Turbo vs. Supercharger
#11
10-10-2006, 03:18 PM
RE: Turbo VS Supercharger; My Experiences
yes
also no one said anything about centrifugal superchargers, or is that the same as a vortech thing...
also no one said anything about centrifugal superchargers, or is that the same as a vortech thing...
#12
10-12-2006, 05:26 PM
RE: Turbo VS Supercharger; My Experiences
vortech is a centrifugal SC.
On jackson's site, they address the temperature thing, and I wonder what your thoughts are? Granted, they are selling something, so take it with a grain of salt, but it seems to make sense. Sprry to cut and paste the whole thing, just thought hmm, and wondered what you all thought.
"Jackson Racing has been in business for over 25 years doing high performance Honda/Acura tuning and we speak with some sort of authority on the subject of Turbo vs Supercharged Vs Intercooling. Having built turbo Hondas since 1976, the first turbo/intercooled CRX's in 1984, and having run the first turbo/intercooled Honda at the first Battle of the Imports in 1990, we do have experience with all of the above issues and can speak, without bias, having done so. And, having seen first hand the long term effects of turbochargers on daily driven high compression Honda/Acura engines, we have opted to supercharge the future.
For ease of installation, instant power, and low cost, nitrous is the only way to fly. However, that is if you only want to go drag racing. If you want everyday nitrous type power, you have to go to forced induction. That is where the turbo Vs supercharger debate comes in. For absolute peak power where driveability, turbo lag, emissions, and long engine life does not need to be taken into consideration, turbo is the only way to go. But, with all things in this life, there is no free ride. With a properly designed turbo charger system you have the ability to produce huge amounts of boost and horsepower easily. The problem with that amount of boost is that once the turbo spools, it goes to full boost. There is no linear delivery of boost.
Consequently, if the turbo spools at 3000 rpm, you have full boost at a valve speed that is very slow. So, the turbo has lots of time to create cylinder pressure on the rods and pistons because of the very long time that the valve is open. This, in turn, is what creates that huge rush of power when the turbo spools. This is also what causes so many turbo engine failures. Combine that with the fact that the compressor sits within 2" of a glowing 1300 degree cast iron oven, the charge air temperature is always very high. This has created the myth that anything with forced induction has to be intercooled. If you have checked the intake temperature of any of the late model O.E. manufactured intercooled turbos, at the intake manifold, not the outlet of the intercooler, you will find that the intake air temperature is near 200 degrees, even after the intercooler. As an example, a test by Sport Compact Car on a new model Turbo/intercooled German built car, they found the charge air temperature at the throttle plate to be 206 degrees after the intercooler. You see, the intercooler is a great thing as long as you have steady air flowing over it. If you are doing a lot of starts and stops, the effectiveness of the intercooler is diminished. Secondarily, once the air has been cooled, it has to be routed back to the intake manifold. That means that it has to come back into the hot engine compartment and the tubing re-heats the air. Not a lot mind you, but it still happens. Equally important, you have to fill all of that tubing with boost, then, when you shift and the bypass blows open, it empties the tubing, requiring the tubing to be refilled. This is the main cause of poor throttle response and the classic turbo lag in a intercooled turbo car. Now, keep in mind that this is all a mute point if you are at speed. But, then you have to stop. Once you stop, you have to cool the turbo. And heat, being the heart of the turbo, is also the enemy of the engine. To further the intercooler debate, let us consider the Ford supercharged/intercooled T-Bird and the GM (Buick-Pontiac) supercharged/non intercooled cars.
The Ford uses a 90 c.i. Eaton supercharger with as much as 14 psi and an intercooler. GM uses a 62 c.i Eaton supercharger with 8 psi and no intercooler. GM mounts their supercharger "Hot Rod" style, on top of the intake manifold as close to the intake valves as possible, with no intercooler. GM's approach, it appears, is to run less boost and thereby, less discharge temperature, and mount the supercharger as close to the intake valve as possible for maximum driveability. Ford's approach seems to be to go for the maximum effect with an intercooler. But, to push the charge air all the way out to the grill, through the intercooler, and back to the intake manifold, requires a larger supercharger and large quantity of boost. Thus, the 90 c.i. supercharger on the T-Bird and the 62 c.i. Supercharger on the GM models. In the final analysis, both engines have an identical horsepower reading. I am sure you are asking yourself "How can that be?" It is in the systems efficiency.
