I remember reading about ww2 airplanes having a transmissioned 2 spd supercharger for diffrent altitudes, im assuming that the same concept could be carried over to a regular car supercharger, one, a quick gear for high low end boost, and a second for high high end boost, computer controlled shift ofcourse, but i was just wonderin if theres such a thing out there? doesnt have to be for our cars, just in general.
2 spd Supercharger
- Thread starter MrWilson
- Start date
I'd say for a size:benefit relationship that it wouldn't be worth it. But for the WOW factor definately!
I did a quick search and came up with the Rolls Royce Merlin Aircraft engine...
Interesting setup but I stick with what I said above
I did a quick search and came up with the Rolls Royce Merlin Aircraft engine...
Interesting setup but I stick with what I said above
Stack said:I'd say for a size:benefit relationship that it wouldn't be worth it. But for the WOW factor definately!
I did a quick search and came up with the Rolls Royce Merlin Aircraft engine...
Interesting setup but I stick with what I said above
yeah, thats just what i was thinking of. id guess that since its not arround, it wouldnt be worth the effort, lol. Oh well, something to keep in mind once i get my engineering deg.
MichiganTeddyBear
Dedicated LVC Member
yea, sounds like a good idea.. but one thing to remember... those blowers making up 60lbs of boost in some cases.... a lot of them ww2 engines ran at 20-30lbs boost in cruise!
Another thing... the 2 speed and 2 STAGE blowers used, were meant for use where the air was thin... over 10k altitude... they really wouldn't do a hell of a lot of good down here in the thick air! Example.. P51's with 2 speed blowers (some of the merlin and its US built packard or allison equiv), had a lockout on them that prevented high blower until it was over a certain alt. 15k-20k alt is typically where it would switch to high blower... automatically!
Another thing... the 2 speed and 2 STAGE blowers used, were meant for use where the air was thin... over 10k altitude... they really wouldn't do a hell of a lot of good down here in the thick air! Example.. P51's with 2 speed blowers (some of the merlin and its US built packard or allison equiv), had a lockout on them that prevented high blower until it was over a certain alt. 15k-20k alt is typically where it would switch to high blower... automatically!
MichiganTeddyBear said:
right, i got that. They used two diffrent compressors as it were, with the same gear ratio or something like that. I was thinking of having the idea of the transmission on there, with one "compressor" but two diffrent gear ratios . Figgure that you want 15 lbs of boost, well... that comes in at your peak boost, right...your only running x ammt of boost (x = >15) for most of your rev band. I was thinking you could have the one that gives you about 13-15 lbs of boost from your low end, till your mid range, and then shifting to the second gear (so you dont go crazy with boost by top end) droping you back to about 13ish at midrange, and back up to 15 at the top of the rev. so instead of making less boost at lower rpm's your making about the same boost all the time, so you get great pull at the bottom.
MichiganTeddyBear
Dedicated LVC Member
the ww2 implentation varied depending on manuf of engine/blower/exact model. a large number of them actually used the same blower, with 2 different ratios... the 2 stage blowers had 2 compressors... then to make it more complicated, you go 2 stage/2 speed.... 2 blowers, with 2 gears!
but I see what your saying, and with a properly designed setup, you can maintain full boost throughout most of the rev range. I am not a blower expert by anymeans, but if you design your throttle body size to give the boost you want at a certain rpm, then if you go over that rpm, the throttle body would limit amount of air injested, effectivly limiting your boost. or if you wanted to get real fancy smancy.... design and build a variable ratio gearbox for it... that way the blower spins optimal speed all the time!
but I see what your saying, and with a properly designed setup, you can maintain full boost throughout most of the rev range. I am not a blower expert by anymeans, but if you design your throttle body size to give the boost you want at a certain rpm, then if you go over that rpm, the throttle body would limit amount of air injested, effectivly limiting your boost. or if you wanted to get real fancy smancy.... design and build a variable ratio gearbox for it... that way the blower spins optimal speed all the time!
I was just watching speed channel and they were saying something about an alfa, back right after the war, and they had a straight 8 supercharged, 190hp...and then they put on a 2 geared supercharger (like my idea) and it made 320hp.
