A stroke of 65mm would give you 4903cc, which is perfectly fine for the use it's going to have.Originally Posted by jediali
Looking forward to more updates.
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A stroke of 65mm would give you 4903cc, which is perfectly fine for the use it's going to have.
Looking forward to more updates.
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Visca Catalunya!
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I'm pretty sure the Carrera GT has a 5733cc V10...
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my mistake
autozine.org
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currently occupied by work now i have graduated, but i will certainly have something major by the new year. hopefully stroke,combustion chamber redesign and fuel injectors.
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I am not quite sure how your VVL works... How do you deactivate the smaller spring?
Ahh stepless intake manifolds. I know of a few but my favourite is definately the one used on the Mazda 787B (the only wankel and the first japanese car to win Le Mans!) I like the idea of you design but I can see some problems that are fixable. To start I am assuming you want to optimise the whole rev range with the SIM (Stepless Intake Manifold) and I am assuming that it would idle around 1000rpm (slightly above average) and would continue beyond 8000rpm. Now if that is the case then the length of the intake manifold at 1000rpm needs to be 8 times longer than it is at 8000rpm (assuming it doesn't change it's cross sectional area). From the pictures I can see you have a much lower ratio available from the design (only about 2:1 max). Basically the design needs to be able to move more. Also If you are going the stratified root (which I think would be good to do) Then a great place to minimise turbulance is the intake manifold. Now your current design is curved and that is good for saving space but bad if you want the smoothest flow. I suggest using the straight telescopic tube system, the only thing you need to worry about is how you are going to move the pieces... Oh and supporting the moving pieces.
I am pretty sure that FSI engines are still spark ignition direct injection engines. Also I think you might have misunderstood something about FSI. It isn't about making the air as still as possible, in fact during SC operation there is increased motion in a non-chaotic movement (basically it swirls around instead of random turbulance) this concentrates the small amount of fuel injected late in the compression stroke around the spark plug. So basically it is about creating increased organised motion to maintain a combustable air/fuel ratio around the sparkplug while allowing the rest of the cylinder to be full of air only. You are correct about full throttle operation.
Stratified charg operation in FSI enginescheck out this link.
By the way VVT stands for Variable Valve Timing and VVL stands for Variable Valve Lift. There is also VVD which is Variable Valve Duration but that is pretty rare. Also about my asking if you are stuck on using poppet valves I meant that there are other valve systems (rotary valves, disk valves, open ports ect.). Almost all 4 stroke engines in use today use poppet valves.
Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
Engine torque is an illusion.
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great work!
I´d like to mention that the plenum in this picture:
http://www.ultimatecarpage.com/forum...4&d=1163723176
..is not working as well as it could. I prefer to think structure so that air flow doeset go over any "other" intake pipe. I can show few samples for you (click first flg then again these links!)
This is the best known structure of plenum:
Rate from 1-10 is 9 (higher number better structure)
http://www.kovaa.com/?page=shop&psub=view&id=1013
And this is from Toyota IMSA 502E turbo engine this is not the best, but quite good. Rate from 1-10 is 7
http://www.kovaa.com/?page=shop&psub=view&id=1019
Rate from 1-10 is 7 also
http://www.kovaa.com/?page=shop&psub=view&id=1014
Thaks for www.kovaa.com for permission to show prohibited area
Last edited by jkorpi; 11-20-2006 at 02:22 AM.
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i couldn't put figures to my design unless i done genuine calculations, the FSI system only uses spark ignition at full throttle.
all current vvt fits under:
cam phasing variable valve timing - open/close
cam changing variable valve timing - lift/duration
notice how the FSI uses the piston to suppress and slow down tumble at the TDC. the air isn't exactly motionless but i am using FSI as a guideline,
The intake design to me is a balance between gas turbulence and shockwave tuning, like the exhaust, the latter-see pic 1
One can also use nozzles and various cross sections to control air turbulence in a duct, but mostly -see pic 2
therefore a simultaneous equation between developed versions of these expressions would give me design guidelines. This results in a non-linear relationship, ie just cause it revs 8 times higher doesnt mean the intake has to be 8 times shorter necesarily. What was your idea for the 8x length business? also you know quite a bit, did you just spout that (cos your already brainy ) or did you have to research it? One of the reasons my design is so pickable is becaue i havent put time into matching these equations with the actual model
Last edited by jediali; 11-20-2006 at 07:16 AM.
autozine.org
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supergreat work!
I´d like to mention that the plenum in this picture:
http://www.ultimatecarpage.com/forum...4&d=1163723176
..is not working as well as it could. I prefer to think structure so that air flow doeset go over any "other" intake pipe. I can show few samples for you (click first flg then again these links!)
