 

[CurtisEmery]

There is no perfect ratio unfortunately. For that to happen you would have to run the the engine at a constant rpm like a gen set. From what I have seen it is better to let the primary run at a higher pr and keep the secondary at a lower pr were it is more efficient. Thats were charger sizing and gate tuning really come into play.

 

[BHoward6.6]

Ok, that makes sense.
So would there be a ideal % lower for the secondary than the primary?
With a primary P/R of 2.7 and the secondary P/R 1.6, that's about 41% lower.
If the P/R were closer would that even out the work between them?
This stuff is all black magic and voodoo to me.

 

[SickLL7Crenshaw]

What is the ideal compound turbo pressure ratios?
Lets say I have a 483 and a 4094avnt with a total boost of 50psi, and 25psi from the 483.
At sea level that gives a overall P/R of 4.4,
Primary P/R of 2.7
Secondary P/R of 1.6
For daily driving, towing and racing, is there a perfect P/R the two turbo's?
I would think the closer the P/R's are the better.

Idaho Rob used this in another thread awhile back.

(atmospheric pressure) + (overall boost) divided by (atmospheric pressure) = overall P/R
(atmospheric pressure) + (primary boost) divided by (atmospheric pressure) = primary P/R
(Overall P/R) divided by (Primary P/R) = Secondary P/R
(Secondary P/R x (atmospheric pressure) minus (atmospheric pressure) = Secondary Boost

 

[BHoward6.6]

Idaho Rob used this in another thread awhile back.

(atmospheric pressure) + (overall boost) divided by (atmospheric pressure) = overall P/R
(atmospheric pressure) + (primary boost) divided by (atmospheric pressure) = primary P/R
(Overall P/R) divided by (Primary P/R) = Secondary P/R
(Secondary P/R x (atmospheric pressure) minus (atmospheric pressure) = Secondary Boost

Thanks Blake.
I know how to calculate turbo pressure ratio's, I'm trying to find out if there is a ideal relationship between the two turbos and if so what it would be.

 

[chevyburnout1]

Do you have access to your turbo maps? I based my pressure ratios off where it would put my chargers in the closest efficiency range. I biased it more so to the daily driving portion though.

 

[BHoward6.6]

Do you have access to your turbo maps? I based my pressure ratios off where it would put my chargers in the closest efficiency range. I biased it more so to the daily driving portion though.

I do have the GT4094VA map, but when I e-mailed Bullseye Power about a map this is the reply~
"We did not create any MAPS we use engine dyno, wheel dyno and gas stand test equipment for results.

Regards,

Bill Devine
Sales/Marketing Manager
Bullseye Power LLC"