Twin charged bp

[fastivaB6TG25MR]

if you want to see what ducting it will take to make both work together without interference just look at the intake on a mercedes benz c230 kompressor(the m271 engine not the m111) it uses bypass valves(electronic throttle bodies) to isolate the s/c so it can efficiently run N/A as well as s/c

[sketchman]

I'm well aware there is a bypass, that just bleeds off what the m90 is making, doesn't fix the fact you have a huge restriction sitting on top of your freaking motor that you are trying to blow a turbo through. ....for the turbo to feed boost into the motor you will have to try to push that air past your m90.

However if you just put in a big enough (or multiple) regular bypass valve pre SC the idea becomes completely workable.

It's not a simple solution, but the OP says complication is fun, so....

You might even substitute an electronic exhaust cutout for the regular bypass valve and get enough flow capacity.

[koRnhead]

There is no pee supercharger on an m90 people. What don't you people get. The m90 is a roots blower, it sirs on top of your intake. If you want to twincharge you will need to use a centrifugal blower.
Ps thanks for the name change I love it

[bhearts]

However if you just put in a big enough (or multiple) regular bypass valve pre SC the idea becomes completely workable.

It's not a simple solution, but the OP says complication is fun, so....

You might even substitute an electronic exhaust cutout for the regular bypass valve and get enough flow capacity.

Yes, we like it raaw, and wrrrringling.

[sketchman]

There is no pee supercharger on an m90 people. What don't you people get. The m90 is a roots blower, it sirs on top of your intake. If you want to twincharge you will need to use a centrifugal blower.
Ps thanks for the name change I love it

lol No prob.

Of course there is a pre SC. You stick intake ducting from the turbo to the m90, and a plenum under your m90 pre-intake-valves. Then all you need is a big honking "bypass valve" and an intake flange on the plenum post SC. And Bob's your uncle.

[koRnhead]

The rotors on your m90 are always spinning. Since the m90 in essence becomes your intake manifold you cannot avoid the fact that you would be forcing your turbo to try and blow past two spinning rotors. Thus making the huge restriction and making all this a moot point.

[sketchman]

What I'm saying is the m90 does not HAVE to become your intake manifold. You can have a plenum under it. Which can have a secondary intake for the turbo. The turbo has its own path to that intake port on the plenum, and a big bypass lets it open while closing the path to the m90. The m90 keeps spinning but can't build pressure because it is now in a vacuum. And when a pump operates in a vacuum the resistance it creates goes way down, because there's no air to pump.

[Advancedynamix]

What I'm saying is the m90 does not HAVE to become your intake manifold. You can have a plenum under it. Which can have a secondary intake for the turbo. The turbo has its own path to that intake port on the plenum, and a big bypass lets it open while closing the path to the m90. You would simultaneously actuate the big bypass and the m90's bypass and vent the m90 to the turbo's dedicated path. The m90 keeps spinning but can't build pressure because it is now in a vacuum. And when a pump operates in a vacuum the resistance it creates goes way down, because there's no air to pump.

EDIT: Or maybe you wouldn't even need to open the m90's bypass. As soon as you close off the intake to the m90 with the big bypass it would be in vacuum, so maybe it wouldn't matter.

Many companies use roots blowers that aren't connected to the intake manifold. Most Toyota's are like this. I would use a centrifugal charger to blow into the turbo. This provides a seamless torque curve. If you try to balance both chargers with valves and trap doors, you're asking for trouble. You are guaranteed to have a flat spot in your torque curve. This is common when people twin charge first gen MR2s.

[koRnhead]

Would that work in principle yes. I knew what you were saying. In actual engineering and making it happen the m90 is still a bad way to accomplish this. It's inefficient makes way more heat than it should, and honestly do you know how big the m90 is compared to a bp??? I do. I have an m90 car. Making a custom intake manifold to mount it to plus the space for your bypass plus the turbo plumming will not fit inside a festy. Unless you rear engine it. In which case we all know a SHO motor is way cooler. Yes I've had those too.

[sketchman]

I do not know how big an m90 is. It was just the one being mentioned, so I copied it.

If you blow into the turbo with the SC, wouldn't you run into the SC causing a flow restriction when the turbo is getting into its stride?

[bhearts]

Would that work in principle yes. I knew what you were saying. In actual engineering and making it happen the m90 is still a bad way to accomplish this. It's inefficient makes way more heat than it should, and honestly do you know how big the m90 is compared to a bp??? I do. I have an m90 car. Making a custom intake manifold to mount it to plus the space for your bypass plus the turbo plumming will not fit inside a festy. Unless you rear engine it. In which case we all know a SHO motor is way cooler. Yes I've had those too.

I know how big an m90 is also. I'm thinking that it'd be better to have too much displacement and spinning it slower, than to have something the right size and spin it normal speeds. Bigger compressors are always going to put out cooler air per cfm

[koRnhead]

No. You run a ac type clutch on your centrifugal blower. Which let's it free spin and not make surge issues.

And ok bhearts you want to use a blower that's almost as big physical size wise as your motor. The packaging will never work in a festy engine bay.....and regardless of how fast you spin it. It will make tons of heat. They don't call it the Heaton for no reason chief

[sketchman]

So blowing through a SC is a problem but drawing through one isn't? I'm not being a wise guy. I just don't understand that.

[Advancedynamix]

I do not know how big an m90 is. It was just the one being mentioned, so I copied it.

If you blow into the turbo with the SC, wouldn't you run into the SC causing a flow restriction when the turbo is getting into its stride?

Thats why I would do it with a centrifugal charger. If done with a roots blower (screw type blower), you must have a diverter valve to bypass air around the charger, which can be tricky. air flows easily through a centrifugal pump.
A centrifugal charger makes boost by increasing air speed to the point where the weight of the air compresses the air (centrifugal force). This type of charger will not become a restriction if it is the pre or post charger. That's why we see this type of setup on multistage ultra high boost diesel engines found in heavy industrial applications. I'm not making this stuff up, it's really really old technology. lol

The reason I would run the mechanical pump before the exhaust pump is so I could run a more commonly available set of pumps and be balanced. Exhaust heat is going to be a major problem in this setup, which is why I would not run this on pure gasoline. Things are going to melt.

[koRnhead]

You don't draw thru it once it's not making boost. It's complex and that's why a roots blower doesn't work for this type of setup.
Could you m90 a bp. Yeah, tho I think it would b a total dog turd. Too much draw for the 1.8 to make any power with it. A centrifugal off a Honda kit tho would work. But like all twincharged setups. The gain rarely is worth the headaches.