You're misinformed on a few points but others are correct. The main one is on how the catalytic converter works. Once the engine coolant temperature reaches a certain point, typically 160 or 180 degrees, and / or the oxygen sensor reaches 600 degrees, the Engine Computer goes into "closed loop". That means it continues using all the sensors to calculate fuel metering plus it starts looking at the front oxygen sensors. The fuel / air mixture will switch from too rich to too lean a couple of times per second with the average being perfect. When it goes too lean, the unburned oxygen is stored in the catalyst, then, when it goes too rich, that extra fuel mixes with the oxygen and is burned. You can watch those sensor readings switch rich and lean on a scanner that displays live data. I use the Chrysler DRB3. A lot of independent shops have them too because with an additional plug-in card they can do emissions-related stuff on any brand of car or light truck sold in the U.S. Starting with '96 models.
You might think the computer would be happy to see the ideal mixture at all times, and while that would be the goal, that would trigger a fault code related to "fuel / air not switching properly". The computer knows the catalytic converter can't do its job that way.
When the converter is working properly, the gases coming out will be carbon dioxide and water vapor. That vapor is what corrodes exhaust system parts from the inside and is why most original systems are made of stainless steel. Most mufflers also have a tiny drain hole on the bottom in the back where you'll see water dripping from. The important thing to understand is that when the converter is doing its job, the rear, or "downstream" oxygen sensor will detect a slightly rich condition for a long time, perhaps as much as a minute or more, then it will detect a lean condition, also for a long time. (They don't really detect rich exhaust; they fail to detect a lean exhaust. That's different because oxygen sensors only detect that; oxygen, not fuel). The Engine Computer causes the mixture to go too rich, then too lean, then it expects to see the results of that from the upstream oxygen sensor. That switch rate, as I mentioned, is about twice per second. Next, it expects to see a switching rate from the downstream sensor of maybe once or twice per minute. That's what it takes to prevent setting a code.
When the catalytic converter begins to lose its efficiency, less change takes place in the composition of the exhaust gas. What goes out of the converter starts to look more and more like what's coming in. The switching rate, or frequency, of the downstream O2 sensor picks up and may approach four times per minute, or six times, then more. Based on that higher frequency, the computer knows not enough change is taking place inside the converter. At a pre-programmed point, the fault code "catalytic converter efficiency" will be set and the Check Engine light will turn on.
You are proposing to remove the converters but there are only disadvantages to doing that. You can not remove the downstream O2 sensors because that will be detected by the computer right away. With no converter to change the makeup of the exhaust, the downstream sensor will read exactly the same as the upstream one, and it will switch rich to lean at the same times. That will instantly set the "efficiency" code. Knowing it can't rely on that sensor to see the results of some of the self-tests the computer runs, those tests will be aborted and other potentially minor problems will go undetected. Those problems almost always affect performance, fuel mileage, and emissions, so where is the gain in power or mileage you're seeking?
You have to understand the world the manufacturers live in is extremely competitive. People buy one minivan over the other brand because this one has two extra cup holders. That truck has five more horsepower. This car is rated at one more mile per gallon. Why do you think years ago one manufacturer came out with an engine that was just a couple of cubic inches bigger than their competitors? If they could legally advertise one more horsepower or one more mile per gallon, they would do it because they know that translates into more sales. Now you are going to come along and improve on what a team of researchers and engineers couldn't do. You may succeed in meeting one of your goals but there is going to be a trade-off. I could take the 340 out of my '72 Challenger and build it like a NASCAR 355 and get 850 horsepower from it, ... For perhaps as much as 500 miles, then it's worn out. I'm sure that's not your goal to rebuild your engine every 500 miles.
