Lower Intake Temp
08-22-2005, 03:38 PM
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i have my own theory about the bucking/hesitation. after researching the type of MAF, my option is that the sensors around that area, MAF in particular, malfunctions at high temperatures. The trottle position sensor, and mass air flow sensor will be a little cooler. plus its cheap and easy. so there is a side benefit other than the slightly (if any) lower intake temperature. but this is only my option.
10-11-2005, 03:38 AM
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The mod basically shuts the flow of coolant that would otherwise make its way from the motor from the head to the throttle body then back to the block through the use of 2 ball bearings that're slightly larger in diameter than the opening of metal fittings. The hot coolant flow to the throttle body isn't needed in Hawaii unless you live where it freezes your boogers. I've actually made a mod that completely bypasses the coolant flow so it goes from the head back into the block.
Another way to do this is through the use of a Hondata Insulator Gasket which actually covers the hole where the coolant fitting resides, preventing any coolant from reaching the throttle body. The reason people do this is to help reduce Intake Air Temperatures (hereon referred to as IAT), more than likely to help reduce the chances of bogging. This 75 dollar product is the best thing for my car to this date, yet requires the skill of a technician to install correctly.
A few quick facts about MY00-03 cars:
- The OEM ECU was designed in mind to offer reliability first, then performance in that order. While our engines are capable of much more, Honda had to draw a line to ensure their customers a good driving experience and dependability. With that in mind, the ECU is the heart of the system determining the rules in which the car operates. If you modify, bypass or change the ECU, you are effectively changing those rules, to make this as simple as possible.
- Our engines were designed with high effeciency, which means it has the potential to do a lot with less. Some of these are the ultra high compression (allowing for more power per air/fuel used) and the ability to rev the motor into space. Anyone knows that the more you compress a gas (or a gaseous mixture), the resulting heat will be higher. A car with 8.5 to 1 compression ratio would tend to run a lot cooler than a car having a 11.5 to 1 compression ratio for example. The other has to do with rev potential. Some may wonder "how come my Accord can't rev to 9000rpms, I mean isn't it just 3000rpms more?" The difference in work per sec from 6000 rpms to 9000 rpms is exponentially different. It's like saying a 1 sec difference in race that ends at 3 mph is the same as a race that results in 400 mph finish time. That much more work will definitely result in more heat.
- The common denominator is heat, and the ECU is designed to take into account the IAT (temp of the air coming in), the ECT (engine coolant temperature), Lambda (also known as your oxygen sensor on your exhaust manifold which monitors rich and lean conditions), MAP (manifold absolute pressure) and ignition timing.
When your car is moving 55mph, you have good air flow keeping things cool like your radiator, you're pressing the accelerator which means the butterfly valve in the throttle body is open allowing cool air to enter the engine (and thus helping to cool the intake side of the engine), oil is being pumped throughout the motor and thus carrying with it heat, and engine coolant is also being cycled to a nice and cool radiator up front exposed to incoming fast moving air.
Now you get off the freeway, and now stuck in stop and go traffic. The motor is hot and trying to cool off from the brief drive, so the radiator is now being taxed more with heat, but there's hardly any air going through it except for a plastic fan to suck air in. All the heat under your hood is now trapped and various metal parts under the hood starts soaking in heat. Your intake manifold now acts like a heatsink that starts to heat incoming cool air, your throttle butterfly is now closed except for a tiny hole that allows air to pass through so the car can idle.
The IAT will now rise, ECT will rise, oil temps will rise, compression stays the same, more heat means more risk of damaging the motor or hurting performance. What does the car do? Change the rules through the ECU. The car can't do anything about the heat, but it can try to put the car at less risk by...
1. Pulling or reducing the ignition timing (also known as spark timing). The general idea is you want to add as much timing as the car will allow without knocking and pinging (which can/will result in damage). The result is more torque and better low-end power if you add more ignition timing, less if you pull out. Pulling out timing results in less power, which in turns means less heat to some degree.
2. Richen the fuel mixture (meaning it adds more fuel) because adding more fuel also reduces combustion chamber temperatures, keeping the internals cooler and more manageable. As a rule, when you lean out the fuel (less fuel, more air), combustion temperatures usually rise (and so will power to some degree). Ever wonder why you lose fuel economy when it's super hot outside? This is one of the reasons.
