Turbocharger Cooling

[taledarkside]

+1, thats what i've seen but I havn't been into turbos for years. It just lets the car idle for couple of minutes to cool the turbo and prevent coking of oil.

[bikefreak600]

Originally Posted by Loki047

Really? how is it flowing less CFM? I guess the next step would then be think about the effects EGT have on performance

think about it, basic engine mechanics, at partial throttle there is a flat plate in throttle body or carb that limits the amount of air entering engine lol

unless now they make cars that only run at %100 throttle

if you couldnt control the amount of cfm a engine flows than i guess all performance parts are usless.... and 90% of engine mods are designed to increase air flow

just read my earlier post then do some investigating on how engines work and you will understand

[taledarkside]

But what about diesel where there is no throttle plate. CFM entering the motor is the same.
exhaust, when there is a load is getting a stronger exhaust pulse.

[TripleZ]

Originally Posted by taledarkside

But what about diesel where there is no throttle plate. CFM entering the motor is the same.
exhaust, when there is a load is getting a stronger exhaust pulse.

See my previous post about the energy balance. The turbocharger is spinning but not spinning fast enough to create boost. When you tip into the throttle on a diesel, you add fuel, which adds to the energy in the exhaust. The additional energy spools the turbo which then creates boost.

[TripleZ]

And since were talking turbos........mines bigger than yours.

[LsilverR1]

Originally Posted by Loki047

Really? how is it flowing less CFM? I guess the next step would then be think about the effects EGT have on performance

yes heat has an effect. no reason to go there. we're talking basics here. the MAIN thing that spins the turbo is exhaust flow. think of a rear mount turbo. a TON less heat. turbo still works. then if you want to talk about how a rear mount turbo sucks then we can talk about Paul Major's drag radial corvette.

http://images.google.com/imgres?imgu...a%3DN%26um%3D1

[TripleZ]

Originally Posted by LsilverR1

yes heat has an effect. no reason to go there. we're talking basics here. the MAIN thing that spins the turbo is exhaust flow. think of a rear mount turbo. a TON less heat. turbo still works. then if you want to talk about how a rear mount turbo sucks then we can talk about Paul Major's drag radial corvette.

Heat is a major player in turbocharging, along with pulse tuning the exhaust. The greater the temperature of exhaust gas entering the turbine section, the more energy there is to extract.

But, as you pointed out with the rear mount turbo...... it is possible to do it on just flow alone. Efficiency sucks and there is a large amount of lag..... but it works. The rear mounts are an interesting solution to a tight packaging problem in the engine bay.

[Loki047]

Originally Posted by TripleZ

Heat is a major player in turbocharging, along with pulse tuning the exhaust. The greater the temperature of exhaust gas entering the turbine section, the more energy there is to extract.

But, as you pointed out with the rear mount turbo...... it is possible to do it on just flow alone. Efficiency sucks and there is a large amount of lag..... but it works. The rear mounts are an interesting solution to a tight packaging problem in the engine bay.

What energy are you extracting from volumetric flow?


I would look into pressure and heat as the sources of energy. It's simple to figure out.

[Loki047]

Originally Posted by bikefreak600

think about it, basic engine mechanics, at partial throttle there is a flat plate in throttle body or carb that limits the amount of air entering engine lol

unless now they make cars that only run at %100 throttle

if you couldnt control the amount of cfm a engine flows than i guess all performance parts are usless.... and 90% of engine mods are designed to increase air flow

just read my earlier post then do some investigating on how engines work and you will understand

Let's back up. You are at 100% wot with no load. Now you have load on the engine. What's the vfm difference? Assume the turbo has not spooled ie each scenerio ie the charge pipe is disconnected from the intake.

[taledarkside]

I believe the only place to really learn turbos is taking an engineering class.

all the mechanic books I have don't go into detail about how turbos work. Just, it uses exhaust power to build compression on the other side. The end.

And not too many books even state, you need a load to set off a turbo.