This is the best known structure of plenum:
Rate from 1-10 is 9 (higher number better structure)
http://www.kovaa.com/?page=shop&psub=view&id=1013
And this is from Toyota IMSA 502E turbo engine this is not the best, but quite good. Rate from 1-10 is 7
http://www.kovaa.com/?page=shop&psub=view&id=1019
Rate from 1-10 is 7 also
http://www.kovaa.com/?page=shop&psub=view&id=1014
Thaks for www.kovaa.com for permission to show prohibited area
think of my pictures as guidelins to my ideas, not strictly functional components.
i know cars such as 911 boxer 6's use open plenums (based on resonace intake). These are difficult to engineer and are usually discreet (operate well/designed for 1 engine speed only) or have one or two modes but are not continuosly variable. But my theorie(s) arent based on plenum intakes. As you probably know a plenum operates by using the sudden induction charges to one cylinder to encourage air flow down a neighbouring intake. see:
http://www.autozine.org/technical_sc...ariable-Intake
this page mentions variable length intake (my general approach) and plenums as you discuss. I really want to optimise combustion conditions, ie get the intake charge just right at every rpm. My idea is treat the engine as a human organ, ie something that adjusts itself to conditions, this is converse to most engine today that are optimised for a single sweetpoint (usually 3000rpm in petrol engines).
autozine.org
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i couldn't put figures to my design unless i done genuine calculations, the FSI system only uses spark ignition at full throttle.
all current vvt fits under:
cam phasing variable valve timing - open/close
cam changing variable valve timing - lift/duration
notice how the FSI uses the piston to suppress and slow down tumble at the TDC. the air isn't exactly motionless but i am using FSI as a guideline,
The intake design to me is a balance between gas turbulence and shockwave tuning, like the exhaust, the latter-see pic 1
One can also use nozzles and various cross sections to control air turbulence in a duct, but mostly -see pic 2
therefore a simultaneous equation between developed versions of these expressions would give me design guidelines. This results in a non-linear relationship, ie just cause it revs 8 times higher doesnt mean the intake has to be 8 times shorter necesarily. What was your idea for the 8x length business? also you know quite a bit, did you just spout that (cos your already brainy ) or did you have to research it? One of the reasons my design is so pickable is becaue i havent put time into matching these equations with the actual model
Actually according to Audi FSI engines use spark ignition at all times...
about the VVT I am getting confused I think this is more a question of grammar...
VVT is Variable Valve Timing
VVL is Variable Valve Lift
VVD is Variable Valve Duration
Timing is when the valves open and close in relation to crank angle but not in relation to each other.
Lift is how much the valves open (normally in mm)
Duration is the amount in degrees of crank travel between when the valves open and close.
can we agree to maintain these simple terms as they are instead of calling it all VVT and explaining which one we mean using words like phasing and changing?
Also in FSI engines the piston design is actually helping to maintain constant motion to ensure that the fuel stays near the sparkplug. The ms the air slows down is the ms that the fuel falls away from sparkplug.
About the 8x longer thing about the intake. I did do alot of reseach about 2 stroke tuned exhausts (I worked alot with shockwaves and how they act). The formula you showed about intake length seems like rubbish. As far as I can see it doesn't work if I use SI units. however another equation I found for shockwave timing in exhausts does work and is a linear relationship with engine speed. Hence my saying that it should be able to span a ratio equal to the rev range ratio. Think about it, flow through the intake increase with engine speed in a linear relationship. The time that the shockwave has to return to the intake valve decreases in a linear relation with speed as well. Therefore your intake needs to cover at least the same range ratio that the engine speed does. Unless you only want to optimise a small part of the rev range. of course if the valve timing or duration or lift changes then the length will not be linear but you still need at least 8:1 ratio to cover 1000-8000rpm.
Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
Engine torque is an illusion.
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yes...i will reply later when i have time to get my books together
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1) from a systems design point of view i like the way i have been taught the name of VVT systems (i expect (and hope) you are not getting confused by the manufacturers names for theses systems because that is largely misguiding) - (i do know what cam duration etc. is too)
2)is all that FSI stuff on the Audi page? the book i read looks at all lean-burn/heterogeneous mixture/DI petrol systems. This knowledge is repeated in 3 of my automotive textbooks. If you are right (probably are) then my system would not be based on a FSI system.
3) as for intake. I have no actual numbers, but i think various shockwaves can be used to help other cylinders therefore timing (hence distance) can be selected from other cylinders (if you get me). also there can be various regimes, where different cylinders are using different cylinders as the revs climb due to the lack of intake variability.
thanks for your time on this, its good to get a few people interested in discussing this. I am approaching the end of what i can really talk about from theory before getting my head back into the books and doing some simulations. seems you probably have a few more ideas how would you go about improving what ive proposed.
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1) from a systems design point of view i like the way i have been taught the name of VVT systems (i expect (and hope) you are not getting confused by the manufacturers names for theses systems because that is largely misguiding) - (i do know what cam duration etc. is too
2)is all that FSI stuff on the Audi page? the book i read looks at all lean-burn/heterogeneous mixture/DI petrol systems. This knowledge is repeated in 3 of my automotive textbooks. If you are right (probably are) then my system would not be based on a FSI system.
