Chargecooling through overboost (a path beyond 300 RWHP)
03-07-2005, 09:37 PM
#28
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Why don't you use the heat to supercool the intake air?
I'd use 2 intercoolers to maximize the intake air cooling power. 1st I'd install an air/water intercooler (to get the temperature down to near ambient) and then another air/glycol intercooler (to get it down below ambient). Instead of running an airconditioner to cool the glycol, I'd use an ammonia refrigerator. I would take the excess heat coming from the oil, water and most of all the exhaust gases to power that thing and then I'd use a large glycol bath to increase the cooling capacity (since you won't run at full throttle all the time).
http://www.nh3tech.org/absorption.html
I'm pretty sure this way you could maximize power and efficiency of a turbocharged engine, since cooling power is basically free. But it would probably also be the most complicated way to cool it and maybe end up being pretty heavy too and if you ever get into a serious accident, if the accident itself (due to that powerful engine) doesn't kill you, the ammonia might.
I'd use 2 intercoolers to maximize the intake air cooling power. 1st I'd install an air/water intercooler (to get the temperature down to near ambient) and then another air/glycol intercooler (to get it down below ambient). Instead of running an airconditioner to cool the glycol, I'd use an ammonia refrigerator. I would take the excess heat coming from the oil, water and most of all the exhaust gases to power that thing and then I'd use a large glycol bath to increase the cooling capacity (since you won't run at full throttle all the time).
http://www.nh3tech.org/absorption.html
I'm pretty sure this way you could maximize power and efficiency of a turbocharged engine, since cooling power is basically free. But it would probably also be the most complicated way to cool it and maybe end up being pretty heavy too and if you ever get into a serious accident, if the accident itself (due to that powerful engine) doesn't kill you, the ammonia might.
03-07-2005, 10:21 PM
#30
It would just be cheaper to get a commercial water chiller system and mount it on a trailer with a Catapillar generator set. When you think you might get into a race hook it up and tow it with you. Hook up some quick disconect hoses to the air/liquid IC and you have a big heat sink.
03-08-2005, 12:33 AM
#31
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There is no chiller.
The air cools by expansion. Upon reflection, I realized that the throttle body acts as the expansion valve. If you increase boost and limit the airflow (by not opening the throttle all the way), this has the same effect. Indeed if the throttle were electronic like the 350Z, pulling the throttle into the control loop would allow this charge cooling effect without ant additional hardware.
Simply reprogram the system to close the throttle a little to limit manifold pressure while shoving the boost past where you normally would at WOT. The cooler will dump the heat and density will increase. The system has to have an electronic throttle, because the driver can't be trusted to avoid WOT.
I used to do this with my old XR4TI, without realizing that this was what I was doing . Just as the boost came up, I backed off the throttle a little to keep it from detonation. This seemed to make it a bit faster than pure WOT all the way.
The air cools by expansion. Upon reflection, I realized that the throttle body acts as the expansion valve. If you increase boost and limit the airflow (by not opening the throttle all the way), this has the same effect. Indeed if the throttle were electronic like the 350Z, pulling the throttle into the control loop would allow this charge cooling effect without ant additional hardware.
Simply reprogram the system to close the throttle a little to limit manifold pressure while shoving the boost past where you normally would at WOT. The cooler will dump the heat and density will increase. The system has to have an electronic throttle, because the driver can't be trusted to avoid WOT.
I used to do this with my old XR4TI, without realizing that this was what I was doing . Just as the boost came up, I backed off the throttle a little to keep it from detonation. This seemed to make it a bit faster than pure WOT all the way.
03-08-2005, 01:06 AM
#32
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Originally Posted by silverx8
There is no chiller.
The air cools by expansion. Upon reflection, I realized that the throttle body acts as the expansion valve. If you increase boost and limit the airflow (by not opening the throttle all the way), this has the same effect. Indeed if the throttle were electronic like the 350Z, pulling the throttle into the control loop would allow this charge cooling effect without ant additional hardware.
Simply reprogram the system to close the throttle a little to limit manifold pressure while shoving the boost past where you normally would at WOT. The cooler will dump the heat and density will increase. The system has to have an electronic throttle, because the driver can't be trusted to avoid WOT.
I used to do this with my old XR4TI, without realizing that this was what I was doing . Just as the boost came up, I backed off the throttle a little to keep it from detonation. This seemed to make it a bit faster than pure WOT all the way.
The air cools by expansion. Upon reflection, I realized that the throttle body acts as the expansion valve. If you increase boost and limit the airflow (by not opening the throttle all the way), this has the same effect. Indeed if the throttle were electronic like the 350Z, pulling the throttle into the control loop would allow this charge cooling effect without ant additional hardware.
Simply reprogram the system to close the throttle a little to limit manifold pressure while shoving the boost past where you normally would at WOT. The cooler will dump the heat and density will increase. The system has to have an electronic throttle, because the driver can't be trusted to avoid WOT.
