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Discussion Starter #1
What will your 1st be...?????

I plan on a hot air intake (better for turbocharged cars due to less piping?), get rid of all cats other than the main one that will be replaced with a highflow cat.

Eventually get all bolt ons without messing with the turbo or ECU.

BTW, does anyone know the stock diameter of the turboback and is it mandrel bent?
 

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short ram intake and catless downpipe
 

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Already put on the Turbo XS; turbo-back exhaust...........(kept the stock muffler) & an Injen intake. I had the Injen from my old 02' WRX and it fit.
The sound is good and the difference in throttle response and high end power is worth the money.
 

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Discussion Starter #6
I was looking at the new Turboxs turboback exhaust (27.8 hp at wheels). It sounds pretty damn mean. I wonder if they dyno tested it on a US spec STi or the 2.0L model? Once christmas time rolls around I will probably have enough saved for it. I'd also want to see what people who have the system think of it... It's a pretty impressive gain for just piping...Gotta love turbos :D
 

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Discussion Starter #8
what I understood is that for TC less pipingis better for the airflow (less restrictive). Cold air is always better for any NA or TC engine but since the TC is so hot from the exhaust gases drawing in cold air with all that extra piping is kind of pointless since it will immediately warm up once it goes through the compresor.
 

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masti said:
Already put on the Turbo XS; turbo-back exhaust...........(kept the stock muffler) & an Injen intake. I had the Injen from my old 02' WRX and it fit.
The sound is good and the difference in throttle response and high end power is worth the money.
Masti, did you use the same CEL resistor fix that WRX's are using?? I am about to put a Helix DP on my STi, but am pausing ot consider the CEL issue and how this may effect the STi ECU.

thanks.
 

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blueballs said:
what I understood is that for TC less pipingis better for the airflow (less restrictive). Cold air is always better for any NA or TC engine but since the TC is so hot from the exhaust gases drawing in cold air with all that extra piping is kind of pointless since it will immediately warm up once it goes through the compresor.
:roll:

Stop talking, you're lowering the average IQ in here.
Cold air is ALWAYS better than hot air, which is why placing an intake near a turbocharger or exhaust manifold will almost always get you a loss in power. 9 times out of 10, intakes and BOV's are done just for the sound and not for the performance gain.
 

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Discussion Starter #12
Mr. Pizzo - you're an ignorant fool to start calling people names when you really have no idea of what you're talking about. You must be some sort of Einstien to come up with precise statistical info like:
9 times out of 10, intakes and BOV's are done just for the sound and not for the performance gain.
With insight like yours, no wonder you are at a higher IQ level than me... :roll:

Please do not embarass yourself by making me prove you wrong and showing that it is you who are judgemental and posess the low IQ.

I could write a paper on the topic based on personal experiences with a CAI and a "under the hood" or HAI and dynotesting and research done by others. Here are my general points of a CAI vs. a HAI

Benefits of a CAI:

-Cooler air drawn from outside due to filter being placed outside the engine bay
-Sound
-Better low end power vs. a HAI

Benefits of a HAI:

-Much shorter piping used which means one gets a much higher flow rate
-Sound
-Better High end power vs. a CAI

Now with a turbocharged application one will draw cooler air from the outside. Maybe up to 30 F degrees differencewith a CAI. The difference in air temp at the throttle body between a HAI and a CAI will be about 1-5 degrees. Why? As the air passes through the turbo, 1400+ degrees F exhaust gasses will heat up the air drawn in at around 260-350 degrees F until the intercooler. The air temp difference will be minimal by the time it enters your engine.

Now to talk about air flow. The easiest way to visualize it is picture trying to suck in air as fast as possible. Now do that with a straw in your mouth. Harder, huh? Air flow is greatly increased with less piping which will make the strain on the turbo much less. It will not have to work or "suck" as hard in order to achieve the same psi. This is why the HAI gives much better power at higher rpms than CAIs. CAIs give you better low speed and low rpm power since the air in the engine bay is stationary, heat collects under the hood. As soon as you get going, fresh air is being brought into the engine bay from the outside. This coupled with less restrictive piping and a better flow rate make a well designed "under the hood" intake better than a CAI in a moving vehicle.

Again this is a big debate that goes on in all car forums. CAI vs. HAI.
In this type of car, I would prefer a well designed HAI over a CAI. If someone wants to dynotest the differences, by all means give us some insight.

Again for Mr. 2 Fast, 2 Furriest Pizzo - If could get into this much more if you want to. I did not want to waste my time with name callers such as yourself. Let's try to be constructive, not destructive. :wink:
 

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I see what you're saying, but then again, I don't.
I've never seen benefits from throwing hot air into a motor as compared to colder air. In accordance with all of my previous experience and 8th grade physics, cold air is denser than hot air. That is why people go crazy for intercoolers and water injection, to increase efficiency

A properly designed intake system (read:well flowing air filter shielded from engine heat with a cold source) will get you gains, it just seems that it's semantics getting in the way. ;-)

I don't have dyno results, but I do know that I was getting very high IAT's when I tried a "HAI" on an Audi inline 5 turbo. I got better results moving the cone down to the bumper and ducting air to it. Maybe we're both standing in different places looking at the same piece of cake, so to speak.
 

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Discussion Starter #15
There's more to it than your cold air vs hot air argument. For an optimally designed intake it's a combination of cooler air AND least restrictive (shorter) air path. If you look at dyno graphs of the same car with a CAI vs a HAI you will see similar gains at different ends of the RPM range. Again this is open to debate because since you are standing still in a dyno, it doesn't accurately account for cooler outside air coming into the engine bay and feeding the HAI with outside air.
You cannot forget how important less piping is. Think about the placement of the intercooler in the STi...Right on top of a piping hot engine instead of a front mount...Why?...because less piping = less restriction.

Again intake designs are different. You are right that cold air is always better, but in order to get that cooler air you sacrifice increased air flow due to the long piping needed to get the filter to the bumper or fenderwell.

*personaly, I prefer some top end in my STi scince the power curve dips past 6000rpms and with AWD low end power is not as improtant to me. To each his own... 8)
 

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mistkerl said:
I'm putting Bull Horns on mine, :)
Right on! Maybe a nice set of deer antlers, which, in the winter, would show off the cars ability to be nimble in the snow.

Anyone thought of a warm air intake? Half-way between hot and cold with none of the benefits. Sounds like what I need.
 
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