Is 450-500 WHP achievable with boost being under 24 psi ?
#16
Evolved Member
iTrader: (6)
alright that makes sense. I was under the impression that the turbos flow rate meant that if it made the same horsepower with less boost it was the same as running the smaller turbo with more boost. But i can see how boosting a turbo much higher would cause a lot more heat and such.
#17
Ya i agree with Scorke and some of the others as well, it makes sense. ........Thanks everyone!
I have another question but not sure if i should put it in the drive train section or here, let me know i u guys think i should move it..anyways.... its the following:
what determines how high an engine can rev? meaning what's the highest rpm it could go up to. is it displacement? or more of the porecision machining that took place on the mechanical components of the system. I guess, why cann;t a 2.0l engine rev as high as the 1000cc motorbike engine? what does it take for an engineer to design such a thing? would like ur comments.
Thanks
I have another question but not sure if i should put it in the drive train section or here, let me know i u guys think i should move it..anyways.... its the following:
what determines how high an engine can rev? meaning what's the highest rpm it could go up to. is it displacement? or more of the porecision machining that took place on the mechanical components of the system. I guess, why cann;t a 2.0l engine rev as high as the 1000cc motorbike engine? what does it take for an engineer to design such a thing? would like ur comments.
Thanks
Last edited by detroit pistins; Dec 24, 2008 at 08:07 AM.
#18
Evolved Member
iTrader: (5)
Ya i agree with Scorke and some of the others as well, it makes sense. ........Thanks everyone!
I ahev another question but not sure if i should put it in the drive train section or here, let me know i u guys think i should move it..anyways.... its the following:
what determines how high an engine can rev? meaning what's the highest rpm it could go up to. is it displacement? or more of the porecision machining that took place on the mechanical components of the system. I guess, why cann;t a 2.0l engine rev as high as the 1000cc motorbike engine? what does it for an engineer to design such a thing? would like ur comments.
Thanks
I ahev another question but not sure if i should put it in the drive train section or here, let me know i u guys think i should move it..anyways.... its the following:
what determines how high an engine can rev? meaning what's the highest rpm it could go up to. is it displacement? or more of the porecision machining that took place on the mechanical components of the system. I guess, why cann;t a 2.0l engine rev as high as the 1000cc motorbike engine? what does it for an engineer to design such a thing? would like ur comments.
Thanks
First your pistons have weight, which may seem obviously but listen further. As you spin the motor you are moving the pistons up and down faster and faster. Well that motion translates into forces upon the rods, crank, and wrist pin of the piston. Quite simply if the lower assembly isn't strong enough you will simply make the lower assembly fly apart. A rod bolt will stretch, rod snap, piston break, or some other failure that will end your engine. One very important thing to consider on the bottom end is the stroke. Stroke is the distance that the piston has to travel up and down per rev. Longer strokes means that piston can be moving quite fast at even pretty modest RPM.
Secondly we have the valve train which needs to be able to close that valve fast enough before the piston decides to slam into it. If the valve springs aren't up to the job you could potentially have a piston slap a valve at high rpm . Well no need to describe how bad that would be. At the very least your springs will not be adequate and you'll loose compression as the valve bounces around on the seat.
Generally speaking if you want to have a higher RPM limit you decrease the stroke of the motor, assuming you have tapped out the physical limits of the parts. In this way you reduce piston speed and allow the rev limit to climb. To make the 2.0L motor capable of a 10k rpm limit all that's really required is a beefy valve train upgrade spring wise and a forged set of internals. To go higher will require taking stroke out of the motor to allowing for lower piston speeds thus allowing higher rpm limits.
Last edited by RoadSpike; Dec 23, 2008 at 10:21 PM.
#20
Evolved Member
iTrader: (5)
I'll borrow a few bits out of http://www.kidzuku.com/StrokeOrNot.pdf which is the stroke sticky in the drive train section. Read up on the pdf its good information on what your asking.