3) as for intake. I have no actual numbers, but i think various shockwaves can be used to help other cylinders therefore timing (hence distance) can be selected from other cylinders (if you get me). also there can be various regimes, where different cylinders are using different cylinders as the revs climb due to the lack of intake variability.
thanks for your time on this, its good to get a few people interested in discussing this. I am approaching the end of what i can really talk about from theory before getting my head back into the books and doing some simulations. seems you probably have a few more ideas how would you go about improving what ive proposed.
1) Nope I dont assume anything from names only, I do my own research and find out how systems work. It is just that to me VVT cant have anything to do with lift or duration, only the timing is affected by VVT. Plus your statement about all VVT systems fitting into one of two catergories seems misleading as BMW's VVL system Valvetronic is neither a cam changing nor a cam phasing system infact the change in lift is brought about without doing anything to the camshafts at all only the lifter arm ratio is changed. (by the way a system that can do the same sort of thing would be great on your V10!)
2) Most of it is but I did read a few mags that went into alot of detail about the "new" FSI system. I believe the FSI system differs because it isn''t throttled by the amount of petrol injected (they still have throttle valves) the whole point is to reduce the amount of fuel injected during part throttle operation.
3) I am a little confused now... Do you plan on designing an intake where all cylinders breath from a common plenum? or are you planning on making an intake so that each cylinder has it's own open intake? I was assuming the later hence the 8x thing (this isn't true for Plenum designs). I believe designing each cylinder with it's own intake is a much better idea for a few reasons. First of all if you want to use shockwaves to the most advantage you have to use them fast and without them having to change shape too much and you need to contain them as much as possible. With plenum chambers you have to allow for all of this to happen anyways (ie shockwaves have to travel further, any use you put them to will happen later, the shockwaves will be forced to change shape and force vectors, and there is increased possiblity of wasting energy due to imperfect seals ect.) IIM (Independant Intake Manifolds) are the way to go.
4) About improving your design: Basically you should know exactly what you want to do with this motor (not it's use but why you want to make it at all) Engines today have many parts that can be bettered by design. I want to look at your engine and see new ideas a unique engine not just a "spec monster" that has the same basic design with all the right numbers.
Ideas for things to change:
-Throttle valves: current engines have at least two sets of throttle valves normally one in the throttle body(s) and the intake valves themselves (yes they too act as throttle valves!) Get rid of the throttle body valves (all they do is cause pumping losses and add weight) get better throttle control out of the actual intake valves.
-Valve Activation. Todays engines are pretty good at this but there is still much room for improvement. Personally I want to see a combined stepless wide range VVT, VVL, and VVD system attached to both the intake and exhaust cams. If you can do this with a minimum of parts and with little added friction and weight that is the key!
-If you really want to improve something look at the crankshaft and con-rod system itself. Todays best crankshafts are only 30% effecient!!! massive room for improvement however don't you dare think the scotch yoke is the answer (it tops out at 22%) and don't change the reciprocating style piston movement (you should strive to make it move in a more sinusoidal way though) I have an idea about how to increase the effeciency alittle (up to about 45-50%) if you want...
-I always thought it would be great if an engine could change from being a 4 stroke to a 2 stroke or maybe use a cycle with more than 4 strokes for low speed economy, 4 stroke operation for mid power operation and 2 stroke for max power!
there is alot more that you could think about...
other than that though I would go with independant intakes pulse optimising exhaust and keep your stratified charge theory.
Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
Engine torque is an illusion.
Enthusiast
OK great, seems you have some nice ideas (thinking outside the box), and its funny we both want the same thing. we are narrowing down what should really be done on the V10.
Just to clean up the intake question, the plenum is treated more like a branch. for example if all 10 intake tracts lead back to a common branch then:
when intake valve opens expansion wave is created, it travels back up intake tract and reaches branch, at the branch the wave splits in 2, a compression wave travels down other 9 intake tracts towards cylinders(useful),a expansion wave travels back down the same tract (not so useful). i guess technically this is a plenum but it is small and exists in all intake systems.I like your IIM system, sounds great, i see them on racing engines.
i don't want a spec-monster (nice term) but a further extension to an engine such as the RS4 V8, superb low end torque but also high end capability.
Last edited by jediali; 11-21-2006 at 04:17 PM.
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Sorry to take this off topic, but we have been waiting nearly a year for hightower99 to post dyno graphs of any of his ideas that give massive improvements.
Any chance any are available yet?
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No Mr. Craig, I expect you to die! On the inside. Of heartbreak. You emo bitch
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Technically you should use the PM system for this instead of disrupting threads...
Anyways I do have the two dyno charts I need, however they are on paper and the changes from stock to tuned includes more than just epoxy on the intakes so it isn't definitive proof.
Please use the PM system from now on concerning this matter.
Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
Engine torque is an illusion.
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