"rely on the rapid expansion of hot exhaust gases exiting the cylinders. These gases spin the turbine blades of the pump"

[taledarkside]

Turbochargers also provide more direct fuel savings when compared to a supercharger. The volume, speed and pressure of exhaust gases flowing out of the engine are not only related to engine speed, but also to engine load. An engine under a heavy load has higher internal pressures and temperatures than an engine running under a light load at the same speed. This effect is found on all internal combustion engines, but is especially true for diesel engines. Because the turbocharger is connected to the engine's fuel system, which regulates the supply of fuel in relation to the boost being generated, extra fuel is only delivered when the engine is under load and boost pressures are high. A vehicle with a turbocharged engine travelling at a constant speed on a flat road is placing a relatively small load on its engine- exhaust pressure, boost and fuel delivery is therefore low, and fuel consumption will be close to that of a naturally-aspirated vehicle. The same vehicle maintaining the same speed up a hill will place the engine under a greater load, generating a greater exhaust pressure, raising turbocharger speed, increasing boost pressure and thus causing more fuel to be delivered and more power to be produced. Because boost is related to engine load, the turbocharger only runs at full capacity when the engine is under load. A supercharger, directly geared to the engine, has boost relating solely to engine speed, resulting in higher fuel consumption.

blah blah message to short

[Loki047]

Pressure and temp. Hmm sounds like something I was saying earlier

And yes the best way to learn about turbos is to take some ME courses specifically some intrrnal combustion engines and thermo. I actually spent half a year on a design project with turbo design and patent application. I am a little rusty but the basicshavent changed.

[TripleZ]

I worked at IHI Turbo for a few years. I am definitely more of a supercharger guy as this one is my design. http://www.motivemag.com/pub/feature..._Genesis.shtml

But turbos are fairly easy to learn once you know what the physics are. I was forced to do turbo matching for the aftermarket my first 6 months there........now THAT'll teach you whats going on.

If you really want to learn turbos, here's a couple of books.
Turbocharging the Internal Combustion Engine, N. Watson - (Out of print, but best book)
Advanced Engine Technologies, Heinz Heisler - (Covers alot of engine technology plus a little turbocharging)
Fundamentals of Turbocharging, Nicholas C. Baines - (Haven't read it, but colleges have it)
Axial and Radial Turbines, Hany Moustapha - (More focused on Aeronautical)

[LsilverR1]

Originally Posted by TripleZ

But, as you pointed out with the rear mount turbo...... it is possible to do it on just flow alone. Efficiency sucks and there is a large amount of lag..... but it works. The rear mounts are an interesting solution to a tight packaging problem in the engine bay.

yeah. the dude has broken all kinds of records with that car and is in the final round at most races....all with his inefficient turbo setup and he runs in a class where he has to compete against cars that all go by the same rules as far as engine size and turbo size. so how is it that he's kickin ass? Ive seen dudes like you preach about how its so much less efficient since the day ppl started doing rear mount setups. and everyday you get proved wrong cuz there are some guys kickin some major ass with rear mount setups.

[auditech]

This is a great book...

http://www.amazon.com/Maximum-Boost-.../dp/0837601606

[TripleZ]

Originally Posted by LsilverR1

yeah. the dude has broken all kinds of records with that car and is in the final round at most races....all with his inefficient turbo setup and he runs in a class where he has to compete against cars that all go by the same rules as far as engine size and turbo size. so how is it that he's kickin ass? Ive seen dudes like you preach about how its so much less efficient since the day ppl started doing rear mount setups. and everyday you get proved wrong cuz there are some guys kickin some major ass with rear mount setups.

The fact that he finishes first doesn't prove me wrong.......driver, suspension settings, engine tuning, all come into play for a win. The turbo system and matching WOULD BE better if it was located closer to the engine. You can then take advantage of pulse tuning along with not loosing so much heat. For what he does, the rear mount system works. He is able to sit at the line, rev the engine and wait for the turbo to spool. It works for drag racing, but its still inefficient.

[Loki047]

Originally Posted by auditech

This is a great book...

http://www.amazon.com/Maximum-Boost-.../dp/0837601606

Corky is the shit. He is doing some custom work on my manifold and downpipe for me. He's always willing to talk shop.

[LsilverR1]

Originally Posted by TripleZ

The fact that he finishes first doesn't prove me wrong.......driver, suspension settings, engine tuning, all come into play for a win. The turbo system and matching WOULD BE better if it was located closer to the engine. You can then take advantage of pulse tuning along with not loosing so much heat. For what he does, the rear mount system works. He is able to sit at the line, rev the engine and wait for the turbo to spool. It works for drag racing, but its still inefficient.

Originally Posted by TripleZ

The fact that he finishes first doesn't prove me wrong.......driver, suspension settings, engine tuning, all come into play for a win. The turbo system and matching WOULD BE better if it was located closer to the engine. You can then take advantage of pulse tuning along with not loosing so much heat. For what he does, the rear mount system works. He is able to sit at the line, rev the engine and wait for the turbo to spool. It works for drag racing, but its still inefficient.