More or less if we want to forget a whole world of other things on why the bottom end will or wont take 10k rpm its simply about acceleration. That is how fast the piston and rod combo change direction at any given point in time. This would equate to the G forces involved and how many G's the material your using can stand before it simply gives up and becomes so elastic its unstable or snaps.
#21
Not really certain what you mean by "how well".
I'll borrow a few bits out of http://www.kidzuku.com/StrokeOrNot.pdf which is the stroke sticky in the drive train section. Read up on the pdf its good information on what your asking.
More or less if we want to forget a whole world of other things on why the bottom end will or wont take 10k rpm its simply about acceleration. That is how fast the piston and rod combo change direction at any given point in time. This would equate to the G forces involved and how many G's the material your using can stand before it simply gives up and becomes so elastic its unstable or snaps.
I'll borrow a few bits out of http://www.kidzuku.com/StrokeOrNot.pdf which is the stroke sticky in the drive train section. Read up on the pdf its good information on what your asking.
More or less if we want to forget a whole world of other things on why the bottom end will or wont take 10k rpm its simply about acceleration. That is how fast the piston and rod combo change direction at any given point in time. This would equate to the G forces involved and how many G's the material your using can stand before it simply gives up and becomes so elastic its unstable or snaps.
Thanks for the link, i have been reading it for a while but not done yet.
i think when it comes to the material of the internals, as long as they stay within the elastic range then we should be fine simply because all material undergo surface stresses and fatigue at high temps, and accelartion, its when they cross the yielding point and all the deformations becomes plastic then that's when u start breaking things up and interfere with other components such as teh cylinder walls...etc. thus, what do u think if titanium was used for the material which has lower weight and higher yielding point (assumming that material cost is not an issue), u think higher rpm revs are achievable this way?
Thanks
#22
Evolved Member
iTrader: (5)
Thanks for the link, i have been reading it for a while but not done yet.
i think when it comes to the material of the internals, as long as they stay within the elastic range then we should be fine simply because all material undergo surface stresses and fatigue at high temps, and accelartion, its when they cross the yielding point and all the deformations becomes plastic then that's when u start breaking things up and interfere with other components such as teh cylinder walls...etc. thus, what do u think if titanium was used for the material which has lower weight and higher yielding point (assumming that material cost is not an issue), u think higher rpm revs are achievable this way?
Thanks
i think when it comes to the material of the internals, as long as they stay within the elastic range then we should be fine simply because all material undergo surface stresses and fatigue at high temps, and accelartion, its when they cross the yielding point and all the deformations becomes plastic then that's when u start breaking things up and interfere with other components such as teh cylinder walls...etc. thus, what do u think if titanium was used for the material which has lower weight and higher yielding point (assumming that material cost is not an issue), u think higher rpm revs are achievable this way?
Thanks
#28
Evolved Member
iTrader: (10)
Have to resurrect this thread once more, since I thought of it as very interesting. When is it adviseable to upgrade the internals of the car? rods, pistons, crank. i am running a simple evo 9 with stock parts and don't know if it's wiser to strengthen now or to strengthen when I or if I ever upgrade the turbo.
Pistins, what hp did u end up making? what did u do?
Pistins, what hp did u end up making? what did u do?
#29
Have to resurrect this thread once more, since I thought of it as very interesting. When is it adviseable to upgrade the internals of the car? rods, pistons, crank. i am running a simple evo 9 with stock parts and don't know if it's wiser to strengthen now or to strengthen when I or if I ever upgrade the turbo.
Pistins, what hp did u end up making? what did u do?
Pistins, what hp did u end up making? what did u do?
for ur question, i think its best to built the motor at first especialy if ur eventualy thinking of it just to avoid any other components that might fail down the road, such as breaking the block incase u throw a rod or something. I think ur decision is a function of both, how much power u r planning on making, and how much of an impact ur wallet is welling to take.
cheers!