I used to do this with my old XR4TI, without realizing that this was what I was doing . Just as the boost came up, I backed off the throttle a little to keep it from detonation. This seemed to make it a bit faster than pure WOT all the way.
03-08-2005, 07:43 AM
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silverrx8, cooling the air flow without increasing air restriction is the only way to go. You have to come up with ways to increase cooling power without increasing air restriction, there's no alternative.
Look at it thermodynamically: How much work it takes to generate that pressure in the first place. It's adiabatic compression (not isothermal) and the compressor has an efficiency of less than 70%. You don't want to waste all that energy by using a restrictor after doing all that work. Remember that you have to take that energy from somewhere in the first place.
Look at it thermodynamically: How much work it takes to generate that pressure in the first place. It's adiabatic compression (not isothermal) and the compressor has an efficiency of less than 70%. You don't want to waste all that energy by using a restrictor after doing all that work. Remember that you have to take that energy from somewhere in the first place.
03-08-2005, 11:25 AM
#34
I wanted you to do it Fred. 
Let's see, so what your saying is that all we need is to get an oversize TB ( and the RX is electronic) and program it not to open all the way? The oversize is so that you get the same area as before when you opened the smaller one.
It's to obvious for me to know where to start. There is an opimum size for the Tb yet we can't use it that way because we want some delta accross the throttle plate. You can get away with less than you can with a carb but there is a need for some. This is the reason that if you buy an oversize TB yet have not done anything else you will have drivability problems.
If this were so then why does it not work normally asperated?
This whole idea of making more mass flow then restricting it to thin it out is rediculous. There is no such thing as a free lunch.
Your experiance with your old car is believable because it was going into detonation and by lifting you reduce the mass flow and the amount of pressure produced in the chamber is less. That is the exact point I was making about your not being able to just put more mass in because it is cooler and fits. When you got the mass in you are going to get more pressure and that is limited by many factors mainly the fuel. I go back to the bold print above.
But it is good to see you thinking. Just don't expect to come up with something the factorys don't know already. Not impossable, just not common. If there was such an easy way to increase performance don't think they are hiding it from you.
I'm a big fan of reduced intake temps, that is why I'm playing with the axial flow compressor. Did you know that Champ Cars do not use coolers? They use turbos built by the best engine builders in the world. They would like to but the rules don't allow them. So don't you think they would love to find a way to get cooling by just changing the throttle? Or any other way of getting around the rules.
Yes, that is the example I was looking for. Champ Cars with engines built by Honda, Toyota, Ford. I can't keep up with who is suppling engines for what anymore so I might be outdated. Point is that they don't lack for resorces.
Look, any of you guys that can come up with a better way to cool the charge is wasting his time here. You can make yourself a lot of money by
going to some of the endurance teams that run turbos. You can be rich instead of insulted.
Yes, and what Globi says^^^^^^^^
Let's see, so what your saying is that all we need is to get an oversize TB ( and the RX is electronic) and program it not to open all the way? The oversize is so that you get the same area as before when you opened the smaller one.
It's to obvious for me to know where to start. There is an opimum size for the Tb yet we can't use it that way because we want some delta accross the throttle plate. You can get away with less than you can with a carb but there is a need for some. This is the reason that if you buy an oversize TB yet have not done anything else you will have drivability problems.
If this were so then why does it not work normally asperated?
This whole idea of making more mass flow then restricting it to thin it out is rediculous. There is no such thing as a free lunch.
Your experiance with your old car is believable because it was going into detonation and by lifting you reduce the mass flow and the amount of pressure produced in the chamber is less. That is the exact point I was making about your not being able to just put more mass in because it is cooler and fits. When you got the mass in you are going to get more pressure and that is limited by many factors mainly the fuel. I go back to the bold print above.
But it is good to see you thinking. Just don't expect to come up with something the factorys don't know already. Not impossable, just not common. If there was such an easy way to increase performance don't think they are hiding it from you.
I'm a big fan of reduced intake temps, that is why I'm playing with the axial flow compressor. Did you know that Champ Cars do not use coolers? They use turbos built by the best engine builders in the world. They would like to but the rules don't allow them. So don't you think they would love to find a way to get cooling by just changing the throttle? Or any other way of getting around the rules.
Yes, that is the example I was looking for. Champ Cars with engines built by Honda, Toyota, Ford. I can't keep up with who is suppling engines for what anymore so I might be outdated. Point is that they don't lack for resorces.
Look, any of you guys that can come up with a better way to cool the charge is wasting his time here. You can make yourself a lot of money by
going to some of the endurance teams that run turbos. You can be rich instead of insulted.
Yes, and what Globi says^^^^^^^^
Last edited by Richard Paul; 03-08-2005 at 11:29 AM.
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