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- MP5T / 944
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Forced Induction 101
- Thread starter Brian MP5T
- Start date
What about having an electric air horn right before the turbine. That way it would only have a positive effect on the spool and would drag the turbine like an electric motor. Just an idea. It would take some thought to keep the exhaust from reverting back through the air horn. Maybe the air horn could pull it's source air from the exhaust itself, so if the exhaust gets reverted backwards through it, it acts as a wastegate.
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- MP5T / 944
It is interesting however, it would have to survive 1600 Deg F and a massive surge of backpressure when the Gas is hit to WOT.
I like the way you have thought out of the box, but there will be more pressure before the turbo than after so you will not be able to use the Exhaust as you have pictured. To get backpressure there is a major negative for the spool and the sign of a large problem, most systems have large Downpipes and Catless 3.0" pipes to remove the backpressure there. To use pressure from an air tank is interesting. What comes to my mind is that if you add massive pressure into the manifold, it will spool the turbo, but it will also make a shitload of backpressure for the Ex Valves to deal with and counter performance by making it more dificult for the valves to clear the spent gasses.
I'll mill it over but I think that although it is a cool idea, I think it would have to be tweaked alot for it to be practical if functional at all. Sorry, I'm not trying to be nagative towards your idea.
An idea that is simple and common is to drive a large turbo with a smaller turbo in series. This uses the cold wheels of both, the small feeds into the large to kick it up fast and then it freespools as the large turbo is up to speed...
I like the way you have thought out of the box, but there will be more pressure before the turbo than after so you will not be able to use the Exhaust as you have pictured. To get backpressure there is a major negative for the spool and the sign of a large problem, most systems have large Downpipes and Catless 3.0" pipes to remove the backpressure there. To use pressure from an air tank is interesting. What comes to my mind is that if you add massive pressure into the manifold, it will spool the turbo, but it will also make a shitload of backpressure for the Ex Valves to deal with and counter performance by making it more dificult for the valves to clear the spent gasses.
I'll mill it over but I think that although it is a cool idea, I think it would have to be tweaked alot for it to be practical if functional at all. Sorry, I'm not trying to be nagative towards your idea.
An idea that is simple and common is to drive a large turbo with a smaller turbo in series. This uses the cold wheels of both, the small feeds into the large to kick it up fast and then it freespools as the large turbo is up to speed...
Yeah, I'll admit that there are many issues that would prevent this from working well. I was especially concerned with the effects it would have on exhaust reversion back into the cylinders since the pressure doesn't care which was it's going.
The 'in series twin-turbo' setup is definitely a cool idea, and I know they use that quite a bit. All these ideas really have no place on a street Protege, but I still like talking about them.
I just thought of another idea while typing this. What about a turbo with a second turbine sandwiched in between the main turbine and the compressor wheel, but still attached to the shaft. It could be smaller than the main turbine and it's sole purpose is to pre-spool it. This pre-spool turbine could be driven by the pressure tank that I mentioned earlier. I'll whip something up in Photoshop to show you what I mean.
Edit: This is what I mean
The 'in series twin-turbo' setup is definitely a cool idea, and I know they use that quite a bit. All these ideas really have no place on a street Protege, but I still like talking about them.
I just thought of another idea while typing this. What about a turbo with a second turbine sandwiched in between the main turbine and the compressor wheel, but still attached to the shaft. It could be smaller than the main turbine and it's sole purpose is to pre-spool it. This pre-spool turbine could be driven by the pressure tank that I mentioned earlier. I'll whip something up in Photoshop to show you what I mean.
Edit: This is what I mean
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I see, It is obviouly possible and would work better than your last idea. Just to let you know how mych force is applied to a turbine to spool it. There is normally 33% energy loss to heat in a regular internal combustion engine. So, a 130 Hp Protege dumps 43 Hp in Heat energy to the tailpipe and radiator. This is what is used to spool the turbine. Lets say 30 Hp to the Pipe. What would a 30 Hp lawnmower engine look like? It would be rather large. So the point I'm trying to make is that if you plan to pre-spool the turbo and not waste your efforts, you have to apply alot of force to the turbine when it is not being fed by the Ex of the car. Your air tank would be empty in no time and it costs either eletrical energy to compress air or mechanical energy. The WRC guys really solved the problem easy, injecting fuel into the EX mani and throwing the timing out to lunch caused the Poping that I spoke of, it's impractical for anything but a race car and is hell on the EX mani, when your car only has to last 100 Km, it's ok.
Bi-Charging trys to eliminate the lag just like Twin Turbo except that a turbo feeds a supercharger or vise versa. Think about the pros and cons of that...
Bi-Charging trys to eliminate the lag just like Twin Turbo except that a turbo feeds a supercharger or vise versa. Think about the pros and cons of that...
