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Discussion Starter · #1 ·
Has anyone ported the throttle body as described in projectwrx.com and if so were there any problems or suggestions you would make. Describe everything that is not included in the instructions. I want to do this asap if I can.
 

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I believe that MrBob (?) has done this mod. I'm 99% sure that I've read someone on this board has done it. Maybe PM him.
 

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If you're gonna do it, do it right. Have it bored out. I use this place for all my machining work:
http://www.leitnerbush.com/
Speak to Steve or Bill and tell them I sent you. They can bore it out and tapper it. Do beautiful work. They will be building my 600 HP Sti block BTW and built our project car's 210 whp Type R motor.
 

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Discussion Starter · #4 ·
I cannot wait to have that done because I need my car everyday and I could find far better ways to spend my money on my car than to pay someone else to port it. I am sure they do a grat job but, I am trying to do everything myself with the help of my brother, and everything I do to my car I want to install so if anything goes wrong and I must take it to Subaru I can remove what I need. I am somewhat a novice to working on a car but I am obsessed about my car and racing. Luckily, I have my brother to help and he is experienced with mechanical work. I am trying to find info on all diy work so I can plan my next move.
 

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You can not bore it out yourself. You have to have it done by a mcahine shop and install a new butterfly plate (brass preferably). Some people just dremel out their TB but I have no idea why. It doesn't do anything. Mine is stiill stock and I'll making 311 whp. I don't think it's a problem.
 

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Discussion Starter · #6 ·
How much do you think it would cost to port the tb and should both sides be done along with the intake manifold matched?
 

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I know of a guy (don't have his business card handy) that bores out your stock TB for $150. I had him do my TB on my 3000GT, and he does really good work. You take it off the car, send it to him, and he sends it back with a day or two turnaround. I think my car was down for a week, but that was only because I didn't pay the extra shipping to have it rushed.

What he told me, was each throttle body he does custom, so he will only take out what is safe without leaving the walls too thin. I think he bored mine over 3mm on the Mitsu. He said 3-5mm is average. New butterfly valve with it with a grinded shaft. Really nice. If anyone is interested, I can try to find his phone #.

RESULTS: Well, for my NA 3000GT, it helped a little with throttle response on throttle dip in. I also think it helped slightly reshape my torque curve a bit, but I don't think it resulted in many HP. Don't know how effective this would be on a Turbo car.
 

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Precisely. This is what L&B does also. They machine it out and then tapper and polish it on the inside. Then just port match your manifold and voila. More power and torque across the board. There's no downside to doing it apart from the downtime.
 
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