My god dude really?

Taken from his page...

Team Major Sets The Bar in Extreme Radial
11/25/08 - Arriving on Thursday Paul and the team goes a 7.36 @ 203 right off the trailer in testing. The word was out we had the field covered by a minimum of 2 tenths. The next day we would improve on that with a qualifying pass of 7.25 @ 205 and 7.28 @ 204, setting the track records for both ET and MPH.


Ok so he's racing against other cars under the same rules and is just as fast or faster. you must not know that much about these classes. there are multiple cars in each class that compete with the worlds most advanced and quality parts. money is no object for the top guys. so this guy is not alone beating up on guys with junk. there are MANY great racers in these classes and the class he competes in is one of the most popular classes.

I am not gonna say his setup is more efficient...or even dead equal with a normally mounted turbo setup. but what he's proving is that even if it is "slighly" more inefficient, its not much. See the car in person (I have). doesnt take any longer to spool it than the normal turbo cars. So this info basically says that you need to update your thinking on how this stuff works.

Im done taking about this. believe what you want. I have given an example that is pretty damn valid. this is just one example. If you go to the lsx shootout races...you will see a TON of fbodies with 88, 91, 98, 102mm's hanging off the back. and these cars are FLYING.

Good luck with your passenger car knowledge...while theres people making 2000+ hp with inefficient turbo setups.

[taledarkside]

Originally Posted by TripleZ

I worked at IHI Turbo for a few years. I am definitely more of a supercharger guy as this one is my design.

If you really want to learn turbos, here's a couple of books.
Turbocharging the Internal Combustion Engine, N. Watson - (Out of print, but best book)
Advanced Engine Technologies, Heinz Heisler - (Covers alot of engine technology plus a little turbocharging)
Fundamentals of Turbocharging, Nicholas C. Baines - (Haven't read it, but colleges have it)
Axial and Radial Turbines, Hany Moustapha - (More focused on Aeronautical)

thinking of getting a mechanic engineering degree just to add to the stuff I already have.

just out of curiosity. How do you do the R&D on a turbo? build a prototype and see if it has the correst boost, lag, spool spin etc... if it fails draw a new one on autocad(etc..) and retry with another prototype?

and how do you build a prototype turbo cast then finish it up with a CNC machine? those blades have some tight angles.

[Loki047]

There is so much bad information here it's aggravating. A remote mounted turbo is always. Yes always a poor alternative to a direct mounted setup. Also if CFM drove turbos remote mounted turbos would not be less efficient. With remote mounts you also I crease your charge pipe to a volume that is less advantagous.

[TripleZ]

Originally Posted by taledarkside

thinking of getting a mechanic engineering degree just to add to the stuff I already have.

just out of curiosity. How do you do the R&D on a turbo? build a prototype and see if it has the correst boost, lag, spool spin etc... if it fails draw a new one on autocad(etc..) and retry with another prototype?

and how do you build a prototype turbo cast then finish it up with a CNC machine? those blades have some tight angles.

For the compressor wheel and turbine wheel.
New turbocharger design relies heavily on multi-axis CFD analysis for the performance side. They try to build the prototype in cyber-space first and run through several iterations before ever cutting a tool. Beyond that, every company has design guidelines for speed, diameters, material limits, clearances, etc.

Once the designer is happy with the wheel and housing, prototypes are made by 5-axis CNC out of billet. This is a really cool process to watch and it takes alot of times since your cutting with a very small bit. The prototypes are tested and tweaks are made by Senior engineers. Repeat and continue.

The final performance iteration that's approved is again cut by 5-axis CNC. Then finely polished by hand to a mirror like finish. Negative master molds are made from a silicon type substance, then a positive is made from another type of silicon. Once you have a positive flexible mold, the plaster casting molds are made, which you pour the aluminum into.

Now that you have a cast wheel, more limit testing is completed. Burst tests, overspeed, high temperature endurance, low temperature starts, etc. Lots of parts are chucked at this point.

For the center section.
A center section takes a different approach since its more mechanical than flow oriented. Once the bearing, lube, and cooling designs are finished on the internal components, the outer shell is designed to accept a certain range of compressor and turbine wheels, dictated by the peak bearing loads.

Prototypes are made from rapid investment cast dies. The parts are then tested for limit conditions, peak compressor speeds, cold and hot endurance, lack of lubrication, min and max bearing clearances. The cool ones are where proximity probes are installed and on a running turbo you can see the different mode shapes that the turbine shaft vibrates at.