By the way, for that larger diameter exhaust you think is going to make a noticeable difference, look at the size of the pipes on an NHRA top fuel dragster. They burn over ten gallons of nitro methane and all the air to go with it, in less than 700 revolutions of the engine in four seconds. They're approaching hydrolock by stuffing so much liquid in the engine, but it all comes out as a gas. You don't see any liquid dripping out. That's a HUGE pile of gas they're trying to get out. Calculate how long it takes you to burn ten gallons of gas, then tell me you need to get 1/100th the volume through your exhaust system. If you don't think the manufacturer would go with a larger exhaust system, regardless of the tiny additional cost, to get more power, you can be sure the guys who totally rebuild an engine after every four-second race would spend the money, ... If it would help.
A better example is my buddy owns a body shop and he specializes in rebuilding smashed one and two-year-old Dodge trucks, mostly diesels. One of his first ones was a '99 dually diesel that he regularly used to drag around a three-car hauler with no problems, power-wise. He decided after more than 100,000 miles that he wanted more power so he added a "chip" with three levels of power increase. The first thing he promptly did was tear up the transmission. Can't haul many cars around that way. What did he gain?
I helped him three years ago rebuild an '06 dually that was hit real hard in the front. Part of my job was to install a chip on that one too. After he took it out for its first test drive and the clutch was slipping under wide-open-throttle, a local fuel injection service company identified the previous owner had installed an over-size turbo and over-size injectors. He had the CAPABILITY to produce unusable horsepower, so what did he gain? Sure, it launches like a Viper, but who drives like that? Just because the injector CAN squirt more fuel in a given period of time doesn't mean they do.
You also have to understand diesels work differently than gas engines. With gas, too much or too little air is a bad thing. Only the perfect mixture results in the best fuel mileage, the best power, and the lowest emissions. Diesels are wide-open to air all the time and will take in as much as possible. Power and speed are controlled by the amount of fuel squirted into the cylinders. By packing the air tighter, a turbocharger dramatically increases its temperature so they run it through an intercooler to bring it back down. Normal air temperature has a cooling effect on the intake valves that you don't want to lose. Because all that air that got stuffed in under pressure expands a lot when it gets burned, the exhaust system has to be big enough to accommodate that without restriction. That's why they use 4" diameter pipes. Because air compresses, the volume of the air going in stays the same, and is a lot lower than what goes out. The MASS or weight of the air is the same going in and going out, but not the volume, so the intake side can be smaller than the exhaust side. You may think that's like sucking through a straw, but it's a pretty big straw that is more than sufficient for the engine's needs. Since going bigger wouldn't affect emissions, and it would barely impact the cost, don't you think the manufacturer would have done it if there would have been some value to it?
The same is true with a gas engine but to a lesser extent. Your air intake system will already allow you to go over 100 miles per hour at less than wide-open-throttle. Do you need more than that? Your exhaust system will handle that too. There's a reason the guys at the auto parts stores ask you your engine size when you buy replacement exhaust system parts. The manufacturer knew larger pipes were needed for the needs of larger engines under the most extreme conditions, so that's what they came with. There's that numbers game again. If a 2 1/2" exhaust system meant they could advertise five more horsepower than if they used a 2 1/4" system, you can be sure they would have done it.
The biggest misconception comes in with your desire to cool the incoming air. That is exactly opposite of what we tried to do since forever. First you must understand liquid gas does not burn, period. Fire safety instructors do a demonstration where they throw a lit match onto a pan of gasoline, ... And it puts the match out. It isn't until that gas starts to vaporize that the vapors will burn. Even then, the entire pan of gas doesn't explode. Only the vapors burn as they boil off over quite a long period of time.
The problem we had with carburetors was they were designed to make liquid gas vaporize so it would burn in the cylinders. There isn't time for the burning vapors to heat the liquid droplets and vaporize them so they too burn in the cylinders. Instead, the heat makes them vaporize in the exhaust system. It doesn't produce any power there. Every carburetor was carefully calibrated to the specific engine and they almost always had two circuits, an idle circuit and a high-speed circuit. Those were the only two points that could be adjusted for a perfect mixture. In between they had to dump in too much gas. That extra gas would be wasted, but going a little too lean would cause an objectionable hesitation or stumble.
