For Car Junkies

[Brian S]

"Ford used a electro hydro clutch or something."


What's your source of this info?

[March Hare]

...the mechanical exterior mods are all possible..


... the question is.. How do you change the compression ratio of the piston with the flip of a switch?.. everybody knows that a supercharged piston is dished concave to REDUCE the compression ratio...


.... so when you TURN THE BLOWER OFF?.. won't the engine knock like a diesel from trying to run the engine un-aspirated with a very low compression ratio?

[mfpmax]

Quote: Originally posted by Brian S on 15i 1/2Mayi 1/22007




"Ford used a electro hydro clutch or something."

What's your source of this info?

A few magazine articles(and possibly the PDF file from SVT's website) about the Super Stallion concept. Ford was developing the system and just tossed it on the car supposedly. Similar concept to the magnetic fluid shock dampening systems found on Mercedes actually.

[mfpmax]

Quote: Originally posted by March Hare on 16i 1/2Mayi 1/22007




...the mechanical exterior mods are all possible..

... the question is.. How do you change the compression ratio of the piston with the flip of a switch?.. everybody knows that a supercharged piston is dished concave to REDUCE the compression ratio...

.... so when you TURN THE BLOWER OFF?.. won't the engine knock like a diesel from trying to run the engine un-aspirated with a very low compression ratio?

If that was the case, many turbocharged engines with low compression ratios would run extremely horrible when the turbo is not spooled up. That however is not the case. Also along with switching the supercharger on and off, the switch could be tied into the ECU(if EFI) to change the timing tables to raise igintion timing while the supercharger is off, then knock it back down when the supercharger is on.





I know when I ran my turbo with the wastegate open I expereinced no such problems...what I did experience was my car was unbearably slow! OMG the horry.

[DetritusMaximus]

march hare-





You don't have to run high boost on the supercharger. You can basically build a decent relatively low compression motor, 8-1 or so, and then run a modest amount of boost. If you build a 250-300 hp aspirated motor and set up the supercharger to add 50-75% more hp at the upper end of the rpm range, then it wouldn't be so bad. Remember, the 6-71 will produce a TON of torque.


We're not talking about building 600-800 hp.


That is one of the trade-offs for having a functional switchable compressor.





Personally, being able to say I have a controllable supercharger isn't worth the compromise. Just build a fuel injected motor with a working supercharger. It will be docile and probably be capable of more power than with carbs. MPG will be better than with carbs.


And cheaper, too.


I'd guesstimate the cost difference might be enough to buy and ship a Falcon coupe....!

[Foxtrot X-Ray]

It all depends on how much Boost you're pumping into the engine. (Which is controlled by the ratio between the size of the crank and blower pulleys.





A somewhat higher compression ratio can be used if the blower pumps in a lower level of boost.





Also, an intercooler can allow More boost to be pumped into the same engine by reducing the temperature of the inlet charge.





Mickey Thompson was supposed to've experimented with superchargers & freon & nitrous Oxide cooled intercoolers back in the sixties.





Yes, I said Nitrous Oxide COOLED.


I imagine great care must have been taken to avoid Leaks..





He also did some neat stuff with multiple blowers and spraying Nitrous on the outside of the block for cooling.





Seemed to be a "Try it and See" kinda guy.

[aussie muscle]

Quote: Originally posted by Brian S on 15 May 2007




[div]


I've never seen or heard of a centrifugal clutch on a supercharger. Where can I find info on this? I've heard of a Nissan 350z GT-S Concept. It uses a Centrifugal blower, not Positive Displacement, and the on/off method doesn't seem to be specified.[/div]

I've never heard of one on a supercharger either. The principle behind the centrifugal clutch is the higher the rpm, the greater the centrifugal force. this force is used to engage the mechanism. Weed trimmers use them to engage the spinner head. at idle, the force is too low and the clutch is disengaged. when you rev it the force engages it and the weed whacker is in action. i guess that when the engine revs to enough rpm the blower is engaged and adds boost. You can also find a centrifugal govenor on steam engines, it works in reverse, more rpm causes it to engage a brake keeping the rpm down.

[March Hare]

... freon only gets ice cold ( without compressing ) if it is vented to air... so the freon cooled intercoolers are a big no-no nowdays.. my friend that ownes 2 Bonneville cars just uses a big bottle of CO2.. he plumbs it to the intercooler with a small fitting, installs a tiny vent hose on the opposite side of the cooler and then just cracks the bottle.


... It's not as expensive as NO2 to reload the CO2 bottle and you can get them refilled at anyplace that does soda fountain bottles.

[mfpmax]

"Freon" ICs are not out...but they aren't that in either. Ford had a Concept Lightning that used the A/C charge to "chill" the Air to Water Intercooler charge I believe for a short burst.

[Foxtrot X-Ray]

IIRC, Thompson Did use the freon intercooler Compressed..


Just had the functional equivalent of an evaporator inside the intake manifold.








An idea I had at lunchtime..





I wonder what would it take to retrofit an old V-8 as a Variable Displacement engine?





Some machinery to disable the valves on four cylinders at the flick of a switch.





When you don't need Power, leave 'em off..


When you want the power, turn 'em back on again.





Wonder which would work better, disabling the front four cylinders or the left of right bank??








OOOOOOOOOOOOOOOOH..





Four mode V-8.





Variable displacement, a Switchable Supercharger AND a Nitrous Oxide system..