Twin supercharging a 5.0

MadMikeyL

SCCoA Member
Ok, I want to get some input on this idea I have been messing around with for a while.

I have a 91 cougar 5.0L. I was thinking of doing a twin supercharged setup using the eaton M90 blowers, and a custom upper intake manifold. The idea would be to replace the upper intake with a structure that will serve as a plenum accepting the boost from both blowers as well as have a frame that holds the blowers in place. Here is the catch. If I build this, I can not afford to have a second car. Nor do I want to have 2 blowers running at all times as that would quickly kill my engine, not to mention my gas mileage. I was thinking about running the blowers by an electric motor, and having an electric linear actuator set up so that one switch would simultaneously start the blowers spinning and seal off an intake hole that would be used to bypass them whenever I have them switched off. I know I would have to have a custom hood with probably at least a 4" rise to clear all the plumbing and everything, but I just want to know if anyone sees any problems. I will post a sketch of the design at this address.

www.angelfire.com/punk3/scnjpunk/2blowers.jpg

Let me know what you think. Thanks.
Mike
 
Take a look HERE , this guy has been running a twin Eaton blown 351W powered Turbo Coupe for a few years.


cheers
Ed Nicholson
SCCoO
 
i dont know

I wouldnt know of any problems but i like that idea of having to switch themoff whenever you want, kind of like there will be 4 turbos on your car at once,, sounds awesome, good luck-
Damon
 
with regards to the twin eaton blown 351, I know of that car and I have asked that guy several questions as I was designing it. I am basically taking the main structure of his design for my car. But his car is running a speed density system, not a mass air. Also he doesn't have any kind of bypass valve at all. His car is under boost all the time, making it thorougly impractical as an everyday driver. With regards to thinking one blower would be enough, I doubt it, and it certainly wouldn't be as cool.
 
If i were you, buy a junker car to drive. pretty much any way you set it up it will hog the gas and break down just because of the performance factor.
 
buying a junker

Getting the actual vehicle isn't the problem. I still have both my 89SC and a 79 firebird formula. The problem is I can't afford to put both cars on my insurance, and what's the point of building this thing if I can't drive it.
 
When you say "running the blowers by an electric motor" do you mean you would do this instead of the accessory belt off the crank pulley? Seems like you'd need a very powerful electric motor to do that, in fact I would have thought it wasn't possible. Maybe I misunderstood what you said.
 
That is what I meant. I didn't think it would need to be that powerful of a motor. Like I said, I want to be able to turn them on and off, and running them off the crank would not let me do that. I thought an electric motor would be an easy enough way to do that. I was thinking maybe something like a modified starter. My figuring was if it is powerful enough to crank an engine over, then turning 2 90ci blowers would be no problem. But I don't know much about it so I could be wrong. If I am, let me know. Also if anyone knows of another way that I could turn them on or off without using an electric motor, let me know. Thanks.
Mike
 
Mad running them off an electrical motor is completely impractical...A strong enough electrical motor to spin a blower at high rpm woul dnot only be large and heavy, youd need to plug into a house to use them..However if you used an electric clutch setup at the blower such as that found on an AC compressor that would work..Why youd want to do that I have no idea...I still believe one blower would be enough:O)..Unless of course your looking for mega HP..Then Id say go turbo:O)..And not running a bypas would not make the car impractical..However it would increase blower life..I dont mean to knock your idea but what is it yoru exactly looking to do with the car
 
Electric powered SC's just wouldn't work. They suck 50-70 hp when at speed pumping air. Try pricing and figuring out how to wire up a 70hp electric motor from a 12 volt system. Uh, yeah, right.

Same problem with electric clutches on the front of them. It would have to be quite an electric clutch when you consider the impact that they would have to absorb if engauged when the engine is turning 2800 rpm and the SC tries to come up to speed in the blink of an eye. I can see the pieces flying already.

The MR2 from Toyota had a electro-mechanical clutch on their SC but it was very unique and the SC was just a tiny thing. A computer was used to gradually engauge the clutch so it wasn't just an instant on/off type of design.
 
electro-mechanical clutch

I am looking for mega power, but I absolutely despise turbo lag, and I am also a big fan of low end torque, which turbos don't help at all. The other thing is I want this car to be a daily driver that can be made killer without opening the hood. Basically I don't intend to use the blowers all the time, just when someone challenges me at a light, or once in a while on the highway at night. With regards to the clutch blowing up trying to get the blowers up to 2800rpm, would that work if I only turned the blowers on at idle? That would work just fine for my purposes. Also why would not having a bypass valve increase blower life and not decrease engine life? I don't understand that. Thanks for your input.
Mike
 
O.k.

Here is what you would have to do in theory. But if you think I can help you with the practical application of the theory, you're mistaken. I can't imagine the engineering that would have to go into makeing something like this work.

Create an intake system that allows you to route incoming air into the supercharger and back into the intake manifold, or directly into the intake manifold bypassing the supercharger. This is because if they are not spinning, they won't allow any air to flow through them.

Second, create some sort of clutched drive system you can turn on and off and whim. This would likely need to be either a hydraulic type of clutch, or electro-magentic. Either system would need to have some way of gradually engauging or dis-engauging to prevent shock to the input shaft of the SC, or the crankshaft of the engine.
 
Just use bypass valves similar to what comes on them stock. When the bypass valve is open (anytime there is vacuum) it only takes 1/2 HP to spin the supercharger.

Hitting the throttle quickly, drops vacuum to zero and the bypass valve closes forcing the air into the engine instead of allowing a portion of it to recirculate.

David
 
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In theory, the clutch problem would be solved if you just shut the car off before engaging the clutches. However, the amount of money that you would spend to TRY to develop this would easily pay for the insurance on another vehicle. It would be easier to just make a "quick on/quick off" belt that you can put on to turn the superchargers when you want to run them. It would mean getting out of the car and spending a few mins under the hood, but these ideas of electric motors, etc, just seem completely impractical. Just my opinions, it's your car.
 
Like I said, that really doesn't work for what I want from the car. I might end up just doing that, but if there is any way in the world that I can switch them on and off instead, I am going to do that. If using a vacuum operated bypass valve is the only way it can be done, then building it is just a matter of time and money.
 
Celeb DV is a major prick. Just thought I'd share...

Anywho, wouldn't you be better off going with a single M112? (isn't that the next size up??) I realize that that isn't going switch on switch off able... but you know... what about picking up a junkyard turbo and going with one of the supercharger/turbo setups that I've heard about? That way you'd get the immediate response of the supercharger and then the turbo would kick in like a bat out of hell... and I think with the turbo you can you some variable electronic blow off valve or something??? This way at least you would be able to disable the turbo part of the car? Also, I thought that sometimes with twin turbos they had them set up so one kicked in at very low rpm and then the other would pick it up at higher RPM?
 
There are some new superchargers that use a clutch pulley like an thermal clutch, they spin freely and then engage and lock up and make the supercharger spin. I forget what models are using this set up though.
 
If you shut the superchargers off, you will still need a bypass valve or the engine wouldn't run in normally aspirated mode.

David
 
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