Merlin vs. DB 601/603/605: Superchargers & engine performance

[gjs238]

I've read of Stanley Hooker's great improvements to the Merlin supercharger, and the subsequent excellent high altitude performance of that engine.

How did the DB series of engines performance compare, at high and low altitudes?
Did the DB engines have 2-stage superchargers, or were they just more efficient and/or larger single-stage units?
Were the DB superchargers inferior, but compensated by other factors such as engine design?
Basically, how did the DB engines compare at high altitude, and if they performed as well as or better than the Merlin, how did they achieve that?

[Aurum]

Originally Posted by gjs238

Did the DB engines have 2-stage superchargers, or were they just more efficient and/or larger single-stage units?
Were the DB superchargers inferior, but compensated by other factors such as engine design?

It was discused here for several times. Look in previous topics.

Originally Posted by gjs238

I've read of Stanley Hooker's great improvements to the Merlin supercharger, and the subsequent excellent high altitude performance of that engine.

Did Merlin have hydraulic transmission of supercharger like DB & JuMo engeens?

[jerryw]

From a top secret WW2 file.

[hrandy]

I have read many many books on the Merlin with never a hint of a fluid drive for the Merlin. Jerry assuming you are the author of the AEHS Torque Meter article on "Early intercooled Merlins" you have again shown an incredible talent for finding obscure but facsinating history. Tell us more about the hydraulic drive Merlin. The side entry supercharger makes me think it predates Hookers' work.