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Does anybody makea cold air intake for our cars yet?


mycotopian

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Wouldn't having a colder charge in the first place help the efficiency of the IC? Ex. instead of cooling 100 degree air with a WAI you would be cooling 70 degree air with a CAI. I just think that a colder charge from a CAI would keep the overall IC temp lower as it is easier to cool something that is already at a lower temperature. Or is the IC always so damn hot that it doesn't make a difference? Anyone got any dyno evidence?

 

Hell, just buy the CAI and borrow a WAI and dyno both. :)

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Wouldn't having a colder charge in the first place help the efficiency of the IC? Ex. instead of cooling 100 degree air with a WAI you would be cooling 70 degree air with a CAI. I just think that a colder charge from a CAI would keep the overall IC temp lower as it is easier to cool something that is already at a lower temperature. Or is the IC always so damn hot that it doesn't make a difference? Anyone got any dyno evidence?

 

Hell, just buy the CAI and borrow a WAI and dyno both. :)

 

no because the turbo runs so hot, that lower turbo inlet temps are elminated by the immense heat created by compression and proximity to 1450degree exhaust temperatures.

 

check out clubwrx.net for a billion discussions on this, and data logging to boot.

 

dR

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no because the turbo runs so hot, that lower turbo inlet temps are elminated by the immense heat created by compression and proximity to 1450degree exhaust temperatures.

 

check out clubwrx.net for a billion discussions on this, and data logging to boot.

 

dR

 

exactly...itll just get hot again right after the intake

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no because the turbo runs so hot, that lower turbo inlet temps are elminated by the immense heat created by compression and proximity to 1450degree exhaust temperatures.

 

check out clubwrx.net for a billion discussions on this, and data logging to boot.

 

dR

 

As a rule of thumb, for every degree you can lower the air temp going into the turbo, the air leaving the turbo will drop by the same amount, and the exhaust temps will drop by twice that.

 

I seem to remember that PVT (pressure x volume x temp) before compression will equal PVT after compression, less any heat losses to the surroundings.

 

Therefore the air entering the IC will drop also, giving a denser charge of air.

 

How this theory works on the Legacy I couldn't say as you would need to put temp sensors into the air flow, but I have done alot of work on marine engines and proven this time and again.

 

It is possible that the differences are so negligable it's not worth the expense to gain a small amount, but there will be some gain.

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As a rule of thumb, for every degree you can lower the air temp going into the turbo, the air leaving the turbo will drop by the same amount, and the exhaust temps will drop by twice that.

 

I seem to remember that PVT (pressure x volume x temp) before compression will equal PVT after compression, less any heat losses to the surroundings.

 

Therefore the air entering the IC will drop also, giving a denser charge of air.

 

How this theory works on the Legacy I couldn't say as you would need to put temp sensors into the air flow, but I have done alot of work on marine engines and proven this time and again.

 

It is possible that the differences are so negligable it's not worth the expense to gain a small amount, but there will be some gain.

 

good answer

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  • 2 months later...
  • 3 weeks later...

SPT shorty intake will be available sometime between the 1st and 2nd quarter of 06. Absolutely no issues with warranty and it doesn't screw with the AFR either. It'll even be dealer installable for those of you who don't like to turn wrenches. :)

 

Fits OBXT and LGT. For those of you with the other cars, an application for WRX/STI/FXT will be launched at the same time as well.

 

A heat shield for the intake should be following this product for those of you that would like that sort of thing.

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In the stock airbox, incoming air has to go around a corner from the filter to the MAF. The splitter is there to straighten it out, especially because the MAF is located very close to the apex of that corner.

 

In the SPT intake, the filter is pretty much in line with the MAF, making the screen unnecessary because the flow stays laminar. To be sure of this, I've monitored the MAF voltage under all sorts of conditions and it never shows any signs of turbulent airflow. The graph is always nice and smooth. It also flows a bit more air even without modifying anything else in the car.

 

:)

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Reason I ask this question is the Perrin and other short intakes seem to lean the map out a bit. Datalogs by members here show higher EGT,leaner AF, and the fact the MAF simply reads less air volume (mass in grams is the parameter on the datalog I think). With the MAF reading (thinking) it's seeing less air (in reality it is not) it will add fuel for that amount of air wich is less. The MAF housing on the Perrin is the same size as stock.
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