The additional problem came in when the engine was cold. That prevented the gas from vaporizing properly. Two things took care of that. The carburetor usually sat right above an exhaust passage in the intake manifold or there was engine coolant circulating near it to warm the base of the carburetor. That solved the vaporizing problem once the engine was warmed up. For the cold engine we needed a choke. By blocking air flow, engine vacuum sucked in more fuel. That did not result in more power. The goal simply was to pour in so much raw fuel in hopes a large enough percentage would vaporize to make the engine run smoothly. A large percentage of that fuel went out the exhaust, wasted. Cold air killed fuel mileage and greatly increased emissions. It did nothing to increase horsepower. Now you want to go back to what we tried for decades to solve.
Fuel injectors are more efficient in vaporizing gasoline because they spray it in much smaller droplets. That increases the overall air contact area. There still isn't time for 100 percent of it to vaporize so the amount of fuel commanded by the computer has been carefully programmed for many variable conditions, and one of them is air temperature. More fuel will be commanded when the air temperature is colder. Again, that does not translate into more power. A very specific amount of fuel is needed for each cylinder, and the extra just goes out the exhaust without contributing to the production of power.
The purported goal of cold air intake systems is to condense the air so more can be packed into each cylinder, just like turbochargers do. In every engine other than a Chrysler, the weight of that air is measured by the mass air flow sensor, and the computer uses that to calculate how much fuel to use. Chrysler is the only manufacturer that has been able to make an engine run right without a mass air flow sensor. They use the speed-density system with just a map sensor that measures intake manifold vacuum to calculate engine load. That sensor also measures barometric pressure just before engine start-up. Higher barometric pressure means more air pressure pushing the air into the engine. Colder air temperatures means more air by weight going into the engine. Both of those factors dictate how much fuel is needed to create the perfect mixture. If your intake system cools the air, more air goes in, you have a lean condition. That is detected by the O2 sensor, and the computer commands more fuel to correct that mixture. What you have gained is more engine speed. You must either let off the gas pedal, or if the engine is idling, the computer will close the automatic idle speed motor to restrict incoming air flow around the throttle blade. At that point you have gained nothing except dumped more unvaporized fuel into the exhaust system. You'll have increased emissions, increased fuel consumption, and no change in power. The only way you would get more power is if you packed more fuel into the cylinders to go with that extra air. You already have the capability to do that, but that only occurs at wide-open-throttle. Unless you're on the racetrack, how often do you drive at wide-open-throttle?
The companies that sell cold air intake systems and larger exhaust systems are selling an illusion. Colder air means more air. The computer adds more fuel and you get more engine speed. I do the same thing with my minivan by pushing the gas pedal further. I get more air, more fuel, and more speed. What WILL change is how far you have to push the gas pedal to start getting that power. You'll get the power sooner, but you won't get more total power at the high end. That's where the illusion comes in. For both of us, the only restriction to engine breathing that matters is the throttle blade. Everything else has less restriction. The best you could hope to do is totally remove the fresh air intake system and the entire exhaust system. That won't give you an increase in anything until you eliminate the throttle blade.
As for the rust issue, parking on snow is less of a problem than driving in salt. I live in Wisconsin, the road salt capital of the world! Since my ten-car garage is filled with, ... Uhm, ... Much more than cars, my daily driver '88 Grand Caravan sits in the snow-covered driveway all the time. In fact, it has never been in the garage since it was new. The original muffler lasted 18 years, and after 25 years, all the other pipes are still original and in good shape. I DO have a '93 Dynasty that I painted the muffler on when it was new, but not to prevent rust. That was to mask the big silver blob hanging down in the rear. The cheapy replacement mufflers for my Caravan get loud after about a year from the internal baffles rusting away, then the housing rusts through after two years. All three rusted from the inside first, not from the outside. In fact, due to its location, it rarely even gets hit with the slop with the salt in it. Painting your exhaust parts might make you feel good but it's not going to extend its life. Instead of wasting your money on paint, put it toward a stainless steel system. Had I bought the $180.00 stainless steel muffler from the dealer seven years ago, I would have gotten a much better value. At the time I had no idea my van would be so uncommonly reliable and that it would last this long. So far I've spent $105.00 on four mufflers, and each one required crawling around in granite, on my back, for four hours to make them fit and to make custom hangers. What did I gain?
