I apologize as I have been remiss. I had wanted to write this review sooner but have not had the time to think it through and actually write it up.
I received the new SCC magazine nearly a week ago, Feb 2009 edition, Vol 21, No.02 and this little article in the back of it, Test Bench, page 80 to be exact, really caught my eye. With all the talk of installing new intakes around here, which is the best, the most horsepower or mileage increase, etc, I thought this was highly significant.
The way the article is written, difficult to fully understand for a non-engineer such as myself, I had to read it twice to make sure what they were trying to
say.
Many of the graphs included are also so jumbled together that they too are hard to understand. Perhaps this is why they did not publish this article sooner and relegated it to the back pages of this issue?
Here"s my review of the article and I hope I understood their findings correctly:
The base car they used was a stock 2006 WRX with some miles on it using the stock-box.
They measured each of the three intakes for length using the centerline, not outside measurement.
The three intakes are:
1) The stock air-box and filter, 16.5" long.
2) An Injen CAI, 30.75" in length
3) A K&N Typhoon SRI, 7.75" in length.
Not surprisingly, they discovered that different length intakes produce different results based on their resonant frequencies.
A Short Ram is liable to produce the best HP up high in the rev range, but the trade-off is less HP and torque down low, and lost torque in the upper range as well.
They also discovered the CAI produces the best torque characteristics while also improving HP, but not as much as the SRI.
The stock box was the best of both worlds. It"s medium length producing the best combination of HP and torque for every day driving on the street, but is also a trade off in max HP and bottom end torque. They claim this could be improved upon significantly if the air/fuel mixture was leaned out. That the stock, SAFE fuel map settings ran the car richer than is good for producing the best power and mileage.
In fact, they also claimed that one of the most significant things about an aftermarket intake was that it fooled the MAF sensor into thinking that less air was passing through it and therefore causing the PCM/ECU to trim the mixture.
Isn"t that interesting? We are all spending our hard earned dollars (me included,) up to $500 for the more costly ones, primarily just to lean out the mixture slightly and modify (tune, if you will) resonant frequency.
Add to that just how small the actual improvemnents are and I have to ask, is it really worth it?
I received the new SCC magazine nearly a week ago, Feb 2009 edition, Vol 21, No.02 and this little article in the back of it, Test Bench, page 80 to be exact, really caught my eye. With all the talk of installing new intakes around here, which is the best, the most horsepower or mileage increase, etc, I thought this was highly significant.
The way the article is written, difficult to fully understand for a non-engineer such as myself, I had to read it twice to make sure what they were trying to
say.
Many of the graphs included are also so jumbled together that they too are hard to understand. Perhaps this is why they did not publish this article sooner and relegated it to the back pages of this issue?
Here"s my review of the article and I hope I understood their findings correctly:
The base car they used was a stock 2006 WRX with some miles on it using the stock-box.
They measured each of the three intakes for length using the centerline, not outside measurement.
The three intakes are:
1) The stock air-box and filter, 16.5" long.
2) An Injen CAI, 30.75" in length
3) A K&N Typhoon SRI, 7.75" in length.
Not surprisingly, they discovered that different length intakes produce different results based on their resonant frequencies.
A Short Ram is liable to produce the best HP up high in the rev range, but the trade-off is less HP and torque down low, and lost torque in the upper range as well.
They also discovered the CAI produces the best torque characteristics while also improving HP, but not as much as the SRI.
The stock box was the best of both worlds. It"s medium length producing the best combination of HP and torque for every day driving on the street, but is also a trade off in max HP and bottom end torque. They claim this could be improved upon significantly if the air/fuel mixture was leaned out. That the stock, SAFE fuel map settings ran the car richer than is good for producing the best power and mileage.
In fact, they also claimed that one of the most significant things about an aftermarket intake was that it fooled the MAF sensor into thinking that less air was passing through it and therefore causing the PCM/ECU to trim the mixture.
Isn"t that interesting? We are all spending our hard earned dollars (me included,) up to $500 for the more costly ones, primarily just to lean out the mixture slightly and modify (tune, if you will) resonant frequency.
Add to that just how small the actual improvemnents are and I have to ask, is it really worth it?