The GM system appears to be more efficient overall. Less load from the supercharger, intercooler, and all of the related plumbing equals better throttle response and an overall better driving package. Now, I am not saying that an air to water intercooler, mounted close to the engine would not be a great piece, it is just that in some engine compartments, it is not possible to package it. So, intercooling is fine if the system is not parasitic by design with plumbing running everywhere, and the net effect of the intercooler system in day to day driving, and that is what I am speaking of, is positive."
On jackson's site, they address the temperature thing, and I wonder what your thoughts are? Granted, they are selling something, so take it with a grain of salt, but it seems to make sense. Sprry to cut and paste the whole thing, just thought hmm, and wondered what you all thought.
"Jackson Racing has been in business for over 25 years doing high performance Honda/Acura tuning and we speak with some sort of authority on the subject of Turbo vs Supercharged Vs Intercooling. Having built turbo Hondas since 1976, the first turbo/intercooled CRX's in 1984, and having run the first turbo/intercooled Honda at the first Battle of the Imports in 1990, we do have experience with all of the above issues and can speak, without bias, having done so. And, having seen first hand the long term effects of turbochargers on daily driven high compression Honda/Acura engines, we have opted to supercharge the future.
For ease of installation, instant power, and low cost, nitrous is the only way to fly. However, that is if you only want to go drag racing. If you want everyday nitrous type power, you have to go to forced induction. That is where the turbo Vs supercharger debate comes in. For absolute peak power where driveability, turbo lag, emissions, and long engine life does not need to be taken into consideration, turbo is the only way to go. But, with all things in this life, there is no free ride. With a properly designed turbo charger system you have the ability to produce huge amounts of boost and horsepower easily. The problem with that amount of boost is that once the turbo spools, it goes to full boost. There is no linear delivery of boost.
Consequently, if the turbo spools at 3000 rpm, you have full boost at a valve speed that is very slow. So, the turbo has lots of time to create cylinder pressure on the rods and pistons because of the very long time that the valve is open. This, in turn, is what creates that huge rush of power when the turbo spools. This is also what causes so many turbo engine failures. Combine that with the fact that the compressor sits within 2" of a glowing 1300 degree cast iron oven, the charge air temperature is always very high. This has created the myth that anything with forced induction has to be intercooled. If you have checked the intake temperature of any of the late model O.E. manufactured intercooled turbos, at the intake manifold, not the outlet of the intercooler, you will find that the intake air temperature is near 200 degrees, even after the intercooler. As an example, a test by Sport Compact Car on a new model Turbo/intercooled German built car, they found the charge air temperature at the throttle plate to be 206 degrees after the intercooler. You see, the intercooler is a great thing as long as you have steady air flowing over it. If you are doing a lot of starts and stops, the effectiveness of the intercooler is diminished. Secondarily, once the air has been cooled, it has to be routed back to the intake manifold. That means that it has to come back into the hot engine compartment and the tubing re-heats the air. Not a lot mind you, but it still happens. Equally important, you have to fill all of that tubing with boost, then, when you shift and the bypass blows open, it empties the tubing, requiring the tubing to be refilled. This is the main cause of poor throttle response and the classic turbo lag in a intercooled turbo car. Now, keep in mind that this is all a mute point if you are at speed. But, then you have to stop. Once you stop, you have to cool the turbo. And heat, being the heart of the turbo, is also the enemy of the engine. To further the intercooler debate, let us consider the Ford supercharged/intercooled T-Bird and the GM (Buick-Pontiac) supercharged/non intercooled cars.
The Ford uses a 90 c.i. Eaton supercharger with as much as 14 psi and an intercooler. GM uses a 62 c.i Eaton supercharger with 8 psi and no intercooler. GM mounts their supercharger "Hot Rod" style, on top of the intake manifold as close to the intake valves as possible, with no intercooler. GM's approach, it appears, is to run less boost and thereby, less discharge temperature, and mount the supercharger as close to the intake valve as possible for maximum driveability. Ford's approach seems to be to go for the maximum effect with an intercooler. But, to push the charge air all the way out to the grill, through the intercooler, and back to the intake manifold, requires a larger supercharger and large quantity of boost. Thus, the 90 c.i. supercharger on the T-Bird and the 62 c.i. Supercharger on the GM models. In the final analysis, both engines have an identical horsepower reading. I am sure you are asking yourself "How can that be?" It is in the systems efficiency.
