GS1150E TURBOS

[Anonymous]

Hello everyone:

I'm a new proud owner of a 85 GS1150E. So far I have changed the front end to a inverted GSXR unit, purchased an extended swingarm with air tank installed for the air shifter. also GSXR wheels. The reason for this topic is to pick you brains on turbo systems. This will be my first system i have ever used so any and all info would be appreciated.

brands
exhaust
prices, used or new
where to buy
what to look for
ect ect ect

thank you

 

[Guest]

Mr. Turbo has a kit for your bike that includes everything for $3995.00 USD.

http://www.mrturbo.com/

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[lecroy]

I bought this kit new in the mid 80's. I would not recommend going to a draw system like this now. Get ready to drain your wallet is all I have to say.

 

[mike J]

I bought this kit new in the mid 80's. I would not recommend going to a draw system like this now. Get ready to drain your wallet is all I have to say.


Just out of curiousity, what is a "draw through system"? I havwe heard this trem used before but I don't know what that means. Also what are the downsides to this? I have heard guys tell me that a turbo is useless for street riding as they make no power unless wide open. Tia Mike J

 

[lecroy]

On a draw system, like the one shown, the fuel/air is mixed before being compressed. Air enters the carb first, then the compressor, then the engine. Like a tire pump, as the air is compressed it gains heat. A lot of heat. On a 30PSI system, the air can get over 300 degrees F. On the shown system there is no way to add a cooler. So the engine sees the hot mixture. There are a few ways to combat the heat with it. I would run methanol. Adding a cooler would cause problems on the system shown. First, there is no room. Second, if you move things around to add the cooler, the mixture of the fuel and air is not going to like all that surface.

The other system is a blow type where the air is first compressed and then mixed with the fuel. On this system a cooler can be easily added after the compressor. Because there is no fuel in the air at this point, there is no problems with condensation. The turbo can be mounted in the front, next to the exhaust where it should be.

The other problem is the GS has fixed timing. As pressure goes up, the timing needs to retard. With methanol, it burns slower than gasoline, so it need to be advanced. In my case I just run the the bike at a fixed timing. This is fine but it sure won't make HP this way. The best thing would be to run a blow type system with fuel injection.

The turbin works by taking heat from the exhaust and converting it to motion which drives the compressor. If you can make heat, you can create boost. So, no you do not have to be wide open to build pressure.

 

[marcovandevelde]

I've done a home-made system on my 1100E. Find it on http://home.wanadoo.nl/marcovandevelde/turbo GSX.htm

It's not the best- nor the fastest system, but it works fine at approx 200Hp and doesn't cost an arm and a leg.

Oh and my system boosts from 3000 rpm onwards!

Marco.

 

[Robert Corrie]

Almost, a turbo makes power from the exhaust gasses (yes the gassses are hot, but its the flow that does it) spining up the turbine on the impeller side that is attached to the compressor side via a common shaft. Boost is dependant on rpm,that's why there is "Turbo Lag". If you get on the gas hard from low revs it takes time for the turbo to spool up and start to build boost. Once you have good boost, then the fun begins.

 

[lecroy]

The turbocharger drive operates on thermodynamics.

It is a common misconception that the exhaust turbine half of the turbo is driven purely by the kinetic energy of the exhaust (like holding a kid's toy pinwheel behind your tailpipe). While the kinetic energy of the exhaust flow does contribute to the work performed by the turbo, the vast majority of the energy transfered comes from a different source.

When we talk about gasses: High heat, high pressure, and low volume are all high energy states. Low heat, low pressure, and large volumes are low energy states.

Exhaust gases exit the cylinders at high temperature and high pressure and enters the turbine inlet (a very small space). At this point, we have very high pressure, and very high heat, so our gas has a very high energy level.

As it passes through the diffuser and into the turbine housing, it moves from a small space into a large one. Accordingly, it expands, cools, slows down, and dumps all that energy - into the turbine that we've so cleverly positioned in the housing so that as the gas expands, it pushes against the turbine blades, causing it to rotate and recovering some energy from the heat of the exhaust.

This is a measurable effect: Stick an EGT upstream and downstream of the turbo, and you see a tremendous difference in temperature.

All else being equal, the amount of work that can be done across an exhaust turbine is determined by the pressure differential at the inlet and outlet. In english, raise the turbo inlet pressure, lower the outlet pressure, or both, and you make more power. Pressure is heat, heat is pressure.

