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I have a 2.5 rs 01 and i wanted to get a aftermarket throttle body. Does anyone know where i could get one? Thanks
 

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The Thread Stopper
11 WRX, Matte black
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None such exist. You can get a TB spacer or you can Port and Polish your stock one. That's about it. You really aren't gonna see big gains from either though (if any). These aren't Hondas with restrictive airways nor are they domestics that have 90mm MAFs for their V8s.
 

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1997 Legacy 2.5GT sedan
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Using FalconRS's example of a V8, consider that the ubiquitous 5.0L Mustang made 225hp through a stock 55mm throttle body. The stock TB on my '97 EJ25 is 60mm. (Or maybe 62mm? It's been a while since I measured it.) So the TB is plenty big for the power that the engine puts out.
 

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1999 Subaru Impreza 2.5rs BDP
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just hook up a leaf blower to your intake track and it will add like 15 hp. seriously. people have done it before.
 

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2001 Subaru Outback, EJ253
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Isn't the stock intake manifold supposed to be the more restrictive part? So why doesn't anybody make an aftermarket one?

Also is the throttlebody spacer compatible with after market CAIs?
 

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1999 Subaru Impreza 2.5rs BDP
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throttle body spacer compatibility depends on what year you have. People don't make aftermarket intake manifolds but people with older RSs (like 04 and below) swap out their OEM intake manifold for newer manifolds which flow better (05 and up).
 

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scoobaroo said:
just hook up a leaf blower to your intake track and it will add like 15 hp. seriously. people have done it before.
I seriously hope your kidding.

scoobaroo said:
throttle body spacer compatibility depends on what year you have. People don't make aftermarket intake manifolds but people with older RSs (like 04 and below) swap out their OEM intake manifold for newer manifolds which flow better (05 and up).
Except that the 05 and up are a real tough conversion as there's no mounting for a throttle cable (05+ is DWB) and several things like sensor locations and mounting points changed. You can do it, you just need some creativity.
 

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Modsterdomus
2000 STM RS Sedan 5spd
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Kost how did you pop your TB? We may have an extra from our parts engine for sale... PM me if interested.

Chris
 

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Kostamojen said:
Actually... Theres a video on youtube that is quite serious and has dyno proof.
Actually....that video on YouTube is a well known internet hoax in the car world that's been circulating on forums since before YouTube existed.
 

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there are aftermarket intake manifolds but not for N/A applications. I do think a good ITB, would rock. I have been wanting to build one for a while, and if I ever find a set of matching throttle bodies I might try. The CAM shafts/valve train are the restriction for N/A motors. Yes the heads flow really well but the Cams could be a lot better.

Oh and I say the leaf blower is for real. I don’t think it would do much but it would add horse power.
 

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FalconRS said:
Nope, it's not.
How can you say that? proof? any positive pressure in the intake would gain power. all you have to do is flow the same CFM that the engine pulls under vacuum and you would have power. I am sure a leaf blower could put out much more than that. Now I am not saying that it would do a lot but it would do something and I am sure you could dyno the difference.
 

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2013 Subaru BRZ GBS
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FYI, the EZ30 throttle body is 70mm...
Jurzeyfresh said:
Kost how did you pop your TB? We may have an extra from our parts engine for sale... PM me if interested.

Chris
The bearing is starting to go bad. Its thouroughly cleaned and still sticking :(

I have a lead on a TB right now, but if that falls through ill let you know.
 

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amorton said:
How can you say that? proof? any positive pressure in the intake would gain power.
Airflow and air pressure are not synonymous.

Airflow through a fan cannot create positive pressure. See the thread on electric superchargers. You need:

1. No way for the air to sneak backwards (IE reverse airflow through the gaps in a fan blade when the air can't overcome 0 vacuum to produce positive pressure)

2. A strong enough electric motor that doesn't stall out when a COMPRESSOR WHEEL (MUCH different from a fan) reaches into positive pressure.

There's a MASSIVE difference between a compressor and a fan. I suggest you kids read up.
 

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you missed my point, you don't have to create pressure at all, you only need to flow more volume than the volume of the engine can. If you can achieve this than the motor no longer needs to expend energy to fill the cylinder with air. that energy that was spent pulling air into the block is gained back. So like I said all you need to do is flow more than the engine can suck.
 

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amorton said:
you missed my point, you don't have to create pressure at all, you only need to flow more volume than the volume of the engine can.
Much like my point went over your head. You CAN'T get more air in than the engine can flow WITHOUT positive pressure. That's the whole point of boost.

If you can achieve this than the motor no longer needs to expend energy to fill the cylinder with air. that energy that was spent pulling air into the block is gained back. So like I said all you need to do is flow more than the engine can suck.
Without positive pressure, the cylinders will still fill with the same amount of air. Oxygen + gasoline = power (extreme layman's terms, but applies here). Further, the intake stroke itself isn't responsible for all the air coming in. A large portion of it comes from the scavenging effect, which isn't assisted without positive pressure.

How bout I put it to you this way:

Leaf Blower: $69
Cold Air Intake: $250

Q: If it really worked, why would you even bother spending money on an intake for a 5 hp when a leaf blower gets you 15?

A: It doesn't work.

It's a hoax. A hoax that's been around since the beginning of sport-compact performance (IE long before most of you were driving or even thought about driving).
 
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