The GM system appears to be more efficient overall. Less load from the supercharger, intercooler, and all of the related plumbing equals better throttle response and an overall better driving package. Now, I am not saying that an air to water intercooler, mounted close to the engine would not be a great piece, it is just that in some engine compartments, it is not possible to package it. So, intercooling is fine if the system is not parasitic by design with plumbing running everywhere, and the net effect of the intercooler system in day to day driving, and that is what I am speaking of, is positive."
#13
10-12-2006, 06:34 PM
RE: Turbo VS Supercharger; My Experiences
On a car like this, a turbo would be the way to go unless you feel like building a 'built' motor to really make use of a supercharger. If you're limited on how much you can boost due to the strength of the motor or even cooling, you're going to do better with something that is not going to drag power off the motor to turn. Depending on what type of supercharger you use, your 9 PSI of boost could/will be very hot, which may have boost, but the oxygen within the boost is lower. I don't know what type of blower you used, but if it was a roots style, that is by far the most inefficient SC out there.
I've had experience with both a turbocharged SHO and a several supercharged SHO's and these motors take VERY well to both. These motors are strong enough to just up the boost on a supercharger if you're not fast enough. Just 9 PSI net me 381 whp. Yes, the turbo SHO at the same PSI put out more power (~30 more whp)at the same boost, but last I checked, the fastest SHO is still supercharged (if rumors are correct, 637whp).
I agree, with these tiny, rev-happy motors, you'll most likely want a turbo if you're shooting for lots of power. I personally do not like the lag when trying to run up the mountains or on a road course. I like being able to step on the throttle after slowing down for a turn and have all the power right there.
Looking at the graphs, the SC has a much flatter torque curve. Yes, it still has less torque in more places, but it does have a nice flat, usable torque curve. The turbo graph looks very similiar to what a centrifical blower graph looks like (and remote-mounted turbos).
I've had experience with both a turbocharged SHO and a several supercharged SHO's and these motors take VERY well to both. These motors are strong enough to just up the boost on a supercharger if you're not fast enough. Just 9 PSI net me 381 whp. Yes, the turbo SHO at the same PSI put out more power (~30 more whp)at the same boost, but last I checked, the fastest SHO is still supercharged (if rumors are correct, 637whp).
I agree, with these tiny, rev-happy motors, you'll most likely want a turbo if you're shooting for lots of power. I personally do not like the lag when trying to run up the mountains or on a road course. I like being able to step on the throttle after slowing down for a turn and have all the power right there.
Looking at the graphs, the SC has a much flatter torque curve. Yes, it still has less torque in more places, but it does have a nice flat, usable torque curve. The turbo graph looks very similiar to what a centrifical blower graph looks like (and remote-mounted turbos).
#14
10-12-2006, 11:42 PM
RE: Turbo VS Supercharger; My Experiences
Packman, never read that before, was definitely some good info.
Like I said, heating issues are limited at low boost applications on the JRSC. However, I've driven both the supercharger and the turbocharger hard for extended period of times. When I opened the hood, even at low boost applications, the supercharger assembly and valve cover were HOT!! I mean you could feel it on your face hot. Too many moving parts, the two large rotors chopping at the air added with the extra load of the engine creates a lot more heat than my turbo setup ever has.
Remember, 10psi on an M45 has been known to create 300* IAT temps!!! Excuse me, but although 200-210 is a bit on the high side... I'll take them any day over 280+.
As for comparing graphs, take in mind that I do have a turbo that is on the large size for this engine. A smaller turbo would obviously create torque a lot earlier, but probably not make the same gains. This turbo setup is designed for the track and highway ripping, I'm only concerned about numbers 5000RPMs and above.
Comparing a supercharged V8 to a supercharged I4 is two totally different things.
Like I said, heating issues are limited at low boost applications on the JRSC. However, I've driven both the supercharger and the turbocharger hard for extended period of times. When I opened the hood, even at low boost applications, the supercharger assembly and valve cover were HOT!! I mean you could feel it on your face hot. Too many moving parts, the two large rotors chopping at the air added with the extra load of the engine creates a lot more heat than my turbo setup ever has.
Remember, 10psi on an M45 has been known to create 300* IAT temps!!! Excuse me, but although 200-210 is a bit on the high side... I'll take them any day over 280+.
As for comparing graphs, take in mind that I do have a turbo that is on the large size for this engine. A smaller turbo would obviously create torque a lot earlier, but probably not make the same gains. This turbo setup is designed for the track and highway ripping, I'm only concerned about numbers 5000RPMs and above.
