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tC throttle body questions-strange ?'s

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Old 08-20-2010 | 04:25 AM
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Default tC throttle body questions-strange ?'s

Whats the difficulty in tearing down a throttle body. i picked one up for a project today and want to do a port/polish with knife edge and have the case powder coated. anyone have any experience in knife edging the tc's throttle body, will i need a new butterfly valve, and if so anyone have any leads on one
Old 08-20-2010 | 04:30 AM
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Wasn't there a guy on here who did this service minus the powder coating? Maybe I'm dreaming. Thought he charged $100.

Also, is our throttle body a bottleneck?
Old 08-20-2010 | 04:45 AM
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i wasnt aware anyone here could do it, i dont mind doing it myself i just want to do some research first
Old 08-20-2010 | 07:20 PM
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120 views and no love, i know im not the first to need to take this thing apart
Old 08-20-2010 | 09:14 PM
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You could just get a bigger throttle body. I put an RX-8 TB on the NA scion tC I just finished building up and the throttle response is amazing. Took me a day to make the adapter plate with no prior experience in doing such. Pretty easy and like I said the throttle response is just miles better.
Old 08-20-2010 | 11:15 PM
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yeah but the sensor and/or chip had to be swapped didnt it, the electronic portion of a rx8 throttle body isnt the same
Old 08-21-2010 | 02:14 AM
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You shouldn't have to change anything at all but I had a 04 RX-8 throttle body that was sitting in a junkyard for years so it probably just went bad. Even if you are required to change the back plate(It's just that small black plastic part) it takes all of 10 minutes and some #10-32 bolts and nuts.

EDIT: I also tried to take apart the mechanical parts of the stock Scion TB but the screws holding the butterfly valve were stuck on so bad I just abandoned it and went the RX8 route. You also have to take the backplate off anyway to get the shaft out and you have to have a special tool( or a modified small screw driver) to get the return spring back into place. It's really not worth the effort.
Old 08-21-2010 | 04:36 AM
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i was mostly doing it to powdercoat it, the knife edge and port/polish was just because i was going to have to tear it down anywhere to be able to put it in oven
Old 08-22-2010 | 04:42 AM
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Originally Posted by Max Hughes
You could just get a bigger throttle body. I put an RX-8 TB on the NA scion tC I just finished building up and the throttle response is amazing. Took me a day to make the adapter plate with no prior experience in doing such. Pretty easy and like I said the throttle response is just miles better.

Do you have any videos or pics or anything? I love to see this.
Old 08-22-2010 | 08:14 PM
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A member on here used to do it, like 9 months ago. Rx8 tb? What is the size difference stock for stock?
Old 08-22-2010 | 09:57 PM
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The RX-8 TB is 70mm vs the stock TC's 55mm TB.

http://www.youtube.com/watch?v=Rtc5X...layer_embedded
Old 08-23-2010 | 01:31 AM
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help please for disassembling the stock TB
Old 08-23-2010 | 02:17 AM
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Originally Posted by Murphys_Law
help please for disassembling the stock TB
1. Remove the two phillips screws securing the butterfly flap to the TB shaft
2. Open the throttle to WOT And the flap should slide out of the shaft. You'll have to pull it a little because it's pretty tight in there.
3. Remove the backplate from the TB to expose the gears.
4. Shaft should slide out, examine the return spring so you know how to properly reinstall it.
Old 08-23-2010 | 05:00 AM
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just drill out the rivets? never been in a throttle body before
Old 08-23-2010 | 06:24 AM
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Yea drill the head off then use a strong narrow piece of metal(I use a small screw driver I sharpened to a point) to knock out the rivet.

I learned from this video:

http://www.youtube.com/watch?v=y7tb6-0Rg2U
Old 08-25-2010 | 02:35 AM
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Do you have a video of step by step in how you install the rx-8 throttle body.
Old 08-25-2010 | 02:43 AM
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Originally Posted by Max Hughes
Yea drill the head off then use a strong narrow piece of metal(I use a small screw driver I sharpened to a point) to knock out the rivet.
Get a punch and save yourself the pain of using a cheap screw driver. Problem solved.
Old 08-25-2010 | 04:20 AM
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punch or drift
Old 08-28-2010 | 06:23 PM
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Hey Murphy good thread asking some questions that I was wondering myself. But I just got to ask one question to people that have done this before.

When swapping out tC TB with RX-8 TB does CEL light come on at any given time due to the TB swap? And is the computer required for a re-tuning or just let it run idle for about 10 minutes to adjust to new changes?

Thanks in advance for anyone that can help me out with those answers. I can't seem to find a straight answer anywhere. And I hope whatever your trying to do gets done with Murphy! Take care.
Old 09-27-2010 | 06:17 AM
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I keep hearing whispers about swapping the RX-8 tb and heard someone made an adapter plate that sells for 100 something. But near $400 for a complete tb swap is insane. Especially for only 5 hp. You can get a good turbo kit for 2k these days, four times the price. Which will give you 100 hp. So save up your money for something else. If you were already running a turbo application and looking for ways to squeeze out some more ponies it'd be a good buy. Granted 5hp is a lot on a car with 160 hp but there's no way you'd feel it. Maybe in throttle response but i don't think its a half second of throttle response that's costing you a race. Wherever it might be.



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