Bruce
03-16-2004, 10:30 AM
There are numerous books devoted entirely to I/C design.
What I'm going to attemptting to do here, is give enough facts, about how things relate to TRs., so people can deside on what makes the most sense for them to do.
Again, while some of it obviously will spill over into other applications, this is about TRs.
First, let's look at the stocker. It mounts behind the radiator, with ducting for it extending down, and below the radiator. And the "in" neck has a bit of a restriction in that it's ID is rather small. It uses a fan, driven at crank speed so that there is some air movement at low vehicle speeds to keep from getting excesively hot. Being so well shrouded, that even at freeway speeds, if you were to remove the fan, and ducting, there is little cooling of the charge air. If you were to install the MAT sensor in the intake, and drive around, you'll note that it takes along time for the MAT to recover from in boost temps., without the fan/shroud, even at freeway speeds. It's rather heavy, and that allows is for it to act as sort of a thermal flywheel. During the initial boost phase, it can absorb alot of heat, and while it does shed some heat, it takes along time for that to happen, so it, just in a way dampens how long it takes for the MAT temps to build, and just slightly limits the temps., unless your at a sustained high speed.
So increasing it's size, does add mass, and increase it's ability to act as a better heat sink. And with properly designed necks, can be a bit less of a restricton.
Then we have Front Mounts. Now they have no fans, or ducting, and are mounted in front of the radiator. And while the core is larger, you also gain surface area in the plumbing to and from it. Also, with this increase in volume you also in a way, you min the vallies in the manifold pulsations from the valves opening and closing, since the plenum is in effect made larger.
And next, air to liquid heat exchangers. They can use engine coolant, a seperate cooling system, or an ice type cooling media. I haven't seen a TR using the engine coolant, so we'll pass on talking about it. The seperate cooling system, is good in so far as that it allows the I/C to recover from being hot, without the car having to move, and is mostly just limited by how large the it's radiator is for how effectively it does that. The also can add a far amount more weight then a F/M. And then we have the Ice Coolers. And as long as they have ice in them, they can reduce the MATs to less then ambient. While they add a fair amount of weight, properly done, you can move most of the weight to where it does in fact do you alot of good.
And finally chemical intercooling. Which is Water (or other chemcials) Injection. Which takes in a huge amount of info., to fully understand since it in fact can alter the combustion reaction. While not a chemist, I'll just mention that the cooling effect is just part of what goes on. It's lighter then either if the above, for normal street use. But, unless the car is in boost, and the system on, it doesn't afford any cooling.
Almost looks like it would take a combination of these to have the ultimate setup. Maybe, some aspects of all of them <g>.
What I'm going to attemptting to do here, is give enough facts, about how things relate to TRs., so people can deside on what makes the most sense for them to do.
Again, while some of it obviously will spill over into other applications, this is about TRs.
First, let's look at the stocker. It mounts behind the radiator, with ducting for it extending down, and below the radiator. And the "in" neck has a bit of a restriction in that it's ID is rather small. It uses a fan, driven at crank speed so that there is some air movement at low vehicle speeds to keep from getting excesively hot. Being so well shrouded, that even at freeway speeds, if you were to remove the fan, and ducting, there is little cooling of the charge air. If you were to install the MAT sensor in the intake, and drive around, you'll note that it takes along time for the MAT to recover from in boost temps., without the fan/shroud, even at freeway speeds. It's rather heavy, and that allows is for it to act as sort of a thermal flywheel. During the initial boost phase, it can absorb alot of heat, and while it does shed some heat, it takes along time for that to happen, so it, just in a way dampens how long it takes for the MAT temps to build, and just slightly limits the temps., unless your at a sustained high speed.
So increasing it's size, does add mass, and increase it's ability to act as a better heat sink. And with properly designed necks, can be a bit less of a restricton.
Then we have Front Mounts. Now they have no fans, or ducting, and are mounted in front of the radiator. And while the core is larger, you also gain surface area in the plumbing to and from it. Also, with this increase in volume you also in a way, you min the vallies in the manifold pulsations from the valves opening and closing, since the plenum is in effect made larger.
And next, air to liquid heat exchangers. They can use engine coolant, a seperate cooling system, or an ice type cooling media. I haven't seen a TR using the engine coolant, so we'll pass on talking about it. The seperate cooling system, is good in so far as that it allows the I/C to recover from being hot, without the car having to move, and is mostly just limited by how large the it's radiator is for how effectively it does that. The also can add a far amount more weight then a F/M. And then we have the Ice Coolers. And as long as they have ice in them, they can reduce the MATs to less then ambient. While they add a fair amount of weight, properly done, you can move most of the weight to where it does in fact do you alot of good.
And finally chemical intercooling. Which is Water (or other chemcials) Injection. Which takes in a huge amount of info., to fully understand since it in fact can alter the combustion reaction. While not a chemist, I'll just mention that the cooling effect is just part of what goes on. It's lighter then either if the above, for normal street use. But, unless the car is in boost, and the system on, it doesn't afford any cooling.
Almost looks like it would take a combination of these to have the ultimate setup. Maybe, some aspects of all of them <g>.