Now ask any car mechanic or autobuff about what happens when you have a 4 cylinder motor that has a slightly taller 1st gear (the S2k's 1st gear is like most other car's 2nd gear), then pull out ignition timing, and richen the air-fuel mixture... what's going to happen? It's going to bog, buck or shake. Add to this that the Honda ECU is incredibly paranoid, meaning if the OEM ECU were a person trying to walk across the street, it freaks out at the first sign of a car on the road. It's not willing to take any risks. It's very easy to trigger the OEM ECU to go into what they call "Protection Mode" which does #1 to #2 until the ECU senses that the ECT (engine coolant temp) starts to drop to what it considers "normal".
Another way to do this is through the use of a Hondata Insulator Gasket which actually covers the hole where the coolant fitting resides, preventing any coolant from reaching the throttle body. The reason people do this is to help reduce Intake Air Temperatures (hereon referred to as IAT), more than likely to help reduce the chances of bogging. This 75 dollar product is the best thing for my car to this date, yet requires the skill of a technician to install correctly.
A few quick facts about MY00-03 cars:
- The OEM ECU was designed in mind to offer reliability first, then performance in that order. While our engines are capable of much more, Honda had to draw a line to ensure their customers a good driving experience and dependability. With that in mind, the ECU is the heart of the system determining the rules in which the car operates. If you modify, bypass or change the ECU, you are effectively changing those rules, to make this as simple as possible.
- Our engines were designed with high effeciency, which means it has the potential to do a lot with less. Some of these are the ultra high compression (allowing for more power per air/fuel used) and the ability to rev the motor into space. Anyone knows that the more you compress a gas (or a gaseous mixture), the resulting heat will be higher. A car with 8.5 to 1 compression ratio would tend to run a lot cooler than a car having a 11.5 to 1 compression ratio for example. The other has to do with rev potential. Some may wonder "how come my Accord can't rev to 9000rpms, I mean isn't it just 3000rpms more?" The difference in work per sec from 6000 rpms to 9000 rpms is exponentially different. It's like saying a 1 sec difference in race that ends at 3 mph is the same as a race that results in 400 mph finish time. That much more work will definitely result in more heat.
- The common denominator is heat, and the ECU is designed to take into account the IAT (temp of the air coming in), the ECT (engine coolant temperature), Lambda (also known as your oxygen sensor on your exhaust manifold which monitors rich and lean conditions), MAP (manifold absolute pressure) and ignition timing.
When your car is moving 55mph, you have good air flow keeping things cool like your radiator, you're pressing the accelerator which means the butterfly valve in the throttle body is open allowing cool air to enter the engine (and thus helping to cool the intake side of the engine), oil is being pumped throughout the motor and thus carrying with it heat, and engine coolant is also being cycled to a nice and cool radiator up front exposed to incoming fast moving air.
Now you get off the freeway, and now stuck in stop and go traffic. The motor is hot and trying to cool off from the brief drive, so the radiator is now being taxed more with heat, but there's hardly any air going through it except for a plastic fan to suck air in. All the heat under your hood is now trapped and various metal parts under the hood starts soaking in heat. Your intake manifold now acts like a heatsink that starts to heat incoming cool air, your throttle butterfly is now closed except for a tiny hole that allows air to pass through so the car can idle.
The IAT will now rise, ECT will rise, oil temps will rise, compression stays the same, more heat means more risk of damaging the motor or hurting performance. What does the car do? Change the rules through the ECU. The car can't do anything about the heat, but it can try to put the car at less risk by...
1. Pulling or reducing the ignition timing (also known as spark timing). The general idea is you want to add as much timing as the car will allow without knocking and pinging (which can/will result in damage). The result is more torque and better low-end power if you add more ignition timing, less if you pull out. Pulling out timing results in less power, which in turns means less heat to some degree.
2. Richen the fuel mixture (meaning it adds more fuel) because adding more fuel also reduces combustion chamber temperatures, keeping the internals cooler and more manageable. As a rule, when you lean out the fuel (less fuel, more air), combustion temperatures usually rise (and so will power to some degree). Ever wonder why you lose fuel economy when it's super hot outside? This is one of the reasons.
Now ask any car mechanic or autobuff about what happens when you have a 4 cylinder motor that has a slightly taller 1st gear (the S2k's 1st gear is like most other car's 2nd gear), then pull out ignition timing, and richen the air-fuel mixture... what's going to happen? It's going to bog, buck or shake. Add to this that the Honda ECU is incredibly paranoid, meaning if the OEM ECU were a person trying to walk across the street, it freaks out at the first sign of a car on the road. It's not willing to take any risks. It's very easy to trigger the OEM ECU to go into what they call "Protection Mode" which does #1 to #2 until the ECU senses that the ECT (engine coolant temp) starts to drop to what it considers "normal".
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