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High performance crossover pipe


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  • 2 weeks later...
Originally posted by dave valiant

I don't suppose any of these parts will work on an EA81-T?

 

All these parts are currently installed on an EA81 T right now. The header primaries aren't ideal for the ports on this engine, but it still spools up like mad.

On a side note, the old wagon met defeat last week to a slightly modified (full exhaust and intake) WRx. Got me by one and half car lengths. This system on an EA82 would have changed the outcome of that race.

I have since sold the car (I'm a poor loser) and am now looking at a 300+ HP version of this project using a EJ18 engine in a wagon and some of our Impreza components (header, etc>)

 

Tom

 

Tech Works

Engineering Inc.

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hey techworks,

 

What are the I.D.s of the tubing for this EA82T crossover.

 

Primaries?

 

after merge collector?

 

I have read that opening the crossover pipe too far slows down the exhaust and therefore increases turbo lag. What have you found in your pipe?

 

In the photos I've seen, I can't tell if this crossover uses an up-pipe or is it one piece?

 

garner

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Originally posted by garner

hey techworks,

 

What are the I.D.s of the tubing for this EA82T crossover.

 

Primaries?

 

after merge collector?

 

I have read that opening the crossover pipe too far slows down the exhaust and therefore increases turbo lag. What have you found in your pipe?

 

In the photos I've seen, I can't tell if this crossover uses an up-pipe or is it one piece?

 

garner

 

The ID of the primaries is 1 7/8". The proper ID for the EA81 should be 1 1/2" aproximately. You are correct to be concerned about exhaust gas velocity. This is partly why the collector merges just before the turbine inlet. I had expected this combo to be very "laggy" on the EA81, but this proved to be not the case. Part of the reason for the quick spool up on this application is due to the GT17 turbo. It spools to 15 psi by 2200 rpm! There is no up pipe needed with this header as the collector terminates at the turbo flange. Seperating the primary flow until just before the turbo helps maintain the steady flow of pulses to the turbo while maintaining maximum high rpm flow potential.

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Originally posted by carfreak85

Also, if one pipe it 2x longer than the other, it would have the same effect as an equal lenth pipe.

 

Correct, this is known as "tuned-length" and is how the very expensive SYMS headers for the Imprezas are configured.

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  • 8 months later...

I have since sold the car (I'm a poor loser) and am now looking at a 300+ HP version of this project using a EJ18 engine in a wagon and some of our Impreza components (header, etc>)

 

Tom

 

Tech Works

Engineering Inc.

Since another old post has crepted up, figured I may as well join the trend. :brow: Has anyone gotten any updates on this project?
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