That was something I wasn't sure about; how much force it would take to spin it. But I figured that it would just need a quick burst to get it moving. My idea for filling the pressure tank is the same as truck air horns. It would build pressure from an electric pump into a small pressure tank, then release it in a large burst. I'm not sure how practical that would be for street use, but it would be interesting on a drag car with a huge turbo. At the line it could release a burst of air to bring the boost up off the line. Most air horns use 120-150 psi, which I would think would be enough to spin it up until the engine takes over.
How would you refill the pressure tank? I'm sure using that much air to spool up the turbo wouldn't last long, because I had the same idea of using an air compressor to force air into the intake (how I wasn't sure) but to use that kind of airflow just wouldn't last long at all.
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- MP5T / 944
Spooled said:
Almost none at all.
Also It would take so much of the spool away once under load. You have effectively added an Ex Powered Coolant pump.
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peep this twin charger... i read about it in Popular Science yesterday.
http://www.autoblog.com/entry/1234000860064670/
oh and in popular science i believe it said it got 39mpg
http://www.autoblog.com/entry/1234000860064670/
oh and in popular science i believe it said it got 39mpg
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Great Read, I posted it over so it will not become a Red X..
LINK said:Autoweek drives VWs Twincharger
Posted Oct 24, 2005, 7:00 AM ET by Eric Bryant
Related entries: Economy
Those lucky bums over at Autoweek recently had a chance to flog a Euro-market VW Golf GT that was equipped with the manufacturers new 1.4L turbo- and supercharged Twincharger (or TSI) engine. So, how does it perform? Much like one would expect from a powerplant that manages to make 121 HP/L and also provides nearly 85% of its peak torque at 1250 RPM, meaning that words such as flexible, responsive, and linear are used. Yummy. Theres no word on fuel economy, but one can imagine that its potentially rather good (and probably also heavily dependent on ones driving style).
excellent job on 99% of the thread, cannot say id agere with what you said about the injection. Any turbocharged motor will benefit from water/meth injection.Regardless if they already have a FMIC or not, reduced intake temps are reduced intake temps. Being able to cool the motor and prevent detonation are added bonuses. There are no drawbacks. Your analogy of changing the pulley on a SC is incorrect. There is no drag or parasytic loss from injecting the fluid whatsoever. With a properly setup kit you can only gain from a injection kit regardless of you having a stock MSP or a 11 second dragster, its just added performance and reliability. It is not a bandaid unless you use it as a bandaid. Sure you wanna run 8psi more than stock without buying any fuel system upgrades, ya its a bandaid, but if you wanna improve the efficiency and reliability of any motor, then put er on no question.
Just cause Corky said its a bandaid doesnt mean you have to use it as one.
Just cause Corky said its a bandaid doesnt mean you have to use it as one.
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jeffmsp said:
I agree with you on most of what you posted, there are very good benifits to running it but IMO as long as the engine can run "Whatever Prerssure" with and without the injection without detonating, I would choose to run no water injection. I am happy that you got the basic concept and flow of what I was saying. My overall point was that it's not required if the system is designed properly.
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jeffmsp said:
Short vs. Equal...
The longer length of a manifold has two negatives.
1. Expanding Hot gas spools the turbo, the longer it is, the colder it can get.
2. There is more volume to overcome before the turbo starts to spool.
I have kept most of the heat in with DEI, My EGT runs normally 1300 Deg at 70 MPH. I don't notice any more lag over the MSP or even a WRX.
Have a look at the 944 Turbo setup. Porsche takes the Manifold down under the oil pan about 2 Feet over and then up a foot to the turbo. It sits completely on the other side of the engine bay. There is always a balance between "TEXT BOOK" and "POSSIBLE / REAL WORLD"
Yes, on paper, Perfect case would be Short and Equal, but I was stunned with the 3000 RPM Pickup of the MP5T on a dead spool. I wanted the turbo where it is and thought It would make a diference, but it didnt. It's almost instantly at max boost even as low as 3000 RPM. There are a couple of peeps on this forum who have driven my car and they all come back with a big perma smile.
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RyanJayG said:
The Flow of the collector defiately makes a diference. How it merges into the turbo housing is much more important than the length of the runners compared to each other...
I agree, but I grouped them together because both are relatively difficult (if not truely impossible) to achieve with a true short runner design.
if you are doing long runners then you might as well utilize a pyramid collector as well.
I would even go to say that the collector Beau builds on the SS manifold is superior to both the thumper and MSP manifolds becaust of its length (the collector is about 6" long all by itself) and the angle it takes (more straight into the turbine housing).
I'm just saying that if you are going to utilize an equal length (or close to it) manifold you might as well get a proper collector while you are at it.
if you are doing long runners then you might as well utilize a pyramid collector as well.
I would even go to say that the collector Beau builds on the SS manifold is superior to both the thumper and MSP manifolds becaust of its length (the collector is about 6" long all by itself) and the angle it takes (more straight into the turbine housing).
I'm just saying that if you are going to utilize an equal length (or close to it) manifold you might as well get a proper collector while you are at it.