To get back to your original questions: "So every car is as efficiant as it can be straight from the factory?"
Yes, and I've stated why. It takes a specific number of BTUs of energy to move a specific weight at a specific speed, and a specific rate of speed increase. You don't improve on that by making the engine consume more fuel, no matter how efficiently that is done. What you CAN reduce is air flow resistance and friction. That's why all manufacturers have huge wind tunnels and chassis dynomometers. That's why cars have hood stickers instead of hood emblems, and it's why windshields hit your forehead, ... Less wind resistance.
"I believe cars are made due to minimum standards set forth by the automotive industry".
I can't imagine what you're thinking to come up with that, and I can't imagine what you think you're going to design better. There will always be trade-offs and compromises. A '66 Buick Wildcat was so huge you needed binoculars to look in the mirror and see the tail lights, but they got 23 miles per gallon too with that real heavy car. The trade-off was you could die from breathing the exhaust. Do you really want to go back to those days? You can suck on your tail pipe all you want, but all you're going to get is bored.
You'll have to be more specific when you say "minimum standards". Compare your truck to one from the '60s or '70s. Heck, drive a '93 or older Ramcharger, then tell me you prefer that ride quality over your Durango's. Chrysler has always been the leader in innovations that actually benefit car owners. They were first with alternators, (they copyrighted that term), air bags, anti-lock brakes, (1969), lockup torque converters. No clueless politician was involved with any of those things. Look at the fit and finish of any Chrysler product from the '70s, then look at any new car or truck today. It took a friend weeks of massaging on one of my Challengers to make things fit half as well as on any new car. THOSE were minimum standards. No manufacturer can stick with minimum standards and stay in business. They are all in constant competition with their competitors to be the best, not just good enough. If you believe otherwise, start your own car company and see how many you sell.
"I've already added more spark using e3 spark plugs and performance distributors Screamin Demon coil cap and rotor with brass terminals and a 10mm wires"
You can't get more spark unless you change the laws of physics. What you CAN get is the capability of achieving a higher spark voltage if that is what is required to jump the spark plug's gap. Once that voltage is reached and the spark occurs, there can't be any further increase in voltage. We used to pull one spark plug wire off to create a much bigger gap, then we'd watch on the analyzer screen to see how high the voltage could go. The typical original ignition coil could produce around 18,000 to 20,000 volts. If a spark plug required 8,000 volts, that was all that was developed, and no more. (Think of a dam on the river. If it's ten feet high, the water has to reach ten feet, then it will run over. The water in the lake behind it will never get higher than ten feet even if it rains a pile. If it does rain a lot, there will be the CAPACITY for the water to go higher, but only if the height of the dam is increased. Increasing the dam height is the same as increasing the spark plug's gap). If the gap on the plug wore or was adjusted too large and it required 21,000 volts for the spark to jump, there would be no spark if the coil could only develop 20,000 volts. THAT is where having the higher capacity becomes a benefit. Your higher capacity can overcome some misfires caused by the spark plug or wire, but if you're looking for all these tricks to result in some improvement, you have already looked at the basics, so now instead of lighting off the fuel / air mixture, you're REALLY lighting off the fuel / air mixture. With your original ignition system, all you did was create pressure in the cylinder to push the piston down. With your new system, you're creating pressure to push the piston down. A stronger spark won't result in more power unless it is overcoming some other problem. That's where I'm assuming you don't have some other problem that needs overcoming. With all the work you're going through, you would have checked that already. Power is a factor of the amount of fuel, the fuel / air ratio, compression ratio, and where the crankshaft is when the piston gets pushed down, (ignition timing). As long as that fuel ignites, spark is not a factor in determining how much power is produced. To think otherwise would be to think a forest fire's severity is determined by the size of the match used to start it.
