More Pix...Cold Air Intake (slow connection beware)
04-10-02, 10:35 PM
#26
One suggestion - I'd also recommend screening off the hose where it enters in front of the rad - Bugs and stuff will end up splattered all over your air filter without something there to stop them - especially if you do any highway driving at night. I used regular nylon bug screen (just a thought)
04-11-02, 03:29 AM
#28
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In theory the colder the air the more dense it becomes which for a given quantity of air will give you more power, assuming the carb settings are changed.
The theory is that for each 12 degrees cooler you get, there is a one hp increase. In the case of a RX7 cruising at 60mph the difference between under bonnet and outside air temperature is about 5 degrres giving a theoritical 1/2 hp increase. In practice it frequently decreases without dyno tuning to recalibrate the carby settings.
In a turbo set-up the incoming air is boosted which incrreases temperature consderable, thua an intercooler really works at high boost. In the 12AT set-up which uses 6lb boost the factory set-up is without an intercooler. Run a 13BT at 12 plus boost. its essential.
Thus for a 12A a cold air duct is not necessary, like most body kits its cosmetic to make the car look fast.
However if you are doing 1/4 mile events and the car is standing around then cold air ducting will be an low cost advantage.
In many cases the problem is lack of air flow is more of a problem and the ducting will reduce flow and topend power.l If you have seen for example REVHEDs system the snorkle is opened up to cope with the increased demand for air with a worked motor.
The final point is the 12A carb is fed warm air if the outside air is cold in order to keep the air- fue mixture constant. Thus putting on cold air ducting is irrelevant.
The theory is that for each 12 degrees cooler you get, there is a one hp increase. In the case of a RX7 cruising at 60mph the difference between under bonnet and outside air temperature is about 5 degrres giving a theoritical 1/2 hp increase. In practice it frequently decreases without dyno tuning to recalibrate the carby settings.
In a turbo set-up the incoming air is boosted which incrreases temperature consderable, thua an intercooler really works at high boost. In the 12AT set-up which uses 6lb boost the factory set-up is without an intercooler. Run a 13BT at 12 plus boost. its essential.
Thus for a 12A a cold air duct is not necessary, like most body kits its cosmetic to make the car look fast.
However if you are doing 1/4 mile events and the car is standing around then cold air ducting will be an low cost advantage.
In many cases the problem is lack of air flow is more of a problem and the ducting will reduce flow and topend power.l If you have seen for example REVHEDs system the snorkle is opened up to cope with the increased demand for air with a worked motor.
The final point is the 12A carb is fed warm air if the outside air is cold in order to keep the air- fue mixture constant. Thus putting on cold air ducting is irrelevant.
04-11-02, 05:35 AM
#29
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you need to remove the flapper valve thingy in the snorkel so you will not suck air through the bottom of your snorkel where your preheater hose used to be. This is controlled by a thermo spring so if you get cold air it will engage the flapper valve and you will suck air through the little hole and out of the engine compartment, negating your cold air intake. But otherwise it looks great!
04-11-02, 09:26 AM
#31
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Originally posted by yayarx7
you need to remove the flapper valve thingy in the snorkel so you will not suck air through the bottom of your snorkel where your preheater hose used to be. This is controlled by a thermo spring so if you get cold air it will engage the flapper valve and you will suck air through the little hole and out of the engine compartment, negating your cold air intake. But otherwise it looks great!
you need to remove the flapper valve thingy in the snorkel so you will not suck air through the bottom of your snorkel where your preheater hose used to be. This is controlled by a thermo spring so if you get cold air it will engage the flapper valve and you will suck air through the little hole and out of the engine compartment, negating your cold air intake. But otherwise it looks great!
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