 

[Robert Corrie]

No flow ,no go . Period. Simple fact, the flow of whatever fluid moves across the turbine blades turns them and through the common shaft turns the impeller,creating boost. Pressure is not heat,pressure is pressure.If I stack up bricks is the one on the bottom hotter? No.

 

[lecroy]

If you want to understand the relationship between pressure and heat, pump up your tires with a hand pump. Do you think the pump is getting hot from the friction alone? Of course not. This is the basic idea behind how the diesel engine works. As the air is compressed, it gains energy and is heated. Fuel is directly injected into the high pressure and auto ignites.

So while the air heats as it becomes compressed, it also cools as it expands. Another good example would be how an air conditioner works.

The turbin is the same. It is just converting this energy into motion.

The best thing would be for you to go to your local library and do some research on the subject.

 

[lecroy]

Pressure is not heat,pressure is pressure.If I stack up bricks is the one on the bottom hotter? No.

You have a valid point about the bricks, but you need to remember that they will act different than a compressable gas.

 

[RacingJake]

Those air molecules don't like to be compress do they.

Our -60's turbines used for air start and power for jet aircraft would get up to 500 degrees on the compressor stage only, now the turbine side of the house could get over 1800 degress. The fun part was cranking them up over 42,000 rpms.

 

[flyingace]

increased pressure = increased heat is part of Charles Law. This governs gases, not solids. See http://www.pmel.org/HandBook/HBpage20.htm

 

[RacingJake]

I bet with enough pressure you can change the state of a brick too, maybe turn it into a liquid then gas :idea:

 

[RacingJake]

So while the air heats as it becomes compressed, it also cools as it expands. Another good example would be how an air conditioner works.

A heat exchanger and 2 air research turbo can change 450 degree inlet air into 40 degree outlet air just by the use of expansion. All you need is volume.

 

[Anonymous]

Turbo housing

Turbo housing

A turbo can work just as well when mounted a good distance from the head. The turbine housing needs to be sized appropriately to make proper use of the kinetic energy of the exhaust gasses. If a turbo which is sized to harness the energy of the exhaust gasses as they expand is used too far from the head then the result will not be good.

Do a little google search and you will find companies mounting turbos under the boot floor of sedans and trucks. Doing this eliminates the need for an intercooler as well. The results are very impressive. Just like playing naturally aspirated, the combination (i.e. turbine housing) needs to be matched.

 

[lecroy]

Re: Turbo housing

Re: Turbo housing

My bike does not have a boot floor, but maybe next time I can find a way to add one.

 

[melray]

interesting discussion, missed point-

interesting discussion, missed point-

Marco your project is just brilliant, well done sir! Any clues on a starting point for jetting?

Gentlemen! Yes, heat is pressure, however you could put a torch on the turbine blades until they melted and no boost would occur. Or do as the previous owner of my donor turbo did, burn the car down around the turbo... still no boost.

No question that maintaining the temp of the exhaust gasses will maintain the pressure level, also that cooling those gases reduces the pressure, however it is the flow of those gases pushing the turbine blades that spins the air compressor, producing the intake pressure we seek.

Marco's (wow! ) installation demonstrates that enough flow can be had to be effective, even with the cooling of a full size 4-1 exhaust upstream of the turbo. How much power can a skinny rear tire use, anyway?

 

[marcovandevelde]

Melray, thanks for your enthousiasm.

My bike indeed has a longer-than-usual-exhaust path to the turbo, but works great nevertheless. The benefit is that I have created a smooth, even flow with these equal length downtubes. The downside is a bit more lag, but as I use a VNT turbo, this lag has become neglectable.

Starting point on jetting?
I currently have DJ126 mains in there (orig. 34mm mikunis), and lifted the jetneedles one clip-position higher. Don't remember the airscrew-setting.
This way it runs a bit rich (with dynamic boostcompensation on the floatbowls!), I still need to put it on the dyno to check fuelling throughout the range. I can only do that in a couple of weeks as my clutch is fried now. Will fit a lockup clutch to prevent re-frying too.

I have chosen a 160/60-18 rear tyre, as I rather want the tyre to spin than the std. trans to break. For a wider tyre I'd need an offset sprocket anyway, not a good idea with this kinda power.

Greetz, Marco.

 

[lecroy]

Hello all you one time posters