Where you'll really see the benefit with higher voltage ignition systems is when something was done to make that mixture harder to fire. One of those conditions is high compression. We had high compression engines in the '60s, around 10.5 to 1, and they ran quite nicely with that old technology. Race engines often are around 12: 1 and require a reliable spark. The hardest ones to fire are when the mixture is too lean. Remember Chrysler's Lean Burn ignition systems of the mid '70s? That was another first for the industry. A wide-scale use of a computer to control ignition timing. With a lean fuel mixture, the molecules of fuel are further apart and it is much harder for the flame front to jump from one to the next. That system was no "minimum standard". That was a real attempt at getting better fuel mileage. They got a bad reputation because old-school mechanics didn't know how they worked, but by today's standards they were so terribly simply a high school student could understand them.
If you really want a reliable and strong spark, go back to that NHRA dragster. The ignition systems produce around 40 amps of current when the spark occurs. A single misfire will result in the engine exploding, as we see once in a while, so they have to be reliable. Then, the spark plug electrodes are consumed halfway through the run. The engine fires on hot spots and detonation for the second half of the run. As you can see, there are always trade-offs. I suspect you don't want to be replacing spark plugs each time you hop into the truck and buzz off into the sunset.
"as far as the CAT I'm sure all the fuel will be spent so I won't have any sensor issues the computer will sense a clean burn and better fuel economy(no issue there)"
I think I covered that enough. Now you'll understand what the computer is looking for from all of the oxygen sensors. It's not looking for a "clean burn". It's looking for the changes in the readings under various specific conditions. It won't see those changes with no converter, and it won't see them with no sensor to report them.
The biggest thing I ever did to increase power and fuel mileage was to install a gas mileage camshaft. I did that on a '69 318 engine that I put in my '78 LeBaron station wagon with that Lean Burn system and lockup torque converter. The profile of the lobes is different. That sets the "personality" of the engine. In this case the profile for better fuel mileage was the same as what was used in motor homes. Retarding valve timing one or two degrees, (which is a real lot), increases low-end torque, and yes, I could squeal the tires all over the place! The trade-off was I needed to be sure I had enough room to pull out and pass someone on the highway. Motor homes need a lot of low-end torque to get out of their own way at a stop sign, but once they're up to highway speed, they remain fairly steady and maximum power is not needed there.
I also had an old '78 Monaco police car that was just the opposite. That 440 went from 0 to 60 just like any 318, but from 60 to 90 it about tore the seats off the hinges! That camshaft profile was advanced one or two degrees to provide acceleration on the high end for pursuits. Both cars were real fun to drive but they acted entirely differently.
If you don't want to go through the work of replacing the camshaft and lifters, look into making a change in the sprocket. On my older V-8 engines there is a woodruff key between the camshaft and sprocket to set its position. Chrysler's Direct Connection racing program offered offset keys with 2, 4, or 6 degrees offset. Two degrees will make more of a noticeable change than anything else you're trying to do, ... Unless the computer somehow gets involved and does something to counteract that change. You DO have a camshaft position sensor but that only synchronizes injector firing times. That can be off a lot and you'll never notice it. An offset key can be installed either way to advance or retard the camshaft. If you think of tightening the timing chain on the side that pulls on the cam sprocket, that would advance it a little. Think of "T" for "tight", "T" for "top end", and "T" for, ... Uhm, ... "Advanced". An advanced camshaft will increase power at high speeds. If the timing chain was loose, the slack would have to be taken up before the camshaft would start to turn. That makes it late. Remember "L" for "loose, "L" for "late", and "L" for more low-end torque. I'm sure there will be some ramifications to the level of emissions, but common sense dictates it should not be significant.
Saturday, March 2nd, 2013 AT 11:16 PM