Comparing a supercharged V8 to a supercharged I4 is two totally different things.
#15
10-12-2006, 11:45 PM
RE: Turbo VS Supercharger; My Experiences
ORIGINAL: BurryTheSpeedo
yes
also no one said anything about centrifugal superchargers, or is that the same as a vortech thing...
yes
also no one said anything about centrifugal superchargers, or is that the same as a vortech thing...
Pretty much, it's simple. Instead of spinning a turbo with exhaust gases, use your crank instead. Boost increases with RPMs, but they are VERY expensive systems and often times argued not to be worth it.
#16
10-13-2006, 10:00 AM
RE: Turbo VS Supercharger; My Experiences
good points, I guess all I ever hear about are the huge turbos, and motors that have to run over 5K to make power. My car is a DD, never going to race it but might go to the track once or twice. but nothing big. I like the way a SC is smooth in it's power delivery, and you're right, a V8 is no comparison to a little 4 banger. If you aren't going for the biggest power, the simplicity of being able to bolt it on in an afternoon is nice.
although the heat has me worried a little, looking at the vortech SC it does have an aftercooler option, but for the price you could get a good turbo kit.
although the heat has me worried a little, looking at the vortech SC it does have an aftercooler option, but for the price you could get a good turbo kit.
#18
10-13-2006, 11:01 AM
RE: Turbo VS Supercharger; My Experiences
ORIGINAL: packman5280
good points, I guess all I ever hear about are the huge turbos, and motors that have to run over 5K to make power. My car is a DD, never going to race it but might go to the track once or twice. but nothing big. I like the way a SC is smooth in it's power delivery, and you're right, a V8 is no comparison to a little 4 banger. If you aren't going for the biggest power, the simplicity of being able to bolt it on in an afternoon is nice.
although the heat has me worried a little, looking at the vortech SC it does have an aftercooler option, but for the price you could get a good turbo kit.
good points, I guess all I ever hear about are the huge turbos, and motors that have to run over 5K to make power. My car is a DD, never going to race it but might go to the track once or twice. but nothing big. I like the way a SC is smooth in it's power delivery, and you're right, a V8 is no comparison to a little 4 banger. If you aren't going for the biggest power, the simplicity of being able to bolt it on in an afternoon is nice.
although the heat has me worried a little, looking at the vortech SC it does have an aftercooler option, but for the price you could get a good turbo kit.
If you want a small streetable setup, honestly just get a smaller T3 turbo or 14B and use that. They will create boost early and be easy to use on the streets. But, in all honesty, spooling at or above 5K isn't as bad as it always seems to sound. Just drop a gear and well hey, you're back to boosting.
I find my setup to be a great daily driver setup, I'm not in boost when I don't want to be, and it's not but a downshift away when I want it.
#19
10-14-2006, 06:25 PM
RE: Turbo VS Supercharger; My Experiences
i agree with what u guys all say totally but theres just times when ur driving around, maybe after a long crappy day at work, when u romp on it, u dont want to wait for the boost 2 kick in, u want just full power right then and there, thats when i want it. also, i love the acceleration part of a car the most, to me its fast if it can push u back in ur seat the second the pedal is to the floor. a turbo u have to wait a while. i had a supercharged grand prix gtp, i loved acceleration in that it was perfect for me cuz i didnt drive any higher than 80 really so a turbo for me is pointless.
#20
10-14-2006, 08:02 PM
RE: Turbo VS Supercharger; My Experiences
ORIGINAL: yoRt
i agree with what u guys all say totally but theres just times when ur driving around, maybe after a long crappy day at work, when u romp on it, u dont want to wait for the boost 2 kick in, u want just full power right then and there, thats when i want it. also, i love the acceleration part of a car the most, to me its fast if it can push u back in ur seat the second the pedal is to the floor. a turbo u have to wait a while. i had a supercharged grand prix gtp, i loved acceleration in that it was perfect for me cuz i didnt drive any higher than 80 really so a turbo for me is pointless.
i agree with what u guys all say totally but theres just times when ur driving around, maybe after a long crappy day at work, when u romp on it, u dont want to wait for the boost 2 kick in, u want just full power right then and there, thats when i want it. also, i love the acceleration part of a car the most, to me its fast if it can push u back in ur seat the second the pedal is to the floor. a turbo u have to wait a while. i had a supercharged grand prix gtp, i loved acceleration in that it was perfect for me cuz i didnt drive any higher than 80 really so a turbo for me is pointless.