is this possible?

Asa

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ok, some of this may be just from ignorance, so bear with me please

was reading about GM's new DOD engine (Displacement On Demand, uses collapsible lifter's to turn a V8 to a V4, and a V6 to an I3 when full HP isn't needed, think of that exhaust going from a gnat to a lion when the pedal is floored), and then later i read a post on this site (i think it was XECUTE's "I'm going to Blow my Budget!" not sure though, might have even been a different site) that talked about a supercharger that had an AC clutch on the pulley so that it was only activated at a certain time
those both got me thinking about a BOD engine (Boost On Demand), where you could flip a switch, have the supercharger and all related systems engage and go hauling ass down the road, then when you were done burning the ricer or the V8 next to you, switch it off, and have a nice mild I6 to get you down the road

here's where the ignorance comes in:
1) i know there would be compression issues, NA engines have a higher compression ratio than forced induction engines
2) i don't know how superchargers engage normally (not for sure at least, i'm pretty sure that because they build boost in relation to RPM, they are on all the time), so i don't know if there is something like an AC clutch in normal supercharged systems
3) i don't know how AC clutches work, i'm pretty sure that there's a solenoid or some similar thing that engages the clutch when you flip the switch to turn on the AC

is there a way around the comp. issues? how much engineering would this take? what am i really missing (besides my mind, i saw that thing just the other day)? could this work? am i really late in current events and it is already under someone's hood? am i the only one who thinks this would be cooler than wakulla springs, fl on a hot summer day?

PS - if this is possible, and is a new idea, and someone else wants to "borrow" it, please feel free, if it will work, i won't be able to put it into use for a while
 
It's called a turbo. There's no "off" switch per se, but the stupid pedal does a pretty good job of controlling things, don't mash it you get no boost.

The whole business of clutches and by-pass circuits on mechanicaly driven superchargers adds levels of complexity and increases the possible failure modes beyond what you really want to deal with.
 
hmm, ok, new idea, same concept though
have a turbo-ed motor, but using butterfly valves like the ones at this website:
http://www.quicktimeperformance.com/
and have it so that the cut-out goes to a normal exhaust, the turbo goes through a different system
..........
i think i'm being stubbornly stupid, i know it would be a pain in the butt, and it would have problems from here to the moon, but...........

anyone else have an idea, or know of someone that has done this or something similar?[/img]
 
Oh boy, don't get me started again.... :lol:

The rule should be the same as airplane engines...have a failsafe system, but don't use something that's gonna break, and either take your life or leave you stranded. Don't see many EFI systems and solid state feed- back control systems on propellor plans, do ya? Just magnetos, spare compensating carbs, and hand cotroll for fuel/air mixture based on an exhast gas temperature reading. Take a leaf from there book!

StrangeRanger is right in what he says. Fan clutching a supercharger is adding another system that may fail. No doubt about it. Period. But...

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http://www.oguraclutch.co.jp/english/e_products/sc/sc-1.htm

That's exactly what the Japs do on there twin lobe blowers on Toyota Soarers, Carinas, Coronas equiped with the SC12 blower. It's good for 30% power boost, is small and light, but it plateus at 250 hp. They've made it work, and now "Ogura Superchargers" build them from Toyota patterns. It's not a real smooth unit, because of its twin lobe (not three lobe) design, but it will grow to the next "big-thing" if the Japs sell it in Aussie and America.

Already the Aussies are using the Toyota SC12 en mass, and my mate Richard has one on his 88 GM Holden Commodore V6 with GM 3800 engine. It boosts power from the NZ spec 175 hp to 228 hp on demand! It runs the standard 8.5:1 compression ratio, and doesn't knock, ping or even fart. Rebuilds of the superchargers are very complicated, though, and a service industry for them is growing, but it is built like a watch in the typical Jap style. The Castlemain Rod Shop did the design for the swop on to in-line and V6 Holden and Nissan engines, and it is very well engineered!

The supercharger is limited size wise to 250 cid. After that, you have to lower the rev range or get two of them hooked up...don't laugh it's been done! So a scremer 300 i6 could use two for 300+ hp, or just one for a low rev (less than 4500 rpm) 250 hp I6, if it did 190 hp with some moderate mods to the cam and intake.

If you really want to add systems to your Ricer Racer, then take a leaf out of this guy who has turboed his Nissan Skyline. The 2.4 turbo is a weapon. Colin Townsend helped him do the conversion, and he has a 1970 Valiant with a 265 Hemi 6 that does 375 hp at the wheels with LP Gas and a big hair dryer. He has a special by-pass choke at the head of the turbo to generate big boost!

http://www.picknowl.com.au/homepages/wardr/lpg.htm

Hope you enjoy these links. You'll find them quite a feed...
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emoticons care of RougeS
 
Strange,
but several times have seen Eaton type blower for Mercedes with electro-mag clutches similar to ac clutch.
"VIVA MAD MAX"
 
8)
hmm, ok, new idea, same concept though
have a turbo-ed motor, but using butterfly valves like the ones at this website:
http://www.quicktimeperformance.com/
and have it so that the cut-out goes to a normal exhaust, the turbo goes through a different system
you dont need to go to that level of complexity. you can get a PTO wastegate for a turbo. PTO stands for part throttle open, which means the wastegate is open untill you nail the throttle and engine vacuum drops. it then closes untill the desired boost level is reached at which time it opens again to prevent overboosting the engine.
 
StrangeRanger":wnc11oye said:
It's called a turbo. There's no "off" switch per se, but the stupid pedal does a pretty good job of controlling things, don't mash it you get no boost.

The whole business of clutches and by-pass circuits on mechanicaly driven superchargers adds levels of complexity and increases the possible failure modes beyond what you really want to deal with.

I have seen somewhere someone was working on a electrically clutch operated turbo.

But yeah I agree I thought the point of turbos was kinda the power on demand?
 
Yeah, but if you size the turbo to give you 27 lbs. of boost at 9500 RPM, you may need to do some equally strange things to allow the poor engine to run at all at 2500. :roll:

I'll ley the Honda boys work this one out for themselves.
 
Wheres UncleBen when you need him?

If you do it right, a turbo will leap large buildings in a single bound! No need for extra systems.
 
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