Hope this answers your question...... and if you have the time and the will..... a Mechanical engineering degree is definitely worth it. Although, strangely....... I still have to bow down to Pilotx1 once in awhile.

[Dave13]

Pilotx1 weighs a buck-O-five. I'm not bowing down to him. I have to remember to be nice to him, he may be helping me with a project this winter.

[Pilotx1]

hahahaha nothin like commentary withough the backstory from triple

I used to concern myself being as light as I am, that is, until i found out that our bokes test riders are in the 165lb range ready to ride, right where I am... NO RESPRING NEEDED

dave bring the springs tomorrow for milenko

[Triple88a]

I like this thread. Turbo threads always excite me especially on the honda or mustang forums that show up when googling :-D

In the 3 pages of this thread its pretty clear that many people dont really know how a turbo works (not that there is anything wrong with that). Skim through this as a start since it has pics to show you. (since i cant post links yet since i'm a new member here), type in howstuffworks dot com and then turbo in the search bar.

[LsilverR1]

Originally Posted by Loki047

There is so much bad information here it's aggravating. A remote mounted turbo is always. Yes always a poor alternative to a direct mounted setup. Also if CFM drove turbos remote mounted turbos would not be less efficient. With remote mounts you also I crease your charge pipe to a volume that is less advantagous.

wow look how inefficient a remote mount turbo is




Paul+Majors+208+MPH+-+7.41+%40+208.23+MPH+(On+Drag+R

[Loki047]

Originally Posted by LsilverR1

wow look how inefficient a remote mount turbo is




Paul+Majors+208+MPH+-+7.41+%40+208.23+MPH+(On+Drag+R

I assume that was a dyno run or a trip down the strip either way it's not debatable. Unless you have changed the laws of thermodynamics and fluids. In which let's talk we can retire tomorrow. If there are dyno plots of the same car with a direct mout and a remote mount showing equal performance I'm interested.

Debating the effciency loss is a valid debate.

[taledarkside]

Originally Posted by TripleZ

Hope this answers your question...... and if you have the time and the will..... a Mechanical engineering degree is definitely worth it. Although, strangely....... I still have to bow down to Pilotx1 once in awhile.

yup, sure does. thanks. Its always interesting on the way things get made.

couple more questions if you have time.

When a client wants your company to make something. Do they tell you"hey go make this for this application" or do you setup a team and couple engineers come up with ideas on getting general specs.

And for R&D type stuff. Special engineers will work on new theories to turbo development? different bearings, cooling systems, picking different metals (steel with 2% carbon, 5% alumn, 10%copper)


I only bowdown to pilot for his fabrication skills.

[Triple88a]

Taledarkside, i think you're leaning a bit more towards the manufacturing end which is different.

[TripleZ]

Originally Posted by taledarkside

yup, sure does. thanks. Its always interesting on the way things get made.

couple more questions if you have time.

When a client wants your company to make something. Do they tell you"hey go make this for this application" or do you setup a team and couple engineers come up with ideas on getting general specs.

And for R&D type stuff. Special engineers will work on new theories to turbo development? different bearings, cooling systems, picking different metals (steel with 2% carbon, 5% alumn, 10%copper)


I only bowdown to pilot for his fabrication skills.

For an application that has existing hardware available, like for example a 200HP turbocharged 2.0L engine, the client (GM, Chrysler, etc.) give performance targets for efficiency, spool time, torque, and power. Its then up the the engineer to select from available existing compressor wheels, housings, and center sections to meet those requirements. There is some give and take between the two teams. Most often, the performance numbers from the turbo are dropped into a engine model like GT-Power, and tweaks are made to the selection.

New hardware is more complex. There is alot of back and forth. Engine CAD models exhanged, packaging and pierce points have to be nailed down, all while achieving the targeted performance. It boils down to, do new parts need to be invented, or can existing technology be repackaged.

For R&D, it really depends on the size of the company. A larger company, and you will be either in application engineering (matching turbos, repackaging existing technology, new castings, etc.) or research, which involves new materials, approaches, patent opportunities. Smaller the company, and the more hats you wear. Few firms still have pure research departments, so even as an application engineer, your going to be inventing new technologies for the customer.

For me, the best spot to be is in test and development. A design engineer deals with CAD, customer wants, suppliers, pricing, and timetables. A test engineer deals with customer duty cycles, durability, testing, and problem solving. If you break it, you get to invent something to fix it. Much more satisfying.

[Vcook]

where does this badboy factor in?