roots/twin screw

[tuscandom]

just a question out of curiosity..anyone tried a roots or twin screw on a speed six..would be interesting to see the effects of a twin screw as regards to drivaing characteristics ??
just curious

[GreenV8S]

Isn't the speed 6 more about revs than stumpy torque? I would have thought a centrefugal blower would be more suitable.

[warpig1]

have purchased eaton m-45 charger for said conversion, just waiting for some spare time to begin the conversion

[GreenV8S]

warpig1 said:

have purchased eaton m-45 charger for said conversion, just waiting for some spare time to begin the conversion

You'll need at least two of those, and probably three, if you want to see any power increase. They're far too small for that engine.

[warpig1]

GreenV8S said:

warpig1 said:

have purchased eaton m-45 charger for said conversion, just waiting for some spare time to begin the conversion

You'll need at least two of those, and probably three, if you want to see any power increase. They're far too small for that engine.

sorry my mistake its an m-90

[tuscandom]

are all eatons rootes type chargers ?

[GreenV8S]

tuscandom said:

are all eatons rootes type chargers ?

The M45/60/90/112 are all twisted vane Rootes type blowers.

A single M90 would do at a pinch as long as you don't want much boost, an M112 would be more suitable. But they're big old b*ggers. The equivalent centrefugal blowers are far smaller and easier to package, more efficient at higher boost levels, shame they just don't pack the same low end punch. What we really need is for somebody to come up with a cost effective CVT drive for these. I've seen a two speed auto drive, but that was pretty expensive.

[tuscandom]

what do you think to the twin supercharger set up,twin screw with a cenrifugal blower to give boost all through the rev range ??

[GreenV8S]

tuscandom said:

what do you think to the twin supercharger set up,twin screw with a cenrifugal blower to give boost all through the rev range ??

Anything is possible. You can add a turbo, NOS, hyperbar pre-boost etc. But is it sensible? It seems like an awful lot of extra work for relatively small gains. If you want high boost levels and are just doing 'what ifs' for the heck of it without regard to difficulty/cost then I would have thought that a big turbo with a rootes blower to get it started made sense.

[chuntington101]

tuscandom said:

what do you think to the twin supercharger set up,twin screw with a cenrifugal blower to give boost all through the rev range ??

twin screws are very effective as they internal compress the air where as roots dont. this means much lower intake charge temps. however one advantage of the roots, and probalby why the manuftacures run them, is once the bypas valve is open there is very little energy sapped by the blower. a twin screw will still be compresing some air and thus sapping some power.

i dont really think a roots would be the best setup for a Speed 6 engine. take a look at what the BMW M3 guys are doing. most are running Rotex blowers as they are VERY small (easy to package) and would give a stornger top end than most roots.

thanks Chris.